The brightest star in the night sky, in Canis Major.
The Sun and the bodies gravitationally bound to it.
The body of myth and lore humans built around the stars and night sky.
The Sun is the star at the center of the Solar System, around which the planets and other bodies orbit.
Mercury is the smallest planet in the Solar System and the closest to the Sun.
Venus is the second planet from the Sun and is similar in size to Earth.
Earth is the third planet from the Sun and the only world known to support life.
Saturn is the sixth planet from the Sun and is known for its prominent ring system.
Uranus is the seventh planet from the Sun and is classified as an ice giant.
Neptune is the eighth and most distant known planet from the Sun in the Solar System.
Pluto is a dwarf planet in the Kuiper Belt beyond the orbit of Neptune.
Ceres is a dwarf planet and the largest object in the asteroid belt between Mars and Jupiter.
Eris is a distant dwarf planet in the scattered disc of the outer Solar System.
Haumea is a dwarf planet located beyond the orbit of Neptune in the Kuiper Belt.
Makemake is a dwarf planet in the Kuiper Belt beyond the orbit of Neptune.
The Moon is Earth's only natural satellite.
Phobos is the larger and inner of the two natural satellites of Mars.
Deimos is the smaller and outer of the two natural satellites of Mars.
Io is the innermost of the four Galilean moons of Jupiter and is intensely volcanic.
Europa is one of the four Galilean moons of Jupiter, covered by a shell of water ice.
Ganymede is a Galilean moon of Jupiter and the largest moon in the Solar System.
Callisto is the outermost of the four Galilean moons of Jupiter and is heavily cratered.
Titan is the largest moon of Saturn and has a dense, nitrogen-rich atmosphere.
Enceladus is an icy moon of Saturn that vents plumes of water ice from its south pole.
Triton is the largest moon of Neptune and orbits in a retrograde direction.
Antares is a red supergiant and the brightest star in the constellation Scorpius.
Deneb is a luminous blue-white supergiant and the brightest star in the constellation Cygnus.
Altair is the brightest star in the constellation Aquila and one of the nearest naked-eye stars.
Aldebaran is an orange giant and the brightest star in the constellation Taurus.
Spica is the brightest star in the constellation Virgo and is itself a close binary system.
Arcturus is an orange giant and the brightest star in the constellation Boötes.
Capella is the brightest star in the constellation Auriga and is a system of multiple stars.
Procyon is the brightest star in the constellation Canis Minor and one of the nearest stars to the Sun.
Pollux is an orange giant and the brightest star in the constellation Gemini.
Castor is a multiple-star system in the constellation Gemini, traditionally paired with Pollux.
Regulus is the brightest star in the constellation Leo and lies close to the ecliptic.
Fomalhaut is the brightest star in the constellation Piscis Austrinus and hosts a prominent debris disk.
Scorpius is a zodiacal constellation of the southern sky, recognized as one of the 88 modern constellations.
Cygnus is a northern constellation lying along the plane of the Milky Way, one of the 88 modern constellations.
Aquila is a constellation on the celestial equator, one of the 88 modern constellations.
Taurus is a large zodiacal constellation of the northern sky, one of the 88 modern constellations.
Virgo is the second-largest constellation and a zodiacal constellation, one of the 88 modern constellations.
Boötes is a northern constellation, one of the 88 modern constellations.
Auriga is a northern constellation, one of the 88 modern constellations.
Canis Minor is a small constellation, one of the 88 modern constellations.
Gemini is a zodiacal constellation of the northern sky, one of the 88 modern constellations.
Leo is a zodiacal constellation of the northern sky, one of the 88 modern constellations.
Piscis Austrinus is a southern constellation, one of the 88 modern constellations.
The barred spiral galaxy that contains the Solar System, the Sun, and all stars visible to the naked eye.
The nearest large spiral galaxy to the Milky Way and the most distant object readily visible to the naked eye.
A spiral galaxy in the Local Group, the third-largest member after Andromeda and the Milky Way.
A grand-design spiral galaxy interacting with a smaller companion galaxy, NGC 5195.
A galaxy notable for its bright nucleus and a prominent dust lane that gives it a hat-like appearance.
A satellite dwarf galaxy of the Milky Way and one of the closest galaxies to our own.
A dwarf galaxy near the Milky Way, visible to the naked eye from the Southern Hemisphere.
A diffuse emission nebula and active star-forming region, one of the brightest nebulae visible to the naked eye.
A supernova remnant produced by a stellar explosion recorded by astronomers in 1054 CE.
A young open cluster embedded in a star-forming nebula, famous for the 'Pillars of Creation' imaged by Hubble.
A planetary nebula formed by gas shed by a dying star, appearing as a luminous ring.
A large emission nebula and star-forming region, one of only a few visible to the naked eye.
The supermassive black hole at the center of the Milky Way, imaged by the Event Horizon Telescope in 2022.
The supermassive black hole at the heart of galaxy M87, the first black hole ever directly imaged, in 2019.
A bright open star cluster of hot young stars, easily visible to the naked eye.
The nearest open star cluster to the Solar System, forming a V-shaped grouping of stars.
The brightest and most massive globular cluster orbiting the Milky Way.
Apollo 11 was the NASA mission that in July 1969 first landed humans on the Moon, with Neil Armstrong and Buzz Aldrin walking on the lunar surface.
Voyager 1 is a NASA space probe launched in 1977 that explored Jupiter and Saturn and has since become the most distant human-made object, traveling in interstellar space.
Voyager 2 is a NASA space probe launched in 1977 and the only spacecraft to have flown past all four giant planets: Jupiter, Saturn, Uranus, and Neptune.
Cassini–Huygens was a NASA–ESA–ASI mission launched in 1997 that orbited Saturn from 2004 to 2017 and delivered the Huygens probe to the surface of its moon Titan.
New Horizons is a NASA space probe launched in 2006 that performed the first close flyby of the dwarf planet Pluto in 2015.
Juno is a NASA space probe launched in 2011 that entered orbit around Jupiter in 2016 to study the planet's composition, gravity, and magnetic field.
Mars Science Laboratory is the NASA mission that delivered the Curiosity rover to Mars in 2012 to investigate the planet's climate and geology.
Parker Solar Probe is a NASA spacecraft launched in 2018 to fly through the Sun's outer atmosphere, making the closest approaches to the Sun of any spacecraft.
The Spitzer Space Telescope was a NASA infrared space observatory operating from 2003 to 2020.
The Chandra X-ray Observatory is a NASA space telescope launched in 1999 that observes the universe in X-ray wavelengths.
The Kepler Space Telescope was a NASA space observatory launched in 2009 that discovered thousands of exoplanets by monitoring stars for transit dimming.
TESS (Transiting Exoplanet Survey Satellite) is a NASA space telescope launched in 2018 that surveys nearby bright stars to detect transiting exoplanets.
The Mauna Kea Observatories are a collection of independent astronomical research facilities located near the summit of Mauna Kea on the island of Hawaii.
The W. M. Keck Observatory is an astronomical observatory on Mauna Kea, Hawaii, operating two of the largest optical and infrared telescopes in the world.
The Very Large Array is a radio astronomy observatory in New Mexico consisting of 27 movable parabolic antennas arranged in a Y-shaped configuration.
ALMA is an international radio observatory of millimeter and submillimeter antennas located on the Chajnantor plateau in the Atacama Desert of northern Chile.
Palomar Observatory is an astronomical observatory in California, home to the historic 200-inch Hale Telescope.
The Jet Propulsion Laboratory is a NASA federally funded research and development center in California that builds and operates robotic spacecraft.
Roscosmos is the state corporation responsible for the space program of the Russian Federation.
SpaceX is an American aerospace company that designs, manufactures, and launches rockets and spacecraft.
ISRO (Indian Space Research Organisation)
ISRO is the national space agency of India, responsible for the country's space exploration and satellite programs.
Galileo Galilei was an Italian astronomer and physicist who pioneered telescopic astronomy, discovering the four largest moons of Jupiter.
Edwin Hubble was an American astronomer whose observations established that the universe is expanding and that galaxies lie far beyond the Milky Way.
Nicolaus Copernicus was a Renaissance astronomer who formulated the heliocentric model placing the Sun at the center of the universe.
Johannes Kepler was a German astronomer who formulated the three laws of planetary motion.
William Herschel was a German-British astronomer who discovered the planet Uranus in 1781.
Edmond Halley was an English astronomer who computed the orbit of the comet that now bears his name and predicted its return.
Subrahmanyan Chandrasekhar was an Indian-American astrophysicist known for the Chandrasekhar limit on white dwarf mass, for which he shared the 1983 Nobel Prize in Physics.
A prominent summer meteor shower whose radiant lies in the constellation Perseus, produced by debris from comet Swift–Tuttle.
A reliable December meteor shower whose radiant lies in the constellation Gemini.
A November meteor shower whose radiant lies in the constellation Leo, associated with comet Tempel–Tuttle.
An October meteor shower whose radiant lies in the constellation Orion, produced by debris from Halley's Comet.
An early-January meteor shower known for a short, sharp peak of activity.
A short-period comet (1P/Halley) that returns to the inner Solar System roughly every 76 years.
A long-period comet discovered in 2020 that became a bright naked-eye object in the Northern Hemisphere sky.
A periodic comet (109P/Swift–Tuttle) that is the parent body of the Perseid meteor shower.
In Greek mythology, the goddess of the hunt and the Moon, daughter of Zeus and Leto and twin sister of Apollo.
In Greek mythology, the king of the gods who ruled from Mount Olympus.
In Greek mythology, a Titaness who, by Zeus, became the mother of the twins Apollo and Artemis.
In Greek mythology, the god of light, music, and prophecy, son of Zeus and Leto and twin brother of Artemis.
In Greek mythology, a Gorgon whose gaze turned onlookers to stone and who was slain by the hero Perseus.
In Greek mythology, a Titan condemned to hold up the sky and the father of the Pleiades.
In Greek mythology, the sea monster sent to devour Andromeda before she was rescued by Perseus.
In Greek mythology, the king of Aethiopia, husband of Cassiopeia and father of Andromeda.
In Greek mythology, the seven daughters of the Titan Atlas, placed among the stars as the Pleiades cluster.
A catalogue of 110 deep-sky objects compiled by Charles Messier.
A supernova remnant in Taurus, the expanding debris of a star that exploded in 1054 AD.
A rich, compact globular cluster in the constellation Aquarius.
A bright globular cluster in Canes Venatici containing hundreds of thousands of stars.
A nearby globular cluster in Scorpius, one of the closest such clusters to the Sun.
A large, bright globular cluster in the constellation Serpens.
An open star cluster in Scorpius whose brightest stars suggest the shape of a butterfly.
A bright open cluster in Scorpius noted by the ancient astronomer Ptolemy.
A giant emission nebula and star-forming region in Sagittarius.
A globular cluster in Ophiuchus located near the center of the Milky Way.
A globular cluster in the constellation Ophiuchus.
A rich open cluster in Scutum whose stars form a V-shape resembling flying ducks.
A loosely concentrated globular cluster in Ophiuchus.
The brightest globular cluster in the northern sky, located in Hercules.
A dense globular cluster in Pegasus, one of the most concentrated clusters known.
An emission nebula in Serpens famous for the Pillars of Creation star-forming columns.
A bright emission nebula and star-forming region in Sagittarius, also called the Swan Nebula.
A small open star cluster in the constellation Sagittarius.
A markedly oval-shaped globular cluster in Ophiuchus.
A combination emission, reflection, and dark nebula in Sagittarius divided by dust lanes.
A young open star cluster in the constellation Sagittarius.
A bright globular cluster in Sagittarius, one of the nearest to Earth.
An open star cluster in the constellation Sagittarius.
An open star cluster in the constellation Scutum.
A bright planetary nebula in Vulpecula, the ejected shell of a dying Sun-like star.
A globular cluster in the constellation Sagittarius.
A small open star cluster in the constellation Cygnus.
A dense globular cluster in the constellation Capricornus.
The nearest large spiral galaxy to the Milky Way, located in Andromeda.
A dwarf elliptical galaxy in Andromeda, a satellite of the Andromeda Galaxy.
A spiral galaxy in Triangulum and the third-largest member of the Local Group.
An open star cluster in the constellation Perseus.
A large, bright open star cluster in the constellation Gemini.
A young open star cluster in the constellation Auriga.
The richest open star cluster in the constellation Auriga.
An open star cluster in the constellation Auriga.
A loose open star cluster in the constellation Cygnus.
An open star cluster in Canis Major, located just south of Sirius.
A bright diffuse nebula and active star-forming region in the sword of Orion.
An emission nebula in Orion that forms part of the larger Orion Nebula complex.
A nearby open star cluster in Cancer, visible to the naked eye as a hazy patch.
A bright, nearby open star cluster in Taurus, also known as the Seven Sisters.
A rich open star cluster in the constellation Puppis.
A bright open star cluster in the constellation Puppis.
An open star cluster in the constellation Hydra.
A giant elliptical galaxy in Virgo, a bright member of the Virgo Cluster.
An open star cluster in the constellation Monoceros.
A grand-design spiral galaxy in Canes Venatici interacting with a smaller companion.
A rich open star cluster in the constellation Cassiopeia.
A globular cluster in the constellation Coma Berenices.
A globular cluster in Sagittarius belonging to the Sagittarius Dwarf Galaxy.
A large, loosely concentrated globular cluster in Sagittarius.
A globular cluster in the constellation Lyra.
A planetary nebula in Lyra appearing as a glowing ring of gas around a dying star.
A barred spiral galaxy in Virgo, a member of the Virgo Cluster.
An elliptical galaxy in the Virgo Cluster within the constellation Virgo.
A large elliptical galaxy in Virgo, part of the Virgo Cluster.
A barred spiral galaxy in Virgo and a member of the Virgo Cluster.
A spiral galaxy in Canes Venatici with bright, patchy spiral arms.
A spiral galaxy in Coma Berenices with a prominent dark dust band across its core.
A spiral galaxy in Leo, one of the members of the Leo Triplet.
A spiral galaxy in Leo and the largest member of the Leo Triplet.
One of the oldest known open star clusters, located in Cancer.
A globular cluster in the constellation Hydra.
A loosely concentrated globular cluster in the constellation Sagitta.
A faint, distant globular cluster in the constellation Aquarius.
A face-on grand-design spiral galaxy in the constellation Pisces.
A dense, distant globular cluster in the constellation Sagittarius.
A planetary nebula in Perseus, one of the faintest objects in the Messier catalogue.
A barred spiral galaxy in Cetus with an active galactic nucleus, a prototypical Seyfert galaxy.
A reflection nebula in Orion, the brightest diffuse reflection nebula in the sky.
A globular cluster in the constellation Lepus, unusual for its location away from the galactic center.
A dense globular cluster in the constellation Scorpius.
A grand-design spiral galaxy in Ursa Major, one of the brightest galaxies in the sky.
An edge-on starburst galaxy in Ursa Major undergoing intense star formation.
A barred spiral galaxy in Hydra noted for its bright, well-defined spiral arms.
A lenticular galaxy in Virgo within the heart of the Virgo Cluster.
A lenticular galaxy in Coma Berenices, a member of the Virgo Cluster.
A lenticular galaxy in Virgo near the center of the Virgo Cluster.
A supergiant elliptical galaxy in Virgo hosting a supermassive black hole and a relativistic jet.
A spiral galaxy in Coma Berenices, a member of the Virgo Cluster.
An elliptical galaxy in Virgo within the Virgo Cluster.
A spiral galaxy in Virgo and a member of the Virgo Cluster.
A barred spiral galaxy in Coma Berenices, a member of the Virgo Cluster.
A bright globular cluster in the constellation Hercules.
An open star cluster in the constellation Puppis.
A spiral galaxy in Canes Venatici with a bright inner ring of star formation.
A barred spiral galaxy in Leo, part of the Leo I group of galaxies.
A spiral galaxy in Leo and the brightest member of the Leo I group.
A planetary nebula in Ursa Major whose two dark patches resemble an owl's eyes.
An edge-on spiral galaxy in Coma Berenices, a member of the Virgo Cluster.
A nearly face-on grand-design spiral galaxy in Coma Berenices.
A grand-design spiral galaxy in Coma Berenices, one of the brightest in the Virgo Cluster.
A large face-on spiral galaxy in Ursa Major with sprawling spiral arms.
An open star cluster in the constellation Cassiopeia.
A spiral galaxy in Virgo seen nearly edge-on, with a prominent dust lane and bright bulge.
An elliptical galaxy in Leo and a member of the Leo I group.
A spiral galaxy in Canes Venatici with an active galactic nucleus.
An edge-on barred spiral galaxy in the constellation Ursa Major.
A barred spiral galaxy in the constellation Ursa Major.
Rhea is the second-largest moon of Saturn and an icy, heavily cratered world.
Iapetus is a moon of Saturn known for its striking two-toned surface, with one dark and one bright hemisphere.
Dione is an icy moon of Saturn marked by bright wispy fractures across its surface.
Tethys is an icy moon of Saturn featuring the enormous Ithaca Chasma canyon and the large Odysseus crater.
Mimas is an inner moon of Saturn dominated by the huge impact crater Herschel.
Oberon is the outermost of the large moons of Uranus and is heavily cratered.
Miranda is the smallest of the five major moons of Uranus and has an unusually jumbled, varied surface.
Ariel is a moon of Uranus and the brightest of its major satellites.
Umbriel is a moon of Uranus and the darkest of its major satellites.
Nereid is a moon of Neptune with one of the most eccentric orbits of any known moon in the Solar System.
Proteus is one of the larger inner moons of Neptune and one of the darkest objects in the Solar System.
Amalthea is a small, reddish inner moon of Jupiter orbiting closer to the planet than the Galilean moons.
Charon is the largest moon of the dwarf planet Pluto, roughly half Pluto's diameter.
JAXA (Japan Aerospace Exploration Agency)
JAXA is Japan's national space agency, responsible for the country's aerospace research, satellite operations, and human spaceflight contributions including the Kibo module on the International Space Station.
CNSA (China National Space Administration)
CNSA is the national space agency of the People's Republic of China, overseeing the country's civil space program including launch vehicles, lunar exploration, and crewed spaceflight.
Arianespace is a European launch service provider that markets and operates launches of the Ariane family of rockets from the Guiana Space Centre.
United Launch Alliance is an American launch service provider, a joint venture of Boeing and Lockheed Martin, that operates the Atlas and Delta families of rockets.
The Saturn V was a NASA super heavy-lift launch vehicle that carried the Apollo missions to the Moon and launched the Skylab space station.
Falcon 9 is a partially reusable two-stage orbital launch vehicle developed and operated by SpaceX.
Falcon Heavy is a partially reusable heavy-lift launch vehicle derived from the Falcon 9 and operated by SpaceX.
Starship is a fully reusable super heavy-lift launch system being developed by SpaceX for crewed and cargo missions to Earth orbit, the Moon, and Mars.
Ariane 5 was a European heavy-lift launch vehicle operated by Arianespace, notable for launching the James Webb Space Telescope in 2021.
Atlas V is an expendable launch vehicle operated by United Launch Alliance that has launched numerous NASA science and planetary missions.
The Space Launch System is NASA's super heavy-lift launch vehicle developed to carry the Orion spacecraft and crew under the Artemis program.
Soyuz is a family of expendable launch vehicles operated by Roscosmos that has long carried crews and cargo to orbit, including to the International Space Station.
Long March 5 is a Chinese heavy-lift launch vehicle that has launched missions including the Tianwen-1 Mars probe and modules of the Tiangong space station.
The PSLV is an expendable launch vehicle operated by ISRO that has launched many Earth observation satellites as well as the Chandrayaan-1 and Mangalyaan missions.
The International Space Station is a crewed modular space station in low Earth orbit, operated as a partnership among NASA, Roscosmos, ESA, JAXA, and the CSA.
ESO's optical/infrared array of four 8.2-metre telescopes at Cerro Paranal in Chile's Atacama Desert.
A pair of 8.1-metre optical/infrared telescopes, one in Hawaii and one in Chile, giving coverage of both hemispheres.
The world's largest fully steerable radio telescope, a 100-metre dish in Green Bank, West Virginia.
FAST (Five-hundred-meter Aperture Spherical Telescope)
The world's largest single-dish radio telescope, a 500-metre aperture instrument in Guizhou, China.
An optical survey observatory in Chile conducting the wide, fast, deep Legacy Survey of Space and Time.
An ESA space observatory charting the positions, distances, and motions of nearly two billion stars in the Milky Way.
A NASA infrared space telescope designed for wide-field surveys of dark energy and exoplanets.
A 16th-century Danish astronomer renowned for his exceptionally accurate naked-eye observations of the heavens.
A Greco-Roman astronomer whose Almagest codified the geocentric model that dominated astronomy for over a millennium.
An ancient Greek astronomer credited with compiling an early star catalogue and discovering the precession of the equinoxes.
A German-British astronomer who discovered several comets and was among the first women paid for scientific work.
An American astronomer whose discovery of the Cepheid period–luminosity relation gave astronomers a way to measure cosmic distances.
An American astronomer who developed the stellar spectral classification system still in use today.
An American astronomer whose study of galaxy rotation curves provided strong evidence for dark matter.
An American astronomer and planetary scientist celebrated for his research and his work communicating science to the public.
An American astronomer and NASA's first chief of astronomy, often called the 'Mother of Hubble' for her role in space-based astronomy.
A catalogue of nearly 8,000 deep-sky objects.
A large emission nebula in Cygnus whose shape resembles the continent of North America.
An emission nebula and star-forming region in Orion, near the star Alnitak.
Part of the Veil Nebula, a supernova remnant in Cygnus also known as the Witch's Broom Nebula.
A bipolar planetary nebula in Scorpius with one of the hottest known central stars.
A complex planetary nebula in the constellation Draco, one of the first to be studied with a spectroscope.
A large emission nebula in the constellation Monoceros surrounding a young open star cluster.
A giant elliptical galaxy in Virgo whose supermassive black hole was the first to be directly imaged.
A bright barred spiral starburst galaxy in the constellation Sculptor.
An edge-on spiral galaxy in Coma Berenices noted for its slender, needle-like profile.
A prominent radio galaxy in Centaurus, one of the closest active galaxies to Earth.
A barred spiral galaxy in the constellation Eridanus with a striking central bar structure.
A double-barred spiral galaxy in the Fornax Cluster, in the constellation Fornax.
An extended autumn meteor shower with a radiant in the constellation Taurus, associated with Comet Encke.
Carina is a southern constellation representing the keel of the ship Argo, home to the bright star Canopus.
Eridanus is a long southern constellation representing a celestial river, terminating at the bright star Achernar.
Centaurus is a bright southern constellation depicting a centaur and containing several of the sky's most luminous stars.
Crux, the Southern Cross, is the smallest of the 88 modern constellations and a prominent southern-sky asterism.
Ursa Major, the Great Bear, is a large northern constellation containing the seven stars of the Big Dipper asterism.
Ophiuchus is a large equatorial constellation depicting a man holding a serpent, straddling the celestial equator.
Capricornus is a faint zodiacal constellation traditionally represented as a sea goat.
Aries is a mid-sized zodiacal constellation representing the ram, with Hamal as its brightest star.
Canopus is a white supergiant and the second-brightest star in the night sky, the luminary of the constellation Carina.
Achernar is a hot blue main-sequence star and the brightest star in the constellation Eridanus.
Hadar (Beta Centauri) is a blue giant multiple star system and the second-brightest star in the constellation Centaurus.
Acrux (Alpha Crucis) is the brightest star in the constellation Crux and the southernmost first-magnitude star.
Gacrux (Gamma Crucis) is a red giant marking the top of the Southern Cross in the constellation Crux.
Bellatrix is a blue giant marking the left shoulder of the hunter in the constellation Orion.
Mintaka is a multiple star system forming the westernmost star of Orion's Belt in the constellation Orion.
Alnilam is a blue supergiant forming the central star of Orion's Belt in the constellation Orion.
Alnitak is a hot blue triple star system forming the easternmost star of Orion's Belt in the constellation Orion.
Saiph is a blue supergiant marking the lower-right knee of the hunter in the constellation Orion.
Dubhe is an orange giant and one of the two 'pointer' stars of the Big Dipper in the constellation Ursa Major.
Merak is a white main-sequence star and a 'pointer' of the Big Dipper in the constellation Ursa Major.
Alkaid is a hot blue star marking the end of the Big Dipper's handle in the constellation Ursa Major.
Mizar is a well-known multiple star system in the handle of the Big Dipper in the constellation Ursa Major.
Alioth is the brightest star in the constellation Ursa Major and sits in the handle of the Big Dipper.
Denebola is a white main-sequence star marking the tail of the lion in the constellation Leo.
Algol is a famous eclipsing binary, the prototype 'Demon Star', in the constellation Perseus.
Mirfak is a yellow-white supergiant and the brightest star in the constellation Perseus.
Rasalhague is a white binary star and the brightest star in the constellation Ophiuchus.
Vindemiatrix is a yellow giant and one of the brighter stars in the constellation Virgo.
Sadr is a yellow-white supergiant marking the heart of the swan in the constellation Cygnus.
Albireo is a celebrated colorful double star marking the head of the swan in the constellation Cygnus.
Deneb Algedi (Delta Capricorni) is an eclipsing binary and the brightest star in the constellation Capricornus.
Hamal is an orange giant and the brightest star in the constellation Aries.
Alpheratz is a blue-white star marking the head of the chained princess in the constellation Andromeda.
Mirach is a red giant in the constellation Andromeda, often used as a guide to nearby galaxies.
Schedar is an orange giant and the brightest star in the constellation Cassiopeia.
Caph is a yellow-white star forming one corner of the distinctive W-shape of the constellation Cassiopeia.
A large equatorial constellation, one of the 88 modern constellations, lying along the zodiac.
A northern constellation, one of the 88 modern constellations, recognizable by the Great Square asterism.
A faint northern zodiacal constellation, one of the 88 modern constellations.
A southern zodiacal constellation, one of the 88 modern constellations.
A large constellation in the southern sky, one of the 88 modern constellations, often called the Whale or Sea Monster.
An ultra-cool red dwarf star about 40 light-years away that hosts seven known terrestrial planets.
A Sun-like star in Cygnus hosting Kepler-22b, the first habitable-zone planet found by the Kepler mission.
A red dwarf star in Cygnus hosting Kepler-186f, the first Earth-size planet found in a habitable zone.
A Sun-like star in Pegasus whose planet HD 209458 b was the first exoplanet observed transiting its star.
A red dwarf star in Libra hosting a system of confirmed super-Earth and Neptune-mass planets.
An F-type main-sequence star in Cygnus noted for unusual, irregular dimming events detected by Kepler.
A roughly Earth-mass planet in the habitable zone of Proxima Centauri, the nearest known exoplanet to the Solar System.
The innermost of the seven known terrestrial planets orbiting TRAPPIST-1.
The second terrestrial planet from the ultra-cool dwarf star TRAPPIST-1.
The third terrestrial planet in the TRAPPIST-1 system.
A habitable-zone terrestrial planet in the TRAPPIST-1 system, comparable in size to Earth.
A habitable-zone terrestrial planet orbiting TRAPPIST-1.
The sixth of the seven known terrestrial planets orbiting TRAPPIST-1.
The outermost of the seven known terrestrial planets orbiting TRAPPIST-1.
A hot Jupiter and the first exoplanet discovered orbiting a Sun-like star, announced in 1995.
A super-Earth-to-Neptune-size planet in the habitable zone of the Sun-like star Kepler-22.
The first validated Earth-size planet found orbiting in the habitable zone of another star.
A hot Jupiter and the first exoplanet observed transiting its host star and to have its atmosphere detected.
A super-Earth orbiting very close to 55 Cancri, with a likely scorching, possibly molten surface.
A confirmed super-Earth orbiting the red dwarf Gliese 581, one of the earliest low-mass planets found near a habitable zone.
One of the largest objects in the asteroid belt, visited by NASA's Dawn.
One of the most massive asteroids in the main belt.
A large, dark asteroid in the outer main belt.
A near-Earth asteroid sampled by NASA's OSIRIS-REx.
A near-Earth asteroid sampled by Japan's Hayabusa2.
A near-Earth asteroid orbited by NASA's NEAR Shoemaker.
A near-Earth asteroid sampled by Japan's Hayabusa.
A metal-rich main-belt asteroid and NASA mission target.
A near-Earth asteroid studied for its close approaches to Earth.
A long-period comet that was widely visible to the naked eye in 1997.
A comet that passed very close to Earth in 1996.
A periodic comet orbited and landed on by ESA's Rosetta mission.
A comet that broke apart and collided with Jupiter in 1994.
The constellation Antlia (Antliae) — 10 catalogued stars in this encyclopedia.
The constellation Apus (Apodis) — 13 catalogued stars in this encyclopedia.
The constellation Ara (Arae) — 18 catalogued stars in this encyclopedia.
The constellation Caelum (Caeli) — 4 catalogued stars in this encyclopedia.
The constellation Camelopardalis (Camelopardalis) — 45 catalogued stars in this encyclopedia.
The constellation Canes Venatici (Canum Venaticorum) — 16 catalogued stars in this encyclopedia.
The constellation Cepheus (Cephei) — 48 catalogued stars in this encyclopedia.
The constellation Chamaeleon (Chamaeleontis) — 13 catalogued stars in this encyclopedia.
The constellation Circinus (Circini) — 10 catalogued stars in this encyclopedia.
The constellation Columba (Columbae) — 19 catalogued stars in this encyclopedia.
The constellation Coma Berenices (Comae Berenices) — 24 catalogued stars in this encyclopedia.
The constellation Corona Australis (Coronae Australis) — 21 catalogued stars in this encyclopedia.
The constellation Corona Borealis (Coronae Borealis) — 19 catalogued stars in this encyclopedia.
The constellation Corvus (Corvi) — 11 catalogued stars in this encyclopedia.
The constellation Crater (Crateris) — 11 catalogued stars in this encyclopedia.
The constellation Delphinus (Delphini) — 12 catalogued stars in this encyclopedia.
The constellation Dorado (Doradus) — 15 catalogued stars in this encyclopedia.
The constellation Draco (Draconis) — 79 catalogued stars in this encyclopedia.
The constellation Equuleus (Equulei) — 6 catalogued stars in this encyclopedia.
The constellation Fornax (Fornacis) — 12 catalogued stars in this encyclopedia.
The constellation Grus (Gruis) — 22 catalogued stars in this encyclopedia.
The constellation Hercules (Herculis) — 77 catalogued stars in this encyclopedia.
The constellation Horologium (Horologii) — 10 catalogued stars in this encyclopedia.
The constellation Hydra (Hydrae) — 71 catalogued stars in this encyclopedia.
The constellation Hydrus (Hydri) — 10 catalogued stars in this encyclopedia.
The constellation Indus (Indi) — 10 catalogued stars in this encyclopedia.
The constellation Lacerta (Lacertae) — 21 catalogued stars in this encyclopedia.
The constellation Leo Minor (Leonis Minoris) — 14 catalogued stars in this encyclopedia.
The constellation Lepus (Leporis) — 26 catalogued stars in this encyclopedia.
The constellation Lupus (Lupi) — 48 catalogued stars in this encyclopedia.
The constellation Lynx (Lyncis) — 29 catalogued stars in this encyclopedia.
The constellation Mensa (Mensae) — 7 catalogued stars in this encyclopedia.
The constellation Microscopium (Microscopii) — 15 catalogued stars in this encyclopedia.
The constellation Monoceros (Monocerotis) — 37 catalogued stars in this encyclopedia.
The constellation Musca (Muscae) — 18 catalogued stars in this encyclopedia.
The constellation Norma (Normae) — 14 catalogued stars in this encyclopedia.
The constellation Octans (Octantis) — 17 catalogued stars in this encyclopedia.
The constellation Pavo (Pavonis) — 28 catalogued stars in this encyclopedia.
The constellation Phoenix (Phoenicis) — 26 catalogued stars in this encyclopedia.
The constellation Pictor (Pictoris) — 15 catalogued stars in this encyclopedia.
The constellation Pisces (Piscium) — 50 catalogued stars in this encyclopedia.
The constellation Puppis (Puppis) — 89 catalogued stars in this encyclopedia.
The constellation Pyxis (Pyxidis) — 12 catalogued stars in this encyclopedia.
The constellation Reticulum (Reticuli) — 11 catalogued stars in this encyclopedia.
The constellation Sagitta (Sagittae) — 8 catalogued stars in this encyclopedia.
The constellation Sagittarius (Sagittarii) — 69 catalogued stars in this encyclopedia.
The constellation Sculptor (Sculptoris) — 17 catalogued stars in this encyclopedia.
The constellation Scutum (Scuti) — 11 catalogued stars in this encyclopedia.
The constellation Serpens (Serpentis) — 37 catalogued stars in this encyclopedia.
The constellation Sextans (Sextantis) — 6 catalogued stars in this encyclopedia.
The constellation Telescopium (Telescopii) — 15 catalogued stars in this encyclopedia.
The constellation Triangulum (Trianguli) — 11 catalogued stars in this encyclopedia.
The constellation Triangulum Australe (Trianguli Australis) — 11 catalogued stars in this encyclopedia.
The constellation Tucana (Tucanae) — 19 catalogued stars in this encyclopedia.
The constellation Vela (Velorum) — 75 catalogued stars in this encyclopedia.
The constellation Volans (Volantis) — 14 catalogued stars in this encyclopedia.
The constellation Vulpecula (Vulpeculae) — 25 catalogued stars in this encyclopedia.
Yellow dwarf in Centaurus, about 4.3 light-years from Earth.
Blue giant in Crux, about 279 light-years from Earth.
Main-sequence star in Centaurus, about 4.3 light-years from Earth.
Blue giant in Canis Major, about 405 light-years from Earth.
Subgiant in Scorpius, about 571 light-years from Earth.
Blue giant in Taurus, about 134 light-years from Earth.
Subgiant in Carina, about 113 light-years from Earth.
Subgiant in Grus, about 101 light-years from Earth.
Wolf-Rayet star in Vela, about 1,117 light-years from Earth.
Blue giant in Sagittarius, about 143 light-years from Earth.
Star in Canis Major, about 1,607 light-years from Earth.
Red giant in Carina, about 605 light-years from Earth.
Star in Scorpius, about 300 light-years from Earth.
Main-sequence star in Auriga, about 81.1 light-years from Earth.
Red supergiant in Triangulum Australe, about 391 light-years from Earth.
Subgiant in Gemini, about 109 light-years from Earth.
Main-sequence star in Vela, about 80.5 light-years from Earth.
Subgiant in Pavo, about 179 light-years from Earth.
Blue giant in Canis Major, about 493 light-years from Earth.
Red giant in Hydra, about 180 light-years from Earth.
Red giant in Leo, about 130 light-years from Earth.
Red giant in Cetus, about 96.3 light-years from Earth.
Main-sequence star in Sagittarius, about 228 light-years from Earth.
Red supergiant in Centaurus, about 58.8 light-years from Earth.
Red giant in Ursa Minor, about 131 light-years from Earth.
Red giant in Grus, about 177 light-years from Earth.
Main-sequence star in Andromeda, about 393 light-years from Earth.
Subgiant in Cassiopeia, about 549 light-years from Earth.
Subgiant in Centaurus, about 130 light-years from Earth.
Star in Carina, about 766 light-years from Earth.
Blue supergiant in Puppis, about 1,084 light-years from Earth.
Main-sequence star in Corona Borealis, about 75.0 light-years from Earth.
Red supergiant in Vela, about 545 light-years from Earth.
Red giant in Draco, about 154 light-years from Earth.
Subgiant in Scorpius, about 491 light-years from Earth.
Blue giant in Centaurus, about 428 light-years from Earth.
Red supergiant in Scorpius, about 63.7 light-years from Earth.
Blue giant in Lupus, about 465 light-years from Earth.
Main-sequence star in Centaurus, about 306 light-years from Earth.
Main-sequence star in Boötes, about 203 light-years from Earth.
Red supergiant in Pegasus, about 690 light-years from Earth.
Blue giant in Scorpius, about 483 light-years from Earth.
Red giant in Phoenix, about 84.7 light-years from Earth.
Main-sequence star in Ursa Major, about 83.2 light-years from Earth.
Main-sequence star in Ophiuchus, about 88.4 light-years from Earth.
Red giant in Pegasus, about 196 light-years from Earth.
Subgiant in Cepheus, about 49.0 light-years from Earth.
Blue supergiant in Canis Major, about 1,989 light-years from Earth.
Subgiant in Vela, about 572 light-years from Earth.
Red giant in Cygnus, about 72.7 light-years from Earth.
Blue giant in Pegasus, about 133 light-years from Earth.
Red giant in Cetus, about 249 light-years from Earth.
Main-sequence star in Ophiuchus, about 366 light-years from Earth.
Subgiant in Centaurus, about 382 light-years from Earth.
Main-sequence star in Scorpius, about 404 light-years from Earth.
Main-sequence star in Leo, about 58.4 light-years from Earth.
Star in Lepus, about 2,219 light-years from Earth.
Subgiant in Centaurus, about 415 light-years from Earth.
Blue giant in Corvus, about 154 light-years from Earth.
Subgiant in Sagittarius, about 88.2 light-years from Earth.
Main-sequence star in Libra, about 185 light-years from Earth.
Red giant in Serpens, about 74.0 light-years from Earth.
Main-sequence star in Aries, about 58.7 light-years from Earth.
Star in Corvus, about 146 light-years from Earth.
Main-sequence star in Auriga, about 166 light-years from Earth.
Subgiant in Columba, about 261 light-years from Earth.
Main-sequence star in Cassiopeia, about 99.4 light-years from Earth.
Blue giant in Lupus, about 383 light-years from Earth.
Subgiant in Boötes, about 37.2 light-years from Earth.
Subgiant in Musca, about 315 light-years from Earth.
Red giant in Auriga, about 493 light-years from Earth.
Star in Vela, about 117 light-years from Earth.
Subgiant in Scorpius, about 576 light-years from Earth.
Red supergiant in Puppis, about 807 light-years from Earth.
Red giant in Sagittarius, about 348 light-years from Earth.
Red giant in Aquila, about 395 light-years from Earth.
Star in Draco, about 92.1 light-years from Earth.
Red giant in Ophiuchus, about 171 light-years from Earth.
Main-sequence star in Virgo, about 38.1 light-years from Earth.
Main-sequence star in Carina, about 456 light-years from Earth.
Blue giant in Orion, about 2,330 light-years from Earth.
Main-sequence star in Centaurus, about 58.8 light-years from Earth.
Subgiant in Libra, about 75.8 light-years from Earth.
Red giant in Ophiuchus, about 81.8 light-years from Earth.
Star in Eridanus, about 89.4 light-years from Earth.
Star in Hercules, about 139 light-years from Earth.
Red giant in Hercules, about 360 light-years from Earth.
Subgiant in Crux, about 345 light-years from Earth.
Star in Draco, about 380 light-years from Earth.
Subgiant in Lupus, about 421 light-years from Earth.
Star in Lepus, about 160 light-years from Earth.
Subgiant in Hercules, about 35.0 light-years from Earth.
Subgiant in Hydrus, about 24.3 light-years from Earth.
Red supergiant in Sagittarius, about 78.2 light-years from Earth.
Main-sequence star in Scorpius, about 474 light-years from Earth.
Subgiant in Pegasus, about 392 light-years from Earth.
Star in Triangulum Australe, about 40.4 light-years from Earth.
Star in Puppis, about 63.5 light-years from Earth.
Main-sequence star in Ara, about 267 light-years from Earth.
Red supergiant in Ara, about 646 light-years from Earth.
Blue supergiant in Perseus, about 752 light-years from Earth.
Blue giant in Taurus, about 403 light-years from Earth.
Main-sequence star in Gemini, about 51.5 light-years from Earth.
Main-sequence star in Hydrus, about 71.8 light-years from Earth.
Blue giant in Cygnus, about 165 light-years from Earth.
Red giant in Tucana, about 200 light-years from Earth.
Main-sequence star in Triangulum Australe, about 184 light-years from Earth.
Red giant in Gemini, about 232 light-years from Earth.
Star in Eridanus, about 161 light-years from Earth.
Star in Sagittarius, about 510 light-years from Earth.
Main-sequence star in Canes Venatici, about 115 light-years from Earth.
Main-sequence star in Scorpius, about 586 light-years from Earth.
Main-sequence star in Canis Minor, about 162 light-years from Earth.
Blue giant in Scorpius, about 697 light-years from Earth.
Main-sequence star in Perseus, about 638 light-years from Earth.
Star in Aquarius, about 537 light-years from Earth.
Star in Perseus, about 243 light-years from Earth.
Main-sequence star in Carina, about 1,437 light-years from Earth.
Star in Pegasus, about 214 light-years from Earth.
Main-sequence star in Corvus, about 86.9 light-years from Earth.
Red giant in Puppis, about 182 light-years from Earth.
Star in Aquarius, about 524 light-years from Earth.
Star in Leo, about 247 light-years from Earth.
Blue giant in Taurus, about 445 light-years from Earth.
Red supergiant in Eridanus, about 203 light-years from Earth.
Red giant in Sagittarius, about 96.9 light-years from Earth.
Star in Hydra, about 134 light-years from Earth.
Star in Scorpius, about 1,930 light-years from Earth.
Main-sequence star in Aquila, about 83.0 light-years from Earth.
Blue giant in Grus, about 211 light-years from Earth.
Star in Triangulum, about 127 light-years from Earth.
Star in Ursa Minor, about 487 light-years from Earth.
Red giant in Ursa Major, about 145 light-years from Earth.
Subgiant in Scorpius, about 501 light-years from Earth.
Blue giant in Perseus, about 516 light-years from Earth.
Blue supergiant in Canis Major, about 2,764 light-years from Earth.
Red giant in Corvus, about 318 light-years from Earth.
Main-sequence star in Canis Major, about 362 light-years from Earth.
Star in Auriga, about 2,132 light-years from Earth.
Main-sequence star in Musca, about 342 light-years from Earth.
Star in Boötes, about 86.8 light-years from Earth.
Main-sequence star in Capricornus, about 327 light-years from Earth.
Main-sequence star in Gemini, about 845 light-years from Earth.
Red giant in Ursa Major, about 230 light-years from Earth.
Star in Draco, about 97.4 light-years from Earth.
Red giant in Sagittarius, about 146 light-years from Earth.
Red giant in Indus, about 98.3 light-years from Earth.
Blue giant in Centaurus, about 420 light-years from Earth.
Red giant in Hydra, about 144 light-years from Earth.
Star in Hydra, about 167 light-years from Earth.
Subgiant in Hercules, about 75.1 light-years from Earth.
Subgiant in Ursa Major, about 47.3 light-years from Earth.
Red giant in Columba, about 87.2 light-years from Earth.
Red giant in Ara, about 486 light-years from Earth.
Subgiant in Centaurus, about 383 light-years from Earth.
Red giant in Lynx, about 203 light-years from Earth.
Red giant in Vela, about 239 light-years from Earth.
Red giant in Hercules, about 377 light-years from Earth.
Blue giant in Draco, about 329 light-years from Earth.
Blue giant in Puppis, about 372 light-years from Earth.
Blue giant in Sagittarius, about 239 light-years from Earth.
Subgiant in Ursa Major, about 44.0 light-years from Earth.
Main-sequence star in Circinus, about 54.0 light-years from Earth.
Main-sequence star in Auriga, about 243 light-years from Earth.
Red giant in Lepus, about 213 light-years from Earth.
Red giant in Scorpius, about 126 light-years from Earth.
Red giant in Ophiuchus, about 91.5 light-years from Earth.
Main-sequence star in Orion, about 26.3 light-years from Earth.
Subgiant in Cepheus, about 46.0 light-years from Earth.
Star in Cygnus, about 143 light-years from Earth.
Subgiant in Lupus, about 884 light-years from Earth.
Blue giant in Cepheus, about 685 light-years from Earth.
Red giant in Serpens, about 60.5 light-years from Earth.
Star in Ophiuchus, about 106 light-years from Earth.
Subgiant in Pictor, about 96.5 light-years from Earth.
Blue giant in Aquila, about 286 light-years from Earth.
Red giant in Libra, about 288 light-years from Earth.
Red giant in Hydra, about 101 light-years from Earth.
Red giant in Puppis, about 194 light-years from Earth.
Blue giant in Lyra, about 620 light-years from Earth.
Red giant in Hydrus, about 214 light-years from Earth.
Red giant in Andromeda, about 106 light-years from Earth.
Main-sequence star in Aquarius, about 161 light-years from Earth.
Subgiant in Ophiuchus, about 436 light-years from Earth.
Red giant in Draco, about 101 light-years from Earth.
Subgiant in Lepus, about 186 light-years from Earth.
Blue giant in Carina, about 342 light-years from Earth.
Main-sequence star in Dorado, about 169 light-years from Earth.
Main-sequence star in Carina, about 483 light-years from Earth.
Blue supergiant in Ara, about 1,113 light-years from Earth.
Red giant in Gemini, about 385 light-years from Earth.
Main-sequence star in Scorpius, about 73.5 light-years from Earth.
Main-sequence star in Ursa Major, about 80.5 light-years from Earth.
Red giant in Ophiuchus, about 151 light-years from Earth.
Red giant in Perseus, about 308 light-years from Earth.
Red giant in Sagittarius, about 122 light-years from Earth.
Star in Reticulum, about 162 light-years from Earth.
Main-sequence star in Leo, about 165 light-years from Earth.
Star in Puppis, about 1,199 light-years from Earth.
Subgiant in Gemini, about 58.7 light-years from Earth.
Main-sequence star in Orion, about 977 light-years from Earth.
Star in Ursa Major, about 179 light-years from Earth.
Main-sequence star in Cassiopeia, about 412 light-years from Earth.
Subgiant in Aquila, about 50.6 light-years from Earth.
Subgiant in Lupus, about 512 light-years from Earth.
Star in Hydra, about 129 light-years from Earth.
Main-sequence star in Virgo, about 74.1 light-years from Earth.
Red giant in Carina, about 658 light-years from Earth.
Main-sequence star in Orion, about 1,098 light-years from Earth.
Red giant in Virgo, about 198 light-years from Earth.
Red supergiant in Cepheus, about 836 light-years from Earth.
Star in Taurus, about 150 light-years from Earth.
Subgiant in Cepheus, about 46.5 light-years from Earth.
Red giant in Phoenix, about 234 light-years from Earth.
Main-sequence star in Pegasus, about 204 light-years from Earth.
Main-sequence star in Taurus, about 484 light-years from Earth.
Subgiant in Centaurus, about 437 light-years from Earth.
Star in Lupus, about 117 light-years from Earth.
Subgiant in Pavo, about 135 light-years from Earth.
Subgiant in Lupus, about 442 light-years from Earth.
Subgiant in Triangulum, about 63.3 light-years from Earth.
Subgiant in Hercules, about 27.1 light-years from Earth.
Star in Leo, about 274 light-years from Earth.
Subgiant in Carina, about 447 light-years from Earth.
Main-sequence star in Aquila, about 124 light-years from Earth.
Subgiant in Ursa Major, about 138 light-years from Earth.
Yellow dwarf in Cassiopeia, about 19.4 light-years from Earth.
Subgiant in Carina, about 455 light-years from Earth.
Star in Boötes, about 122 light-years from Earth.
Red giant in Cetus, about 124 light-years from Earth.
Main-sequence star in Cetus, about 79.6 light-years from Earth.
Subgiant in Centaurus, about 506 light-years from Earth.
Star in Hercules, about 109 light-years from Earth.
Star in Leo, about 1,269 light-years from Earth.
Subgiant in Telescopium, about 278 light-years from Earth.
Red giant in Ursa Major, about 399 light-years from Earth.
Main-sequence star in Grus, about 129 light-years from Earth.
Star in Boötes, about 225 light-years from Earth.
Red giant in Canis Major, about 1,121 light-years from Earth.
Yellow dwarf in Cetus, about 11.9 light-years from Earth.
Red giant in Cepheus, about 115 light-years from Earth.
Subgiant in Canis Major, about 659 light-years from Earth.
Subgiant in Gemini, about 60.5 light-years from Earth.
Red giant in Sagitta, about 258 light-years from Earth.
Red giant in Pegasus, about 106 light-years from Earth.
Star in Sagittarius, about 365 light-years from Earth.
Main-sequence star in Pegasus, about 92.3 light-years from Earth.
Main-sequence star in Virgo, about 38.6 light-years from Earth.
Blue supergiant in Vela, about 1,591 light-years from Earth.
Subgiant in Eridanus, about 29.5 light-years from Earth.
Main-sequence star in Lyra, about 962 light-years from Earth.
Main-sequence star in Leo, about 130 light-years from Earth.
Red giant in Taurus, about 147 light-years from Earth.
Red giant in Cancer, about 303 light-years from Earth.
Main-sequence star in Serpens, about 170 light-years from Earth.
Star in Hydra, about 130 light-years from Earth.
Star in Serpens, about 105 light-years from Earth.
Main-sequence star in Eridanus, about 178 light-years from Earth.
Main-sequence star in Draco, about 26.3 light-years from Earth.
Subgiant in Pavo, about 19.9 light-years from Earth.
Subgiant in Lupus, about 338 light-years from Earth.
Main-sequence star in Lepus, about 70.5 light-years from Earth.
Red giant in Crater, about 186 light-years from Earth.
Red giant in Cetus, about 275 light-years from Earth.
Subgiant in Eridanus, about 154 light-years from Earth.
Subgiant in Scorpius, about 474 light-years from Earth.
Main-sequence star in Ursa Major, about 358 light-years from Earth.
Red giant in Lupus, about 275 light-years from Earth.
Star in Gemini, about 141 light-years from Earth.
Red giant in Boötes, about 160 light-years from Earth.
Star in Capricornus, about 106 light-years from Earth.
Main-sequence star in Gemini, about 101 light-years from Earth.
Main-sequence star in Lepus, about 29.1 light-years from Earth.
Red giant in Crux, about 230 light-years from Earth.
Red giant in Andromeda, about 177 light-years from Earth.
Blue giant in Orion, about 494 light-years from Earth.
Main-sequence star in Virgo, about 35.6 light-years from Earth.
Main-sequence star in Ara, about 198 light-years from Earth.
Subgiant in Vela, about 493 light-years from Earth.
Subgiant in Vela, about 61.4 light-years from Earth.
Red giant in Cetus, about 114 light-years from Earth.
Star in Gemini, about 189 light-years from Earth.
Red giant in Libra, about 224 light-years from Earth.
Main-sequence star in Aries, about 166 light-years from Earth.
Red giant in Musca, about 90.9 light-years from Earth.
Red giant in Pavo, about 352 light-years from Earth.
Red giant in Hydra, about 113 light-years from Earth.
Star in Taurus, about 291 light-years from Earth.
Star in Pisces, about 350 light-years from Earth.
Blue giant in Taurus, about 382 light-years from Earth.
Red giant in Puppis, about 1,133 light-years from Earth.
Red giant in Scorpius, about 132 light-years from Earth.
Main-sequence star in Andromeda, about 687 light-years from Earth.
Star in Musca, about 127 light-years from Earth.
Subgiant in Delphinus, about 101 light-years from Earth.
Subgiant in Ursa Major, about 77.7 light-years from Earth.
Star in Aquarius, about 91.9 light-years from Earth.
Main-sequence star in Serpens, about 155 light-years from Earth.
Star in Taurus, about 162 light-years from Earth.
Blue supergiant in Ara, about 813 light-years from Earth.
Main-sequence star in Corona Borealis, about 112 light-years from Earth.
Main-sequence star in Libra, about 367 light-years from Earth.
Red giant in Indus, about 612 light-years from Earth.
Star in Draco, about 303 light-years from Earth.
Blue giant in Orion, about 1,052 light-years from Earth.
Red giant in Aquarius, about 271 light-years from Earth.
Blue giant in Pyxis, about 879 light-years from Earth.
Red giant in Sagitta, about 594 light-years from Earth.
Subgiant in Eridanus, about 58.2 light-years from Earth.
Subgiant in Cassiopeia, about 593 light-years from Earth.
Star in Carina, about 1,561 light-years from Earth.
Star in Capricornus, about 157 light-years from Earth.
Red giant in Auriga, about 786 light-years from Earth.
Red giant in Ursa Major, about 184 light-years from Earth.
Red giant in Eridanus, about 305 light-years from Earth.
Star in Pisces, about 138 light-years from Earth.
Red giant in Hercules, about 137 light-years from Earth.
Subgiant in Ophiuchus, about 86.9 light-years from Earth.
Blue giant in Orion, about 1,342 light-years from Earth.
Subgiant in Aquila, about 44.7 light-years from Earth.
Main-sequence star in Serpens, about 70.4 light-years from Earth.
Main-sequence star in Lepus, about 48.5 light-years from Earth.
Star in Puppis, about 353 light-years from Earth.
Red giant in Auriga, about 126 light-years from Earth.
Blue giant in Taurus, about 405 light-years from Earth.
Main-sequence star in Eridanus, about 10.5 light-years from Earth.
Red supergiant in Cygnus, about 843 light-years from Earth.
Main-sequence star in Virgo, about 135 light-years from Earth.
Red giant in Draco, about 113 light-years from Earth.
Red giant in Aquarius, about 385 light-years from Earth.
Red giant in Octans, about 69.1 light-years from Earth.
Main-sequence star in Taurus, about 209 light-years from Earth.
Red giant in Cetus, about 235 light-years from Earth.
Star in Hercules, about 193 light-years from Earth.
Subgiant in Cygnus, about 66.3 light-years from Earth.
Main-sequence star in Ophiuchus, about 103 light-years from Earth.
Red giant in Vela, about 300 light-years from Earth.
Main-sequence star in Cygnus, about 121 light-years from Earth.
Main-sequence star in Lacerta, about 103 light-years from Earth.
Star in Dorado, about 1,007 light-years from Earth.
Main-sequence star in Monoceros, about 677 light-years from Earth.
Star in Lepus, about 114 light-years from Earth.
Red giant in Sagittarius, about 142 light-years from Earth.
Red giant in Volans, about 108 light-years from Earth.
Red giant in Ara, about 299 light-years from Earth.
Main-sequence star in Pegasus, about 38.3 light-years from Earth.
Red supergiant in Perseus, about 879 light-years from Earth.
Star in Perseus, about 557 light-years from Earth.
Star in Taurus, about 156 light-years from Earth.
Main-sequence star in Orion, about 1,073 light-years from Earth.
Main-sequence star in Delphinus, about 254 light-years from Earth.
Star in Capricornus, about 386 light-years from Earth.
Main-sequence star in Aquarius, about 208 light-years from Earth.
Star in Volans, about 140 light-years from Earth.
Red giant in Carina, about 95.0 light-years from Earth.
Star in Gemini, about 120 light-years from Earth.
Subgiant in Ursa Major, about 116 light-years from Earth.
Subgiant in Boötes, about 176 light-years from Earth.
Red giant in Perseus, about 113 light-years from Earth.
Red giant in Leo Minor, about 94.9 light-years from Earth.
Red giant in Cygnus, about 884 light-years from Earth.
Main-sequence star in Fornax, about 46.4 light-years from Earth.
Subgiant in Serpens, about 228 light-years from Earth.
Subgiant in Puppis, about 347 light-years from Earth.
Red giant in Cygnus, about 124 light-years from Earth.
Main-sequence star in Corona Borealis, about 146 light-years from Earth.
Star in Carina, about 1,342 light-years from Earth.
Star in Andromeda, about 86.1 light-years from Earth.
Star in Eridanus, about 214 light-years from Earth.
Main-sequence star in Lynx, about 125 light-years from Earth.
Main-sequence star in Pisces, about 151 light-years from Earth.
Red giant in Draco, about 333 light-years from Earth.
Main-sequence star in Hercules, about 455 light-years from Earth.
Main-sequence star in Ophiuchus, about 173 light-years from Earth.
Red giant in Apus, about 447 light-years from Earth.
Red giant in Hydra, about 234 light-years from Earth.
Subgiant in Centaurus, about 525 light-years from Earth.
Star in Taurus, about 154 light-years from Earth.
Blue giant in Perseus, about 1,121 light-years from Earth.
Subgiant in Reticulum, about 97.4 light-years from Earth.
Star in Draco, about 148 light-years from Earth.
Main-sequence star in Musca, about 325 light-years from Earth.
Blue giant in Carina, about 320 light-years from Earth.
Main-sequence star in Vela, about 87.5 light-years from Earth.
Main-sequence star in Hercules, about 338 light-years from Earth.
Red giant in Hercules, about 119 light-years from Earth.
Red giant in Horologium, about 115 light-years from Earth.
Red giant in Scutum, about 199 light-years from Earth.
Main-sequence star in Pictor, about 63.4 light-years from Earth.
Star in Columba, about 234 light-years from Earth.
Main-sequence star in Serpens, about 36.7 light-years from Earth.
Main-sequence star in Vela, about 101 light-years from Earth.
Blue giant in Draco, about 491 light-years from Earth.
Main-sequence star in Centaurus, about 131 light-years from Earth.
Star in Triangulum Australe, about 607 light-years from Earth.
Red giant in Columba, about 263 light-years from Earth.
Subgiant in Apus, about 156 light-years from Earth.
Main-sequence star in Andromeda, about 130 light-years from Earth.
Main-sequence star in Aquarius, about 164 light-years from Earth.
Red giant in Eridanus, about 110 light-years from Earth.
Red giant in Hercules, about 753 light-years from Earth.
Star in Aquila, about 1,382 light-years from Earth.
Star in Vela, about 1,853 light-years from Earth.
Subgiant in Centaurus, about 428 light-years from Earth.
Subgiant in Scorpius, about 472 light-years from Earth.
Blue giant in Taurus, about 383 light-years from Earth.
Star in Virgo, about 59.6 light-years from Earth.
Red giant in Phoenix, about 144 light-years from Earth.
Main-sequence star in Lupus, about 180 light-years from Earth.
Red giant in Grus, about 183 light-years from Earth.
Main-sequence star in Aries, about 164 light-years from Earth.
Red giant in Leo, about 124 light-years from Earth.
Red giant in Eridanus, about 137 light-years from Earth.
Red giant in Cygnus, about 135 light-years from Earth.
Main-sequence star in Hydra, about 113 light-years from Earth.
Subgiant in Virgo, about 265 light-years from Earth.
Star in Centaurus, about 906 light-years from Earth.
Main-sequence star in Centaurus, about 358 light-years from Earth.
Red giant in Hydra, about 263 light-years from Earth.
Main-sequence star in Hydra, about 122 light-years from Earth.
Main-sequence star in Taurus, about 117 light-years from Earth.
Main-sequence star in Lupus, about 443 light-years from Earth.
Main-sequence star in Centaurus, about 412 light-years from Earth.
Subgiant in Hercules, about 307 light-years from Earth.
Red giant in Libra, about 163 light-years from Earth.
Star in Sagittarius, about 127 light-years from Earth.
Main-sequence star in Hercules, about 155 light-years from Earth.
Star in Equuleus, about 190 light-years from Earth.
Blue supergiant in Ophiuchus, about 1,231 light-years from Earth.
Main-sequence star in Scorpius, about 471 light-years from Earth.
Red giant in Phoenix, about 142 light-years from Earth.
Main-sequence star in Phoenix, about 77.7 light-years from Earth.
Blue giant in Eridanus, about 675 light-years from Earth.
Star in Perseus, about 254 light-years from Earth.
Red giant in Volans, about 141 light-years from Earth.
Red giant in Monoceros, about 148 light-years from Earth.
Red giant in Cancer, about 131 light-years from Earth.
Main-sequence star in Cygnus, about 375 light-years from Earth.
Main-sequence star in Phoenix, about 299 light-years from Earth.
Main-sequence star in Cassiopeia, about 157 light-years from Earth.
Red giant in Canis Major, about 64.4 light-years from Earth.
Main-sequence star in Ursa Major, about 78.8 light-years from Earth.
Red supergiant in Cygnus, about 1,059 light-years from Earth.
Main-sequence star in Perseus, about 477 light-years from Earth.
Red giant in Aquarius, about 163 light-years from Earth.
Main-sequence star in Sagittarius, about 314 light-years from Earth.
Red giant in Columba, about 472 light-years from Earth.
Main-sequence star in Lynx, about 52.4 light-years from Earth.
Subgiant in Carina, about 543 light-years from Earth.
Main-sequence star in Sagittarius, about 182 light-years from Earth.
Red giant in Eridanus, about 296 light-years from Earth.
Star in Pyxis, about 416 light-years from Earth.
Blue giant in Lupus, about 195 light-years from Earth.
Star in Volans, about 738 light-years from Earth.
Main-sequence star in Pavo, about 105 light-years from Earth.
Star in Grus, about 309 light-years from Earth.
Star in Pegasus, about 365 light-years from Earth.
Red giant in Auriga, about 230 light-years from Earth.
Main-sequence star in Centaurus, about 379 light-years from Earth.
Blue supergiant in Perseus, about 1,245 light-years from Earth.
Star in Cygnus, about 124 light-years from Earth.
Main-sequence star in Ursa Major, about 81.7 light-years from Earth.
Red giant in Monoceros, about 498 light-years from Earth.
Star in Tucana, about 75.2 light-years from Earth.
Subgiant in Carina, about 52.9 light-years from Earth.
Red giant in Cetus, about 293 light-years from Earth.
Main-sequence star in Volans, about 125 light-years from Earth.
Subgiant in Leo, about 77.2 light-years from Earth.
Star in Cygnus, about 769 light-years from Earth.
Main-sequence star in Centaurus, about 339 light-years from Earth.
Star in Norma, about 129 light-years from Earth.
Star in Gemini, about 1,376 light-years from Earth.
Subgiant in Eridanus, about 522 light-years from Earth.
Subgiant in Canis Major, about 911 light-years from Earth.
Main-sequence star in Perseus, about 718 light-years from Earth.
Subgiant in Draco, about 68.6 light-years from Earth.
Red giant in Pavo, about 218 light-years from Earth.
Red giant in Aquila, about 144 light-years from Earth.
Subgiant in Corvus, about 48.7 light-years from Earth.
Red giant in Aquila, about 155 light-years from Earth.
Red giant in Pyxis, about 207 light-years from Earth.
Main-sequence star in Ophiuchus, about 16.6 light-years from Earth.
Blue giant in Delphinus, about 331 light-years from Earth.
Star in Camelopardalis, about 872 light-years from Earth.
Main-sequence star in Triangulum, about 112 light-years from Earth.
Subgiant in Crux, about 414 light-years from Earth.
Star in Cancer, about 331 light-years from Earth.
Subgiant in Pisces, about 104 light-years from Earth.
Star in Eridanus, about 122 light-years from Earth.
Subgiant in Aquarius, about 168 light-years from Earth.
Red giant in Virgo, about 294 light-years from Earth.
Main-sequence star in Boötes, about 47.4 light-years from Earth.
Red giant in Aquarius, about 318 light-years from Earth.
Star in Chamaeleon, about 63.8 light-years from Earth.
Star in Vela, about 229 light-years from Earth.
Yellow dwarf in Perseus, about 34.4 light-years from Earth.
Subgiant in Centaurus, about 259 light-years from Earth.
Main-sequence star in Lupus, about 316 light-years from Earth.
Main-sequence star in Leo, about 220 light-years from Earth.
Red giant in Boötes, about 263 light-years from Earth.
Red giant in Orion, about 186 light-years from Earth.
Red giant in Musca, about 301 light-years from Earth.
Main-sequence star in Crater, about 82.3 light-years from Earth.
Red giant in Centaurus, about 209 light-years from Earth.
Red giant in Ara, about 361 light-years from Earth.
Red giant in Gemini, about 271 light-years from Earth.
Main-sequence star in Crux, about 358 light-years from Earth.
Main-sequence star in Circinus, about 99.7 light-years from Earth.
Star in Cepheus, about 865 light-years from Earth.
Main-sequence star in Lupus, about 777 light-years from Earth.
Main-sequence star in Virgo, about 72.5 light-years from Earth.
Red giant in Pegasus, about 156 light-years from Earth.
Main-sequence star in Eridanus, about 88.6 light-years from Earth.
Red giant in Lyra, about 298 light-years from Earth.
Red giant in Crater, about 159 light-years from Earth.
Subgiant in Cetus, about 650 light-years from Earth.
Main-sequence star in Hydrus, about 140 light-years from Earth.
Blue giant in Carina, about 1,326 light-years from Earth.
Red giant in Canis Major, about 261 light-years from Earth.
Main-sequence star in Capricornus, about 162 light-years from Earth.
Red giant in Andromeda, about 189 light-years from Earth.
Star in Orion, about 117 light-years from Earth.
Red giant in Serpens, about 382 light-years from Earth.
Red giant in Corona Australis, about 474 light-years from Earth.
Blue giant in Puppis, about 1,647 light-years from Earth.
Main-sequence star in Perseus, about 36.3 light-years from Earth.
Main-sequence star in Andromeda, about 44.0 light-years from Earth.
Star in Telescopium, about 126 light-years from Earth.
Red giant in Triangulum Australe, about 202 light-years from Earth.
Red giant in Chamaeleon, about 418 light-years from Earth.
Star in Vela, about 1,822 light-years from Earth.
Star in Centaurus, about 390 light-years from Earth.
Red giant in Eridanus, about 151 light-years from Earth.
Main-sequence star in Corona Australis, about 125 light-years from Earth.
Blue giant in Canis Major, about 442 light-years from Earth.
Star in Grus, about 109 light-years from Earth.
Star in Hydra, about 264 light-years from Earth.
Blue giant in Hydrus, about 152 light-years from Earth.
Red supergiant in Grus, about 330 light-years from Earth.
Red giant in Sagittarius, about 182 light-years from Earth.
Main-sequence star in Orion, about 155 light-years from Earth.
Star in Perseus, about 901 light-years from Earth.
Red giant in Capricornus, about 843 light-years from Earth.
Star in Virgo, about 163 light-years from Earth.
Star in Orion, about 157 light-years from Earth.
Subgiant in Octans, about 149 light-years from Earth.
Main-sequence star in Pisces, about 44.7 light-years from Earth.
Blue giant in Gemini, about 545 light-years from Earth.
Main-sequence star in Capricornus, about 47.9 light-years from Earth.
Red giant in Libra, about 168 light-years from Earth.
Red giant in Lacerta, about 621 light-years from Earth.
Red giant in Taurus, about 342 light-years from Earth.
Main-sequence star in Hydra, about 160 light-years from Earth.
Red giant in Corona Borealis, about 221 light-years from Earth.
Star in Crux, about 64.4 light-years from Earth.
Subgiant in Pegasus, about 112 light-years from Earth.
Subgiant in Taurus, about 380 light-years from Earth.
Main-sequence star in Corona Borealis, about 375 light-years from Earth.
Main-sequence star in Monoceros, about 384 light-years from Earth.
Subgiant in Andromeda, about 168 light-years from Earth.
Blue giant in Hercules, about 393 light-years from Earth.
Star in Gemini, about 155 light-years from Earth.
Subgiant in Ophiuchus, about 83.2 light-years from Earth.
Main-sequence star in Gemini, about 58.9 light-years from Earth.
Star in Aquarius, about 187 light-years from Earth.
Star in Eridanus, about 210 light-years from Earth.
Subgiant in Cepheus, about 85.5 light-years from Earth.
Main-sequence star in Piscis Austrinus, about 487 light-years from Earth.
Red giant in Scorpius, about 343 light-years from Earth.
Red giant in Virgo, about 255 light-years from Earth.
Main-sequence star in Boötes, about 99.0 light-years from Earth.
Main-sequence star in Hercules, about 62.6 light-years from Earth.
Red giant in Centaurus, about 183 light-years from Earth.
Star in Puppis, about 522 light-years from Earth.
Main-sequence star in Orion, about 303 light-years from Earth.
Star in Leo Minor, about 154 light-years from Earth.
Star in Piscis Austrinus, about 154 light-years from Earth.
Main-sequence star in Hercules, about 315 light-years from Earth.
Main-sequence star in Pegasus, about 53.1 light-years from Earth.
Subgiant in Taurus, about 154 light-years from Earth.
Star in Ursa Minor, about 304 light-years from Earth.
Main-sequence star in Pavo, about 30.2 light-years from Earth.
Blue supergiant in Camelopardalis, about 1,941 light-years from Earth.
Star in Cepheus, about 136 light-years from Earth.
Red giant in Lyra, about 736 light-years from Earth.
Star in Perseus, about 121 light-years from Earth.
Main-sequence star in Eridanus, about 57.5 light-years from Earth.
Red giant in Cygnus, about 201 light-years from Earth.
Star in Scutum, about 916 light-years from Earth.
Main-sequence star in Ophiuchus, about 525 light-years from Earth.
Blue supergiant in Puppis, about 1,656 light-years from Earth.
Blue giant in Pavo, about 1,431 light-years from Earth.
Red giant in Aquarius, about 202 light-years from Earth.
Main-sequence star in Draco, about 303 light-years from Earth.
Blue supergiant in Cygnus, about 2,886 light-years from Earth.
Main-sequence star in Lupus, about 414 light-years from Earth.
Main-sequence star in Centaurus, about 63.3 light-years from Earth.
Blue giant in Cygnus, about 1,106 light-years from Earth.
Red giant in Apus, about 157 light-years from Earth.
Yellow dwarf in Coma Berenices, about 29.8 light-years from Earth.
Subgiant in Corona Australis, about 56.4 light-years from Earth.
Main-sequence star in Hercules, about 204 light-years from Earth.
Red giant in Gemini, about 125 light-years from Earth.
Main-sequence star in Virgo, about 225 light-years from Earth.
Main-sequence star in Tucana, about 28.0 light-years from Earth.
Red giant in Aquarius, about 150 light-years from Earth.
Main-sequence star in Chamaeleon, about 298 light-years from Earth.
Yellow dwarf in Canes Venatici, about 27.5 light-years from Earth.
Red giant in Cepheus, about 280 light-years from Earth.
Blue giant in Scorpius, about 555 light-years from Earth.
Subgiant in Eridanus, about 508 light-years from Earth.
Main-sequence star in Serpens, about 173 light-years from Earth.
Subgiant in Cetus, about 393 light-years from Earth.
Red giant in Ursa Minor, about 359 light-years from Earth.
Star in Perseus, about 797 light-years from Earth.
Main-sequence star in Taurus, about 156 light-years from Earth.
Red giant in Lynx, about 382 light-years from Earth.
Subgiant in Centaurus, about 149 light-years from Earth.
Subgiant in Tucana, about 68.3 light-years from Earth.
Subgiant in Eridanus, about 811 light-years from Earth.
Subgiant in Perseus, about 422 light-years from Earth.
Main-sequence star in Eridanus, about 293 light-years from Earth.
Yellow dwarf in Eridanus, about 19.7 light-years from Earth.
Yellow dwarf in Hercules, about 417 light-years from Earth.
Main-sequence star in Cancer, about 188 light-years from Earth.
Star in Dorado, about 66.7 light-years from Earth.
Star in Scorpius, about 166 light-years from Earth.
Main-sequence star in Cepheus, about 96.5 light-years from Earth.
Blue giant in Andromeda, about 717 light-years from Earth.
Red giant in Pisces, about 279 light-years from Earth.
Subgiant in Delphinus, about 126 light-years from Earth.
Main-sequence star in Taurus, about 154 light-years from Earth.
Star in Sagittarius, about 134 light-years from Earth.
Red giant in Pisces, about 182 light-years from Earth.
Main-sequence star in Centaurus, about 467 light-years from Earth.
Star in Cetus, about 84.1 light-years from Earth.
Main-sequence star in Lupus, about 336 light-years from Earth.
Subgiant in Taurus, about 456 light-years from Earth.
Main-sequence star in Taurus, about 398 light-years from Earth.
Red giant in Pisces, about 149 light-years from Earth.
Star in Pegasus, about 263 light-years from Earth.
Subgiant in Cygnus, about 159 light-years from Earth.
Star in Ophiuchus, about 112 light-years from Earth.
Red giant in Antlia, about 366 light-years from Earth.
Red giant in Draco, about 994 light-years from Earth.
Star in Capricornus, about 197 light-years from Earth.
Main-sequence star in Grus, about 132 light-years from Earth.
Main-sequence star in Taurus, about 45.5 light-years from Earth.
Main-sequence star in Hydra, about 310 light-years from Earth.
Main-sequence star in Piscis Austrinus, about 143 light-years from Earth.
Star in Vela, about 841 light-years from Earth.
Main-sequence star in Andromeda, about 500 light-years from Earth.
Main-sequence star in Aquarius, about 175 light-years from Earth.
Subgiant in Lepus, about 852 light-years from Earth.
Star in Ophiuchus, about 244 light-years from Earth.
Main-sequence star in Ursa Minor, about 369 light-years from Earth.
Star in Capricornus, about 569 light-years from Earth.
Main-sequence star in Leo, about 287 light-years from Earth.
Subgiant in Taurus, about 149 light-years from Earth.
Blue giant in Cetus, about 193 light-years from Earth.
Blue giant in Sculptor, about 777 light-years from Earth.
Main-sequence star in Corvus, about 59.6 light-years from Earth.
Main-sequence star in Hydra, about 587 light-years from Earth.
Main-sequence star in Eridanus, about 165 light-years from Earth.
Main-sequence star in Centaurus, about 595 light-years from Earth.
Blue supergiant in Centaurus, about 1,226 light-years from Earth.
Red giant in Auriga, about 752 light-years from Earth.
Main-sequence star in Taurus, about 409 light-years from Earth.
Star in Leo, about 182 light-years from Earth.
Star in Scorpius, about 291 light-years from Earth.
Star in Aquila, about 337 light-years from Earth.
Main-sequence star in Boötes, about 113 light-years from Earth.
Red giant in Octans, about 299 light-years from Earth.
Blue giant in Carina, about 1,443 light-years from Earth.
Red supergiant in Taurus, about 1,792 light-years from Earth.
Star in Hydra, about 245 light-years from Earth.
Main-sequence star in Centaurus, about 344 light-years from Earth.
Red giant in Eridanus, about 369 light-years from Earth.
Red giant in Leo, about 329 light-years from Earth.
Main-sequence star in Coma Berenices, about 58.1 light-years from Earth.
Main-sequence star in Crux, about 235 light-years from Earth.
Star in Auriga, about 177 light-years from Earth.
Main-sequence star in Serpens, about 203 light-years from Earth.
Subgiant in Lupus, about 404 light-years from Earth.
Main-sequence star in Perseus, about 584 light-years from Earth.
Yellow dwarf in Ursa Major, about 34.0 light-years from Earth.
Red giant in Canis Minor, about 318 light-years from Earth.
Red giant in Ophiuchus, about 19.4 light-years from Earth.
Red giant in Centaurus, about 294 light-years from Earth.
Main-sequence star in Lupus, about 319 light-years from Earth.
Red giant in Lyra, about 252 light-years from Earth.
Main-sequence star in Pavo, about 130 light-years from Earth.
Star in Hercules, about 94.2 light-years from Earth.
Blue giant in Canis Major, about 1,382 light-years from Earth.
Red giant in Lacerta, about 1,647 light-years from Earth.
Main-sequence star in Lyra, about 156 light-years from Earth.
Star in Pegasus, about 927 light-years from Earth.
Main-sequence star in Dorado, about 150 light-years from Earth.
Star in Andromeda, about 164 light-years from Earth.
Red giant in Carina, about 488 light-years from Earth.
Main-sequence star in Vela, about 105 light-years from Earth.
Star in Centaurus, about 1,269 light-years from Earth.
Red giant in Lupus, about 219 light-years from Earth.
Main-sequence star in Andromeda, about 599 light-years from Earth.
Red giant in Ophiuchus, about 901 light-years from Earth.
Main-sequence star in Cassiopeia, about 134 light-years from Earth.
Red giant in Chamaeleon, about 155 light-years from Earth.
Star in Lynx, about 178 light-years from Earth.
Red giant in Lupus, about 326 light-years from Earth.
Main-sequence star in Orion, about 224 light-years from Earth.
Red giant in Aries, about 170 light-years from Earth.
Subgiant in Volans, about 562 light-years from Earth.
Red giant in Coma Berenices, about 167 light-years from Earth.
Blue giant in Carina, about 1,365 light-years from Earth.
Main-sequence star in Piscis Austrinus, about 204 light-years from Earth.
Main-sequence star in Hydra, about 354 light-years from Earth.
Red giant in Lyra, about 832 light-years from Earth.
Red giant in Pavo, about 469 light-years from Earth.
Main-sequence star in Ursa Minor, about 172 light-years from Earth.
Red giant in Taurus, about 187 light-years from Earth.
Star in Cetus, about 383 light-years from Earth.
Main-sequence star in Centaurus, about 510 light-years from Earth.
Subgiant in Phoenix, about 246 light-years from Earth.
Subgiant in Columba, about 870 light-years from Earth.
Main-sequence star in Tucana, about 135 light-years from Earth.
Blue giant in Aquila, about 391 light-years from Earth.
Blue supergiant in Canis Major, about 2,509 light-years from Earth.
Main-sequence star in Lepus, about 728 light-years from Earth.
Subgiant in Eridanus, about 235 light-years from Earth.
Red giant in Perseus, about 360 light-years from Earth.
Star in Monoceros, about 1,059 light-years from Earth.
Subgiant in Hercules, about 916 light-years from Earth.
Red giant in Pisces, about 432 light-years from Earth.
Subgiant in Vela, about 196 light-years from Earth.
Subgiant in Sagittarius, about 519 light-years from Earth.
Star in Columba, about 183 light-years from Earth.
Blue supergiant in Canis Major, about 2,992 light-years from Earth.
Red giant in Aquarius, about 283 light-years from Earth.
Subgiant in Sculptor, about 174 light-years from Earth.
Blue giant in Cepheus, about 315 light-years from Earth.
Main-sequence star in Virgo, about 316 light-years from Earth.
Red giant in Virgo, about 195 light-years from Earth.
Red giant in Leo, about 295 light-years from Earth.
Subgiant in Orion, about 1,087 light-years from Earth.
Yellow dwarf in Orion, about 28.3 light-years from Earth.
Star in Sagitta, about 440 light-years from Earth.
Subgiant in Monoceros, about 122 light-years from Earth.
Red giant in Camelopardalis, about 796 light-years from Earth.
Red giant in Canis Minor, about 254 light-years from Earth.
Main-sequence star in Ophiuchus, about 245 light-years from Earth.
Red giant in Phoenix, about 342 light-years from Earth.
Star in Sagitta, about 425 light-years from Earth.
Main-sequence star in Indus, about 98.8 light-years from Earth.
Main-sequence star in Ophiuchus, about 56.6 light-years from Earth.
Main-sequence star in Puppis, about 465 light-years from Earth.
Subgiant in Indus, about 188 light-years from Earth.
Star in Andromeda, about 230 light-years from Earth.
Star in Pavo, about 500 light-years from Earth.
Subgiant in Puppis, about 1,418 light-years from Earth.
Main-sequence star in Aquarius, about 402 light-years from Earth.
Red giant in Sculptor, about 182 light-years from Earth.
Star in Carina, about 545 light-years from Earth.
Main-sequence star in Centaurus, about 457 light-years from Earth.
Red giant in Hercules, about 369 light-years from Earth.
Star in Hercules, about 861 light-years from Earth.
Star in Cepheus, about 247 light-years from Earth.
Red giant in Gemini, about 321 light-years from Earth.
Main-sequence star in Cygnus, about 642 light-years from Earth.
Blue giant in Canis Major, about 1,735 light-years from Earth.
Red giant in Hydra, about 331 light-years from Earth.
Main-sequence star in Leo, about 127 light-years from Earth.
Main-sequence star in Ophiuchus, about 293 light-years from Earth.
Red giant in Canis Major, about 421 light-years from Earth.
Subgiant in Pegasus, about 170 light-years from Earth.
Star in Lacerta, about 170 light-years from Earth.
Red dwarf in Puppis, about 209 light-years from Earth.
Red giant in Puppis, about 298 light-years from Earth.
Yellow dwarf in Serpens, about 39.5 light-years from Earth.
Subgiant in Orion, about 516 light-years from Earth.
Red giant in Aquarius, about 586 light-years from Earth.
Red giant in Cygnus, about 250 light-years from Earth.
Red giant in Sagittarius, about 449 light-years from Earth.
Main-sequence star in Camelopardalis, about 372 light-years from Earth.
Subgiant in Lyra, about 1,388 light-years from Earth.
Star in Delphinus, about 223 light-years from Earth.
Main-sequence star in Eridanus, about 16.3 light-years from Earth.
Red giant in Eridanus, about 481 light-years from Earth.
Main-sequence star in Lynx, about 157 light-years from Earth.
Red giant in Cetus, about 447 light-years from Earth.
Main-sequence star in Caelum, about 65.8 light-years from Earth.
Red dwarf in Vulpecula, about 297 light-years from Earth.
Red giant in Pisces, about 311 light-years from Earth.
Subgiant in Reticulum, about 59.5 light-years from Earth.
Main-sequence star in Puppis, about 82.5 light-years from Earth.
Red giant in Puppis, about 1,699 light-years from Earth.
Main-sequence star in Puppis, about 93.4 light-years from Earth.
Blue giant in Lupus, about 575 light-years from Earth.
Star in Fornax, about 173 light-years from Earth.
Main-sequence star in Vela, about 210 light-years from Earth.
Red giant in Carina, about 1,178 light-years from Earth.
Subgiant in Chamaeleon, about 351 light-years from Earth.
Main-sequence star in Lepus, about 232 light-years from Earth.
Red giant in Hydra, about 373 light-years from Earth.
Red giant in Aquila, about 108 light-years from Earth.
Red giant in Pisces, about 363 light-years from Earth.
Main-sequence star in Ophiuchus, about 169 light-years from Earth.
Subgiant in Leo, about 184 light-years from Earth.
Red giant in Draco, about 146 light-years from Earth.
Subgiant in Orion, about 607 light-years from Earth.
Main-sequence star in Ursa Major, about 94.0 light-years from Earth.
Star in Eridanus, about 313 light-years from Earth.
Main-sequence star in Crater, about 340 light-years from Earth.
Main-sequence star in Norma, about 530 light-years from Earth.
Star in Piscis Austrinus, about 215 light-years from Earth.
Blue giant in Centaurus, about 438 light-years from Earth.
Main-sequence star in Cassiopeia, about 133 light-years from Earth.
Red giant in Orion, about 350 light-years from Earth.
Main-sequence star in Eridanus, about 46.4 light-years from Earth.
Red giant in Orion, about 945 light-years from Earth.
Main-sequence star in Libra, about 87.8 light-years from Earth.
Main-sequence star in Ursa Major, about 262 light-years from Earth.
Main-sequence star in Equuleus, about 60.3 light-years from Earth.
Main-sequence star in Puppis, about 959 light-years from Earth.
Star in Carina, about 401 light-years from Earth.
Red giant in Centaurus, about 433 light-years from Earth.
Red giant in Aries, about 543 light-years from Earth.
Red giant in Leo, about 201 light-years from Earth.
Main-sequence star in Canis Major, about 424 light-years from Earth.
Red giant in Grus, about 242 light-years from Earth.
Main-sequence star in Boötes, about 51.6 light-years from Earth.
Red giant in Monoceros, about 368 light-years from Earth.
Main-sequence star in Taurus, about 160 light-years from Earth.
Star in Aquarius, about 216 light-years from Earth.
Star in Sextans, about 283 light-years from Earth.
Main-sequence star in Pisces, about 408 light-years from Earth.
Blue giant in Circinus, about 449 light-years from Earth.
Red giant in Reticulum, about 469 light-years from Earth.
Blue giant in Cassiopeia, about 703 light-years from Earth.
Red giant in Ophiuchus, about 199 light-years from Earth.
Main-sequence star in Aquarius, about 149 light-years from Earth.
Main-sequence star in Leo Minor, about 92.1 light-years from Earth.
Red giant in Capricornus, about 456 light-years from Earth.
Main-sequence star in Boötes, about 306 light-years from Earth.
Red giant in Gemini, about 289 light-years from Earth.
Subgiant in Cassiopeia, about 115 light-years from Earth.
Red giant in Eridanus, about 127 light-years from Earth.
Main-sequence star in Cygnus, about 72.5 light-years from Earth.
Subgiant in Tucana, about 373 light-years from Earth.
Subgiant in Puppis, about 69.9 light-years from Earth.
Main-sequence star in Puppis, about 648 light-years from Earth.
Main-sequence star in Pisces, about 107 light-years from Earth.
Main-sequence star in Cygnus, about 59.8 light-years from Earth.
Red giant in Lacerta, about 333 light-years from Earth.
Red giant in Vulpecula, about 339 light-years from Earth.
Red giant in Capricornus, about 171 light-years from Earth.
Main-sequence star in Leo, about 233 light-years from Earth.
Red giant in Pictor, about 177 light-years from Earth.
Main-sequence star in Carina, about 605 light-years from Earth.
Blue giant in Vela, about 1,148 light-years from Earth.
Red giant in Lacerta, about 483 light-years from Earth.
Main-sequence star in Piscis Austrinus, about 136 light-years from Earth.
Star in Aquarius, about 159 light-years from Earth.
Blue giant in Orion, about 1,382 light-years from Earth.
Main-sequence star in Boötes, about 50.9 light-years from Earth.
Main-sequence star in Tucana, about 251 light-years from Earth.
Red giant in Antlia, about 711 light-years from Earth.
Main-sequence star in Capricornus, about 1,056 light-years from Earth.
Main-sequence star in Indus, about 78.8 light-years from Earth.
Main-sequence star in Carina, about 226 light-years from Earth.
Main-sequence star in Serpens, about 190 light-years from Earth.
Red giant in Draco, about 429 light-years from Earth.
Main-sequence star in Andromeda, about 135 light-years from Earth.
Star in Auriga, about 207 light-years from Earth.
Red giant in Pisces, about 169 light-years from Earth.
Red giant in Pegasus, about 394 light-years from Earth.
Subgiant in Lacerta, about 1,717 light-years from Earth.
Star in Telescopium, about 418 light-years from Earth.
Main-sequence star in Centaurus, about 355 light-years from Earth.
Star in Centaurus, about 260 light-years from Earth.
Subgiant in Cepheus, about 89.0 light-years from Earth.
Main-sequence star in Virgo, about 186 light-years from Earth.
Red giant in Aries, about 172 light-years from Earth.
Red giant in Boötes, about 246 light-years from Earth.
Main-sequence star in Sagittarius, about 1,782 light-years from Earth.
Subgiant in Boötes, about 163 light-years from Earth.
Star in Sagittarius, about 985 light-years from Earth.
Main-sequence star in Andromeda, about 80.2 light-years from Earth.
Main-sequence star in Tucana, about 168 light-years from Earth.
Red giant in Orion, about 421 light-years from Earth.
Subgiant in Puppis, about 360 light-years from Earth.
Main-sequence star in Ophiuchus, about 98.1 light-years from Earth.
Subgiant in Cygnus, about 769 light-years from Earth.
Main-sequence star in Andromeda, about 618 light-years from Earth.
Star in Leo Minor, about 185 light-years from Earth.
Red giant in Auriga, about 232 light-years from Earth.
Main-sequence star in Libra, about 380 light-years from Earth.
Star in Ursa Major, about 104 light-years from Earth.
Main-sequence star in Hydra, about 518 light-years from Earth.
Star in Canis Major, about 441 light-years from Earth.
Red giant in Pegasus, about 329 light-years from Earth.
Red giant in Sagittarius, about 832 light-years from Earth.
Star in Pegasus, about 175 light-years from Earth.
Main-sequence star in Lupus, about 519 light-years from Earth.
Yellow dwarf in Boötes, about 21.9 light-years from Earth.
Red giant in Cepheus, about 182 light-years from Earth.
Subgiant in Cetus, about 272 light-years from Earth.
Main-sequence star in Lacerta, about 555 light-years from Earth.
Blue supergiant in Lacerta, about 2,249 light-years from Earth.
Red giant in Canis Minor, about 572 light-years from Earth.
Star in Camelopardalis, about 2,509 light-years from Earth.
Red giant in Caelum, about 181 light-years from Earth.
Red giant in Camelopardalis, about 184 light-years from Earth.
Subgiant in Lupus, about 428 light-years from Earth.
Red giant in Sagittarius, about 339 light-years from Earth.
Star in Scorpius, about 879 light-years from Earth.
Subgiant in Ursa Major, about 509 light-years from Earth.
Main-sequence star in Taurus, about 423 light-years from Earth.
Red giant in Perseus, about 467 light-years from Earth.
Star in Vulpecula, about 189 light-years from Earth.
Red giant in Cygnus, about 1,032 light-years from Earth.
Red giant in Leo, about 959 light-years from Earth.
Red giant in Reticulum, about 526 light-years from Earth.
Star in Lynx, about 817 light-years from Earth.
Subgiant in Lupus, about 1,091 light-years from Earth.
Main-sequence star in Ara, about 378 light-years from Earth.
Star in Hercules, about 472 light-years from Earth.
Blue giant in Vulpecula, about 335 light-years from Earth.
Main-sequence star in Hercules, about 250 light-years from Earth.
Red giant in Corona Australis, about 179 light-years from Earth.
Subgiant in Draco, about 74.5 light-years from Earth.
Red giant in Eridanus, about 231 light-years from Earth.
Main-sequence star in Ophiuchus, about 361 light-years from Earth.
Red giant in Draco, about 372 light-years from Earth.
Main-sequence star in Scorpius, about 479 light-years from Earth.
Blue giant in Orion, about 884 light-years from Earth.
Star in Vela, about 1,056 light-years from Earth.
Red supergiant in Carina, about 1,140 light-years from Earth.
Blue giant in Ophiuchus, about 755 light-years from Earth.
Main-sequence star in Pegasus, about 162 light-years from Earth.
Main-sequence star in Scorpius, about 503 light-years from Earth.
Subgiant in Orion, about 1,136 light-years from Earth.
Main-sequence star in Hydra, about 56.5 light-years from Earth.
Red giant in Ursa Major, about 256 light-years from Earth.
Main-sequence star in Sagittarius, about 190 light-years from Earth.
Star in Corona Borealis, about 170 light-years from Earth.
Main-sequence star in Sculptor, about 137 light-years from Earth.
Subgiant in Camelopardalis, about 359 light-years from Earth.
Red giant in Eridanus, about 184 light-years from Earth.
Red giant in Vela, about 1,853 light-years from Earth.
Star in Phoenix, about 246 light-years from Earth.
Main-sequence star in Hydra, about 314 light-years from Earth.
Main-sequence star in Hercules, about 51.8 light-years from Earth.
Main-sequence star in Perseus, about 314 light-years from Earth.
Main-sequence star in Lupus, about 393 light-years from Earth.
Red giant in Antlia, about 190 light-years from Earth.
Red giant in Boötes, about 243 light-years from Earth.
Star in Draco, about 229 light-years from Earth.
Main-sequence star in Lynx, about 274 light-years from Earth.
Red giant in Pisces, about 129 light-years from Earth.
Subgiant in Libra, about 94.3 light-years from Earth.
Red supergiant in Cygnus, about 2,764 light-years from Earth.
Main-sequence star in Puppis, about 241 light-years from Earth.
Red giant in Perseus, about 288 light-years from Earth.
Main-sequence star in Andromeda, about 309 light-years from Earth.
Red giant in Pisces, about 179 light-years from Earth.
Main-sequence star in Eridanus, about 328 light-years from Earth.
Star in Cassiopeia, about 200 light-years from Earth.
Star in Leo, about 94.6 light-years from Earth.
Star in Carina, about 398 light-years from Earth.
Main-sequence star in Centaurus, about 426 light-years from Earth.
Main-sequence star in Crux, about 385 light-years from Earth.
Main-sequence star in Taurus, about 173 light-years from Earth.
Red giant in Pyxis, about 560 light-years from Earth.
Main-sequence star in Crux, about 384 light-years from Earth.
Star in Corona Australis, about 558 light-years from Earth.
Main-sequence star in Ophiuchus, about 134 light-years from Earth.
Main-sequence star in Orion, about 2,861 light-years from Earth.
Main-sequence star in Serpens, about 76.8 light-years from Earth.
Red giant in Puppis, about 773 light-years from Earth.
Main-sequence star in Scorpius, about 495 light-years from Earth.
Red giant in Ursa Major, about 524 light-years from Earth.
Main-sequence star in Aries, about 333 light-years from Earth.
Main-sequence star in Puppis, about 759 light-years from Earth.
Star in Hydra, about 769 light-years from Earth.
Main-sequence star in Vela, about 165 light-years from Earth.
Blue giant in Centaurus, about 365 light-years from Earth.
Red giant in Ursa Minor, about 459 light-years from Earth.
Subgiant in Norma, about 128 light-years from Earth.
Blue giant in Pavo, about 439 light-years from Earth.
Red giant in Draco, about 342 light-years from Earth.
Red giant in Pegasus, about 476 light-years from Earth.
Subgiant in Ophiuchus, about 104 light-years from Earth.
Main-sequence star in Eridanus, about 377 light-years from Earth.
Blue supergiant in Orion, about 1,802 light-years from Earth.
Main-sequence star in Hercules, about 175 light-years from Earth.
Main-sequence star in Corona Borealis, about 473 light-years from Earth.
Main-sequence star in Orion, about 116 light-years from Earth.
Star in Ophiuchus, about 273 light-years from Earth.
Subgiant in Lacerta, about 172 light-years from Earth.
Star in Centaurus, about 263 light-years from Earth.
Subgiant in Lupus, about 56.9 light-years from Earth.
Star in Aquila, about 2,836 light-years from Earth.
Main-sequence star in Delphinus, about 220 light-years from Earth.
Main-sequence star in Orion, about 365 light-years from Earth.
Main-sequence star in Aries, about 343 light-years from Earth.
Star in Norma, about 219 light-years from Earth.
Red giant in Dorado, about 85.6 light-years from Earth.
Main-sequence star in Puppis, about 803 light-years from Earth.
Star in Puppis, about 1,503 light-years from Earth.
Main-sequence star in Puppis, about 222 light-years from Earth.
Main-sequence star in Virgo, about 384 light-years from Earth.
Main-sequence star in Taurus, about 158 light-years from Earth.
Main-sequence star in Monoceros, about 919 light-years from Earth.
Star in Vulpecula, about 236 light-years from Earth.
Star in Lupus, about 220 light-years from Earth.
Subgiant in Cancer, about 181 light-years from Earth.
Star in Cetus, about 75.6 light-years from Earth.
Red giant in Pisces, about 384 light-years from Earth.
Red giant in Canis Major, about 405 light-years from Earth.
Subgiant in Carina, about 968 light-years from Earth.
Red giant in Centaurus, about 191 light-years from Earth.
Star in Sagittarius, about 870 light-years from Earth.
Red giant in Sagittarius, about 762 light-years from Earth.
Main-sequence star in Ursa Major, about 246 light-years from Earth.
Subgiant in Canis Major, about 96.5 light-years from Earth.
Red giant in Scutum, about 207 light-years from Earth.
Main-sequence star in Perseus, about 539 light-years from Earth.
Main-sequence star in Lyra, about 162 light-years from Earth.
Star in Perseus, about 951 light-years from Earth.
Red giant in Hercules, about 671 light-years from Earth.
Main-sequence star in Draco, about 18.8 light-years from Earth.
Star in Microscopium, about 229 light-years from Earth.
Subgiant in Scutum, about 319 light-years from Earth.
Red giant in Pisces, about 446 light-years from Earth.
Main-sequence star in Ursa Major, about 126 light-years from Earth.
Yellow dwarf in Cancer, about 81.8 light-years from Earth.
Main-sequence star in Lepus, about 173 light-years from Earth.
Main-sequence star in Canes Venatici, about 180 light-years from Earth.
Star in Leo Minor, about 578 light-years from Earth.
Red giant in Aquarius, about 433 light-years from Earth.
Red giant in Virgo, about 400 light-years from Earth.
Main-sequence star in Aquarius, about 179 light-years from Earth.
Red giant in Cassiopeia, about 208 light-years from Earth.
Main-sequence star in Vela, about 353 light-years from Earth.
Red giant in Hydra, about 295 light-years from Earth.
Star in Hydrus, about 219 light-years from Earth.
Red giant in Apus, about 762 light-years from Earth.
Main-sequence star in Fornax, about 371 light-years from Earth.
Star in Cygnus, about 266 light-years from Earth.
Red giant in Leo, about 406 light-years from Earth.
Main-sequence star in Perseus, about 310 light-years from Earth.
Red giant in Monoceros, about 450 light-years from Earth.
Subgiant in Cygnus, about 1,726 light-years from Earth.
Main-sequence star in Indus, about 11.8 light-years from Earth.
Subgiant in Puppis, about 619 light-years from Earth.
Red giant in Puppis, about 232 light-years from Earth.
Red giant in Carina, about 2,346 light-years from Earth.
Red giant in Crux, about 120 light-years from Earth.
Main-sequence star in Phoenix, about 249 light-years from Earth.
Yellow dwarf in Auriga, about 41.2 light-years from Earth.
Star in Taurus, about 417 light-years from Earth.
Main-sequence star in Aquarius, about 294 light-years from Earth.
Star in Scutum, about 202 light-years from Earth.
Main-sequence star in Equuleus, about 118 light-years from Earth.
Main-sequence star in Lepus, about 416 light-years from Earth.
Blue supergiant in Scorpius, about 2,568 light-years from Earth.
Red giant in Cepheus, about 356 light-years from Earth.
Main-sequence star in Hydra, about 449 light-years from Earth.
Star in Sagittarius, about 84.8 light-years from Earth.
Main-sequence star in Crater, about 280 light-years from Earth.
Red giant in Orion, about 508 light-years from Earth.
Red dwarf in Orion, about 651 light-years from Earth.
Subgiant in Aquarius, about 504 light-years from Earth.
Main-sequence star in Microscopium, about 182 light-years from Earth.
Main-sequence star in Centaurus, about 390 light-years from Earth.
Red giant in Centaurus, about 210 light-years from Earth.
Subgiant in Reticulum, about 70.7 light-years from Earth.
Blue giant in Cetus, about 576 light-years from Earth.
Star in Pyxis, about 192 light-years from Earth.
Red giant in Aquila, about 184 light-years from Earth.
Red giant in Pyxis, about 503 light-years from Earth.
Star in Crater, about 353 light-years from Earth.
Main-sequence star in Dorado, about 38.0 light-years from Earth.
Star in Coma Berenices, about 290 light-years from Earth.
Red giant in Puppis, about 177 light-years from Earth.
Star in Canes Venatici, about 264 light-years from Earth.
Subgiant in Orion, about 929 light-years from Earth.
Main-sequence star in Leo Minor, about 233 light-years from Earth.
Red giant in Ophiuchus, about 206 light-years from Earth.
Subgiant in Pictor, about 1,299 light-years from Earth.
Red giant in Hydra, about 157 light-years from Earth.
Subgiant in Ursa Major, about 113 light-years from Earth.
Star in Carina, about 261 light-years from Earth.
Subgiant in Crux, about 854 light-years from Earth.
Star in Capricornus, about 294 light-years from Earth.
Red giant in Cassiopeia, about 195 light-years from Earth.
Red giant in Auriga, about 523 light-years from Earth.
Blue giant in Hercules, about 372 light-years from Earth.
Main-sequence star in Gemini, about 83.6 light-years from Earth.
Red giant in Leo, about 585 light-years from Earth.
Red giant in Andromeda, about 369 light-years from Earth.
Main-sequence star in Norma, about 122 light-years from Earth.
Main-sequence star in Aquarius, about 157 light-years from Earth.
Red giant in Corona Borealis, about 117 light-years from Earth.
Main-sequence star in Eridanus, about 404 light-years from Earth.
Main-sequence star in Sagittarius, about 416 light-years from Earth.
Main-sequence star in Cygnus, about 1,418 light-years from Earth.
Yellow dwarf in Virgo, about 27.9 light-years from Earth.
Subgiant in Cygnus, about 861 light-years from Earth.
Main-sequence star in Carina, about 65.2 light-years from Earth.
Star in Vela, about 2,548 light-years from Earth.
Star in Centaurus, about 182 light-years from Earth.
Main-sequence star in Eridanus, about 116 light-years from Earth.
Main-sequence star in Phoenix, about 200 light-years from Earth.
Main-sequence star in Camelopardalis, about 762 light-years from Earth.
Main-sequence star in Cassiopeia, about 378 light-years from Earth.
Subgiant in Aquarius, about 436 light-years from Earth.
Red giant in Serpens, about 375 light-years from Earth.
Red giant in Ursa Major, about 315 light-years from Earth.
Main-sequence star in Cetus, about 87.1 light-years from Earth.
Main-sequence star in Pisces, about 308 light-years from Earth.
Main-sequence star in Corona Australis, about 193 light-years from Earth.
Subgiant in Centaurus, about 637 light-years from Earth.
Main-sequence star in Lupus, about 364 light-years from Earth.
Main-sequence star in Puppis, about 377 light-years from Earth.
Star in Pavo, about 90.7 light-years from Earth.
Main-sequence star in Boötes, about 94.8 light-years from Earth.
Red giant in Libra, about 309 light-years from Earth.
Red giant in Musca, about 430 light-years from Earth.
Red giant in Cepheus, about 203 light-years from Earth.
Subgiant in Vulpecula, about 811 light-years from Earth.
Red giant in Coma Berenices, about 324 light-years from Earth.
Star in Canes Venatici, about 386 light-years from Earth.
Main-sequence star in Ursa Major, about 192 light-years from Earth.
Red giant in Orion, about 1,259 light-years from Earth.
Red giant in Pegasus, about 592 light-years from Earth.
Red giant in Virgo, about 280 light-years from Earth.
Red giant in Eridanus, about 187 light-years from Earth.
Main-sequence star in Phoenix, about 173 light-years from Earth.
Main-sequence star in Camelopardalis, about 175 light-years from Earth.
Star in Puppis, about 1,213 light-years from Earth.
Main-sequence star in Hydra, about 507 light-years from Earth.
Main-sequence star in Carina, about 454 light-years from Earth.
Red giant in Canes Venatici, about 601 light-years from Earth.
Yellow dwarf in Centaurus, about 383 light-years from Earth.
Subgiant in Ara, about 70.0 light-years from Earth.
Red giant in Hydrus, about 339 light-years from Earth.
Red giant in Apus, about 297 light-years from Earth.
Red giant in Cetus, about 234 light-years from Earth.
Red giant in Monoceros, about 493 light-years from Earth.
Star in Hydra, about 337 light-years from Earth.
Star in Draco, about 2,118 light-years from Earth.
Main-sequence star in Orion, about 145 light-years from Earth.
Red giant in Leo, about 604 light-years from Earth.
Subgiant in Capricornus, about 253 light-years from Earth.
Red giant in Sagittarius, about 367 light-years from Earth.
Red giant in Cepheus, about 313 light-years from Earth.
Red giant in Perseus, about 211 light-years from Earth.
Main-sequence star in Draco, about 75.5 light-years from Earth.
Red giant in Virgo, about 545 light-years from Earth.
Main-sequence star in Capricornus, about 98.7 light-years from Earth.
Main-sequence star in Ophiuchus, about 167 light-years from Earth.
Main-sequence star in Coma Berenices, about 295 light-years from Earth.
Red giant in Cetus, about 587 light-years from Earth.
Main-sequence star in Lynx, about 250 light-years from Earth.
Blue giant in Pegasus, about 695 light-years from Earth.
Red giant in Pegasus, about 148 light-years from Earth.
Subgiant in Leo, about 69.7 light-years from Earth.
Main-sequence star in Ophiuchus, about 406 light-years from Earth.
Subgiant in Andromeda, about 191 light-years from Earth.
Main-sequence star in Eridanus, about 290 light-years from Earth.
Main-sequence star in Camelopardalis, about 991 light-years from Earth.
Subgiant in Taurus, about 141 light-years from Earth.
Main-sequence star in Orion, about 1,615 light-years from Earth.
Main-sequence star in Puppis, about 929 light-years from Earth.
Subgiant in Lupus, about 142 light-years from Earth.
Star in Scorpius, about 2,548 light-years from Earth.
Main-sequence star in Pavo, about 93.1 light-years from Earth.
Red giant in Virgo, about 675 light-years from Earth.
Main-sequence star in Antlia, about 339 light-years from Earth.
Red giant in Octans, about 217 light-years from Earth.
Red giant in Auriga, about 602 light-years from Earth.
Main-sequence star in Scorpius, about 413 light-years from Earth.
Star in Cepheus, about 394 light-years from Earth.
Main-sequence star in Ophiuchus, about 651 light-years from Earth.
Red giant in Pegasus, about 368 light-years from Earth.
Main-sequence star in Musca, about 383 light-years from Earth.
Main-sequence star in Vela, about 1,717 light-years from Earth.
Star in Carina, about 234 light-years from Earth.
Blue supergiant in Scorpius, about 557 light-years from Earth.
Main-sequence star in Vulpecula, about 991 light-years from Earth.
Star in Grus, about 275 light-years from Earth.
Red giant in Corona Borealis, about 99.5 light-years from Earth.
Main-sequence star in Aries, about 129 light-years from Earth.
Subgiant in Ursa Major, about 66.5 light-years from Earth.
Main-sequence star in Ursa Major, about 117 light-years from Earth.
Subgiant in Coma Berenices, about 310 light-years from Earth.
Main-sequence star in Hydra, about 222 light-years from Earth.
Star in Cygnus, about 611 light-years from Earth.
Red giant in Boötes, about 704 light-years from Earth.
Red giant in Ursa Minor, about 457 light-years from Earth.
Red giant in Coma Berenices, about 332 light-years from Earth.
Red giant in Auriga, about 416 light-years from Earth.
Subgiant in Perseus, about 507 light-years from Earth.
Main-sequence star in Cygnus, about 525 light-years from Earth.
Main-sequence star in Taurus, about 161 light-years from Earth.
Main-sequence star in Hercules, about 666 light-years from Earth.
Main-sequence star in Cassiopeia, about 61.1 light-years from Earth.
Main-sequence star in Carina, about 492 light-years from Earth.
Red giant in Boötes, about 233 light-years from Earth.
Main-sequence star in Scorpius, about 135 light-years from Earth.
Main-sequence star in Microscopium, about 197 light-years from Earth.
Red giant in Boötes, about 372 light-years from Earth.
Subgiant in Pegasus, about 299 light-years from Earth.
Main-sequence star in Aquarius, about 782 light-years from Earth.
Main-sequence star in Eridanus, about 740 light-years from Earth.
Main-sequence star in Cassiopeia, about 1,431 light-years from Earth.
Main-sequence star in Eridanus, about 110 light-years from Earth.
Blue supergiant in Taurus, about 1,553 light-years from Earth.
Subgiant in Orion, about 538 light-years from Earth.
Main-sequence star in Sagittarius, about 410 light-years from Earth.
Main-sequence star in Vulpecula, about 233 light-years from Earth.
Blue supergiant in Cygnus, about 2,330 light-years from Earth.
Star in Virgo, about 118 light-years from Earth.
Red giant in Crater, about 376 light-years from Earth.
Main-sequence star in Carina, about 500 light-years from Earth.
Red giant in Lynx, about 215 light-years from Earth.
Red giant in Columba, about 106 light-years from Earth.
Red giant in Dorado, about 491 light-years from Earth.
Star in Aquarius, about 838 light-years from Earth.
Subgiant in Boötes, about 122 light-years from Earth.
Blue supergiant in Canis Major, about 1,217 light-years from Earth.
Star in Canes Venatici, about 199 light-years from Earth.
Red giant in Ophiuchus, about 405 light-years from Earth.
Subgiant in Pegasus, about 1,623 light-years from Earth.
Main-sequence star in Ursa Major, about 41.7 light-years from Earth.
Main-sequence star in Hercules, about 180 light-years from Earth.
Red giant in Andromeda, about 563 light-years from Earth.
Main-sequence star in Capricornus, about 161 light-years from Earth.
Red giant in Draco, about 315 light-years from Earth.
Red giant in Canis Major, about 988 light-years from Earth.
Star in Puppis, about 1,539 light-years from Earth.
Red giant in Vela, about 204 light-years from Earth.
Main-sequence star in Centaurus, about 448 light-years from Earth.
Star in Phoenix, about 248 light-years from Earth.
Main-sequence star in Auriga, about 153 light-years from Earth.
Main-sequence star in Serpens, about 179 light-years from Earth.
Subgiant in Aquarius, about 290 light-years from Earth.
Main-sequence star in Serpens, about 88.9 light-years from Earth.
Red giant in Draco, about 344 light-years from Earth.
Red giant in Cassiopeia, about 329 light-years from Earth.
Red giant in Hercules, about 354 light-years from Earth.
Yellow dwarf in Boötes, about 40.8 light-years from Earth.
Main-sequence star in Cetus, about 70.1 light-years from Earth.
Subgiant in Corona Australis, about 98.5 light-years from Earth.
Red giant in Scutum, about 202 light-years from Earth.
Subgiant in Puppis, about 728 light-years from Earth.
Red giant in Canis Major, about 1,418 light-years from Earth.
Red giant in Puppis, about 1,007 light-years from Earth.
Subgiant in Vela, about 485 light-years from Earth.
Main-sequence star in Centaurus, about 221 light-years from Earth.
Subgiant in Lupus, about 504 light-years from Earth.
Red giant in Lyra, about 255 light-years from Earth.
Subgiant in Andromeda, about 93.3 light-years from Earth.
Subgiant in Hydrus, about 284 light-years from Earth.
Subgiant in Cassiopeia, about 1,129 light-years from Earth.
Subgiant in Taurus, about 636 light-years from Earth.
Main-sequence star in Draco, about 736 light-years from Earth.
Red giant in Boötes, about 187 light-years from Earth.
Red giant in Hercules, about 351 light-years from Earth.
Star in Taurus, about 332 light-years from Earth.
Red giant in Leo, about 360 light-years from Earth.
Red giant in Andromeda, about 530 light-years from Earth.
Star in Sagittarius, about 313 light-years from Earth.
Yellow dwarf in Cetus, about 29.8 light-years from Earth.
Yellow dwarf in Triangulum, about 35.2 light-years from Earth.
Red giant in Grus, about 415 light-years from Earth.
Subgiant in Scorpius, about 79.4 light-years from Earth.
Main-sequence star in Puppis, about 556 light-years from Earth.
Red giant in Carina, about 222 light-years from Earth.
Main-sequence star in Draco, about 85.2 light-years from Earth.
Red giant in Pisces, about 304 light-years from Earth.
Red giant in Grus, about 230 light-years from Earth.
Main-sequence star in Virgo, about 122 light-years from Earth.
Star in Ophiuchus, about 261 light-years from Earth.
Red giant in Circinus, about 408 light-years from Earth.
Star in Puppis, about 3,106 light-years from Earth.
Subgiant in Vela, about 1,331 light-years from Earth.
Yellow dwarf in Centaurus, about 67.4 light-years from Earth.
Red giant in Scorpius, about 290 light-years from Earth.
Main-sequence star in Cassiopeia, about 165 light-years from Earth.
Red giant in Perseus, about 1,178 light-years from Earth.
Main-sequence star in Telescopium, about 612 light-years from Earth.
Main-sequence star in Lynx, about 215 light-years from Earth.
Red giant in Eridanus, about 255 light-years from Earth.
Main-sequence star in Draco, about 99.4 light-years from Earth.
Star in Boötes, about 537 light-years from Earth.
Red giant in Hercules, about 414 light-years from Earth.
Main-sequence star in Ophiuchus, about 57.6 light-years from Earth.
Red giant in Sagittarius, about 1,125 light-years from Earth.
Red giant in Sculptor, about 452 light-years from Earth.
Red giant in Draco, about 247 light-years from Earth.
Red supergiant in Musca, about 1,195 light-years from Earth.
Main-sequence star in Boötes, about 215 light-years from Earth.
Main-sequence star in Sagittarius, about 467 light-years from Earth.
Red giant in Pegasus, about 272 light-years from Earth.
Red giant in Sagittarius, about 298 light-years from Earth.
Main-sequence star in Pavo, about 190 light-years from Earth.
Red giant in Corona Borealis, about 183 light-years from Earth.
Star in Pyxis, about 244 light-years from Earth.
Red giant in Eridanus, about 242 light-years from Earth.
Red giant in Sagittarius, about 208 light-years from Earth.
Red giant in Cygnus, about 231 light-years from Earth.
Red giant in Hydra, about 212 light-years from Earth.
Red giant in Andromeda, about 214 light-years from Earth.
Subgiant in Pyxis, about 247 light-years from Earth.
Main-sequence star in Puppis, about 184 light-years from Earth.
Red giant in Hydra, about 342 light-years from Earth.
Red giant in Hydra, about 488 light-years from Earth.
Subgiant in Carina, about 480 light-years from Earth.
Star in Cetus, about 340 light-years from Earth.
Main-sequence star in Aries, about 262 light-years from Earth.
Subgiant in Taurus, about 625 light-years from Earth.
Star in Taurus, about 364 light-years from Earth.
Main-sequence star in Draco, about 49.8 light-years from Earth.
Star in Pisces, about 234 light-years from Earth.
Main-sequence star in Canis Major, about 1,907 light-years from Earth.
Red giant in Coma Berenices, about 660 light-years from Earth.
Red giant in Sagittarius, about 482 light-years from Earth.
Main-sequence star in Chamaeleon, about 362 light-years from Earth.
Star in Scutum, about 538 light-years from Earth.
Red giant in Scorpius, about 452 light-years from Earth.
Star in Telescopium, about 371 light-years from Earth.
Main-sequence star in Columba, about 335 light-years from Earth.
Main-sequence star in Cetus, about 456 light-years from Earth.
Main-sequence star in Virgo, about 118 light-years from Earth.
Red giant in Cassiopeia, about 174 light-years from Earth.
Main-sequence star in Lacerta, about 1,726 light-years from Earth.
Subgiant in Taurus, about 249 light-years from Earth.
Star in Cygnus, about 289 light-years from Earth.
Main-sequence star in Draco, about 98.7 light-years from Earth.
Main-sequence star in Orion, about 1,039 light-years from Earth.
Star in Coma Berenices, about 283 light-years from Earth.
Main-sequence star in Cetus, about 61.1 light-years from Earth.
Subgiant in Hercules, about 133 light-years from Earth.
Red giant in Gemini, about 339 light-years from Earth.
Star in Microscopium, about 378 light-years from Earth.
Main-sequence star in Apus, about 138 light-years from Earth.
Red giant in Perseus, about 503 light-years from Earth.
Main-sequence star in Vela, about 71.1 light-years from Earth.
Main-sequence star in Hydra, about 680 light-years from Earth.
Yellow dwarf in Centaurus, about 30.1 light-years from Earth.
Main-sequence star in Musca, about 362 light-years from Earth.
Subgiant in Cassiopeia, about 621 light-years from Earth.
Star in Gemini, about 166 light-years from Earth.
Main-sequence star in Vulpecula, about 630 light-years from Earth.
Main-sequence star in Lynx, about 241 light-years from Earth.
Red giant in Cetus, about 288 light-years from Earth.
Red giant in Orion, about 294 light-years from Earth.
Main-sequence star in Scorpius, about 398 light-years from Earth.
Main-sequence star in Centaurus, about 400 light-years from Earth.
Subgiant in Centaurus, about 59.4 light-years from Earth.
Blue giant in Lupus, about 400 light-years from Earth.
Blue giant in Cassiopeia, about 412 light-years from Earth.
Red giant in Indus, about 413 light-years from Earth.
Main-sequence star in Triangulum Australe, about 39.5 light-years from Earth.
Star in Lupus, about 1,953 light-years from Earth.
Yellow dwarf in Taurus, about 50.3 light-years from Earth.
Main-sequence star in Perseus, about 78.9 light-years from Earth.
Red giant in Monoceros, about 203 light-years from Earth.
Red giant in Eridanus, about 656 light-years from Earth.
Red giant in Auriga, about 485 light-years from Earth.
Red giant in Aquila, about 200 light-years from Earth.
Red giant in Aquila, about 1,299 light-years from Earth.
Main-sequence star in Libra, about 294 light-years from Earth.
Main-sequence star in Lepus, about 198 light-years from Earth.
Red giant in Orion, about 465 light-years from Earth.
Star in Hydra, about 211 light-years from Earth.
Subgiant in Crux, about 957 light-years from Earth.
Subgiant in Canes Venatici, about 149 light-years from Earth.
Star in Ophiuchus, about 412 light-years from Earth.
Main-sequence star in Draco, about 89.5 light-years from Earth.
Red giant in Tucana, about 290 light-years from Earth.
Main-sequence star in Cygnus, about 281 light-years from Earth.
Main-sequence star in Pegasus, about 312 light-years from Earth.
Red giant in Hercules, about 392 light-years from Earth.
Main-sequence star in Coma Berenices, about 276 light-years from Earth.
Main-sequence star in Lepus, about 909 light-years from Earth.
Blue giant in Monoceros, about 784 light-years from Earth.
Red giant in Vulpecula, about 325 light-years from Earth.
Red giant in Cetus, about 353 light-years from Earth.
Red giant in Boötes, about 401 light-years from Earth.
Main-sequence star in Virgo, about 185 light-years from Earth.
Subgiant in Libra, about 102 light-years from Earth.
Subgiant in Puppis, about 198 light-years from Earth.
Red supergiant in Camelopardalis, about 500 light-years from Earth.
Red giant in Vela, about 225 light-years from Earth.
Subgiant in Hydra, about 141 light-years from Earth.
Main-sequence star in Centaurus, about 214 light-years from Earth.
Main-sequence star in Corona Australis, about 136 light-years from Earth.
Subgiant in Telescopium, about 708 light-years from Earth.
Star in Draco, about 456 light-years from Earth.
Yellow dwarf in Libra, about 219 light-years from Earth.
Subgiant in Lynx, about 267 light-years from Earth.
Red giant in Monoceros, about 275 light-years from Earth.
Main-sequence star in Cygnus, about 1,035 light-years from Earth.
Main-sequence star in Cygnus, about 139 light-years from Earth.
Star in Coma Berenices, about 291 light-years from Earth.
Main-sequence star in Boötes, about 63.8 light-years from Earth.
Main-sequence star in Taurus, about 94.4 light-years from Earth.
Star in Perseus, about 218 light-years from Earth.
Red giant in Coma Berenices, about 249 light-years from Earth.
Red giant in Pegasus, about 224 light-years from Earth.
Main-sequence star in Ursa Major, about 83.0 light-years from Earth.
Red giant in Aquarius, about 613 light-years from Earth.
Main-sequence star in Horologium, about 179 light-years from Earth.
Red giant in Carina, about 393 light-years from Earth.
Subgiant in Carina, about 674 light-years from Earth.
Yellow dwarf in Hydra, about 49.0 light-years from Earth.
Main-sequence star in Hydra, about 85.8 light-years from Earth.
Star in Centaurus, about 889 light-years from Earth.
Red giant in Virgo, about 461 light-years from Earth.
Red giant in Cygnus, about 445 light-years from Earth.
Blue giant in Aquila, about 1,681 light-years from Earth.
Main-sequence star in Auriga, about 170 light-years from Earth.
Subgiant in Scorpius, about 156 light-years from Earth.
Red giant in Telescopium, about 1,080 light-years from Earth.
Star in Draco, about 487 light-years from Earth.
Red giant in Perseus, about 368 light-years from Earth.
Subgiant in Cygnus, about 909 light-years from Earth.
Main-sequence star in Triangulum, about 291 light-years from Earth.
Red giant in Gemini, about 256 light-years from Earth.
Red giant in Hydra, about 614 light-years from Earth.
Red giant in Puppis, about 861 light-years from Earth.
Blue giant in Canis Major, about 481 light-years from Earth.
Star in Vela, about 1,109 light-years from Earth.
Main-sequence star in Ursa Major, about 339 light-years from Earth.
Red giant in Carina, about 1,032 light-years from Earth.
Red giant in Canes Venatici, about 459 light-years from Earth.
Red giant in Lyra, about 1,106 light-years from Earth.
Red giant in Hydra, about 231 light-years from Earth.
Main-sequence star in Aquila, about 150 light-years from Earth.
Main-sequence star in Piscis Austrinus, about 59.6 light-years from Earth.
Red giant in Lacerta, about 325 light-years from Earth.
Star in Pisces, about 899 light-years from Earth.
Subgiant in Cygnus, about 1,443 light-years from Earth.
Blue supergiant in Libra, about 468 light-years from Earth.
Red giant in Draco, about 602 light-years from Earth.
Main-sequence star in Orion, about 529 light-years from Earth.
Main-sequence star in Ursa Minor, about 97.0 light-years from Earth.
Main-sequence star in Camelopardalis, about 361 light-years from Earth.
Subgiant in Orion, about 899 light-years from Earth.
Red giant in Pavo, about 475 light-years from Earth.
Star in Norma, about 428 light-years from Earth.
Main-sequence star in Pisces, about 153 light-years from Earth.
Main-sequence star in Cassiopeia, about 175 light-years from Earth.
Star in Leo, about 562 light-years from Earth.
Red giant in Sagittarius, about 256 light-years from Earth.
Red giant in Hercules, about 545 light-years from Earth.
Star in Taurus, about 247 light-years from Earth.
Main-sequence star in Perseus, about 151 light-years from Earth.
Red giant in Cassiopeia, about 786 light-years from Earth.
Red giant in Virgo, about 244 light-years from Earth.
Hypergiant in Hercules, about 738 light-years from Earth.
Yellow dwarf in Andromeda, about 41.5 light-years from Earth.
Subgiant in Draco, about 110 light-years from Earth.
Red giant in Scorpius, about 208 light-years from Earth.
Main-sequence star in Fornax, about 484 light-years from Earth.
Blue giant in Andromeda, about 712 light-years from Earth.
Main-sequence star in Auriga, about 238 light-years from Earth.
Subgiant in Aquarius, about 142 light-years from Earth.
Red giant in Virgo, about 308 light-years from Earth.
Main-sequence star in Perseus, about 1,056 light-years from Earth.
Red giant in Libra, about 382 light-years from Earth.
Main-sequence star in Hydra, about 393 light-years from Earth.
Yellow dwarf in Virgo, about 58.7 light-years from Earth.
Red giant in Pegasus, about 549 light-years from Earth.
Main-sequence star in Carina, about 402 light-years from Earth.
Star in Norma, about 1,469 light-years from Earth.
Red giant in Hercules, about 395 light-years from Earth.
Red giant in Reticulum, about 319 light-years from Earth.
Main-sequence star in Phoenix, about 49.3 light-years from Earth.
Blue giant in Cassiopeia, about 701 light-years from Earth.
Main-sequence star in Gemini, about 222 light-years from Earth.
Red giant in Taurus, about 321 light-years from Earth.
Star in Andromeda, about 1,004 light-years from Earth.
Red giant in Columba, about 333 light-years from Earth.
Star in Aries, about 289 light-years from Earth.
Main-sequence star in Coma Berenices, about 278 light-years from Earth.
Star in Aquila, about 154 light-years from Earth.
Main-sequence star in Draco, about 184 light-years from Earth.
Main-sequence star in Orion, about 1,546 light-years from Earth.
Main-sequence star in Boötes, about 388 light-years from Earth.
Star in Leo, about 151 light-years from Earth.
Red giant in Hydra, about 388 light-years from Earth.
Main-sequence star in Auriga, about 85.7 light-years from Earth.
Main-sequence star in Serpens, about 169 light-years from Earth.
Star in Horologium, about 295 light-years from Earth.
Red giant in Puppis, about 695 light-years from Earth.
Star in Musca, about 948 light-years from Earth.
Red giant in Cetus, about 1,190 light-years from Earth.
Red giant in Cygnus, about 916 light-years from Earth.
Main-sequence star in Corona Borealis, about 312 light-years from Earth.
Main-sequence star in Monoceros, about 1,217 light-years from Earth.
Subgiant in Cygnus, about 843 light-years from Earth.
Star in Puppis, about 870 light-years from Earth.
Main-sequence star in Orion, about 1,553 light-years from Earth.
Red supergiant in Cetus, about 2,091 light-years from Earth.
Main-sequence star in Draco, about 74.8 light-years from Earth.
Blue giant in Perseus, about 728 light-years from Earth.
Star in Ursa Major, about 533 light-years from Earth.
Red giant in Auriga, about 379 light-years from Earth.
Main-sequence star in Aquarius, about 262 light-years from Earth.
Blue giant in Fornax, about 847 light-years from Earth.
Star in Canis Minor, about 1,042 light-years from Earth.
Yellow dwarf in Corona Borealis, about 58.3 light-years from Earth.
Main-sequence star in Perseus, about 524 light-years from Earth.
Red giant in Camelopardalis, about 1,463 light-years from Earth.
Main-sequence star in Eridanus, about 233 light-years from Earth.
Red giant in Puppis, about 815 light-years from Earth.
Red giant in Coma Berenices, about 316 light-years from Earth.
Main-sequence star in Centaurus, about 271 light-years from Earth.
Main-sequence star in Virgo, about 258 light-years from Earth.
Main-sequence star in Lupus, about 117 light-years from Earth.
Star in Lupus, about 436 light-years from Earth.
Red giant in Sagittarius, about 291 light-years from Earth.
Red supergiant in Lacerta, about 1,599 light-years from Earth.
Red giant in Hydra, about 896 light-years from Earth.
Red giant in Piscis Austrinus, about 424 light-years from Earth.
Red giant in Leo, about 216 light-years from Earth.
Red giant in Leo, about 246 light-years from Earth.
Main-sequence star in Taurus, about 46.9 light-years from Earth.
Main-sequence star in Lyra, about 122 light-years from Earth.
Main-sequence star in Cygnus, about 69.3 light-years from Earth.
Red supergiant in Sagittarius, about 274 light-years from Earth.
Red giant in Draco, about 165 light-years from Earth.
Blue giant in Vulpecula, about 553 light-years from Earth.
Subgiant in Columba, about 722 light-years from Earth.
Main-sequence star in Tucana, about 155 light-years from Earth.
Main-sequence star in Corona Australis, about 58.4 light-years from Earth.
Star in Camelopardalis, about 2,039 light-years from Earth.
Main-sequence star in Canis Major, about 408 light-years from Earth.
Star in Lynx, about 349 light-years from Earth.
Red giant in Centaurus, about 1,056 light-years from Earth.
Red giant in Sagittarius, about 1,013 light-years from Earth.
Star in Hercules, about 410 light-years from Earth.
Star in Hercules, about 368 light-years from Earth.
Main-sequence star in Canis Major, about 1,245 light-years from Earth.
Red giant in Ursa Minor, about 856 light-years from Earth.
Red giant in Lynx, about 638 light-years from Earth.
Subgiant in Auriga, about 286 light-years from Earth.
Star in Andromeda, about 1,231 light-years from Earth.
Red supergiant in Draco, about 621 light-years from Earth.
Red giant in Pisces, about 529 light-years from Earth.
Star in Canes Venatici, about 262 light-years from Earth.
Main-sequence star in Sagittarius, about 266 light-years from Earth.
Red giant in Gemini, about 484 light-years from Earth.
Star in Andromeda, about 250 light-years from Earth.
Red giant in Lepus, about 233 light-years from Earth.
Red giant in Dorado, about 641 light-years from Earth.
Main-sequence star in Puppis, about 58.5 light-years from Earth.
Red giant in Vela, about 849 light-years from Earth.
Subgiant in Vela, about 904 light-years from Earth.
Red giant in Ursa Major, about 418 light-years from Earth.
Star in Musca, about 502 light-years from Earth.
Red giant in Centaurus, about 494 light-years from Earth.
Red giant in Hercules, about 480 light-years from Earth.
Main-sequence star in Sagitta, about 255 light-years from Earth.
Red giant in Ursa Minor, about 398 light-years from Earth.
Main-sequence star in Draco, about 217 light-years from Earth.
Subgiant in Draco, about 104 light-years from Earth.
Blue supergiant in Sagittarius, about 2,064 light-years from Earth.
Main-sequence star in Aquila, about 465 light-years from Earth.
Red giant in Ursa Major, about 237 light-years from Earth.
Subgiant in Sagittarius, about 252 light-years from Earth.
Main-sequence star in Taurus, about 159 light-years from Earth.
Red giant in Boötes, about 581 light-years from Earth.
Red giant in Hydra, about 362 light-years from Earth.
Red giant in Vela, about 1,310 light-years from Earth.
Blue giant in Centaurus, about 492 light-years from Earth.
Red giant in Draco, about 648 light-years from Earth.
Red giant in Auriga, about 467 light-years from Earth.
Main-sequence star in Piscis Austrinus, about 321 light-years from Earth.
Red giant in Cygnus, about 202 light-years from Earth.
Red giant in Coma Berenices, about 451 light-years from Earth.
Red giant in Vulpecula, about 582 light-years from Earth.
Red giant in Aquila, about 529 light-years from Earth.
Main-sequence star in Puppis, about 235 light-years from Earth.
Main-sequence star in Draco, about 341 light-years from Earth.
Red giant in Hercules, about 698 light-years from Earth.
Red giant in Eridanus, about 236 light-years from Earth.
Red giant in Virgo, about 510 light-years from Earth.
Yellow dwarf in Ursa Major, about 45.9 light-years from Earth.
Main-sequence star in Telescopium, about 157 light-years from Earth.
Red giant in Lepus, about 407 light-years from Earth.
Main-sequence star in Puppis, about 753 light-years from Earth.
Main-sequence star in Vela, about 2,609 light-years from Earth.
Main-sequence star in Centaurus, about 482 light-years from Earth.
Main-sequence star in Scorpius, about 447 light-years from Earth.
Red giant in Ophiuchus, about 493 light-years from Earth.
Main-sequence star in Aries, about 182 light-years from Earth.
Main-sequence star in Cepheus, about 120 light-years from Earth.
Main-sequence star in Monoceros, about 286 light-years from Earth.
Main-sequence star in Andromeda, about 192 light-years from Earth.
Star in Serpens, about 82.8 light-years from Earth.
Red giant in Boötes, about 838 light-years from Earth.
Main-sequence star in Virgo, about 111 light-years from Earth.
Red giant in Auriga, about 324 light-years from Earth.
Star in Gemini, about 159 light-years from Earth.
Main-sequence star in Cygnus, about 215 light-years from Earth.
Red giant in Gemini, about 525 light-years from Earth.
Subgiant in Orion, about 62.8 light-years from Earth.
Main-sequence star in Caelum, about 93.5 light-years from Earth.
Red giant in Pictor, about 362 light-years from Earth.
Subgiant in Puppis, about 80.5 light-years from Earth.
Red giant in Vela, about 1,394 light-years from Earth.
Red giant in Musca, about 221 light-years from Earth.
Main-sequence star in Centaurus, about 507 light-years from Earth.
Main-sequence star in Eridanus, about 202 light-years from Earth.
Star in Perseus, about 790 light-years from Earth.
Red giant in Chamaeleon, about 477 light-years from Earth.
Main-sequence star in Libra, about 309 light-years from Earth.
Red giant in Aquarius, about 214 light-years from Earth.
Main-sequence star in Sculptor, about 503 light-years from Earth.
Star in Auriga, about 2,077 light-years from Earth.
Main-sequence star in Perseus, about 560 light-years from Earth.
Red dwarf in Pegasus, about 782 light-years from Earth.
Red giant in Pisces, about 433 light-years from Earth.
Main-sequence star in Hercules, about 51.0 light-years from Earth.
Red giant in Pictor, about 444 light-years from Earth.
Star in Puppis, about 477 light-years from Earth.
Red giant in Cepheus, about 456 light-years from Earth.
Yellow dwarf in Pyxis, about 63.3 light-years from Earth.
Main-sequence star in Cepheus, about 303 light-years from Earth.
Main-sequence star in Cepheus, about 1,977 light-years from Earth.
Main-sequence star in Taurus, about 382 light-years from Earth.
Main-sequence star in Monoceros, about 1,087 light-years from Earth.
Red giant in Cygnus, about 434 light-years from Earth.
Subgiant in Vulpecula, about 523 light-years from Earth.
Main-sequence star in Ursa Major, about 377 light-years from Earth.
Subgiant in Sagittarius, about 177 light-years from Earth.
Main-sequence star in Cygnus, about 134 light-years from Earth.
Main-sequence star in Apus, about 645 light-years from Earth.
Main-sequence star in Camelopardalis, about 519 light-years from Earth.
Main-sequence star in Lepus, about 278 light-years from Earth.
Main-sequence star in Lepus, about 352 light-years from Earth.
Main-sequence star in Monoceros, about 1,195 light-years from Earth.
Main-sequence star in Puppis, about 103 light-years from Earth.
Red giant in Volans, about 297 light-years from Earth.
Subgiant in Vela, about 240 light-years from Earth.
Star in Scorpius, about 316 light-years from Earth.
Star in Cygnus, about 162 light-years from Earth.
Red giant in Indus, about 467 light-years from Earth.
Main-sequence star in Dorado, about 300 light-years from Earth.
Red giant in Pavo, about 894 light-years from Earth.
Red giant in Pegasus, about 463 light-years from Earth.
Main-sequence star in Pegasus, about 275 light-years from Earth.
Main-sequence star in Draco, about 412 light-years from Earth.
Blue giant in Aquila, about 698 light-years from Earth.
Blue supergiant in Cepheus, about 2,064 light-years from Earth.
Red giant in Draco, about 211 light-years from Earth.
Red giant in Orion, about 187 light-years from Earth.
Red giant in Camelopardalis, about 423 light-years from Earth.
Star in Leo, about 266 light-years from Earth.
Red giant in Hydra, about 218 light-years from Earth.
Main-sequence star in Gemini, about 541 light-years from Earth.
Red giant in Leo, about 500 light-years from Earth.
Main-sequence star in Gemini, about 176 light-years from Earth.
Main-sequence star in Pisces, about 76.5 light-years from Earth.
Main-sequence star in Cetus, about 73.6 light-years from Earth.
Subgiant in Caelum, about 704 light-years from Earth.
Main-sequence star in Sextans, about 278 light-years from Earth.
Main-sequence star in Ophiuchus, about 19.5 light-years from Earth.
Main-sequence star in Tucana, about 149 light-years from Earth.
Subgiant in Puppis, about 590 light-years from Earth.
Subgiant in Puppis, about 1,056 light-years from Earth.
Red giant in Hercules, about 282 light-years from Earth.
Blue giant in Telescopium, about 1,195 light-years from Earth.
Subgiant in Delphinus, about 98.2 light-years from Earth.
Subgiant in Hydra, about 436 light-years from Earth.
Main-sequence star in Chamaeleon, about 572 light-years from Earth.
Main-sequence star in Vulpecula, about 504 light-years from Earth.
Main-sequence star in Taurus, about 454 light-years from Earth.
Star in Cepheus, about 179 light-years from Earth.
Main-sequence star in Leo Minor, about 229 light-years from Earth.
Red giant in Hydra, about 797 light-years from Earth.
Main-sequence star in Taurus, about 147 light-years from Earth.
Subgiant in Taurus, about 167 light-years from Earth.
Yellow dwarf in Mensa, about 33.3 light-years from Earth.
Main-sequence star in Sextans, about 405 light-years from Earth.
Blue giant in Cassiopeia, about 536 light-years from Earth.
Main-sequence star in Camelopardalis, about 68.1 light-years from Earth.
Red giant in Monoceros, about 1,412 light-years from Earth.
Subgiant in Puppis, about 1,095 light-years from Earth.
Star in Vela, about 199 light-years from Earth.
Yellow dwarf in Ursa Major, about 59.9 light-years from Earth.
Red giant in Carina, about 263 light-years from Earth.
Main-sequence star in Crux, about 407 light-years from Earth.
Blue giant in Scutum, about 1,400 light-years from Earth.
Subgiant in Crater, about 140 light-years from Earth.
Subgiant in Capricornus, about 86.8 light-years from Earth.
Red giant in Auriga, about 453 light-years from Earth.
Main-sequence star in Capricornus, about 545 light-years from Earth.
Main-sequence star in Circinus, about 1,510 light-years from Earth.
Star in Puppis, about 861 light-years from Earth.
Main-sequence star in Pegasus, about 632 light-years from Earth.
Main-sequence star in Andromeda, about 421 light-years from Earth.
Main-sequence star in Serpens, about 162 light-years from Earth.
Red giant in Gemini, about 443 light-years from Earth.
Main-sequence star in Coma Berenices, about 199 light-years from Earth.
Red giant in Pegasus, about 388 light-years from Earth.
Red giant in Cygnus, about 404 light-years from Earth.
Red giant in Pegasus, about 619 light-years from Earth.
Red giant in Hercules, about 212 light-years from Earth.
Red giant in Octans, about 291 light-years from Earth.
Red giant in Sagitta, about 160 light-years from Earth.
Main-sequence star in Camelopardalis, about 199 light-years from Earth.
Red giant in Cepheus, about 384 light-years from Earth.
Main-sequence star in Monoceros, about 554 light-years from Earth.
Main-sequence star in Puppis, about 1,016 light-years from Earth.
Main-sequence star in Vela, about 429 light-years from Earth.
Red giant in Ursa Major, about 553 light-years from Earth.
Blue giant in Vela, about 843 light-years from Earth.
Main-sequence star in Musca, about 404 light-years from Earth.
Red giant in Scorpius, about 318 light-years from Earth.
Red giant in Corona Australis, about 485 light-years from Earth.
Red giant in Lacerta, about 609 light-years from Earth.
Main-sequence star in Aries, about 520 light-years from Earth.
Red giant in Hydrus, about 212 light-years from Earth.
Star in Hercules, about 329 light-years from Earth.
Main-sequence star in Perseus, about 320 light-years from Earth.
Red giant in Aquila, about 371 light-years from Earth.
Red giant in Aquarius, about 227 light-years from Earth.
Star in Capricornus, about 792 light-years from Earth.
Star in Hercules, about 251 light-years from Earth.
Red giant in Aries, about 318 light-years from Earth.
Main-sequence star in Taurus, about 396 light-years from Earth.
Main-sequence star in Dorado, about 574 light-years from Earth.
Star in Cepheus, about 380 light-years from Earth.
Red giant in Hydra, about 545 light-years from Earth.
Red giant in Centaurus, about 258 light-years from Earth.
Main-sequence star in Virgo, about 159 light-years from Earth.
Main-sequence star in Triangulum Australe, about 697 light-years from Earth.
Blue giant in Scorpius, about 738 light-years from Earth.
Star in Octans, about 265 light-years from Earth.
Red giant in Lacerta, about 257 light-years from Earth.
Main-sequence star in Leo Minor, about 91.8 light-years from Earth.
Blue giant in Camelopardalis, about 979 light-years from Earth.
Main-sequence star in Cetus, about 233 light-years from Earth.
Main-sequence star in Draco, about 89.0 light-years from Earth.
Main-sequence star in Eridanus, about 83.0 light-years from Earth.
Main-sequence star in Eridanus, about 346 light-years from Earth.
Main-sequence star in Puppis, about 757 light-years from Earth.
Main-sequence star in Centaurus, about 203 light-years from Earth.
Main-sequence star in Pavo, about 80.4 light-years from Earth.
Red dwarf in Cepheus, about 2,452 light-years from Earth.
Star in Grus, about 265 light-years from Earth.
Red giant in Lacerta, about 451 light-years from Earth.
Subgiant in Microscopium, about 116 light-years from Earth.
Star in Triangulum Australe, about 1,208 light-years from Earth.
Main-sequence star in Corona Australis, about 205 light-years from Earth.
Subgiant in Lyra, about 439 light-years from Earth.
Main-sequence star in Hercules, about 263 light-years from Earth.
Red giant in Coma Berenices, about 340 light-years from Earth.
Star in Aquila, about 457 light-years from Earth.
Red giant in Ursa Major, about 227 light-years from Earth.
Red giant in Ursa Major, about 654 light-years from Earth.
Red giant in Aquarius, about 171 light-years from Earth.
Red giant in Auriga, about 236 light-years from Earth.
Main-sequence star in Eridanus, about 309 light-years from Earth.
Main-sequence star in Cygnus, about 400 light-years from Earth.
Yellow dwarf in Ara, about 50.6 light-years from Earth.
Red giant in Puppis, about 316 light-years from Earth.
Red giant in Puppis, about 217 light-years from Earth.
Subgiant in Vela, about 830 light-years from Earth.
Star in Centaurus, about 116 light-years from Earth.
Main-sequence star in Sagittarius, about 223 light-years from Earth.
Star in Scutum, about 329 light-years from Earth.
Subgiant in Horologium, about 142 light-years from Earth.
Red giant in Microscopium, about 234 light-years from Earth.
Main-sequence star in Aquila, about 62.6 light-years from Earth.
Main-sequence star in Phoenix, about 307 light-years from Earth.
Main-sequence star in Piscis Austrinus, about 96.0 light-years from Earth.
Blue giant in Canis Minor, about 624 light-years from Earth.
Blue giant in Pisces, about 454 light-years from Earth.
Red giant in Libra, about 318 light-years from Earth.
Star in Draco, about 344 light-years from Earth.
Main-sequence star in Hercules, about 428 light-years from Earth.
Main-sequence star in Pisces, about 246 light-years from Earth.
Star in Octans, about 142 light-years from Earth.
Main-sequence star in Cancer, about 59.6 light-years from Earth.
Red giant in Camelopardalis, about 2,051 light-years from Earth.
Star in Cancer, about 395 light-years from Earth.
Red giant in Hydra, about 389 light-years from Earth.
Red giant in Cetus, about 582 light-years from Earth.
Red giant in Boötes, about 513 light-years from Earth.
Star in Lupus, about 353 light-years from Earth.
Main-sequence star in Fornax, about 152 light-years from Earth.
Red giant in Phoenix, about 287 light-years from Earth.
Main-sequence star in Norma, about 386 light-years from Earth.
Blue giant in Aquila, about 711 light-years from Earth.
Main-sequence star in Canes Venatici, about 275 light-years from Earth.
Main-sequence star in Cygnus, about 633 light-years from Earth.
Star in Monoceros, about 220 light-years from Earth.
Star in Cygnus, about 3,167 light-years from Earth.
Main-sequence star in Cetus, about 76.3 light-years from Earth.
Main-sequence star in Taurus, about 361 light-years from Earth.
Red giant in Vulpecula, about 272 light-years from Earth.
Subgiant in Camelopardalis, about 924 light-years from Earth.
Main-sequence star in Perseus, about 268 light-years from Earth.
Main-sequence star in Orion, about 718 light-years from Earth.
Main-sequence star in Cancer, about 215 light-years from Earth.
Red giant in Andromeda, about 617 light-years from Earth.
Star in Puppis, about 82.4 light-years from Earth.
Red giant in Gemini, about 594 light-years from Earth.
Red giant in Carina, about 646 light-years from Earth.
Main-sequence star in Carina, about 301 light-years from Earth.
Red giant in Puppis, about 291 light-years from Earth.
Subgiant in Vela, about 1,359 light-years from Earth.
Blue giant in Vela, about 526 light-years from Earth.
Main-sequence star in Centaurus, about 700 light-years from Earth.
Red giant in Centaurus, about 234 light-years from Earth.
Main-sequence star in Camelopardalis, about 109 light-years from Earth.
Red giant in Corvus, about 201 light-years from Earth.
Main-sequence star in Lupus, about 138 light-years from Earth.
Star in Dorado, about 458 light-years from Earth.
Red giant in Corona Borealis, about 619 light-years from Earth.
Red giant in Pavo, about 563 light-years from Earth.
Main-sequence star in Ophiuchus, about 295 light-years from Earth.
Red giant in Gemini, about 662 light-years from Earth.
Main-sequence star in Pavo, about 786 light-years from Earth.
Star in Virgo, about 262 light-years from Earth.
Red giant in Aquarius, about 233 light-years from Earth.
Subgiant in Serpens, about 130 light-years from Earth.
Red giant in Ursa Major, about 521 light-years from Earth.
Hypergiant in Delphinus, about 124 light-years from Earth.
Red giant in Triangulum, about 433 light-years from Earth.
Subgiant in Cygnus, about 1,321 light-years from Earth.
Red giant in Ursa Major, about 478 light-years from Earth.
Red giant in Lynx, about 265 light-years from Earth.
Red giant in Virgo, about 307 light-years from Earth.
Main-sequence star in Hydra, about 98.8 light-years from Earth.
Main-sequence star in Pegasus, about 242 light-years from Earth.
Main-sequence star in Libra, about 74.9 light-years from Earth.
Main-sequence star in Pisces, about 480 light-years from Earth.
Red giant in Phoenix, about 375 light-years from Earth.
Red giant in Canis Major, about 619 light-years from Earth.
Red giant in Lynx, about 433 light-years from Earth.
Blue giant in Vela, about 1,853 light-years from Earth.
Main-sequence star in Carina, about 308 light-years from Earth.
Main-sequence star in Centaurus, about 274 light-years from Earth.
Subgiant in Centaurus, about 285 light-years from Earth.
Main-sequence star in Centaurus, about 82.6 light-years from Earth.
Main-sequence star in Musca, about 330 light-years from Earth.
Main-sequence star in Centaurus, about 437 light-years from Earth.
Main-sequence star in Lupus, about 1,763 light-years from Earth.
Subgiant in Ursa Minor, about 82.7 light-years from Earth.
Red giant in Capricornus, about 580 light-years from Earth.
Main-sequence star in Perseus, about 637 light-years from Earth.
Main-sequence star in Ursa Major, about 86.5 light-years from Earth.
Yellow dwarf in Capricornus, about 108 light-years from Earth.
Yellow dwarf in Puppis, about 53.8 light-years from Earth.
Red giant in Serpens, about 690 light-years from Earth.
Red giant in Virgo, about 247 light-years from Earth.
Main-sequence star in Equuleus, about 331 light-years from Earth.
Star in Circinus, about 276 light-years from Earth.
Star in Pictor, about 256 light-years from Earth.
Red giant in Canis Major, about 367 light-years from Earth.
Main-sequence star in Carina, about 253 light-years from Earth.
Subgiant in Libra, about 399 light-years from Earth.
Main-sequence star in Corona Australis, about 229 light-years from Earth.
Main-sequence star in Eridanus, about 186 light-years from Earth.
Red giant in Cancer, about 373 light-years from Earth.
Star in Andromeda, about 158 light-years from Earth.
Subgiant in Pegasus, about 89.0 light-years from Earth.
Main-sequence star in Aquarius, about 319 light-years from Earth.
Main-sequence star in Coma Berenices, about 265 light-years from Earth.
Subgiant in Cetus, about 51.4 light-years from Earth.
Subgiant in Aquila, about 49.5 light-years from Earth.
Star in Aries, about 119 light-years from Earth.
Main-sequence star in Cygnus, about 708 light-years from Earth.
Red giant in Puppis, about 255 light-years from Earth.
Main-sequence star in Coma Berenices, about 46.7 light-years from Earth.
Main-sequence star in Crater, about 251 light-years from Earth.
Main-sequence star in Cetus, about 173 light-years from Earth.
Main-sequence star in Vela, about 225 light-years from Earth.
Main-sequence star in Carina, about 86.2 light-years from Earth.
Red giant in Musca, about 425 light-years from Earth.
Subgiant in Corvus, about 257 light-years from Earth.
Main-sequence star in Centaurus, about 369 light-years from Earth.
Star in Cassiopeia, about 256 light-years from Earth.
Red giant in Cygnus, about 133 light-years from Earth.
Yellow dwarf in Cassiopeia, about 24.6 light-years from Earth.
Red giant in Indus, about 366 light-years from Earth.
Red giant in Capricornus, about 643 light-years from Earth.
Main-sequence star in Telescopium, about 185 light-years from Earth.
Main-sequence star in Eridanus, about 209 light-years from Earth.
Subgiant in Taurus, about 428 light-years from Earth.
Main-sequence star in Ursa Major, about 63.8 light-years from Earth.
Red supergiant in Cygnus, about 693 light-years from Earth.
Star in Vulpecula, about 1,919 light-years from Earth.
Main-sequence star in Taurus, about 420 light-years from Earth.
Main-sequence star in Cassiopeia, about 278 light-years from Earth.
Main-sequence star in Orion, about 228 light-years from Earth.
Main-sequence star in Draco, about 396 light-years from Earth.
Red giant in Leo, about 332 light-years from Earth.
Red giant in Mensa, about 102 light-years from Earth.
Main-sequence star in Andromeda, about 283 light-years from Earth.
Red giant in Orion, about 343 light-years from Earth.
Red giant in Volans, about 292 light-years from Earth.
Main-sequence star in Canis Major, about 937 light-years from Earth.
Subgiant in Puppis, about 1,489 light-years from Earth.
Main-sequence star in Vela, about 695 light-years from Earth.
Subgiant in Vela, about 443 light-years from Earth.
Star in Ursa Major, about 121 light-years from Earth.
Main-sequence star in Centaurus, about 88.8 light-years from Earth.
Red giant in Ursa Minor, about 428 light-years from Earth.
Red giant in Circinus, about 161 light-years from Earth.
Red giant in Cepheus, about 244 light-years from Earth.
Red giant in Sculptor, about 331 light-years from Earth.
Star in Telescopium, about 272 light-years from Earth.
Subgiant in Columba, about 1,331 light-years from Earth.
Main-sequence star in Aquila, about 780 light-years from Earth.
Main-sequence star in Phoenix, about 604 light-years from Earth.
Red giant in Delphinus, about 480 light-years from Earth.
Red giant in Draco, about 238 light-years from Earth.
Subgiant in Vulpecula, about 297 light-years from Earth.
Subgiant in Cepheus, about 287 light-years from Earth.
Yellow dwarf in Virgo, about 57.3 light-years from Earth.
Subgiant in Cepheus, about 1,989 light-years from Earth.
Star in Andromeda, about 399 light-years from Earth.
Main-sequence star in Aquarius, about 213 light-years from Earth.
Main-sequence star in Sextans, about 322 light-years from Earth.
Red giant in Dorado, about 565 light-years from Earth.
Main-sequence star in Monoceros, about 1,315 light-years from Earth.
Red giant in Monoceros, about 849 light-years from Earth.
Red giant in Carina, about 982 light-years from Earth.
Star in Pyxis, about 224 light-years from Earth.
Subgiant in Draco, about 286 light-years from Earth.
Red giant in Triangulum Australe, about 786 light-years from Earth.
Red giant in Ara, about 456 light-years from Earth.
Yellow dwarf in Fornax, about 71.6 light-years from Earth.
Red giant in Libra, about 695 light-years from Earth.
Main-sequence star in Volans, about 240 light-years from Earth.
Main-sequence star in Cetus, about 69.3 light-years from Earth.
Main-sequence star in Canes Venatici, about 341 light-years from Earth.
Main-sequence star in Lyra, about 136 light-years from Earth.
Red giant in Lynx, about 199 light-years from Earth.
Red giant in Corona Borealis, about 641 light-years from Earth.
Main-sequence star in Gemini, about 142 light-years from Earth.
Star in Andromeda, about 205 light-years from Earth.
Main-sequence star in Camelopardalis, about 469 light-years from Earth.
Red giant in Eridanus, about 994 light-years from Earth.
Main-sequence star in Hydra, about 333 light-years from Earth.
Star in Serpens, about 469 light-years from Earth.
Main-sequence star in Cygnus, about 11.4 light-years from Earth.
Subgiant in Gemini, about 104 light-years from Earth.
Main-sequence star in Orion, about 67.9 light-years from Earth.
Subgiant in Aquarius, about 68.9 light-years from Earth.
Main-sequence star in Camelopardalis, about 327 light-years from Earth.
Red giant in Pictor, about 304 light-years from Earth.
Main-sequence star in Puppis, about 349 light-years from Earth.
Subgiant in Vela, about 1,250 light-years from Earth.
Main-sequence star in Vela, about 279 light-years from Earth.
Red giant in Hydra, about 404 light-years from Earth.
Yellow dwarf in Lyra, about 48.5 light-years from Earth.
Red giant in Microscopium, about 328 light-years from Earth.
Star in Corona Australis, about 396 light-years from Earth.
Star in Gemini, about 1,489 light-years from Earth.
Main-sequence star in Corvus, about 416 light-years from Earth.
Red giant in Lynx, about 626 light-years from Earth.
Red giant in Virgo, about 125 light-years from Earth.
Main-sequence star in Orion, about 446 light-years from Earth.
Red giant in Virgo, about 235 light-years from Earth.
Red giant in Canis Major, about 349 light-years from Earth.
Red giant in Monoceros, about 344 light-years from Earth.
Red giant in Centaurus, about 274 light-years from Earth.
Blue giant in Ara, about 935 light-years from Earth.
Star in Serpens, about 273 light-years from Earth.
Main-sequence star in Taurus, about 90.0 light-years from Earth.
Subgiant in Pisces, about 174 light-years from Earth.
Main-sequence star in Aquarius, about 74.0 light-years from Earth.
Main-sequence star in Phoenix, about 186 light-years from Earth.
Subgiant in Horologium, about 160 light-years from Earth.
Main-sequence star in Camelopardalis, about 685 light-years from Earth.
Red giant in Sagittarius, about 935 light-years from Earth.
Blue giant in Vulpecula, about 393 light-years from Earth.
Main-sequence star in Virgo, about 253 light-years from Earth.
Main-sequence star in Hercules, about 393 light-years from Earth.
Star in Cassiopeia, about 400 light-years from Earth.
Main-sequence star in Eridanus, about 96.0 light-years from Earth.
Red giant in Auriga, about 360 light-years from Earth.
Star in Cancer, about 149 light-years from Earth.
Red giant in Draco, about 588 light-years from Earth.
Main-sequence star in Ursa Major, about 112 light-years from Earth.
Red giant in Cygnus, about 217 light-years from Earth.
Main-sequence star in Lyra, about 231 light-years from Earth.
Star in Canis Minor, about 318 light-years from Earth.
Main-sequence star in Taurus, about 391 light-years from Earth.
Main-sequence star in Cetus, about 87.2 light-years from Earth.
Main-sequence star in Monoceros, about 208 light-years from Earth.
Red giant in Monoceros, about 571 light-years from Earth.
Main-sequence star in Puppis, about 1,568 light-years from Earth.
Main-sequence star in Puppis, about 181 light-years from Earth.
Main-sequence star in Carina, about 313 light-years from Earth.
Subgiant in Centaurus, about 1,365 light-years from Earth.
Main-sequence star in Centaurus, about 158 light-years from Earth.
Star in Lupus, about 260 light-years from Earth.
Subgiant in Eridanus, about 361 light-years from Earth.
Main-sequence star in Auriga, about 530 light-years from Earth.
Red giant in Andromeda, about 258 light-years from Earth.
Star in Vulpecula, about 222 light-years from Earth.
Star in Aquila, about 149 light-years from Earth.
Red giant in Ophiuchus, about 241 light-years from Earth.
Yellow dwarf in Draco, about 46.3 light-years from Earth.
Star in Hydra, about 358 light-years from Earth.
Star in Cancer, about 487 light-years from Earth.
Star in Cancer, about 296 light-years from Earth.
Red giant in Auriga, about 1,208 light-years from Earth.
Red giant in Pisces, about 350 light-years from Earth.
Subgiant in Antlia, about 109 light-years from Earth.
Main-sequence star in Aries, about 94.2 light-years from Earth.
Subgiant in Vela, about 1,106 light-years from Earth.
Main-sequence star in Vela, about 369 light-years from Earth.
Subgiant in Carina, about 476 light-years from Earth.
Main-sequence star in Hydra, about 100 light-years from Earth.
Star in Lupus, about 261 light-years from Earth.
Red giant in Eridanus, about 456 light-years from Earth.
Blue giant in Cancer, about 531 light-years from Earth.
Main-sequence star in Corona Borealis, about 68.8 light-years from Earth.
Main-sequence star in Draco, about 95.5 light-years from Earth.
Main-sequence star in Aquarius, about 379 light-years from Earth.
Main-sequence star in Pisces, about 24.6 light-years from Earth.
Main-sequence star in Camelopardalis, about 336 light-years from Earth.
Blue giant in Eridanus, about 487 light-years from Earth.
Red giant in Hydra, about 245 light-years from Earth.
Main-sequence star in Eridanus, about 655 light-years from Earth.
Main-sequence star in Eridanus, about 251 light-years from Earth.
Red giant in Capricornus, about 231 light-years from Earth.
Star in Orion, about 360 light-years from Earth.
Yellow dwarf in Auriga, about 54.5 light-years from Earth.
Star in Aquarius, about 254 light-years from Earth.
Star in Canis Minor, about 760 light-years from Earth.
Red giant in Scorpius, about 378 light-years from Earth.
Main-sequence star in Pyxis, about 232 light-years from Earth.
Star in Reticulum, about 385 light-years from Earth.
Yellow dwarf in Equuleus, about 184 light-years from Earth.
Yellow dwarf in Reticulum, about 39.2 light-years from Earth.
Main-sequence star in Taurus, about 184 light-years from Earth.
Red giant in Eridanus, about 760 light-years from Earth.
Main-sequence star in Puppis, about 463 light-years from Earth.
Main-sequence star in Vela, about 612 light-years from Earth.
Red giant in Centaurus, about 222 light-years from Earth.
Star in Boötes, about 257 light-years from Earth.
Red dwarf in Ophiuchus, about 577 light-years from Earth.
Yellow dwarf in Hercules, about 628 light-years from Earth.
Main-sequence star in Corona Australis, about 488 light-years from Earth.
Subgiant in Pavo, about 279 light-years from Earth.
Main-sequence star in Cepheus, about 122 light-years from Earth.
Main-sequence star in Perseus, about 459 light-years from Earth.
Red giant in Virgo, about 497 light-years from Earth.
Star in Phoenix, about 242 light-years from Earth.
Blue giant in Capricornus, about 1,136 light-years from Earth.
Main-sequence star in Ophiuchus, about 170 light-years from Earth.
Main-sequence star in Sculptor, about 69.4 light-years from Earth.
Main-sequence star in Canis Minor, about 301 light-years from Earth.
Blue giant in Lacerta, about 1,342 light-years from Earth.
Main-sequence star in Triangulum, about 281 light-years from Earth.
Subgiant in Lepus, about 1,647 light-years from Earth.
Subgiant in Hercules, about 940 light-years from Earth.
Star in Sextans, about 193 light-years from Earth.
Star in Columba, about 273 light-years from Earth.
Red giant in Canis Major, about 402 light-years from Earth.
Red giant in Puppis, about 2,091 light-years from Earth.
Main-sequence star in Camelopardalis, about 70.1 light-years from Earth.
Red giant in Hercules, about 363 light-years from Earth.
Red giant in Draco, about 316 light-years from Earth.
Main-sequence star in Microscopium, about 108 light-years from Earth.
Red giant in Cepheus, about 413 light-years from Earth.
Subgiant in Lyra, about 896 light-years from Earth.
Main-sequence star in Horologium, about 165 light-years from Earth.
Star in Boötes, about 170 light-years from Earth.
Main-sequence star in Ara, about 145 light-years from Earth.
Red giant in Sculptor, about 215 light-years from Earth.
Main-sequence star in Eridanus, about 136 light-years from Earth.
Red giant in Boötes, about 549 light-years from Earth.
Main-sequence star in Serpens, about 231 light-years from Earth.
Red giant in Cepheus, about 424 light-years from Earth.
Main-sequence star in Auriga, about 370 light-years from Earth.
Main-sequence star in Orion, about 538 light-years from Earth.
Main-sequence star in Taurus, about 153 light-years from Earth.
Red giant in Leo, about 270 light-years from Earth.
Star in Camelopardalis, about 319 light-years from Earth.
Star in Vela, about 640 light-years from Earth.
Blue giant in Vela, about 438 light-years from Earth.
Red giant in Carina, about 369 light-years from Earth.
Main-sequence star in Centaurus, about 202 light-years from Earth.
Star in Hydra, about 286 light-years from Earth.
Main-sequence star in Centaurus, about 260 light-years from Earth.
Red giant in Lupus, about 1,095 light-years from Earth.
Red giant in Draco, about 293 light-years from Earth.
Red giant in Lyra, about 324 light-years from Earth.
Subgiant in Leo, about 500 light-years from Earth.
Main-sequence star in Aries, about 780 light-years from Earth.
Main-sequence star in Aquila, about 158 light-years from Earth.
Red giant in Libra, about 417 light-years from Earth.
Red giant in Cepheus, about 303 light-years from Earth.
Star in Ursa Major, about 208 light-years from Earth.
Main-sequence star in Cassiopeia, about 108 light-years from Earth.
Red giant in Andromeda, about 294 light-years from Earth.
Subgiant in Hercules, about 322 light-years from Earth.
Subgiant in Aries, about 509 light-years from Earth.
Main-sequence star in Taurus, about 148 light-years from Earth.
Main-sequence star in Gemini, about 424 light-years from Earth.
Red giant in Virgo, about 440 light-years from Earth.
Main-sequence star in Monoceros, about 872 light-years from Earth.
Main-sequence star in Puppis, about 324 light-years from Earth.
Main-sequence star in Carina, about 896 light-years from Earth.
Main-sequence star in Vela, about 169 light-years from Earth.
Red supergiant in Carina, about 2,652 light-years from Earth.
Red giant in Ursa Major, about 216 light-years from Earth.
Main-sequence star in Crux, about 1,217 light-years from Earth.
Red giant in Apus, about 613 light-years from Earth.
Main-sequence star in Ara, about 88.8 light-years from Earth.
Red giant in Cetus, about 459 light-years from Earth.
Red giant in Cygnus, about 1,576 light-years from Earth.
Main-sequence star in Cepheus, about 257 light-years from Earth.
Red giant in Aquarius, about 270 light-years from Earth.
Star in Octans, about 409 light-years from Earth.
Main-sequence star in Fornax, about 320 light-years from Earth.
Star in Hydrus, about 284 light-years from Earth.
Main-sequence star in Taurus, about 190 light-years from Earth.
Main-sequence star in Aquarius, about 239 light-years from Earth.
Blue giant in Canis Major, about 796 light-years from Earth.
Subgiant in Taurus, about 633 light-years from Earth.
Red giant in Ursa Major, about 720 light-years from Earth.
Red giant in Lepus, about 838 light-years from Earth.
Subgiant in Aquila, about 415 light-years from Earth.
Red giant in Canes Venatici, about 590 light-years from Earth.
Main-sequence star in Eridanus, about 414 light-years from Earth.
Main-sequence star in Gemini, about 491 light-years from Earth.
Star in Cassiopeia, about 458 light-years from Earth.
Main-sequence star in Lynx, about 123 light-years from Earth.
Subgiant in Perseus, about 122 light-years from Earth.
Main-sequence star in Aquila, about 854 light-years from Earth.
Main-sequence star in Boötes, about 252 light-years from Earth.
Subgiant in Volans, about 381 light-years from Earth.
Main-sequence star in Columba, about 133 light-years from Earth.
Main-sequence star in Puppis, about 168 light-years from Earth.
Main-sequence star in Hydra, about 402 light-years from Earth.
Main-sequence star in Carina, about 351 light-years from Earth.
Blue giant in Centaurus, about 691 light-years from Earth.
Subgiant in Corvus, about 3,167 light-years from Earth.
Red giant in Draco, about 271 light-years from Earth.
Main-sequence star in Ara, about 636 light-years from Earth.
Blue giant in Sagittarius, about 1,321 light-years from Earth.
Subgiant in Triangulum Australe, about 127 light-years from Earth.
Star in Dorado, about 219 light-years from Earth.
Main-sequence star in Indus, about 93.6 light-years from Earth.
Subgiant in Aquila, about 219 light-years from Earth.
Red giant in Capricornus, about 1,121 light-years from Earth.
Main-sequence star in Triangulum, about 377 light-years from Earth.
Red supergiant in Pegasus, about 1,394 light-years from Earth.
Star in Triangulum, about 163 light-years from Earth.
Red giant in Boötes, about 265 light-years from Earth.
Main-sequence star in Coma Berenices, about 238 light-years from Earth.
Subgiant in Leo, about 135 light-years from Earth.
Main-sequence star in Aquarius, about 222 light-years from Earth.
Main-sequence star in Camelopardalis, about 172 light-years from Earth.
Main-sequence star in Taurus, about 119 light-years from Earth.
Red giant in Cetus, about 1,076 light-years from Earth.
Red giant in Octans, about 257 light-years from Earth.
Subgiant in Sculptor, about 91.7 light-years from Earth.
Red giant in Perseus, about 253 light-years from Earth.
Main-sequence star in Columba, about 429 light-years from Earth.
Main-sequence star in Pictor, about 113 light-years from Earth.
Star in Canis Major, about 1,254 light-years from Earth.
Red giant in Octans, about 255 light-years from Earth.
Red giant in Cetus, about 622 light-years from Earth.
Main-sequence star in Cassiopeia, about 246 light-years from Earth.
Main-sequence star in Cygnus, about 411 light-years from Earth.
Main-sequence star in Lepus, about 334 light-years from Earth.
Red giant in Grus, about 466 light-years from Earth.
Subgiant in Cancer, about 76.0 light-years from Earth.
Red giant in Hercules, about 974 light-years from Earth.
Red giant in Canis Minor, about 242 light-years from Earth.
Main-sequence star in Hydra, about 451 light-years from Earth.
Star in Vulpecula, about 438 light-years from Earth.
Star in Andromeda, about 355 light-years from Earth.
Main-sequence star in Aries, about 231 light-years from Earth.
Red giant in Vulpecula, about 452 light-years from Earth.
Blue giant in Lynx, about 581 light-years from Earth.
Star in Perseus, about 118 light-years from Earth.
Red giant in Andromeda, about 349 light-years from Earth.
Red giant in Ophiuchus, about 820 light-years from Earth.
Red giant in Sagittarius, about 241 light-years from Earth.
Main-sequence star in Ursa Major, about 213 light-years from Earth.
Main-sequence star in Perseus, about 241 light-years from Earth.
Red giant in Pegasus, about 730 light-years from Earth.
Main-sequence star in Cygnus, about 1,305 light-years from Earth.
Red giant in Gemini, about 635 light-years from Earth.
Main-sequence star in Pegasus, about 183 light-years from Earth.
Star in Mensa, about 794 light-years from Earth.
Main-sequence star in Capricornus, about 180 light-years from Earth.
Star in Equuleus, about 176 light-years from Earth.
Main-sequence star in Horologium, about 149 light-years from Earth.
Subgiant in Canis Major, about 424 light-years from Earth.
Main-sequence star in Puppis, about 411 light-years from Earth.
Subgiant in Carina, about 237 light-years from Earth.
Subgiant in Hydra, about 90.5 light-years from Earth.
Subgiant in Sagittarius, about 158 light-years from Earth.
Star in Aquila, about 247 light-years from Earth.
Red giant in Pictor, about 375 light-years from Earth.
Red giant in Sculptor, about 292 light-years from Earth.
Red giant in Capricornus, about 612 light-years from Earth.
Main-sequence star in Virgo, about 193 light-years from Earth.
Star in Virgo, about 127 light-years from Earth.
Yellow dwarf in Ursa Major, about 31.4 light-years from Earth.
Main-sequence star in Andromeda, about 246 light-years from Earth.
Red giant in Leo, about 386 light-years from Earth.
Red giant in Pictor, about 469 light-years from Earth.
Star in Lynx, about 740 light-years from Earth.
Main-sequence star in Vela, about 252 light-years from Earth.
Red giant in Vela, about 345 light-years from Earth.
Red giant in Centaurus, about 571 light-years from Earth.
Blue supergiant in Scorpius, about 2,718 light-years from Earth.
Star in Andromeda, about 212 light-years from Earth.
Subgiant in Ophiuchus, about 53.3 light-years from Earth.
Star in Pavo, about 122 light-years from Earth.
Main-sequence star in Tucana, about 67.1 light-years from Earth.
Red giant in Serpens, about 373 light-years from Earth.
Main-sequence star in Cassiopeia, about 277 light-years from Earth.
Red giant in Ophiuchus, about 1,091 light-years from Earth.
Main-sequence star in Orion, about 276 light-years from Earth.
Main-sequence star in Taurus, about 641 light-years from Earth.
Main-sequence star in Leo, about 381 light-years from Earth.
Red giant in Eridanus, about 265 light-years from Earth.
Main-sequence star in Perseus, about 542 light-years from Earth.
Main-sequence star in Taurus, about 852 light-years from Earth.
Yellow dwarf in Puppis, about 281 light-years from Earth.
Red giant in Puppis, about 468 light-years from Earth.
Main-sequence star in Centaurus, about 444 light-years from Earth.
Star in Centaurus, about 128 light-years from Earth.
Main-sequence star in Centaurus, about 254 light-years from Earth.
Subgiant in Norma, about 463 light-years from Earth.
Main-sequence star in Sagittarius, about 301 light-years from Earth.
Subgiant in Pavo, about 236 light-years from Earth.
Main-sequence star in Sagittarius, about 19.6 light-years from Earth.
Main-sequence star in Libra, about 238 light-years from Earth.
Subgiant in Octans, about 493 light-years from Earth.
Main-sequence star in Microscopium, about 115 light-years from Earth.
Red supergiant in Sagitta, about 1,019 light-years from Earth.
Main-sequence star in Orion, about 211 light-years from Earth.
Red giant in Orion, about 591 light-years from Earth.
Red supergiant in Pegasus, about 520 light-years from Earth.
Main-sequence star in Pisces, about 275 light-years from Earth.
Red giant in Cancer, about 298 light-years from Earth.
Red giant in Horologium, about 252 light-years from Earth.
Red giant in Orion, about 482 light-years from Earth.
Star in Puppis, about 1,546 light-years from Earth.
Blue giant in Volans, about 435 light-years from Earth.
Subgiant in Vela, about 2,132 light-years from Earth.
Main-sequence star in Carina, about 476 light-years from Earth.
Red giant in Virgo, about 325 light-years from Earth.
Blue supergiant in Sagittarius, about 557 light-years from Earth.
Star in Aquila, about 1,546 light-years from Earth.
Main-sequence star in Telescopium, about 162 light-years from Earth.
Red giant in Cancer, about 415 light-years from Earth.
Red giant in Lynx, about 211 light-years from Earth.
Star in Pegasus, about 109 light-years from Earth.
Star in Lynx, about 487 light-years from Earth.
Main-sequence star in Perseus, about 231 light-years from Earth.
Star in Orion, about 202 light-years from Earth.
Main-sequence star in Taurus, about 534 light-years from Earth.
Red giant in Aquarius, about 587 light-years from Earth.
Star in Auriga, about 193 light-years from Earth.
Blue giant in Auriga, about 1,370 light-years from Earth.
Main-sequence star in Hercules, about 95.2 light-years from Earth.
Main-sequence star in Taurus, about 326 light-years from Earth.
Main-sequence star in Orion, about 523 light-years from Earth.
Main-sequence star in Serpens, about 220 light-years from Earth.
Subgiant in Orion, about 1,561 light-years from Earth.
Star in Dorado, about 232 light-years from Earth.
Red giant in Gemini, about 372 light-years from Earth.
Star in Ursa Major, about 752 light-years from Earth.
Subgiant in Volans, about 169 light-years from Earth.
Main-sequence star in Antlia, about 135 light-years from Earth.
Main-sequence star in Musca, about 347 light-years from Earth.
Main-sequence star in Centaurus, about 600 light-years from Earth.
Red giant in Libra, about 459 light-years from Earth.
Main-sequence star in Cygnus, about 576 light-years from Earth.
Red giant in Microscopium, about 400 light-years from Earth.
Red giant in Pegasus, about 258 light-years from Earth.
Blue giant in Lacerta, about 822 light-years from Earth.
Subgiant in Chamaeleon, about 190 light-years from Earth.
Star in Fornax, about 294 light-years from Earth.
Red giant in Hercules, about 654 light-years from Earth.
Main-sequence star in Aquila, about 979 light-years from Earth.
Red giant in Cetus, about 551 light-years from Earth.
Main-sequence star in Lynx, about 66.0 light-years from Earth.
Subgiant in Lynx, about 180 light-years from Earth.
Star in Camelopardalis, about 381 light-years from Earth.
Main-sequence star in Auriga, about 341 light-years from Earth.
Red giant in Serpens, about 239 light-years from Earth.
Blue giant in Pegasus, about 830 light-years from Earth.
Red giant in Hercules, about 353 light-years from Earth.
Red giant in Virgo, about 238 light-years from Earth.
Main-sequence star in Orion, about 235 light-years from Earth.
Main-sequence star in Cassiopeia, about 640 light-years from Earth.
Red giant in Canis Major, about 660 light-years from Earth.
Star in Vela, about 424 light-years from Earth.
Red giant in Scorpius, about 479 light-years from Earth.
Blue supergiant in Norma, about 1,822 light-years from Earth.
Star in Corona Australis, about 295 light-years from Earth.
Blue giant in Aquarius, about 882 light-years from Earth.
Main-sequence star in Pisces, about 82.2 light-years from Earth.
Red giant in Aquarius, about 757 light-years from Earth.
Main-sequence star in Camelopardalis, about 145 light-years from Earth.
Red giant in Camelopardalis, about 715 light-years from Earth.
Star in Libra, about 311 light-years from Earth.
Main-sequence star in Leo Minor, about 382 light-years from Earth.
Subgiant in Orion, about 1,049 light-years from Earth.
Main-sequence star in Pisces, about 414 light-years from Earth.
Red giant in Pisces, about 777 light-years from Earth.
Red giant in Virgo, about 306 light-years from Earth.
Main-sequence star in Virgo, about 305 light-years from Earth.
Star in Cetus, about 266 light-years from Earth.
Red giant in Cancer, about 607 light-years from Earth.
Subgiant in Taurus, about 115 light-years from Earth.
Main-sequence star in Orion, about 1,469 light-years from Earth.
Red giant in Monoceros, about 470 light-years from Earth.
Red giant in Canis Minor, about 741 light-years from Earth.
Main-sequence star in Canis Major, about 628 light-years from Earth.
Yellow dwarf in Puppis, about 49.6 light-years from Earth.
Star in Hydra, about 291 light-years from Earth.
Main-sequence star in Circinus, about 158 light-years from Earth.
Star in Hercules, about 447 light-years from Earth.
Blue giant in Telescopium, about 760 light-years from Earth.
Main-sequence star in Corona Australis, about 430 light-years from Earth.
Red giant in Draco, about 399 light-years from Earth.
Yellow dwarf in Grus, about 45.0 light-years from Earth.
Star in Tucana, about 304 light-years from Earth.
Star in Horologium, about 161 light-years from Earth.
Red giant in Leo, about 611 light-years from Earth.
Main-sequence star in Lupus, about 407 light-years from Earth.
Subgiant in Canis Minor, about 316 light-years from Earth.
Subgiant in Taurus, about 553 light-years from Earth.
Yellow dwarf in Leo Minor, about 49.1 light-years from Earth.
Red giant in Sagittarius, about 684 light-years from Earth.
Subgiant in Pegasus, about 1,274 light-years from Earth.
Red giant in Camelopardalis, about 492 light-years from Earth.
Main-sequence star in Draco, about 280 light-years from Earth.
Star in Sagittarius, about 1,080 light-years from Earth.
Main-sequence star in Ursa Major, about 273 light-years from Earth.
Red giant in Draco, about 625 light-years from Earth.
Main-sequence star in Pictor, about 85.0 light-years from Earth.
Subgiant in Monoceros, about 1,059 light-years from Earth.
Star in Dorado, about 270 light-years from Earth.
Red giant in Canis Major, about 617 light-years from Earth.
Red giant in Camelopardalis, about 879 light-years from Earth.
Star in Centaurus, about 164 light-years from Earth.
Red giant in Apus, about 375 light-years from Earth.
Red supergiant in Draco, about 740 light-years from Earth.
Yellow dwarf in Scorpius, about 41.7 light-years from Earth.
Main-sequence star in Sagittarius, about 290 light-years from Earth.
Subgiant in Piscis Austrinus, about 207 light-years from Earth.
Red giant in Cepheus, about 366 light-years from Earth.
Red giant in Grus, about 364 light-years from Earth.
Red giant in Triangulum, about 632 light-years from Earth.
Subgiant in Cygnus, about 78.1 light-years from Earth.
Red giant in Capricornus, about 239 light-years from Earth.
Red giant in Pisces, about 408 light-years from Earth.
Main-sequence star in Boötes, about 262 light-years from Earth.
Main-sequence star in Aquila, about 90.9 light-years from Earth.
Red giant in Pisces, about 261 light-years from Earth.
Main-sequence star in Cygnus, about 1,524 light-years from Earth.
Red giant in Serpens, about 230 light-years from Earth.
Yellow dwarf in Hercules, about 46.7 light-years from Earth.
Main-sequence star in Gemini, about 375 light-years from Earth.
Main-sequence star in Taurus, about 291 light-years from Earth.
Main-sequence star in Eridanus, about 61.4 light-years from Earth.
Main-sequence star in Eridanus, about 475 light-years from Earth.
Main-sequence star in Auriga, about 413 light-years from Earth.
Main-sequence star in Carina, about 480 light-years from Earth.
Main-sequence star in Carina, about 106 light-years from Earth.
Yellow dwarf in Hydra, about 99.2 light-years from Earth.
Main-sequence star in Crux, about 362 light-years from Earth.
Red giant in Crux, about 443 light-years from Earth.
Star in Camelopardalis, about 584 light-years from Earth.
Subgiant in Centaurus, about 782 light-years from Earth.
Main-sequence star in Lupus, about 203 light-years from Earth.
Star in Lupus, about 201 light-years from Earth.
Main-sequence star in Scorpius, about 420 light-years from Earth.
Red giant in Draco, about 638 light-years from Earth.
Star in Ophiuchus, about 126 light-years from Earth.
Red giant in Telescopium, about 545 light-years from Earth.
Main-sequence star in Lacerta, about 183 light-years from Earth.
Main-sequence star in Tucana, about 134 light-years from Earth.
Blue giant in Serpens, about 450 light-years from Earth.
Main-sequence star in Boötes, about 186 light-years from Earth.
Main-sequence star in Vulpecula, about 190 light-years from Earth.
Subgiant in Taurus, about 205 light-years from Earth.
Blue giant in Pegasus, about 809 light-years from Earth.
Yellow dwarf in Eridanus, about 176 light-years from Earth.
Main-sequence star in Orion, about 225 light-years from Earth.
Star in Leo, about 354 light-years from Earth.
Red giant in Leo Minor, about 480 light-years from Earth.
Main-sequence star in Cygnus, about 559 light-years from Earth.
Subgiant in Delphinus, about 236 light-years from Earth.
Main-sequence star in Perseus, about 730 light-years from Earth.
Main-sequence star in Orion, about 149 light-years from Earth.
Subgiant in Canis Major, about 529 light-years from Earth.
Red giant in Carina, about 824 light-years from Earth.
Star in Phoenix, about 238 light-years from Earth.
Main-sequence star in Camelopardalis, about 323 light-years from Earth.
Subgiant in Centaurus, about 386 light-years from Earth.
Red giant in Lupus, about 1,365 light-years from Earth.
Red giant in Serpens, about 479 light-years from Earth.
Star in Hercules, about 270 light-years from Earth.
Red giant in Serpens, about 521 light-years from Earth.
Subgiant in Draco, about 671 light-years from Earth.
Star in Pavo, about 142 light-years from Earth.
Main-sequence star in Fornax, about 459 light-years from Earth.
Main-sequence star in Apus, about 1,321 light-years from Earth.
Yellow dwarf in Corona Borealis, about 56.2 light-years from Earth.
Subgiant in Leo Minor, about 37.1 light-years from Earth.
Main-sequence star in Taurus, about 549 light-years from Earth.
Main-sequence star in Aquila, about 500 light-years from Earth.
Red giant in Aquila, about 289 light-years from Earth.
Red giant in Corona Borealis, about 594 light-years from Earth.
Main-sequence star in Boötes, about 291 light-years from Earth.
Red giant in Cetus, about 334 light-years from Earth.
Star in Auriga, about 566 light-years from Earth.
Blue giant in Capricornus, about 534 light-years from Earth.
Main-sequence star in Draco, about 362 light-years from Earth.
Star in Cancer, about 461 light-years from Earth.
Red giant in Draco, about 172 light-years from Earth.
Main-sequence star in Leo, about 528 light-years from Earth.
Main-sequence star in Camelopardalis, about 347 light-years from Earth.
Red giant in Camelopardalis, about 446 light-years from Earth.
Main-sequence star in Canis Major, about 1,326 light-years from Earth.
Main-sequence star in Ursa Major, about 233 light-years from Earth.
Main-sequence star in Apus, about 1,240 light-years from Earth.
Yellow dwarf in Scorpius, about 108 light-years from Earth.
Red giant in Corona Australis, about 1,305 light-years from Earth.
Red giant in Ursa Major, about 280 light-years from Earth.
Subgiant in Horologium, about 56.0 light-years from Earth.
Main-sequence star in Leo, about 108 light-years from Earth.
Blue giant in Cygnus, about 652 light-years from Earth.
Subgiant in Boötes, about 85.1 light-years from Earth.
Red giant in Cetus, about 546 light-years from Earth.
Main-sequence star in Cygnus, about 1,274 light-years from Earth.
Red giant in Virgo, about 677 light-years from Earth.
Subgiant in Libra, about 149 light-years from Earth.
Main-sequence star in Cassiopeia, about 322 light-years from Earth.
Subgiant in Canis Major, about 3,048 light-years from Earth.
Blue giant in Canis Major, about 1,109 light-years from Earth.
Main-sequence star in Puppis, about 538 light-years from Earth.
Main-sequence star in Puppis, about 593 light-years from Earth.
Red giant in Sculptor, about 794 light-years from Earth.
Main-sequence star in Hydra, about 112 light-years from Earth.
Main-sequence star in Scorpius, about 427 light-years from Earth.
Red giant in Ophiuchus, about 407 light-years from Earth.
Main-sequence star in Hercules, about 177 light-years from Earth.
Main-sequence star in Ophiuchus, about 194 light-years from Earth.
Red giant in Ophiuchus, about 153 light-years from Earth.
Red giant in Hercules, about 651 light-years from Earth.
Blue giant in Lyra, about 504 light-years from Earth.
Subgiant in Pavo, about 277 light-years from Earth.
Red giant in Microscopium, about 367 light-years from Earth.
Subgiant in Volans, about 563 light-years from Earth.
Red giant in Pavo, about 302 light-years from Earth.
Red giant in Virgo, about 625 light-years from Earth.
Blue giant in Cassiopeia, about 771 light-years from Earth.
Red giant in Gemini, about 476 light-years from Earth.
Red giant in Leo, about 586 light-years from Earth.
Star in Cetus, about 263 light-years from Earth.
Subgiant in Pisces, about 266 light-years from Earth.
Red giant in Andromeda, about 631 light-years from Earth.
Star in Cetus, about 281 light-years from Earth.
Main-sequence star in Cepheus, about 805 light-years from Earth.
Main-sequence star in Cetus, about 261 light-years from Earth.
Red giant in Phoenix, about 376 light-years from Earth.
Star in Cepheus, about 968 light-years from Earth.
Main-sequence star in Sculptor, about 253 light-years from Earth.
Red giant in Columba, about 392 light-years from Earth.
Main-sequence star in Puppis, about 1,186 light-years from Earth.
Subgiant in Pyxis, about 345 light-years from Earth.
Red giant in Phoenix, about 236 light-years from Earth.
Red giant in Centaurus, about 703 light-years from Earth.
Red giant in Canes Venatici, about 291 light-years from Earth.
Main-sequence star in Scorpius, about 421 light-years from Earth.
Red giant in Corona Australis, about 640 light-years from Earth.
Main-sequence star in Delphinus, about 189 light-years from Earth.
Star in Canes Venatici, about 1,045 light-years from Earth.
Star in Cancer, about 274 light-years from Earth.
Main-sequence star in Hercules, about 406 light-years from Earth.
Star in Perseus, about 982 light-years from Earth.
Main-sequence star in Orion, about 178 light-years from Earth.
Main-sequence star in Scorpius, about 252 light-years from Earth.
Red giant in Camelopardalis, about 940 light-years from Earth.
Red giant in Pisces, about 299 light-years from Earth.
Star in Draco, about 1,056 light-years from Earth.
Blue giant in Aquarius, about 450 light-years from Earth.
Red giant in Leo, about 694 light-years from Earth.
Red giant in Cetus, about 589 light-years from Earth.
Main-sequence star in Piscis Austrinus, about 817 light-years from Earth.
Red giant in Monoceros, about 698 light-years from Earth.
Main-sequence star in Antlia, about 518 light-years from Earth.
Main-sequence star in Hydra, about 182 light-years from Earth.
Main-sequence star in Norma, about 409 light-years from Earth.
Red giant in Cetus, about 476 light-years from Earth.
Main-sequence star in Scorpius, about 556 light-years from Earth.
Subgiant in Ophiuchus, about 135 light-years from Earth.
Main-sequence star in Cetus, about 96.7 light-years from Earth.
Main-sequence star in Ophiuchus, about 108 light-years from Earth.
Red giant in Grus, about 773 light-years from Earth.
Red giant in Lacerta, about 397 light-years from Earth.
Subgiant in Corona Borealis, about 136 light-years from Earth.
Star in Chamaeleon, about 184 light-years from Earth.
Red giant in Draco, about 741 light-years from Earth.
Star in Octans, about 162 light-years from Earth.
Red giant in Andromeda, about 286 light-years from Earth.
Main-sequence star in Monoceros, about 284 light-years from Earth.
Star in Eridanus, about 352 light-years from Earth.
Subgiant in Eridanus, about 156 light-years from Earth.
Red giant in Cygnus, about 399 light-years from Earth.
Subgiant in Cancer, about 194 light-years from Earth.
Red giant in Cancer, about 695 light-years from Earth.
Red giant in Aquila, about 708 light-years from Earth.
Star in Pisces, about 648 light-years from Earth.
Blue giant in Orion, about 1,165 light-years from Earth.
Main-sequence star in Aquarius, about 209 light-years from Earth.
Main-sequence star in Taurus, about 386 light-years from Earth.
Main-sequence star in Camelopardalis, about 378 light-years from Earth.
Star in Columba, about 422 light-years from Earth.
Main-sequence star in Camelopardalis, about 58.3 light-years from Earth.
Subgiant in Monoceros, about 552 light-years from Earth.
Red giant in Puppis, about 743 light-years from Earth.
Main-sequence star in Vela, about 233 light-years from Earth.
Main-sequence star in Hydra, about 206 light-years from Earth.
Blue giant in Crux, about 762 light-years from Earth.
Red giant in Lupus, about 545 light-years from Earth.
Main-sequence star in Draco, about 254 light-years from Earth.
Star in Ophiuchus, about 400 light-years from Earth.
Red giant in Telescopium, about 498 light-years from Earth.
Main-sequence star in Cepheus, about 265 light-years from Earth.
Main-sequence star in Norma, about 349 light-years from Earth.
Star in Pictor, about 116 light-years from Earth.
Main-sequence star in Cepheus, about 245 light-years from Earth.
Main-sequence star in Corvus, about 192 light-years from Earth.
Subgiant in Aquila, about 105 light-years from Earth.
Red giant in Sagittarius, about 500 light-years from Earth.
Main-sequence star in Aries, about 539 light-years from Earth.
Subgiant in Taurus, about 417 light-years from Earth.
Subgiant in Taurus, about 377 light-years from Earth.
Yellow dwarf in Pegasus, about 50.9 light-years from Earth.
Main-sequence star in Taurus, about 114 light-years from Earth.
Subgiant in Eridanus, about 652 light-years from Earth.
Red giant in Reticulum, about 263 light-years from Earth.
Star in Andromeda, about 847 light-years from Earth.
Red giant in Cassiopeia, about 2,091 light-years from Earth.
Red giant in Columba, about 172 light-years from Earth.
Main-sequence star in Canis Major, about 124 light-years from Earth.
Star in Tucana, about 222 light-years from Earth.
Red giant in Gemini, about 316 light-years from Earth.
Main-sequence star in Puppis, about 718 light-years from Earth.
Red giant in Carina, about 338 light-years from Earth.
Main-sequence star in Vela, about 445 light-years from Earth.
Main-sequence star in Vela, about 433 light-years from Earth.
Star in Leo, about 313 light-years from Earth.
Main-sequence star in Lupus, about 388 light-years from Earth.
Star in Lupus, about 2,160 light-years from Earth.
Red giant in Serpens, about 510 light-years from Earth.
Subgiant in Norma, about 775 light-years from Earth.
Star in Corona Australis, about 300 light-years from Earth.
Main-sequence star in Grus, about 336 light-years from Earth.
Red giant in Octans, about 352 light-years from Earth.
Main-sequence star in Piscis Austrinus, about 501 light-years from Earth.
Main-sequence star in Aries, about 337 light-years from Earth.
Star in Cancer, about 393 light-years from Earth.
Star in Octans, about 281 light-years from Earth.
Main-sequence star in Mensa, about 352 light-years from Earth.
Subgiant in Vulpecula, about 1,217 light-years from Earth.
Blue giant in Aquila, about 438 light-years from Earth.
Main-sequence star in Orion, about 1,136 light-years from Earth.
Subgiant in Andromeda, about 124 light-years from Earth.
Star in Taurus, about 1,133 light-years from Earth.
Subgiant in Pegasus, about 321 light-years from Earth.
Main-sequence star in Ursa Major, about 175 light-years from Earth.
Red giant in Hercules, about 397 light-years from Earth.
Subgiant in Virgo, about 189 light-years from Earth.
Subgiant in Chamaeleon, about 310 light-years from Earth.
Main-sequence star in Perseus, about 243 light-years from Earth.
Red giant in Eridanus, about 196 light-years from Earth.
Main-sequence star in Auriga, about 277 light-years from Earth.
Subgiant in Pictor, about 144 light-years from Earth.
Main-sequence star in Lepus, about 460 light-years from Earth.
Red giant in Lynx, about 723 light-years from Earth.
Star in Canis Major, about 706 light-years from Earth.
Main-sequence star in Canis Major, about 269 light-years from Earth.
Red giant in Carina, about 202 light-years from Earth.
Red giant in Carina, about 790 light-years from Earth.
Red giant in Chamaeleon, about 349 light-years from Earth.
Main-sequence star in Ursa Major, about 91.3 light-years from Earth.
Red giant in Centaurus, about 353 light-years from Earth.
Red giant in Hydra, about 412 light-years from Earth.
Red giant in Centaurus, about 662 light-years from Earth.
Red giant in Centaurus, about 498 light-years from Earth.
Main-sequence star in Lupus, about 428 light-years from Earth.
Red giant in Boötes, about 515 light-years from Earth.
Blue supergiant in Scorpius, about 1,359 light-years from Earth.
Blue supergiant in Scorpius, about 2,589 light-years from Earth.
Main-sequence star in Corona Australis, about 336 light-years from Earth.
Star in Lyra, about 267 light-years from Earth.
Red giant in Sagittarius, about 234 light-years from Earth.
Main-sequence star in Sagittarius, about 99.7 light-years from Earth.
Main-sequence star in Cygnus, about 1,109 light-years from Earth.
Main-sequence star in Mensa, about 285 light-years from Earth.
Main-sequence star in Taurus, about 425 light-years from Earth.
Star in Taurus, about 1,782 light-years from Earth.
Star in Coma Berenices, about 201 light-years from Earth.
Main-sequence star in Ursa Major, about 152 light-years from Earth.
Star in Hydra, about 482 light-years from Earth.
Main-sequence star in Coma Berenices, about 270 light-years from Earth.
Red giant in Lynx, about 841 light-years from Earth.
Star in Gemini, about 323 light-years from Earth.
Main-sequence star in Libra, about 115 light-years from Earth.
Red giant in Mensa, about 668 light-years from Earth.
Blue giant in Perseus, about 605 light-years from Earth.
Star in Cepheus, about 307 light-years from Earth.
Red giant in Camelopardalis, about 499 light-years from Earth.
Red giant in Cetus, about 559 light-years from Earth.
Subgiant in Vela, about 1,264 light-years from Earth.
Red giant in Ursa Major, about 826 light-years from Earth.
Main-sequence star in Draco, about 319 light-years from Earth.
Main-sequence star in Centaurus, about 409 light-years from Earth.
Red giant in Hydra, about 440 light-years from Earth.
Red giant in Boötes, about 210 light-years from Earth.
Red dwarf in Ara, about 28.7 light-years from Earth.
Blue giant in Corona Australis, about 1,165 light-years from Earth.
Red supergiant in Scutum, about 2,886 light-years from Earth.
Subgiant in Lyra, about 358 light-years from Earth.
Red giant in Microscopium, about 237 light-years from Earth.
Red giant in Cygnus, about 601 light-years from Earth.
Red giant in Pavo, about 412 light-years from Earth.
Red giant in Cepheus, about 501 light-years from Earth.
Yellow dwarf in Perseus, about 510 light-years from Earth.
Yellow dwarf in Pavo, about 57.4 light-years from Earth.
Star in Grus, about 285 light-years from Earth.
Main-sequence star in Octans, about 194 light-years from Earth.
Red giant in Libra, about 549 light-years from Earth.
Main-sequence star in Aquarius, about 154 light-years from Earth.
Main-sequence star in Ursa Minor, about 618 light-years from Earth.
Red giant in Aquarius, about 388 light-years from Earth.
Red giant in Scorpius, about 948 light-years from Earth.
Main-sequence star in Eridanus, about 586 light-years from Earth.
Main-sequence star in Puppis, about 93.3 light-years from Earth.
Subgiant in Lepus, about 160 light-years from Earth.
Main-sequence star in Canis Major, about 1,102 light-years from Earth.
Main-sequence star in Puppis, about 678 light-years from Earth.
Star in Ursa Major, about 317 light-years from Earth.
Red giant in Draco, about 453 light-years from Earth.
Main-sequence star in Boötes, about 299 light-years from Earth.
Subgiant in Hercules, about 86.0 light-years from Earth.
Red giant in Scorpius, about 288 light-years from Earth.
Main-sequence star in Microscopium, about 325 light-years from Earth.
Red giant in Cygnus, about 1,007 light-years from Earth.
Red giant in Fornax, about 459 light-years from Earth.
Main-sequence star in Crater, about 87.2 light-years from Earth.
Subgiant in Aries, about 872 light-years from Earth.
Red giant in Sagittarius, about 453 light-years from Earth.
Yellow dwarf in Scorpius, about 45.3 light-years from Earth.
Star in Pisces, about 317 light-years from Earth.
Main-sequence star in Leo Minor, about 261 light-years from Earth.
Blue giant in Hydra, about 677 light-years from Earth.
Red giant in Sagittarius, about 2,064 light-years from Earth.
Star in Coma Berenices, about 273 light-years from Earth.
Main-sequence star in Perseus, about 731 light-years from Earth.
Star in Leo, about 287 light-years from Earth.
Yellow dwarf in Eridanus, about 43.3 light-years from Earth.
Red giant in Aquarius, about 546 light-years from Earth.
Main-sequence star in Pegasus, about 233 light-years from Earth.
Main-sequence star in Perseus, about 867 light-years from Earth.
Star in Lepus, about 268 light-years from Earth.
Star in Cetus, about 304 light-years from Earth.
Main-sequence star in Lepus, about 246 light-years from Earth.
Red giant in Monoceros, about 268 light-years from Earth.
Main-sequence star in Vela, about 500 light-years from Earth.
Red giant in Antlia, about 790 light-years from Earth.
Red giant in Sculptor, about 275 light-years from Earth.
Star in Crux, about 1,400 light-years from Earth.
Red giant in Phoenix, about 635 light-years from Earth.
Red giant in Hercules, about 207 light-years from Earth.
Main-sequence star in Sagittarius, about 480 light-years from Earth.
Main-sequence star in Sagittarius, about 160 light-years from Earth.
Subgiant in Cepheus, about 691 light-years from Earth.
Star in Octans, about 126 light-years from Earth.
Star in Vulpecula, about 332 light-years from Earth.
Main-sequence star in Taurus, about 1,496 light-years from Earth.
Red giant in Serpens, about 280 light-years from Earth.
Blue giant in Vulpecula, about 997 light-years from Earth.
Red giant in Leo, about 187 light-years from Earth.
Subgiant in Taurus, about 270 light-years from Earth.
Main-sequence star in Eridanus, about 741 light-years from Earth.
Red giant in Aries, about 208 light-years from Earth.
Star in Virgo, about 407 light-years from Earth.
Main-sequence star in Triangulum, about 392 light-years from Earth.
Star in Eridanus, about 367 light-years from Earth.
Red giant in Orion, about 486 light-years from Earth.
Blue giant in Taurus, about 2,992 light-years from Earth.
Main-sequence star in Columba, about 243 light-years from Earth.
Subgiant in Carina, about 493 light-years from Earth.
Main-sequence star in Carina, about 103 light-years from Earth.
Red giant in Ursa Major, about 500 light-years from Earth.
Main-sequence star in Antlia, about 874 light-years from Earth.
Red giant in Centaurus, about 192 light-years from Earth.
Red giant in Ursa Minor, about 411 light-years from Earth.
Subgiant in Libra, about 229 light-years from Earth.
Main-sequence star in Scorpius, about 408 light-years from Earth.
Red giant in Apus, about 809 light-years from Earth.
Red giant in Ophiuchus, about 403 light-years from Earth.
Main-sequence star in Microscopium, about 184 light-years from Earth.
Red giant in Grus, about 433 light-years from Earth.
Main-sequence star in Tucana, about 318 light-years from Earth.
Main-sequence star in Pisces, about 434 light-years from Earth.
Subgiant in Sculptor, about 232 light-years from Earth.
Red giant in Octans, about 486 light-years from Earth.
Star in Triangulum Australe, about 342 light-years from Earth.
Star in Delphinus, about 246 light-years from Earth.
Main-sequence star in Canes Venatici, about 120 light-years from Earth.
Main-sequence star in Draco, about 75.8 light-years from Earth.
Main-sequence star in Pisces, about 24.3 light-years from Earth.
Main-sequence star in Draco, about 533 light-years from Earth.
Main-sequence star in Taurus, about 372 light-years from Earth.
Subgiant in Boötes, about 160 light-years from Earth.
Main-sequence star in Eridanus, about 25.5 light-years from Earth.
Star in Camelopardalis, about 317 light-years from Earth.
Main-sequence star in Cetus, about 23.4 light-years from Earth.
Main-sequence star in Eridanus, about 26.6 light-years from Earth.
Yellow dwarf in Draco, about 75.2 light-years from Earth.
Main-sequence star in Cancer, about 457 light-years from Earth.
Yellow dwarf in Cancer, about 40.3 light-years from Earth.
Yellow dwarf in Lyra, about 455 light-years from Earth.
Main-sequence star in Sagittarius, about 89.8 light-years from Earth.
Red giant in Hercules, about 2,104 light-years from Earth.
Star in Monoceros, about 94.5 light-years from Earth.
Main-sequence star in Cancer, about 587 light-years from Earth.
Yellow dwarf in Ursa Major, about 29.6 light-years from Earth.
Red giant in Camelopardalis, about 393 light-years from Earth.
Yellow dwarf in Aquila, about 214 light-years from Earth.
Main-sequence star in Pisces, about 307 light-years from Earth.
Star in Leo, about 399 light-years from Earth.
Red dwarf in Cetus, about 299 light-years from Earth.
Yellow dwarf in Boötes, about 118 light-years from Earth.
Red giant in Corona Borealis, about 409 light-years from Earth.
Yellow dwarf in Ara, about 179 light-years from Earth.
Wolf-Rayet star in Mensa, about 125 light-years from Earth.
Red dwarf in Microscopium, about 12.9 light-years from Earth.
Main-sequence star in Ursa Minor, about 522 light-years from Earth.
Red giant in Ophiuchus, about 193 light-years from Earth.
Main-sequence star in Crux, about 124 light-years from Earth.
Main-sequence star in Centaurus, about 319 light-years from Earth.
Main-sequence star in Pisces, about 145 light-years from Earth.
Main-sequence star in Reticulum, about 111 light-years from Earth.
Yellow dwarf in Centaurus, about 124 light-years from Earth.
Yellow dwarf in Andromeda, about 189 light-years from Earth.
Red dwarf in Piscis Austrinus, about 10.7 light-years from Earth.
Star in Carina, about 295 light-years from Earth.
Subgiant in Scorpius, about 162 light-years from Earth.
Yellow dwarf in Grus, about 150 light-years from Earth.
Yellow dwarf in Centaurus, about 129 light-years from Earth.
Red dwarf in Ursa Major, about 8.3 light-years from Earth.
Red giant in Sagittarius, about 361 light-years from Earth.
Subgiant in Aquarius, about 428 light-years from Earth.
Yellow dwarf in Leo Minor, about 409 light-years from Earth.
Subgiant in Phoenix, about 135 light-years from Earth.
Yellow dwarf in Sculptor, about 106 light-years from Earth.
Main-sequence star in Boötes, about 359 light-years from Earth.
Subgiant in Eridanus, about 441 light-years from Earth.
Main-sequence star in Tucana, about 180 light-years from Earth.
Yellow dwarf in Sagittarius, about 189 light-years from Earth.
Red giant in Ursa Major, about 412 light-years from Earth.
Yellow dwarf in Boötes, about 320 light-years from Earth.
Yellow dwarf in Auriga, about 159 light-years from Earth.
Yellow dwarf in Ophiuchus, about 202 light-years from Earth.
Red giant in Eridanus, about 385 light-years from Earth.
Yellow dwarf in Serpens, about 139 light-years from Earth.
Yellow dwarf in Serpens, about 414 light-years from Earth.
Yellow dwarf in Lynx, about 247 light-years from Earth.
Red giant in Virgo, about 103 light-years from Earth.
Red giant in Crater, about 438 light-years from Earth.
Main-sequence star in Ursa Major, about 289 light-years from Earth.
Subgiant in Puppis, about 279 light-years from Earth.
Subgiant in Tucana, about 115 light-years from Earth.
Main-sequence star in Virgo, about 96.7 light-years from Earth.
Red dwarf in Andromeda, about 11.7 light-years from Earth.
Main-sequence star in Monoceros, about 112 light-years from Earth.
Yellow dwarf in Auriga, about 144 light-years from Earth.
Subgiant in Carina, about 108 light-years from Earth.
Yellow dwarf in Hercules, about 259 light-years from Earth.
Yellow dwarf in Cassiopeia, about 245 light-years from Earth.
Yellow dwarf in Ursa Major, about 178 light-years from Earth.
Main-sequence star in Leo, about 515 light-years from Earth.
Yellow dwarf in Cetus, about 321 light-years from Earth.
Yellow dwarf in Cancer, about 264 light-years from Earth.
Main-sequence star in Vela, about 134 light-years from Earth.
Main-sequence star in Antlia, about 90.8 light-years from Earth.
Main-sequence star in Aquarius, about 632 light-years from Earth.
Main-sequence star in Pisces, about 519 light-years from Earth.
Main-sequence star in Taurus, about 740 light-years from Earth.
Main-sequence star in Ophiuchus, about 605 light-years from Earth.
Main-sequence star in Leo, about 162 light-years from Earth.
Main-sequence star in Vela, about 106 light-years from Earth.
Main-sequence star in Piscis Austrinus, about 352 light-years from Earth.
Main-sequence star in Pisces, about 93.1 light-years from Earth.
Main-sequence star in Apus, about 128 light-years from Earth.
Main-sequence star in Hercules, about 373 light-years from Earth.
Main-sequence star in Sextans, about 311 light-years from Earth.
Yellow dwarf in Draco, about 215 light-years from Earth.
Blue supergiant in Cygnus, about 1,941 light-years from Earth.
Main-sequence star in Monoceros, about 1,437 light-years from Earth.
Red dwarf in Pictor, about 12.8 light-years from Earth.
Main-sequence star in Draco, about 11.6 light-years from Earth.
Main-sequence star in Sagitta, about 386 light-years from Earth.
Subgiant in Canis Major, about 184 light-years from Earth.
Main-sequence star in Leo, about 163 light-years from Earth.
Main-sequence star in Chamaeleon, about 113 light-years from Earth.
Red dwarf in Ophiuchus, about 6.0 light-years from Earth.
Red dwarf in Cepheus, about 13.1 light-years from Earth.
Main-sequence star in Cetus, about 116 light-years from Earth.
Main-sequence star in Sagittarius, about 134 light-years from Earth.
Main-sequence star in Draco, about 11.3 light-years from Earth.
Main-sequence star in Pegasus, about 158 light-years from Earth.
Yellow dwarf in Sculptor, about 251 light-years from Earth.
Red dwarf in Canis Minor, about 12.4 light-years from Earth.
Subgiant in Fornax, about 151 light-years from Earth.
Red dwarf in Ophiuchus, about 14.0 light-years from Earth.
Red dwarf in Vela, about 32.2 light-years from Earth.
Red dwarf in Eridanus, about 75.1 light-years from Earth.
Red dwarf in Sagittarius, about 9.7 light-years from Earth.
Red dwarf in Leo, about 33.1 light-years from Earth.
Red dwarf in Tucana, about 86.0 light-years from Earth.
Red dwarf in Virgo, about 10.9 light-years from Earth.
Red dwarf in Monoceros, about 13.5 light-years from Earth.
Star in Scorpius, about 47.0 light-years from Earth.
Red dwarf in Virgo, about 27.3 light-years from Earth.
Red dwarf in Andromeda, about 10.3 light-years from Earth.
Star in Cancer, about 75.8 light-years from Earth.
Red dwarf in Hydra, about 68.3 light-years from Earth.
Yellow dwarf in Pisces, about 13.9 light-years from Earth.
Red dwarf in Aquarius, about 11.1 light-years from Earth.
Red dwarf in Hydra, about 80.0 light-years from Earth.
Red dwarf in Leo, about 7.8 light-years from Earth.
White dwarf in Volans, about 75.8 light-years from Earth.
Star in Ophiuchus, about 42.1 light-years from Earth.
S-type asteroid (Koronis family) — (243) Ida.
Venus & Mercury flyby · NASA · launched 1973.
Mars orbiter & lander · NASA · launched 1975.
Comet orbiter & lander · ESA · launched 2004.
Vesta & Ceres orbiter · NASA · launched 2007.
Solar observatory · ESA / NASA · launched 2020.
Mars rover mission (Perseverance) · NASA · launched 2020.
First lunar impact · USSR · launched 1959.
Mars Exploration Rover (MER-B) · NASA · launched 2003.
Mars Exploration Rover (MER-A) · NASA · launched 2003.
Shield volcano — tallest in the Solar System on Mars.
Lunar mare (Apollo 11 landing site) on The Moon.
Persistent anticyclonic storm on Jupiter.
Cluster with nebulosity in Orion, magnitude 2.5.
Open cluster in Scorpius, magnitude 2.6.
Cluster with nebulosity in Monoceros, magnitude 3.9.
Reflection nebula in Scorpius, magnitude 3.9.
Open cluster in Monoceros, magnitude 3.9.
Globular cluster in Tucana, magnitude 4.09.
Open cluster in Canis Major, magnitude 4.1.
Open cluster in Ophiuchus, magnitude 4.2.
Cluster with nebulosity in Orion, magnitude 4.2.
Cluster with nebulosity in Centaurus, magnitude 4.5.
Cluster with nebulosity in Sagittarius, magnitude 4.6.
Open cluster in Ophiuchus, magnitude 4.6.
Cluster with nebulosity in Monoceros, magnitude 4.8.
Open cluster in Triangulum Australe, magnitude 5.1.
Globular cluster in Ara, magnitude 5.17.
Open cluster in Centaurus, magnitude 5.3.
Open cluster in Centaurus, magnitude 5.33.
Open cluster in Scorpius, magnitude 5.4.
Open cluster in Centaurus, magnitude 5.5.
Open cluster in Scorpius, magnitude 5.5.
Open cluster in Centaurus, magnitude 5.6.
Open cluster in Andromeda, magnitude 5.6.
Globular cluster in Carina, magnitude 5.69.
Open cluster in Andromeda, magnitude 5.7.
Reflection nebula in Orion, magnitude 5.8.
Open cluster in Scorpius, magnitude 5.8.
Open cluster in Centaurus, magnitude 5.9.
Cluster with nebulosity in Ara, magnitude 5.9.
Reflection nebula in Scutum, magnitude 6.1.
Globular cluster in Pavo, magnitude 6.28.
Open cluster in Centaurus, magnitude 6.3.
Open cluster in Vulpecula, magnitude 6.3.
Open cluster in Scorpius, magnitude 6.4.
Open cluster in Cassiopeia, magnitude 6.4.
Cluster with nebulosity in Cassiopeia, magnitude 6.5.
Open cluster in Cassiopeia, magnitude 6.5.
Open cluster in Canis Major, magnitude 6.5.
Globular cluster in Tucana, magnitude 6.58.
Open cluster in Cassiopeia, magnitude 6.7.
Open cluster in Monoceros, magnitude 6.7.
Cluster with nebulosity in Carina, magnitude 6.7.
Cluster with nebulosity in Orion, magnitude 6.8.
Open cluster in Camelopardalis, magnitude 6.9.
Globular cluster in Lupus, magnitude 6.92.
Supernova remnant in Cygnus, magnitude 7.
Open cluster in Cassiopeia, magnitude 7.
Reflection nebula in Gemini, magnitude 7.03.
Open cluster in Monoceros, magnitude 7.1.
Open cluster in Cassiopeia, magnitude 7.1.
Cluster with nebulosity in Vulpecula, magnitude 7.1.
Open cluster in Canis Major, magnitude 7.2.
Cluster with nebulosity in Cygnus, magnitude 7.2.
Open cluster in Monoceros, magnitude 7.2.
Open cluster in Scorpius, magnitude 7.2.
Globular cluster in Ophiuchus, magnitude 7.2.
Cluster with nebulosity in Cepheus, magnitude 7.2.
Globular cluster in Columba, magnitude 7.23.
Planetary nebula in Aquarius, magnitude 7.3.
Open cluster in Monoceros, magnitude 7.3.
Globular cluster in Corona Australis, magnitude 7.32.
Open cluster in Canis Major, magnitude 7.4.
Globular cluster in Scorpius, magnitude 7.4.
Globular cluster in Ophiuchus, magnitude 7.42.
Globular cluster in Ophiuchus, magnitude 7.43.
Open cluster in Monoceros, magnitude 7.5.
Open cluster in Sagittarius, magnitude 7.5.
Open cluster in Monoceros, magnitude 7.6.
Open cluster in Centaurus, magnitude 7.6.
Open cluster in Sagittarius, magnitude 7.6.
H II region in Monoceros, magnitude 7.7.
Planetary nebula in Hydra, magnitude 7.7.
Open cluster in Monoceros, magnitude 7.7.
Open cluster in Canis Major, magnitude 7.7.
Open cluster in Centaurus, magnitude 7.7.
Globular cluster in Musca, magnitude 7.79.
Open cluster in Canis Major, magnitude 7.9.
Open cluster in Circinus, magnitude 7.9.
Open cluster in Cassiopeia, magnitude 7.9.
Open cluster in Vulpecula, magnitude 7.9.
Cluster with nebulosity in Orion, magnitude 8.
Open cluster in Canis Major, magnitude 8.
Globular cluster in Scorpius, magnitude 8.
Open cluster in Sagittarius, magnitude 8.
Planetary nebula in Aquarius, magnitude 8.
Planetary nebula in Centaurus, magnitude 8.1.
Planetary nebula in Ophiuchus, magnitude 8.1.
Globular cluster in Sculptor, magnitude 8.13.
Globular cluster in Telescopium, magnitude 8.17.
Open cluster in Scorpius, magnitude 8.2.
Open cluster in Cassiopeia, magnitude 8.2.
Open cluster in Sagittarius, magnitude 8.2.
Globular cluster in Vela, magnitude 8.24.
Planetary nebula in Andromeda, magnitude 8.3.
Open cluster in Centaurus, magnitude 8.3.
Globular cluster in Centaurus, magnitude 8.31.
Open cluster in Monoceros, magnitude 8.4.
Open cluster in Canis Major, magnitude 8.4.
Barred spiral galaxy in Camelopardalis, magnitude 8.43.
Open cluster in Monoceros, magnitude 8.45.
Lenticular galaxy in Fornax, magnitude 8.48.
Cluster with nebulosity in Dorado, magnitude 8.5.
Open cluster in Monoceros, magnitude 8.5.
Reflection nebula in Monoceros, magnitude 8.5.
Open cluster in Scorpius, magnitude 8.5.
Open cluster in Sagittarius, magnitude 8.5.
Planetary nebula in Cygnus, magnitude 8.5.
Open cluster in Cassiopeia, magnitude 8.5.
Globular cluster in Libra, magnitude 8.52.
Barred spiral galaxy in Sculptor, magnitude 8.54.
Globular cluster in Apus, magnitude 8.56.
Open cluster in Canis Major, magnitude 8.6.
Open cluster in Sagittarius, magnitude 8.6.
Globular cluster in Horologium, magnitude 8.63.
Spiral galaxy in Sculptor, magnitude 8.66.
Globular cluster in Scutum, magnitude 8.69.
Lenticular galaxy in Eridanus, magnitude 8.7.
Open cluster in Cassiopeia, magnitude 8.8.
Open cluster in Scorpius, magnitude 8.8.
Open cluster in Vulpecula, magnitude 8.8.
Globular cluster in Lupus, magnitude 8.86.
Globular cluster in Ara, magnitude 8.86.
Globular cluster in Ara, magnitude 8.87.
Globular cluster in Puppis, magnitude 8.89.
Open cluster in Monoceros, magnitude 8.9.
Open cluster in Centaurus, magnitude 8.9.
Open cluster in Andromeda, magnitude 8.9.
Globular cluster in Dorado, magnitude 8.96.
Reflection nebula in Monoceros, magnitude 9.
Globular cluster in Ophiuchus, magnitude 9.02.
Globular cluster in Ophiuchus, magnitude 9.03.
Barred spiral galaxy in Cygnus, magnitude 9.05.
Globular cluster in Sagittarius, magnitude 9.08.
Elliptical galaxy in Sextans, magnitude 9.09.
Open cluster in Cassiopeia, magnitude 9.1.
Open cluster in Monoceros, magnitude 9.1.
Open cluster in Centaurus, magnitude 9.1.
Barred spiral galaxy in Leo, magnitude 9.11.
Planetary nebula in Vela, magnitude 9.2.
Elliptical galaxy in Cassiopeia, magnitude 9.2.
Barred spiral galaxy in Cetus, magnitude 9.21.
Barred spiral galaxy in Canes Venatici, magnitude 9.24.
Spiral galaxy in Sculptor, magnitude 9.29.
Planetary nebula in Sagittarius, magnitude 9.3.
Open cluster in Cassiopeia, magnitude 9.3.
Lenticular galaxy in Dorado, magnitude 9.31.
Elliptical galaxy in Virgo, magnitude 9.37.
Barred spiral galaxy in Coma Berenices, magnitude 9.38.
Open cluster in Cassiopeia, magnitude 9.4.
Planetary nebula in Fornax, magnitude 9.4.
Elliptical galaxy in Fornax, magnitude 9.4.
Cluster with nebulosity in Dorado, magnitude 9.4.
Open cluster in Canis Major, magnitude 9.4.
Planetary nebula in Puppis, magnitude 9.4.
Open cluster in Centaurus, magnitude 9.4.
Barred spiral galaxy in Antlia, magnitude 9.41.
Spiral galaxy in Pegasus, magnitude 9.41.
Elliptical galaxy in Virgo, magnitude 9.43.
Planetary nebula in Cygnus, magnitude 9.44.
Planetary nebula in Lepus, magnitude 9.44.
Barred spiral galaxy in Leo, magnitude 9.45.
Elliptical galaxy in Perseus, magnitude 9.47.
Globular cluster in Sagittarius, magnitude 9.47.
Globular cluster in Sagittarius, magnitude 9.48.
Barred spiral galaxy in Reticulum, magnitude 9.49.
Reflection nebula in Orion, magnitude 9.5.
Open cluster in Cassiopeia, magnitude 9.5.
Open cluster in Scorpius, magnitude 9.5.
Barred spiral galaxy in Virgo, magnitude 9.53.
Irregular galaxy in Cetus, magnitude 9.54.
Barred spiral galaxy in Fornax, magnitude 9.55.
Barred spiral galaxy in Hydra, magnitude 9.55.
Globular cluster in Lupus, magnitude 9.56.
Barred spiral galaxy in Canes Venatici, magnitude 9.58.
Supernova remnant in Dorado, magnitude 9.59.
Lenticular galaxy in Virgo, magnitude 9.59.
Planetary nebula in Eridanus, magnitude 9.6.
Globular cluster in Dorado, magnitude 9.6.
Open cluster in Monoceros, magnitude 9.6.
Elliptical galaxy in Hydra, magnitude 9.6.
Open cluster in Sagittarius, magnitude 9.6.
Planetary nebula in Gemini, magnitude 9.61.
Globular cluster in Scorpius, magnitude 9.63.
Irregular galaxy in Canes Venatici, magnitude 9.64.
Elliptical galaxy in Eridanus, magnitude 9.65.
Cluster with nebulosity in Dorado, magnitude 9.65.
Planetary nebula in Hercules, magnitude 9.65.
Lenticular galaxy in Virgo, magnitude 9.66.
Barred spiral galaxy in Camelopardalis, magnitude 9.68.
Globular cluster in Scorpius, magnitude 9.68.
Globular cluster in Sagittarius, magnitude 9.68.
Elliptical galaxy in Hydra, magnitude 9.69.
Open cluster in Centaurus, magnitude 9.7.
Globular cluster in Dorado, magnitude 9.7.
Planetary nebula in Carina, magnitude 9.7.
Globular cluster in Boötes, magnitude 9.7.
Elliptical galaxy in Draco, magnitude 9.71.
Elliptical galaxy in Cassiopeia, magnitude 9.72.
Barred spiral galaxy in Canes Venatici, magnitude 9.72.
Barred spiral galaxy in Dorado, magnitude 9.73.
Globular cluster in Dorado, magnitude 9.73.
Elliptical galaxy in Dorado, magnitude 9.75.
Globular cluster in Sagittarius, magnitude 9.75.
Globular cluster in Delphinus, magnitude 9.75.
Barred spiral galaxy in Fornax, magnitude 9.76.
Irregular galaxy in Canes Venatici, magnitude 9.77.
Barred spiral galaxy in Draco, magnitude 9.77.
Globular cluster in Aquila, magnitude 9.78.
Open cluster in Cassiopeia, magnitude 9.8.
Elliptical galaxy in Coma Berenices, magnitude 9.8.
Planetary nebula in Circinus, magnitude 9.8.
Open cluster in Circinus, magnitude 9.8.
Reflection nebula in Sagittarius, magnitude 9.8.
Barred spiral galaxy in Ursa Major, magnitude 9.84.
Globular cluster in Dorado, magnitude 9.85.
Globular cluster in Musca, magnitude 9.85.
Globular cluster in Serpens, magnitude 9.85.
Globular cluster in Hercules, magnitude 9.86.
Elliptical galaxy in Ursa Major, magnitude 9.87.
Cluster with nebulosity in Dorado, magnitude 9.88.
Spiral galaxy in Ursa Major, magnitude 9.88.
Elliptical galaxy in Centaurus, magnitude 9.88.
Lenticular galaxy in Draco, magnitude 9.89.
Globular cluster in Sagittarius, magnitude 9.9.
Spiral galaxy in Coma Berenices, magnitude 9.92.
Elliptical galaxy in Eridanus, magnitude 9.93.
Barred spiral galaxy in Virgo, magnitude 9.93.
Lenticular galaxy in Fornax, magnitude 9.94.
Barred spiral galaxy in Horologium, magnitude 9.95.
Elliptical galaxy in Leo, magnitude 9.96.
Globular cluster in Coma Berenices, magnitude 9.96.
Globular cluster in Scorpius, magnitude 9.96.
Barred spiral galaxy in Boötes, magnitude 9.97.
Reflection nebula in Taurus, magnitude 9.98.
Spiral galaxy in Leo Minor, magnitude 9.98.
Elliptical galaxy in Virgo, magnitude 9.99.
Open cluster in Monoceros, magnitude 10.
Open cluster in Sagittarius, magnitude 10.
Cluster with nebulosity in Cygnus, magnitude 10.
Spiral galaxy in Andromeda, magnitude 10.01.
Irregular galaxy in Sagittarius, magnitude 10.05.
Globular cluster in Lynx, magnitude 10.05.
Globular cluster in Apus, magnitude 10.08.
Spiral galaxy in Canes Venatici, magnitude 10.18.
Barred spiral galaxy in Corvus, magnitude 10.2.
Spiral galaxy in Cancer, magnitude 10.24.
Barred spiral galaxy in Ursa Major, magnitude 10.46.
Globular cluster in Delphinus, magnitude 10.46.
Spiral galaxy in Pegasus, magnitude 10.6.
Barred spiral galaxy in Canes Venatici, magnitude 10.71.
Spiral galaxy in Coma Berenices, magnitude 10.82.
Barred spiral galaxy in Fornax, magnitude 10.88.
Globular cluster in Hydra, magnitude 10.89.
Planetary nebula in Cetus, magnitude 10.9.
Spiral galaxy in Virgo, magnitude 10.92.
Lenticular galaxy in Virgo, magnitude 10.96.
Lenticular galaxy in Leo, magnitude 10.98.
H II region in Cassiopeia, magnitude 11.
Barred spiral galaxy in Corvus, magnitude 11.04.
Barred spiral galaxy in Pegasus, magnitude 11.09.
Planetary nebula in Delphinus, magnitude 11.1.
Planetary nebula in Sagittarius, magnitude 11.2.
Spiral galaxy in Virgo, magnitude 11.32.
Lenticular galaxy in Ursa Major, magnitude 11.35.
Planetary nebula in Ophiuchus, magnitude 11.4.
Elliptical galaxy in Coma Berenices, magnitude 11.45.
Planetary nebula in Ophiuchus, magnitude 11.5.
Planetary nebula in Aquila, magnitude 11.5.
Planetary nebula in Chamaeleon, magnitude 11.6.
Planetary nebula in Sagittarius, magnitude 11.6.
Barred spiral galaxy in Lynx, magnitude 11.71.
Reflection nebula in Monoceros, magnitude 11.85.
Barred spiral galaxy in Centaurus, magnitude 11.86.
Planetary nebula in Cepheus, magnitude 11.89.
Supernova remnant in Gemini, magnitude 12.
Lenticular galaxy in Perseus, magnitude 12.24.
Elliptical galaxy in Ursa Major, magnitude 12.48.
Barred spiral galaxy in Ursa Major, magnitude 12.77.
Spiral galaxy in Octans, magnitude 13.53.
Globular cluster in Fornax, magnitude 13.59.
Lenticular galaxy in Virgo, magnitude 13.82.
Open cluster in Vulpecula, magnitude 14.1.
Lenticular galaxy in Ursa Major, magnitude 14.7.
Lenticular galaxy in Ursa Minor, magnitude 15.
The German Aerospace Center is the national centre for aerospace, energy, and transportation research of Germany, and the country's space agency.
The Centre National d'Études Spatiales is the French government space agency, a major contributor to ESA programmes and operator of the Guiana Space Centre.
The Agenzia Spaziale Italiana is Italy's national space agency, a significant contributor to ESA and to international planetary science missions.
The UK Space Agency is the executive agency responsible for the United Kingdom's civil space programme and its participation in ESA.
KARI (Korea Aerospace Research Institute)
The Korea Aerospace Research Institute is South Korea's aerospace research organisation, developer of the Nuri (KSLV-II) launch vehicle and the Danuri lunar orbiter.
The Agência Espacial Brasileira is the civilian agency responsible for Brazil's space programme.
The UAE Space Agency oversees the United Arab Emirates' space sector, including the Emirates Mars Mission (Hope) orbiter.
Blue Origin is an American commercial aerospace company developing reusable launch vehicles, including the suborbital New Shepard and the orbital New Glenn.
Rocket Lab is a commercial launch and space-systems company best known for the small-lift Electron rocket.
Project Mercury was the first United States human spaceflight programme, putting the first American astronauts into orbit.
Project Gemini developed the rendezvous, docking, and spacewalk techniques needed for the Apollo lunar missions.
The Apollo program landed the first humans on the Moon between 1969 and 1972, carrying out six crewed lunar landings.
Skylab was the first United States space station, crewed by three missions in 1973–1974.
The Space Shuttle was NASA's reusable crewed launch system, flying 135 missions between 1981 and 2011.
Artemis is NASA's programme to return humans to the Moon and establish a sustainable lunar presence, in partnership with international and commercial partners.
The Mariner program conducted the first successful flybys and orbits of Mercury, Venus, and Mars.
The Pioneer program included the first spacecraft to fly through the asteroid belt and past Jupiter and Saturn.
The Voyager program sent two probes on a grand tour of the outer planets; both have since entered interstellar space.
The Viking program placed two orbiter–lander pairs at Mars, returning the first images from the Martian surface and searching for life.
NASA's long-running programme of orbiters, landers, and rovers systematically exploring Mars.
The Soviet Luna program achieved many lunar firsts, including the first impact, first far-side images, and first robotic sample return.
The Lunokhod program operated the first robotic rovers on the Moon.
The Soviet Venera program returned the first data and images from the surface of Venus.
The Vostok program carried out the first human spaceflight, by Yuri Gagarin in 1961.
The Voskhod program achieved the first multi-crew flight and the first spacewalk.
The Soyuz program has provided crewed access to orbit for over five decades and remains a mainstay of ISS crew transport.
China's Chang'e program of lunar orbiters, landers, rovers, and sample-return missions, named for the lunar goddess.
ISRO's lunar exploration program; Chandrayaan-3 achieved the first soft landing near the lunar south pole in 2023.
JAXA's asteroid sample-return program; Hayabusa and Hayabusa2 returned samples from asteroids Itokawa and Ryugu.
NASA's series of medium-class planetary missions, including New Horizons, Juno, and OSIRIS-REx.
NASA's line of lower-cost, focused planetary science missions, including MESSENGER, Dawn, InSight, Lucy, and Psyche.
A planned NASA–ESA campaign to return the rock cores cached by the Perseverance rover to Earth.
A NASA medium-lift launch vehicle used for early Apollo Earth-orbit tests, the Skylab crews, and the Apollo–Soyuz Test Project.
A heavy-lift expendable rocket by United Launch Alliance, retired in 2024, used for national-security and high-energy science launches such as Parker Solar Probe.
United Launch Alliance's successor to the Atlas V and Delta IV families.
A heavy-lift, partially reusable rocket developed by Blue Origin.
A small-lift orbital rocket by Rocket Lab for dedicated small-satellite launches.
Europe's successor to Ariane 5, designed for greater flexibility and lower cost.
A Russian heavy-lift rocket used to launch interplanetary probes, large satellites, and space-station modules.
A Chinese launch vehicle widely used for geostationary satellites and several Chang'e lunar missions.
A Japanese launch vehicle that flew JAXA science missions including Hayabusa2 and the Akatsuki Venus orbiter.
GSLV (Geosynchronous Satellite Launch Vehicle)
ISRO's launcher for heavier payloads to geostationary transfer orbit, used for Chandrayaan-2.
NASA's primary launch centre, home of Launch Complex 39 from which the Apollo Saturn V and the Space Shuttle flew, and now Artemis and commercial crew missions.
The United States' historic eastern launch range adjacent to Kennedy Space Center, used since 1950 for crewed and robotic missions.
A United States launch site on the Pacific coast used primarily for polar and Sun-synchronous orbits.
The world's first and largest spaceport, from which Sputnik 1 and Yuri Gagarin were launched and Soyuz crews still depart for the ISS.
Europe's spaceport near the equator, operated by CNES, ESA, and Arianespace, from which Ariane rockets and the James Webb Space Telescope launched.
JAXA's largest launch complex, used for the H-IIA, H-IIB, and H3 rockets.
ISRO's primary orbital launch site, from which the PSLV and GSLV rockets, Chandrayaan, and Mangalyaan have flown.
China's oldest launch site and the home of its crewed Shenzhou spaceflights.
A Chinese launch site used mainly for polar and Sun-synchronous orbit missions.
A Chinese launch site used for geostationary satellites and several Chang'e lunar missions.
China's coastal, low-latitude launch site for the heavy-lift Long March 5 and crewed and lunar missions.
SpaceX's development and launch site in South Texas for the Starship super heavy-lift system.
A NASA range on the Virginia coast used for suborbital research and small orbital launches.
A northern Russian launch site used heavily for polar-orbit and military launches.
Brazil's equatorial launch site, operated by the Brazilian Space Agency and Air Force.
Sputnik 1 was the first artificial satellite, launched by the Soviet Union and opening the Space Age.
Vostok 1 carried Yuri Gagarin on the first human spaceflight, a single orbit of the Earth.
Freedom 7 carried Alan Shepard on the first United States human spaceflight, a suborbital hop.
Friendship 7 carried John Glenn on the first United States orbital spaceflight, three orbits of the Earth.
Vostok 6 carried Valentina Tereshkova, the first woman to fly in space.
Voskhod 2 was the mission on which Alexei Leonov performed the first spacewalk.
Apollo 8 was the first crewed mission to leave Earth orbit and orbit the Moon, returning the famous 'Earthrise' photograph.
Apollo 13's planned lunar landing was aborted after an oxygen-tank explosion; the crew returned safely in a celebrated rescue.
Apollo 17 was the final crewed Apollo lunar landing, carrying the first scientist-astronaut to the Moon.
Artemis I was the uncrewed first flight of the SLS rocket and Orion spacecraft on a path around the Moon.
Luna 9 achieved the first soft landing on the Moon and returned the first images from the lunar surface.
Luna 17 delivered Lunokhod 1, the first robotic rover to operate on the surface of another world.
Venera 7 made the first soft landing on another planet and the first transmission from the surface of Venus.
BepiColombo is a joint ESA–JAXA mission of two orbiters travelling to Mercury, arriving in the mid-2020s.
Venus Express was ESA's first mission to Venus, studying its dense atmosphere from orbit.
Viking 2 was the second Viking orbiter–lander pair, landing in Utopia Planitia on Mars.
Mars Pathfinder landed using airbags and deployed Sojourner, the first wheeled rover on Mars.
Spirit was one of NASA's twin Mars Exploration Rovers, exploring Gusev crater.
Opportunity was the twin of Spirit, exploring Meridiani Planum for nearly 15 years.
MAVEN studies how Mars lost much of its atmosphere to space over billions of years.
Mangalyaan made India the first nation to reach Mars orbit on its first attempt.
InSight was a stationary lander that studied the deep interior of Mars with a seismometer.
Tianwen-1 was China's first independent Mars mission, combining an orbiter, lander, and the Zhurong rover.
Pioneer 10 was the first spacecraft to traverse the asteroid belt and fly past Jupiter.
Pioneer 11 flew past Jupiter and became the first spacecraft to encounter Saturn.
JUICE is ESA's mission to study Jupiter's icy moons Ganymede, Callisto, and Europa.
Europa Clipper will make dozens of flybys of Jupiter's moon Europa to assess its habitability.
Hayabusa was the first mission to return a sample from an asteroid, the near-Earth asteroid Itokawa.
Hayabusa2 collected surface and subsurface samples of the asteroid Ryugu and returned them to Earth.
OSIRIS-REx collected a sample from the near-Earth asteroid Bennu and returned it to Earth in 2023.
DART was the first planetary-defence test, deliberately impacting the asteroid moonlet Dimorphos to change its orbit.
Lucy is touring a record number of asteroids, including several of Jupiter's Trojan asteroids.
Psyche is travelling to the metal-rich asteroid 16 Psyche to study a possible exposed planetary core.
Chandrayaan-1 was India's first lunar mission, whose instruments helped confirm water on the Moon.
Chandrayaan-3 achieved the first soft landing near the Moon's south pole, making India the fourth nation to land on the Moon.
Chang'e 4 achieved the first soft landing on the far side of the Moon.
Chang'e 5 returned the first lunar samples since the 1970s.
Danuri, the Korea Pathfinder Lunar Orbiter, is South Korea's first mission to the Moon.
The Emirates Mars Mission, or Hope, is the United Arab Emirates' Mars orbiter, the Arab world's first interplanetary mission.
The microwave-oven-sized rover of Mars Pathfinder, the first wheeled vehicle to operate on Mars.
The Rosetta mission's lander, the first spacecraft to make a soft landing on a comet, in 2014.
The first robotic rover to operate on the surface of another world, delivered to the Moon by Luna 17.
China's first Mars rover, delivered by the Tianwen-1 mission to Utopia Planitia.
Yuri Gagarin — the first human to journey into outer space and orbit the Earth, aboard Vostok 1.
Alan Shepard — the first American in space and later commander of Apollo 14, who walked on the Moon.
John Glenn — the first American to orbit the Earth, aboard Friendship 7.
Valentina Tereshkova — the first woman to fly in space, aboard Vostok 6.
Alexei Leonov — the first person to perform a spacewalk, during Voskhod 2.
Frank Borman — commander of Apollo 8, the first crewed mission to orbit the Moon.
Jim Lovell — commander of Apollo 13 and a crew member of Apollo 8.
William Anders — the Apollo 8 astronaut who photographed the iconic 'Earthrise'.
Neil Armstrong — the first person to walk on the Moon, as commander of Apollo 11.
Buzz Aldrin — the second person to walk on the Moon, the lunar module pilot of Apollo 11.
Michael Collins — the Apollo 11 command module pilot who orbited the Moon during the first landing.
Eugene Cernan — the commander of Apollo 17 and the last person to walk on the Moon.
Harrison Schmitt — a geologist on Apollo 17, the first scientist to walk on the Moon.
Sally Ride — the first American woman in space.
Mae Jemison — the first Black woman to travel into space, aboard the Space Shuttle.
Rakesh Sharma — the first Indian citizen to travel to space, aboard Soyuz T-11.
Yang Liwei — the first Chinese astronaut (taikonaut) in space, aboard Shenzhou 5.
Chris Hadfield — a Canadian astronaut and ISS commander known for sharing life in orbit with the public.
Peggy Whitson — the first woman to command the ISS and holder of the US record for cumulative time in space.
A mast-mounted, zoomable stereo camera system on the Perseverance rover.
An instrument on Perseverance that vaporises rock at a distance with a laser to analyse its composition.
An experiment on Perseverance that demonstrated making oxygen from the Martian atmosphere.
The laser spectrometer on Curiosity that analyses Martian rock chemistry from a distance.
Curiosity's onboard chemistry laboratory, which detected organic molecules and methane on Mars.
The primary near-infrared imager of the James Webb Space Telescope.
The Mid-Infrared Instrument on JWST, sensitive to cool, dusty, and distant objects.
The near-infrared spectrograph on JWST, used to probe exoplanet atmospheres and early galaxies.
A versatile camera installed on the Hubble Space Telescope during its final servicing mission.
The instrument on Juno that peers beneath Jupiter's cloud tops to map its deep atmosphere.
Mir was the Soviet and later Russian modular space station, the first long-term research station in orbit and a proving ground for the international cooperation that followed.
Skylab was the first United States space station, crewed by three missions in 1973–1974, which carried out solar astronomy and studies of human adaptation to spaceflight.
Salyut 1 was the world's first space station, launched by the Soviet Union in 1971.
Salyut 6 was a second-generation Soviet space station whose two docking ports enabled long-duration crews and resupply by Progress cargo craft.
Salyut 7 was the last of the Salyut space stations and a bridge to the modular Mir, notable for a daring 1985 mission to revive the powered-down station.
Almaz was a series of Soviet military space stations flown under Salyut designations (Salyut 2, 3, and 5), developed for reconnaissance.
Tiangong is China's modular space station, assembled from the Tianhe core module and the Wentian and Mengtian laboratory modules and continuously crewed since 2022.
Genesis I was an uncrewed experimental inflatable habitat launched by Bigelow Aerospace to test expandable space-structure technology.
Genesis II was a second uncrewed inflatable habitat demonstrator from Bigelow Aerospace, building on Genesis I.
Axiom Station is a planned commercial space station; its first modules are intended to attach to the ISS before later flying free. It is not yet operational.
The Lunar Gateway is a planned small space station in orbit around the Moon, to be built by NASA and international partners as part of the Artemis program. It is not yet operational.
Zarya, the Functional Cargo Block, was the first module of the International Space Station, providing early power and propulsion. It was built in Russia but funded by and belongs to the United States.
Unity (Node 1) was the first US-built ISS module, a connecting node linking the Russian and US segments of the station.
Zvezda, the Service Module, provided the early ISS with life support, crew quarters, and propulsion, and was the structural heart of the Russian segment.
Destiny is the primary research laboratory of the US segment of the ISS, used for microgravity science across many disciplines.
Quest is the ISS joint airlock, from which US spacewalks (EVAs) are staged.
Pirs was a Russian docking compartment and airlock; it was undocked and deorbited in 2021 to make room for the Nauka module.
Harmony (Node 2) is a connecting module that provides docking ports for visiting crewed spacecraft and links the US, European, and Japanese laboratories.
Columbus is ESA's research laboratory on the ISS, hosting European and international microgravity experiments.
Kibo, meaning 'hope', is JAXA's laboratory complex on the ISS — the station's largest module, with an external platform for experiments exposed to space.
Tranquility (Node 3) houses much of the ISS life-support equipment and exercise machines, and connects to the Cupola.
The Cupola is a seven-windowed observation module built by ESA, used for Earth observation and to control the station's robotic arm.
Rassvet is a small Russian module providing docking and storage on the ISS.
Leonardo, originally a reusable cargo carrier built by the Italian Space Agency, was permanently attached to the ISS as a storage module.
Poisk is a Russian module providing a docking port and an airlock for Russian-segment spacewalks.
BEAM is an expandable (inflatable) module attached to the ISS to demonstrate expandable habitat technology in orbit, building on Bigelow's Genesis demonstrators.
Nauka is a Russian multipurpose laboratory module that replaced the Pirs compartment, adding research space, crew quarters, and an airlock.
Prichal is a spherical Russian nodal module with multiple docking ports, attached to Nauka.
Vostok was the first crewed spacecraft, carrying a single cosmonaut; Vostok 1 made Yuri Gagarin the first human in space.
Voskhod was a modified Vostok that carried multi-person crews and supported the first spacewalk.
The Soyuz spacecraft has carried crews to orbit for over five decades and remains a primary means of reaching the ISS.
The Apollo Command and Service Module carried three astronauts to lunar orbit and back; the Command Module was the only part to return to Earth.
The Apollo Lunar Module was the two-stage craft that carried two astronauts from lunar orbit to the surface of the Moon and back.
The Space Shuttle Orbiter was a reusable crewed spaceplane that flew 135 missions, deploying satellites and assembling much of the ISS.
Crew Dragon is SpaceX's crewed spacecraft, which returned human launch capability to the United States in 2020 under NASA's Commercial Crew Program.
Boeing's Starliner is a crewed capsule developed under NASA's Commercial Crew Program; it flew its Crew Flight Test to the ISS in 2024.
Orion is NASA's deep-space crew vehicle for the Artemis program, with a European Service Module built by ESA; it flew uncrewed around the Moon on Artemis I.
Shenzhou is China's crewed spacecraft, derived from Soyuz heritage, which carries taikonauts to the Tiangong space station.
Dream Chaser is a reusable lifting-body spaceplane by Sierra Space; first designed for crew under the Commercial Crew competition, its initial Tenacity vehicle is configured to deliver cargo to the ISS.
Cargo Dragon is the uncrewed resupply variant of SpaceX's Dragon, delivering cargo to the ISS and returning experiments to Earth.
Progress is the long-serving Russian uncrewed cargo spacecraft, derived from Soyuz, that resupplies space stations and reboosts their orbits.
Cygnus is an uncrewed cargo spacecraft by Northrop Grumman that delivers supplies to the ISS under NASA's commercial resupply contracts.
The H-II Transfer Vehicle (Kounotori) was JAXA's uncrewed cargo craft that resupplied the ISS from 2009 to 2020.
ESA's Automated Transfer Vehicle was a large uncrewed cargo craft that resupplied and reboosted the ISS from 2008 to 2014.
The Soviet Salyut program operated the first generation of space stations, including the world's first station, Salyut 1.
The Mir program operated the first modular long-duration space station and pioneered international cooperation in orbit.
The ISS program is the international partnership that builds and operates the continuously crewed International Space Station.
Shenzhou is China's crewed spaceflight program, which first sent a Chinese astronaut to orbit in 2003 and now crews the Tiangong station.
NASA's Commercial Crew Program partners with industry to provide crewed transport to the ISS aboard SpaceX's Crew Dragon and Boeing's Starliner.
China's space-station program, which flew the Tiangong-1 and Tiangong-2 laboratories before assembling the modular Tiangong station.
Sergei Krikalev — a veteran cosmonaut who flew on Mir, the Space Shuttle, and the ISS, and was a member of the first ISS expedition crew.
Gennady Padalka — a cosmonaut who commanded several ISS expeditions and holds the record for the most cumulative time spent in space.
Wang Yaping — a taikonaut who became the first Chinese woman to perform a spacewalk, during a Shenzhou mission to the Tiangong station.
Helen Sharman — the first British astronaut in space, who visited the Mir station in 1991 via the privately funded Project Juno mission.
Samantha Cristoforetti — an ESA astronaut, the first Italian woman in space, who later commanded the International Space Station.
ISS Expedition 1 was the first resident crew of the International Space Station, beginning continuous human presence in orbit. The crew was William Shepherd, Yuri Gidzenko, and Sergei Krikalev.
ISS Expedition 2 was the second resident crew, comprising Yury Usachev, Susan Helms, and James Voss.
ISS Expedition 3 was crewed by Frank Culbertson, Vladimir Dezhurov, and Mikhail Tyurin.
ISS Expedition 4 was crewed by Yury Onufrienko, Carl Walz, and Daniel Bursch.
ISS Expedition 5 was crewed by Valery Korzun, Peggy Whitson, and Sergei Treschev.
ISS Expedition 6 was crewed by Kenneth Bowersox, Nikolai Budarin, and Donald Pettit; the crew returned aboard a Soyuz after the Columbia accident grounded the Shuttle.
ISS Expedition 7, a two-person caretaker crew of Yuri Malenchenko and Edward Lu, kept the station operating after the Columbia accident.
ISS Expedition 8 was a two-person crew of Michael Foale and Alexander Kaleri.
ISS Expedition 9 was crewed by Gennady Padalka and Michael Fincke.
ISS Expedition 10 was a two-person crew of Leroy Chiao and Salizhan Sharipov.
On 18 March 1965, Alexei Leonov left the Voskhod 2 spacecraft to become the first human to perform a spacewalk (extravehicular activity).
The Apollo 11 moonwalk was the first time humans walked on the surface of another world, as Neil Armstrong and Buzz Aldrin explored the Sea of Tranquility.
During Apollo 15, David Scott and James Irwin conducted the first extended lunar surface exploration using the Lunar Roving Vehicle, across three spacewalks.
The first spacewalks to assemble the International Space Station were carried out during the STS-88 mission, connecting the Unity and Zarya modules.
On 18 October 2019, Christina Koch and Jessica Meir conducted the first spacewalk performed entirely by women, outside the International Space Station.
During the Shenzhou 7 mission in 2008, Zhai Zhigang performed the first spacewalk by a Chinese astronaut (taikonaut).
The probe-and-drogue docking system is the long-serving Russian mechanism used by Soyuz and Progress to dock with space stations, including the ISS Russian segment.
The Androgynous Peripheral Attach System is a docking mechanism developed for the Apollo–Soyuz Test Project and later used by the Space Shuttle to dock with Mir and the ISS.
The International Docking System Standard, implemented on the ISS as the International Docking Adapters, allows Crew Dragon and Starliner to dock autonomously.
Environmental Control and Life Support System
The Environmental Control and Life Support System keeps a station's crew alive by recycling air and water, controlling temperature and pressure, and removing carbon dioxide.
The NASA Twins Study compared astronaut Scott Kelly during a year aboard the ISS with his identical twin on Earth, advancing understanding of how spaceflight affects the human body.
In microgravity the human body loses bone mass, a key concern for long-duration spaceflight that is studied and countered aboard the ISS.
Without gravity to work against, muscles weaken in space; resistance exercise aboard stations helps crews maintain strength.
Beyond Earth's protective atmosphere and much of its magnetic field, astronauts face increased radiation, a central challenge for long missions.
In weightlessness, body fluids shift toward the head, contributing to the vision changes studied as Spaceflight-Associated Neuro-ocular Syndrome (SANS).
Radio waves are the longest-wavelength light; radio telescopes study pulsars, galaxies, and the cold gas of the universe.
Millimeter-wave astronomy probes cold molecular gas and dust, the raw material of stars and planets.
Submillimeter astronomy reveals the cold, dusty early stages of star and galaxy formation.
Infrared light penetrates dust and reveals cool objects — forming stars, planets, and distant galaxies.
The near-infrared bridges visible and thermal infrared light, key for studying the early universe and exoplanet atmospheres.
Visible light is the band the human eye sees and the traditional domain of optical telescopes.
Ultraviolet light traces hot young stars and energetic processes; most of it is blocked by Earth's atmosphere.
X-rays come from the hottest, most energetic places in the universe — black holes, neutron stars, and galaxy clusters.
Gamma rays are the most energetic light, produced by supernovae, pulsars, and matter falling into black holes.
Gravitational waves are ripples in spacetime from violent events such as merging black holes and neutron stars, detected by laser interferometers.
Neutrinos are nearly massless particles that stream from nuclear processes in stars and cataclysmic events, detected deep underground or in ice.
Multi-messenger astronomy combines light, gravitational waves, and particles to study a single cosmic event from several independent channels.
The Atacama Desert in northern Chile is one of the driest, clearest places on Earth, hosting many of the world's great observatories.
The island of La Palma in the Canary Islands hosts the Roque de los Muchachos Observatory, one of the premier sites of the Northern Hemisphere.
The geographic South Pole offers extremely dry, stable air and months of darkness, ideal for neutrino, microwave-background, and infrared astronomy.
ESO is a 16-nation intergovernmental organisation that builds and operates major ground-based observatories in Chile, including the VLT and the future ELT.
NSF's NOIRLab is the US national centre for ground-based, night-time optical and infrared astronomy, operating Gemini, CTIO, Kitt Peak, and the Rubin Observatory.
The NRAO operates major radio astronomy facilities for the US scientific community, including the VLA and (as a partner) ALMA.
National Astronomical Observatory of Japan
The NAOJ is Japan's national centre for astronomy, operating the Subaru Telescope and partnering in ALMA.
STScI conducts the science operations of the Hubble and James Webb space telescopes for NASA.
IPAC at Caltech provides science operations and data archives for many infrared and survey missions, including Spitzer and WISE.
The US National Science Foundation funds and stewards major astronomy facilities, including LIGO, NOIRLab, and the NRAO.
National Astronomical Observatories, CAS
The National Astronomical Observatories of the Chinese Academy of Sciences operate China's major astronomical facilities, including the FAST radio telescope.
California Association for Research in Astronomy
CARA, a partnership of Caltech and the University of California (with NASA as a partner), operates the W. M. Keck Observatory.
The National Solar Observatory, an AURA centre funded by the NSF, operates the Daniel K. Inouye Solar Telescope and the GONG network.
The Smithsonian Astrophysical Observatory, part of the Center for Astrophysics | Harvard & Smithsonian, runs the Chandra X-ray Center for NASA.
ESO's Paranal Observatory in the Atacama Desert is home to the Very Large Telescope, one of the most productive ground-based facilities in astronomy.
La Silla was ESO's first observatory, a pioneering site on the edge of the Atacama Desert still productive in exoplanet and survey science.
Cerro Tololo Inter-American Observatory in Chile is a NOIRLab site whose telescopes carried out the Dark Energy Survey.
Kitt Peak National Observatory in Arizona hosts one of the largest collections of optical telescopes in the Northern Hemisphere.
The Roque de los Muchachos Observatory on La Palma is one of the premier observing sites of the Northern Hemisphere, home to the Gran Telescopio Canarias.
Mount Wilson Observatory in California is where Edwin Hubble discovered the expansion of the universe, using the 100-inch Hooker Telescope.
Arecibo Observatory in Puerto Rico operated a 305-metre radio dish — for decades the largest single-dish radio telescope — until its collapse in 2020.
LIGO Hanford in Washington State is one of the two US Laser Interferometer Gravitational-wave Observatory detectors that made the first direct detection of gravitational waves in 2015.
LIGO Livingston in Louisiana is the second US LIGO detector; together with LIGO Hanford it detected the first gravitational waves from merging black holes.
Virgo is a European gravitational-wave detector near Pisa, Italy, that observes together with LIGO to localise sources on the sky.
IceCube embeds thousands of light sensors in a cubic kilometre of Antarctic ice to detect high-energy neutrinos from the cosmos.
Keck I is one of two 10-metre Keck telescopes on Mauna Kea, using a segmented primary mirror of 36 hexagonal segments.
Keck II is the second 10-metre Keck telescope, used with adaptive optics for high-resolution near-infrared studies, including the Galactic Centre.
Gemini North is an 8.1-metre telescope on Mauna Kea, one of the twin Gemini telescopes covering the whole sky.
Gemini South is the 8.1-metre southern Gemini telescope, located on Cerro Pachón in Chile.
The Subaru Telescope, operated by Japan's NAOJ on Mauna Kea, is an 8.2-metre telescope renowned for wide-field imaging.
The Gran Telescopio Canarias on La Palma is one of the largest single-aperture optical telescopes in the world, with a 10.4-metre segmented mirror.
The Large Binocular Telescope in Arizona carries two 8.4-metre mirrors on a single mount, giving it the light-gathering power of an 11.8-metre telescope.
The Hobby–Eberly Telescope at McDonald Observatory in Texas is a 10-metre telescope optimised for spectroscopy, including dark-energy surveys.
SALT in Sutherland, South Africa is the largest single optical telescope in the Southern Hemisphere, a sibling of the Hobby–Eberly design.
The twin 6.5-metre Magellan Telescopes at Las Campanas Observatory in Chile are operated by a US consortium for imaging and spectroscopy.
The 200-inch Hale Telescope at Palomar was the largest in the world for decades and remains a workhorse of optical astronomy.
The 100-inch Hooker Telescope at Mount Wilson was used by Edwin Hubble to discover that the universe is expanding.
ESO's Extremely Large Telescope, under construction in Chile, will be the world's largest optical/infrared telescope with a 39-metre segmented mirror. It is not yet operational.
The Thirty Meter Telescope is a planned 30-metre optical/infrared telescope; its site remains the subject of ongoing decisions. It is not yet operational.
APEX is a 12-metre submillimeter telescope in the Atacama Desert, a pathfinder for ALMA studying cold dust and gas.
The James Clerk Maxwell Telescope on Mauna Kea is a 15-metre submillimeter telescope and a station of the Event Horizon Telescope.
The Submillimeter Array is an eight-antenna interferometer on Mauna Kea operated by the Smithsonian and Taiwan's ASIAA.
MeerKAT is a 64-dish radio array in South Africa and a precursor to the Square Kilometre Array.
LOFAR is a vast low-frequency radio array centred in the Netherlands, made of tens of thousands of simple antennas combined by software.
The Square Kilometre Array is a planned intercontinental radio observatory in South Africa and Australia that will be the world's largest radio telescope. It is not yet operational.
The Daniel K. Inouye Solar Telescope on Haleakalā, Maui is the world's largest solar telescope, resolving features on the Sun as small as 30 kilometres.
The South Pole Telescope is a 10-metre telescope studying the cosmic microwave background and distant galaxy clusters from Antarctica.
The Compton Gamma Ray Observatory (1991–2000) was one of NASA's Great Observatories, mapping the gamma-ray sky and studying gamma-ray bursts.
The Fermi Gamma-ray Space Telescope surveys the entire gamma-ray sky every few hours, studying pulsars, blazars, and gamma-ray bursts.
Herschel was ESA's far-infrared and submillimeter observatory (2009–2013), with the largest single mirror ever flown in space at the time.
ESA's Planck mission (2009–2013) mapped the cosmic microwave background with unprecedented precision, refining the age and composition of the universe.
WISE surveyed the entire sky in infrared light, cataloguing hundreds of millions of objects and, as NEOWISE, tracking near-Earth asteroids.
Euclid is ESA's mission to map the geometry of the dark universe, surveying billions of galaxies to study dark matter and dark energy.
The Solar Dynamics Observatory watches the Sun continuously in many wavelengths, capturing the dynamics of solar activity in extraordinary detail.
SOHO, a joint ESA–NASA mission, has studied the Sun from the L1 point since 1995 and is also the most prolific discoverer of comets.
Hinode is a Japanese-led solar observatory studying the Sun's magnetic field and corona in visible, ultraviolet, and X-ray light.
TRACE (1998–2010) imaged the Sun's transition region and corona in ultraviolet light, revealing the fine structure of magnetic loops.
The Advanced Camera for Surveys is a wide-field Hubble camera that produced many of the telescope's deepest survey images.
The Cosmic Origins Spectrograph studies the ultraviolet light of faint sources to probe the gas between galaxies.
STIS is a versatile Hubble spectrograph used for everything from exoplanet atmospheres to black-hole masses.
NIRISS, contributed by the Canadian Space Agency, provides JWST with slitless spectroscopy and high-contrast imaging.
HIRES on Keck I is a high-resolution optical spectrograph used in many exoplanet discoveries and studies of distant galaxies.
MUSE on the VLT records a spectrum at every point in its field of view, mapping the motions and composition of galaxies.
SPHERE on the VLT is an extreme adaptive-optics instrument that directly images exoplanets and circumstellar discs.
The Sloan Digital Sky Survey has mapped more than a third of the sky and the spectra of millions of galaxies, quasars, and stars, building a 3D map of the universe.
The Two Micron All Sky Survey imaged the entire sky in three near-infrared bands, cataloguing hundreds of millions of stars and galaxies.
WISE surveyed the whole sky in infrared light, producing a catalogue of more than 500 million objects.
Gaia Data Release 3 provides positions, distances, motions, and physical properties for nearly two billion stars — the most detailed map of the Milky Way to date.
Pan-STARRS in Hawaii repeatedly images the sky to discover asteroids, comets, and transient events, including the first interstellar object, ʻOumuamua.
The Dark Energy Survey mapped hundreds of millions of galaxies from Cerro Tololo to probe the nature of cosmic acceleration.
The Legacy Survey of Space and Time, conducted by the Vera C. Rubin Observatory, will image the entire southern sky every few nights for a decade.
The Digitized Sky Survey is a digital scan of historical photographic sky surveys, a foundational all-sky reference for astronomy.
The Hubble Deep Field was a long exposure of a tiny, apparently empty patch of sky that revealed thousands of distant galaxies.
The Hubble Ultra Deep Field went deeper still, capturing some of the most distant galaxies ever seen in visible and near-infrared light.
11 Com b is a gas giant orbiting 11 Com, discovered in 2007 by the radial velocity method.
11 UMi b is a gas giant orbiting 11 UMi, discovered in 2009 by the radial velocity method.
14 And b is a gas giant orbiting 14 And, discovered in 2008 by the radial velocity method.
14 Her b is a gas giant orbiting 14 Her, discovered in 2002 by the radial velocity method.
HD 145675 c is a gas giant orbiting 14 Her, discovered in 2021 by the radial velocity method.
17 Sco b is a gas giant orbiting 17 Sco, discovered in 2020 by the radial velocity method.
18 Del b is a gas giant orbiting 18 Del, discovered in 2008 by the radial velocity method.
1RXS J160929.1-210524 b is a gas giant orbiting 1RXS J160929.1-210524, discovered in 2008 by the direct imaging.
2MASS J01033563-5515561 AB b is a gas giant orbiting 2MASS J01033563-5515561 A, discovered in 2013 by the direct imaging.
2MASS J01225093-2439505 b is a gas giant orbiting 2MASS J01225093-2439505, discovered in 2013 by the direct imaging.
2MASS J02192210-3925225 b is a gas giant orbiting 2MASS J02192210-3925225, discovered in 2015 by the direct imaging.
2MASS J0249-0557 c is a gas giant orbiting 2MASS J0249-0557 A, discovered in 2018 by the direct imaging.
2MASS J03590986+2009361 b is a gas giant orbiting 2MASS J03590986+2009361, discovered in 2024 by the direct imaging.
2M0437 b is a gas giant orbiting 2MASS J04372171+2651014, discovered in 2021 by the direct imaging.
2MASS J04414489+2301513 b is a gas giant orbiting 2MASS J04414489+2301513, discovered in 2010 by the direct imaging.
2MASS J11011926-7732383 b is a gas giant orbiting 2MASS J11011926-7732383, discovered in 2024 by the direct imaging.
2MASS J11550485-7919108 b is a gas giant orbiting 2MASS J11550485-7919108, discovered in 2024 by the direct imaging.
2MASS J12073346-3932539 b is a gas giant orbiting 2MASS J12073346-3932539, discovered in 2004 by the direct imaging.
KOINTREAU-4 b is a gas giant orbiting 2MASS J16262785-2625152, discovered in 2026 by the direct imaging.
2MASS J19383260+4603591 b is a gas giant orbiting 2MASS J19383260+4603591, discovered in 2015 by the eclipse timing variations.
Kepler-451 c is a gas giant orbiting 2MASS J19383260+4603591, discovered in 2022 by the eclipse timing variations.
Kepler-451 d is a gas giant orbiting 2MASS J19383260+4603591, discovered in 2022 by the eclipse timing variations.
2MASS J21252752-8138278 b is a gas giant orbiting 2MASS J21252752-8138278, discovered in 2024 by the direct imaging.
2MASS J22362452+4751425 b is a gas giant orbiting 2MASS J22362452+4751425, discovered in 2016 by the direct imaging.
2MASS J22501512+2325342 b is a gas giant orbiting 2MASS J22501512+2325342, discovered in 2018 by the direct imaging.
4 UMa b is a gas giant orbiting 4 UMa, discovered in 2006 by the radial velocity method.
47 UMa b is a gas giant orbiting 47 UMa, discovered in 1996 by the radial velocity method.
47 UMa c is a gas giant orbiting 47 UMa, discovered in 2001 by the radial velocity method.
47 UMa d is a gas giant orbiting 47 UMa, discovered in 2009 by the radial velocity method.
51 Eri b is an exoplanet orbiting 51 Eri, discovered in 2015 by the direct imaging.
55 Cnc b is a gas giant orbiting 55 Cnc, discovered in 1996 by the radial velocity method.
55 Cnc c is a gas giant orbiting 55 Cnc, discovered in 2004 by the radial velocity method.
55 Cnc d is a gas giant orbiting 55 Cnc, discovered in 2002 by the radial velocity method.
55 Cnc f is a gas giant orbiting 55 Cnc, discovered in 2007 by the radial velocity method.
55 Cnc B b is a super-earth orbiting 55 Cnc B, discovered in 2025 by the radial velocity method.
55 Cnc B c is a super-earth orbiting 55 Cnc B, discovered in 2025 by the radial velocity method.
61 Vir b is a super-earth orbiting 61 Vir, discovered in 2009 by the radial velocity method.
61 Vir c is a mini-neptune orbiting 61 Vir, discovered in 2009 by the radial velocity method.
61 Vir d is a mini-neptune orbiting 61 Vir, discovered in 2009 by the radial velocity method.
7 CMa b is a gas giant orbiting 7 CMa, discovered in 2011 by the radial velocity method.
7 CMa c is a gas giant orbiting 7 CMa, discovered in 2019 by the radial velocity method.
70 Vir b is a gas giant orbiting 70 Vir, discovered in 1996 by the radial velocity method.
75 Cet b is a gas giant orbiting 75 Cet, discovered in 2012 by the radial velocity method.
75 Cet c is a gas giant orbiting 75 Cet, discovered in 2023 by the radial velocity method.
8 UMi b is a gas giant orbiting 8 UMi, discovered in 2015 by the radial velocity method.
91 Aqr b is a gas giant orbiting 91 Aqr, discovered in 2013 by the radial velocity method.
AB Aur b is a gas giant orbiting AB Aur, discovered in 2022 by the direct imaging.
AB Pic b is a gas giant orbiting AB Pic, discovered in 2005 by the direct imaging.
AF Lep b is a gas giant orbiting AF Lep, discovered in 2023 by the direct imaging.
AU Mic b is a mini-neptune orbiting AU Mic, discovered in 2020 by the transit method.
AU Mic c is a mini-neptune orbiting AU Mic, discovered in 2021 by the transit method.
AU Mic d is a terrestrial planet orbiting AU Mic, discovered in 2023 by the transit timing variations.
AU Mic e is a mini-neptune orbiting AU Mic, discovered in 2025 by the radial velocity method.
b Cen AB b is a gas giant orbiting b Cen A, discovered in 2021 by the direct imaging.
Barnard b is a terrestrial planet orbiting Barnard's star, discovered in 2024 by the radial velocity method.
Barnard c is a terrestrial planet orbiting Barnard's star, discovered in 2025 by the radial velocity method.
Barnard d is a terrestrial planet orbiting Barnard's star, discovered in 2025 by the radial velocity method.
Barnard e is a terrestrial planet orbiting Barnard's star, discovered in 2025 by the radial velocity method.
BD-06 1339 b is an exoplanet orbiting BD-06 1339, discovered in 2013 by the radial velocity method.
BD-06 1339 c is a gas giant orbiting BD-06 1339, discovered in 2013 by the radial velocity method.
BD-11 4672 b is a gas giant orbiting BD-11 4672, discovered in 2014 by the radial velocity method.
BD-11 4672 c is a mini-neptune orbiting BD-11 4672, discovered in 2020 by the radial velocity method.
BD-210397 b is a gas giant orbiting BD-210397, discovered in 2023 by the radial velocity method.
BD-210397 c is a gas giant orbiting BD-210397, discovered in 2023 by the radial velocity method.
BD+60 1417 b is a gas giant orbiting BD+60 1417, discovered in 2021 by the direct imaging.
bet Pic b is a gas giant orbiting bet Pic, discovered in 2008 by the direct imaging.
bet Pic c is a gas giant orbiting bet Pic, discovered in 2019 by the radial velocity method.
CD Cet b is a super-earth orbiting CD Cet, discovered in 2020 by the radial velocity method.
CD-35 2722 b is a gas giant orbiting CD-35 2722, discovered in 2011 by the direct imaging.
CFBDSIR J145829+101343 b is a gas giant orbiting CFBDSIR J145829+101343, discovered in 2011 by the direct imaging.
CFHTWIR-Oph 98 b is a gas giant orbiting CFHTWIR-Oph 98 A, discovered in 2020 by the direct imaging.
CHXR 73 b is a gas giant orbiting CHXR 73, discovered in 2006 by the direct imaging.
COCONUTS-2 b is a gas giant orbiting COCONUTS-2 A, discovered in 2021 by the direct imaging.
CT Cha b is a gas giant orbiting CT Cha, discovered in 2007 by the direct imaging.
CWISEP J193518.59-154620.3 b is a gas giant orbiting CWISEP J193518.59-154620.3, discovered in 2025 by the direct imaging.
DENIS-P J082303.1-491201 b is a gas giant orbiting DENIS-P J082303.1-491201, discovered in 2013 by the astrometry.
DH Tau b is a gas giant orbiting DH Tau, discovered in 2004 by the direct imaging.
DMPP-1 b is a mini-neptune orbiting DMPP-1, discovered in 2019 by the radial velocity method.
DMPP-1 c is a mini-neptune orbiting DMPP-1, discovered in 2019 by the radial velocity method.
DMPP-1 d is a super-earth orbiting DMPP-1, discovered in 2019 by the radial velocity method.
DMPP-1 e is a super-earth orbiting DMPP-1, discovered in 2019 by the radial velocity method.
DP Leo b is a gas giant orbiting DP Leo, discovered in 2009 by the eclipse timing variations.
eps Eri b is a gas giant orbiting eps Eri, discovered in 2000 by the radial velocity method.
eps Ind A b is a gas giant orbiting eps Ind A, discovered in 2019 by the radial velocity method.
FU Tau b is a gas giant orbiting FU Tau, discovered in 2008 by the direct imaging.
G 192-15 b is a terrestrial planet orbiting G 192-15, discovered in 2025 by the radial velocity method.
G 192-15 c is a mini-neptune orbiting G 192-15, discovered in 2025 by the radial velocity method.
G 196-3 b is a gas giant orbiting G 196-3, discovered in 2024 by the direct imaging.
G 261-6 b is a terrestrial planet orbiting G 261-6, discovered in 2025 by the radial velocity method.
Gaia-4 b is a gas giant orbiting Gaia-4, discovered in 2025 by the astrometry.
Gaia-5 b is a gas giant orbiting Gaia-5, discovered in 2025 by the astrometry.
gam Cep b is a gas giant orbiting gam Cep, discovered in 2003 by the radial velocity method.
GJ 1002 b is a terrestrial planet orbiting GJ 1002, discovered in 2022 by the radial velocity method.
GJ 1002 c is a terrestrial planet orbiting GJ 1002, discovered in 2022 by the radial velocity method.
GJ 1061 b is a terrestrial planet orbiting GJ 1061, discovered in 2020 by the radial velocity method.
GJ 1061 c is a terrestrial planet orbiting GJ 1061, discovered in 2020 by the radial velocity method.
GJ 1061 d is a terrestrial planet orbiting GJ 1061, discovered in 2020 by the radial velocity method.
GJ 1132 b is a terrestrial planet orbiting GJ 1132, discovered in 2015 by the transit method.
GJ 1132 c is a terrestrial planet orbiting GJ 1132, discovered in 2018 by the radial velocity method.
GJ 1148 b is a gas giant orbiting GJ 1148, discovered in 2010 by the radial velocity method.
GJ 1148 c is a gas giant orbiting GJ 1148, discovered in 2017 by the radial velocity method.
GJ 1151 c is a mini-neptune orbiting GJ 1151, discovered in 2023 by the radial velocity method.
GJ 1214 b is a mini-neptune orbiting GJ 1214, discovered in 2009 by the transit method.
GJ 1265 b is a mini-neptune orbiting GJ 1265, discovered in 2018 by the radial velocity method.
GJ 1289 b is a super-earth orbiting GJ 1289, discovered in 2024 by the radial velocity method.
GJ 15 A b is a terrestrial planet orbiting GJ 15 A, discovered in 2014 by the radial velocity method.
GJ 15 A c is a gas giant orbiting GJ 15 A, discovered in 2018 by the radial velocity method.
GJ 163 b is a mini-neptune orbiting GJ 163, discovered in 2013 by the radial velocity method.
GJ 163 c is a mini-neptune orbiting GJ 163, discovered in 2013 by the radial velocity method.
GJ 163 d is a gas giant orbiting GJ 163, discovered in 2013 by the radial velocity method.
GJ 179 b is a gas giant orbiting GJ 179, discovered in 2009 by the radial velocity method.
GJ 180 b is a mini-neptune orbiting GJ 180, discovered in 2014 by the radial velocity method.
GJ 180 c is a mini-neptune orbiting GJ 180, discovered in 2014 by the radial velocity method.
GJ 180 d is a mini-neptune orbiting GJ 180, discovered in 2020 by the radial velocity method.
GJ 229 A c is a mini-neptune orbiting GJ 229, discovered in 2020 by the radial velocity method.
GJ 229 b is a mini-neptune orbiting GJ 229, discovered in 2014 by the radial velocity method.
GJ 251 b is a super-earth orbiting GJ 251, discovered in 2020 by the radial velocity method.
GJ 251 c is a super-earth orbiting GJ 251, discovered in 2025 by the radial velocity method.
GJ 273 b is a terrestrial planet orbiting GJ 273, discovered in 2017 by the radial velocity method.
GJ 273 c is a terrestrial planet orbiting GJ 273, discovered in 2017 by the radial velocity method.
GJ 3021 b is a gas giant orbiting GJ 3021, discovered in 2000 by the radial velocity method.
GJ 3138 b is a terrestrial planet orbiting GJ 3138, discovered in 2017 by the radial velocity method.
GJ 3138 c is a super-earth orbiting GJ 3138, discovered in 2017 by the radial velocity method.
GJ 3138 d is a mini-neptune orbiting GJ 3138, discovered in 2017 by the radial velocity method.
GJ 317 b is a gas giant orbiting GJ 317, discovered in 2007 by the radial velocity method.
GJ 317 c is a gas giant orbiting GJ 317, discovered in 2016 by the radial velocity method.
GJ 328 b is a gas giant orbiting GJ 328, discovered in 2013 by the radial velocity method.
GJ 328 c is a mini-neptune orbiting GJ 328, discovered in 2023 by the radial velocity method.
GJ 3293 b is a mini-neptune orbiting GJ 3293, discovered in 2015 by the radial velocity method.
GJ 3293 c is a mini-neptune orbiting GJ 3293, discovered in 2015 by the radial velocity method.
GJ 3293 d is a mini-neptune orbiting GJ 3293, discovered in 2017 by the radial velocity method.
GJ 3293 e is a super-earth orbiting GJ 3293, discovered in 2017 by the radial velocity method.
GJ 3323 b is a terrestrial planet orbiting GJ 3323, discovered in 2017 by the radial velocity method.
GJ 3323 c is a terrestrial planet orbiting GJ 3323, discovered in 2017 by the radial velocity method.
GJ 3378 b is a terrestrial planet orbiting GJ 3378, discovered in 2026 by the radial velocity method.
GJ 338 B b is a mini-neptune orbiting GJ 338 B, discovered in 2020 by the radial velocity method.
GJ 341 b is a terrestrial planet orbiting GJ 341, discovered in 2025 by the transit method.
GJ 3470 b is a mini-neptune orbiting GJ 3470, discovered in 2012 by the radial velocity method.
GJ 3512 b is a gas giant orbiting GJ 3512, discovered in 2019 by the radial velocity method.
GJ 3512 c is a gas giant orbiting GJ 3512, discovered in 2020 by the radial velocity method.
GJ 357 b is a terrestrial planet orbiting GJ 357, discovered in 2019 by the transit method.
GJ 357 c is a super-earth orbiting GJ 357, discovered in 2019 by the radial velocity method.
GJ 357 d is a super-earth orbiting GJ 357, discovered in 2019 by the radial velocity method.
GJ 3634 b is a mini-neptune orbiting GJ 3634, discovered in 2010 by the radial velocity method.
GJ 367 b is a terrestrial planet orbiting GJ 367, discovered in 2021 by the transit method.
GJ 367 c is a super-earth orbiting GJ 367, discovered in 2023 by the radial velocity method.
GJ 367 d is a super-earth orbiting GJ 367, discovered in 2023 by the radial velocity method.
GJ 3779 b is a mini-neptune orbiting GJ 3779, discovered in 2018 by the radial velocity method.
GJ 393 b is a terrestrial planet orbiting GJ 393, discovered in 2021 by the radial velocity method.
GJ 3988 b is a super-earth orbiting GJ 3988, discovered in 2023 by the radial velocity method.
GJ 3998 b is a terrestrial planet orbiting GJ 3998, discovered in 2016 by the radial velocity method.
GJ 3998 c is a mini-neptune orbiting GJ 3998, discovered in 2016 by the radial velocity method.
GJ 3998 d is a super-earth orbiting GJ 3998, discovered in 2025 by the radial velocity method.
GJ 411 b is a terrestrial planet orbiting GJ 411, discovered in 2019 by the radial velocity method.
HD 95735 c is a mini-neptune orbiting GJ 411, discovered in 2021 by the radial velocity method.
GJ 414 A b is a mini-neptune orbiting GJ 414 A, discovered in 2021 by the radial velocity method.
GJ 414 A c is a gas giant orbiting GJ 414 A, discovered in 2021 by the radial velocity method.
GJ 422 b is a mini-neptune orbiting GJ 422, discovered in 2014 by the radial velocity method.
GJ 4274 b is a terrestrial planet orbiting GJ 4274, discovered in 2026 by the radial velocity method.
GJ 4274 c is a mini-neptune orbiting GJ 4274, discovered in 2026 by the radial velocity method.
GJ 433 b is a super-earth orbiting GJ 433, discovered in 2013 by the radial velocity method.
GJ 433 c is a gas giant orbiting GJ 433, discovered in 2014 by the radial velocity method.
GJ 433 d is a super-earth orbiting GJ 433, discovered in 2020 by the radial velocity method.
GJ 436 b is a mini-neptune orbiting GJ 436, discovered in 2004 by the radial velocity method.
GJ 480 b is a mini-neptune orbiting GJ 480, discovered in 2020 by the radial velocity method.
GJ 486 b is a terrestrial planet orbiting GJ 486, discovered in 2021 by the radial velocity method.
GJ 504 b is a gas giant orbiting GJ 504, discovered in 2013 by the direct imaging.
GJ 514 b is a super-earth orbiting GJ 514, discovered in 2022 by the radial velocity method.
GJ 536 b is a mini-neptune orbiting GJ 536, discovered in 2016 by the radial velocity method.
GJ 536 c is a super-earth orbiting GJ 536, discovered in 2025 by the radial velocity method.
GJ 581 b is a mini-neptune orbiting GJ 581, discovered in 2005 by the radial velocity method.
GJ 581 e is a terrestrial planet orbiting GJ 581, discovered in 2009 by the radial velocity method.
GJ 625 b is a terrestrial planet orbiting GJ 625, discovered in 2017 by the radial velocity method.
GJ 649 b is a gas giant orbiting GJ 649, discovered in 2009 by the radial velocity method.
GJ 667 C b is a super-earth orbiting GJ 667 C, discovered in 2012 by the radial velocity method.
GJ 667 C c is a super-earth orbiting GJ 667 C, discovered in 2013 by the radial velocity method.
GJ 667 C e is a terrestrial planet orbiting GJ 667 C, discovered in 2013 by the radial velocity method.
GJ 667 C f is a terrestrial planet orbiting GJ 667 C, discovered in 2013 by the radial velocity method.
GJ 667 C g is a super-earth orbiting GJ 667 C, discovered in 2013 by the radial velocity method.
GJ 674 b is a mini-neptune orbiting GJ 674, discovered in 2007 by the radial velocity method.
GJ 676 A b is a gas giant orbiting GJ 676 A, discovered in 2010 by the radial velocity method.
GJ 676 A c is a gas giant orbiting GJ 676 A, discovered in 2016 by the radial velocity method.
GJ 676 A d is a super-earth orbiting GJ 676 A, discovered in 2012 by the radial velocity method.
GJ 676 A e is a mini-neptune orbiting GJ 676 A, discovered in 2012 by the radial velocity method.
GJ 680 b is a gas giant orbiting GJ 680, discovered in 2022 by the radial velocity method.
GJ 682 b is a super-earth orbiting GJ 682, discovered in 2014 by the radial velocity method.
GJ 682 c is a mini-neptune orbiting GJ 682, discovered in 2014 by the radial velocity method.
GJ 685 b is a mini-neptune orbiting GJ 685, discovered in 2019 by the radial velocity method.
GJ 687 b is a mini-neptune orbiting GJ 687, discovered in 2014 by the radial velocity method.
GJ 687 c is a mini-neptune orbiting GJ 687, discovered in 2020 by the radial velocity method.
GJ 740 b is a terrestrial planet orbiting GJ 740, discovered in 2021 by the radial velocity method.
GJ 806 b is a terrestrial planet orbiting GJ 806, discovered in 2023 by the transit method.
GJ 806 c is a super-earth orbiting GJ 806, discovered in 2023 by the radial velocity method.
GJ 832 b is a gas giant orbiting GJ 832, discovered in 2008 by the radial velocity method.
GJ 849 b is a gas giant orbiting GJ 849, discovered in 2006 by the radial velocity method.
GJ 849 c is a gas giant orbiting GJ 849, discovered in 2014 by the radial velocity method.
GJ 86 b is a gas giant orbiting GJ 86, discovered in 1999 by the radial velocity method.
GJ 876 b is a gas giant orbiting GJ 876, discovered in 1998 by the radial velocity method.
GJ 876 c is a gas giant orbiting GJ 876, discovered in 2000 by the radial velocity method.
GJ 876 d is a mini-neptune orbiting GJ 876, discovered in 2005 by the radial velocity method.
GJ 876 e is a mini-neptune orbiting GJ 876, discovered in 2010 by the radial velocity method.
GJ 887 b is a super-earth orbiting GJ 887, discovered in 2020 by the radial velocity method.
GJ 887 c is a mini-neptune orbiting GJ 887, discovered in 2020 by the radial velocity method.
GJ 887 d is a super-earth orbiting GJ 887, discovered in 2026 by the radial velocity method.
GJ 887 e is a terrestrial planet orbiting GJ 887, discovered in 2026 by the radial velocity method.
GJ 896 A b is a gas giant orbiting GJ 896 A, discovered in 2022 by the astrometry.
GJ 900 b is a gas giant orbiting GJ 900 A, discovered in 2024 by the direct imaging.
GJ 9066 c is a gas giant orbiting GJ 9066, discovered in 2020 by the radial velocity method.
GJ 96 b is a mini-neptune orbiting GJ 96, discovered in 2018 by the radial velocity method.
GJ 9827 b is a terrestrial planet orbiting GJ 9827, discovered in 2017 by the transit method.
GJ 9827 c is a terrestrial planet orbiting GJ 9827, discovered in 2017 by the transit method.
GJ 9827 d is a super-earth orbiting GJ 9827, discovered in 2017 by the transit method.
Gl 378 b is a mini-neptune orbiting Gl 378, discovered in 2019 by the radial velocity method.
Gl 410 b is a mini-neptune orbiting Gl 410, discovered in 2025 by the radial velocity method.
Gl 49 b is a super-earth orbiting Gl 49, discovered in 2019 by the radial velocity method.
Gl 686 b is a mini-neptune orbiting Gl 686, discovered in 2018 by the radial velocity method.
Gl 725 A b is a terrestrial planet orbiting Gl 725 A, discovered in 2025 by the radial velocity method.
Gliese 12 b is a terrestrial planet orbiting Gliese 12, discovered in 2024 by the transit method.
GQ Lup b is a gas giant orbiting GQ Lup, discovered in 2004 by the direct imaging.
GSC 06214-00210 b is a gas giant orbiting GSC 06214-00210, discovered in 2010 by the direct imaging.
GU Psc b is a gas giant orbiting GU Psc, discovered in 2014 by the direct imaging.
HD 100546 b is a gas giant orbiting HD 100546, discovered in 2014 by the direct imaging.
HD 100655 b is a gas giant orbiting HD 100655, discovered in 2011 by the radial velocity method.
HD 100777 b is a gas giant orbiting HD 100777, discovered in 2007 by the radial velocity method.
HD 10180 c is an exoplanet orbiting HD 10180, discovered in 2010 by the radial velocity method.
HD 10180 d is an exoplanet orbiting HD 10180, discovered in 2010 by the radial velocity method.
HD 10180 e is a mini-neptune orbiting HD 10180, discovered in 2010 by the radial velocity method.
HD 10180 f is a mini-neptune orbiting HD 10180, discovered in 2010 by the radial velocity method.
HD 10180 g is an exoplanet orbiting HD 10180, discovered in 2010 by the radial velocity method.
HD 10180 h is a gas giant orbiting HD 10180, discovered in 2010 by the radial velocity method.
HD 102117 b is a gas giant orbiting HD 102117, discovered in 2005 by the radial velocity method.
HD 102195 b is a hot jupiter orbiting HD 102195, discovered in 2006 by the radial velocity method.
HD 102956 b is a hot jupiter orbiting HD 102956, discovered in 2010 by the radial velocity method.
HD 104067 b is a gas giant orbiting HD 104067, discovered in 2009 by the radial velocity method.
HD 104067 c is a mini-neptune orbiting HD 104067, discovered in 2024 by the radial velocity method.
HD 104985 b is a gas giant orbiting HD 104985, discovered in 2003 by the radial velocity method.
HD 10647 b is a gas giant orbiting HD 10647, discovered in 2006 by the radial velocity method.
HD 106906 b is a gas giant orbiting HD 106906, discovered in 2013 by the direct imaging.
HD 108147 b is a gas giant orbiting HD 108147, discovered in 2002 by the radial velocity method.
HD 109246 b is a gas giant orbiting HD 109246, discovered in 2010 by the radial velocity method.
HD 110014 b is a gas giant orbiting HD 110014, discovered in 2009 by the radial velocity method.
HD 111232 b is a gas giant orbiting HD 111232, discovered in 2003 by the radial velocity method.
HD 111232 c is a gas giant orbiting HD 111232, discovered in 2022 by the radial velocity method.
HD 112300 b is a gas giant orbiting HD 112300, discovered in 2023 by the radial velocity method.
HD 113538 b is a gas giant orbiting HD 113538, discovered in 2010 by the radial velocity method.
HD 113538 c is a gas giant orbiting HD 113538, discovered in 2010 by the radial velocity method.
HD 113996 b is a gas giant orbiting HD 113996, discovered in 2017 by the radial velocity method.
HD 114386 b is a gas giant orbiting HD 114386, discovered in 2003 by the radial velocity method.
HD 114386 c is a gas giant orbiting HD 114386, discovered in 2026 by the radial velocity method.
HD 114783 b is a gas giant orbiting HD 114783, discovered in 2001 by the radial velocity method.
HD 114783 c is a gas giant orbiting HD 114783, discovered in 2016 by the radial velocity method.
HD 11506 b is a gas giant orbiting HD 11506, discovered in 2007 by the radial velocity method.
HD 11506 c is a gas giant orbiting HD 11506, discovered in 2008 by the radial velocity method.
HD 11506 d is a gas giant orbiting HD 11506, discovered in 2022 by the radial velocity method.
HD 115404 A b is a gas giant orbiting HD 115404 A, discovered in 2022 by the radial velocity method.
HD 115404 A c is a gas giant orbiting HD 115404 A, discovered in 2022 by the radial velocity method.
HD 117618 b is a gas giant orbiting HD 117618, discovered in 2004 by the radial velocity method.
HD 118203 b is a hot jupiter orbiting HD 118203, discovered in 2005 by the radial velocity method.
HD 118203 c is a gas giant orbiting HD 118203, discovered in 2024 by the radial velocity method.
HD 11977 b is a gas giant orbiting HD 11977, discovered in 2005 by the radial velocity method.
HD 125612 b is a gas giant orbiting HD 125612, discovered in 2007 by the radial velocity method.
HD 125612 c is a mini-neptune orbiting HD 125612, discovered in 2009 by the radial velocity method.
HD 125612 d is a gas giant orbiting HD 125612, discovered in 2009 by the radial velocity method.
HD 128311 b is a gas giant orbiting HD 128311, discovered in 2002 by the radial velocity method.
HD 128311 c is a gas giant orbiting HD 128311, discovered in 2005 by the radial velocity method.
HD 128717 b is a gas giant orbiting HD 128717, discovered in 2025 by the astrometry.
HD 130322 b is a gas giant orbiting HD 130322, discovered in 1999 by the radial velocity method.
HD 131496 b is a gas giant orbiting HD 131496, discovered in 2011 by the radial velocity method.
HD 134060 b is a mini-neptune orbiting HD 134060, discovered in 2019 by the radial velocity method.
HD 134060 c is a gas giant orbiting HD 134060, discovered in 2019 by the radial velocity method.
HD 134606 b is a mini-neptune orbiting HD 134606, discovered in 2024 by the radial velocity method.
HD 134606 c is a mini-neptune orbiting HD 134606, discovered in 2024 by the radial velocity method.
HD 134606 d is a gas giant orbiting HD 134606, discovered in 2024 by the radial velocity method.
HD 134606 e is a terrestrial planet orbiting HD 134606, discovered in 2024 by the radial velocity method.
HD 134606 f is a super-earth orbiting HD 134606, discovered in 2024 by the radial velocity method.
HD 134987 b is a gas giant orbiting HD 134987, discovered in 1999 by the radial velocity method.
HD 134987 c is a gas giant orbiting HD 134987, discovered in 2009 by the radial velocity method.
HD 135344 A b is a gas giant orbiting HD 135344 A, discovered in 2025 by the direct imaging.
HD 136352 b is a super-earth orbiting HD 136352, discovered in 2019 by the radial velocity method.
HD 136352 c is a mini-neptune orbiting HD 136352, discovered in 2019 by the radial velocity method.
HD 136352 d is a mini-neptune orbiting HD 136352, discovered in 2019 by the radial velocity method.
HD 136418 b is a gas giant orbiting HD 136418, discovered in 2009 by the radial velocity method.
HD 137388 b is a gas giant orbiting HD 137388, discovered in 2011 by the radial velocity method.
HD 13808 b is a mini-neptune orbiting HD 13808, discovered in 2021 by the radial velocity method.
HD 13808 c is a mini-neptune orbiting HD 13808, discovered in 2021 by the radial velocity method.
HD 141004 b is a mini-neptune orbiting HD 141004, discovered in 2021 by the radial velocity method.
HD 141399 b is a gas giant orbiting HD 141399, discovered in 2014 by the radial velocity method.
HD 141399 c is a gas giant orbiting HD 141399, discovered in 2014 by the radial velocity method.
HD 141399 d is a gas giant orbiting HD 141399, discovered in 2014 by the radial velocity method.
HD 141399 e is a gas giant orbiting HD 141399, discovered in 2014 by the radial velocity method.
HD 142 A d is a gas giant orbiting HD 142, discovered in 2022 by the radial velocity method.
HD 142 b is a gas giant orbiting HD 142, discovered in 2001 by the radial velocity method.
HD 142 c is a gas giant orbiting HD 142, discovered in 2012 by the radial velocity method.
HD 143811 AB b is a gas giant orbiting HD 143811 A, discovered in 2025 by the direct imaging.
HD 145457 b is a gas giant orbiting HD 145457, discovered in 2010 by the radial velocity method.
HD 1461 b is a mini-neptune orbiting HD 1461, discovered in 2010 by the radial velocity method.
HD 1461 c is a super-earth orbiting HD 1461, discovered in 2015 by the radial velocity method.
HD 147379 b is a mini-neptune orbiting HD 147379, discovered in 2017 by the radial velocity method.
HD 147513 b is a gas giant orbiting HD 147513, discovered in 2003 by the radial velocity method.
HD 148427 b is a gas giant orbiting HD 148427, discovered in 2009 by the radial velocity method.
HD 149026 b is a hot jupiter orbiting HD 149026, discovered in 2005 by the radial velocity method.
HD 149143 b is a hot jupiter orbiting HD 149143, discovered in 2005 by the radial velocity method.
HD 1502 b is a gas giant orbiting HD 1502, discovered in 2011 by the radial velocity method.
HD 152581 b is a gas giant orbiting HD 152581, discovered in 2011 by the radial velocity method.
HD 153557 b is a mini-neptune orbiting HD 153557, discovered in 2022 by the radial velocity method.
HD 153557 c is a mini-neptune orbiting HD 153557, discovered in 2022 by the radial velocity method.
HD 153557 d is a gas giant orbiting HD 153557, discovered in 2022 by the radial velocity method.
HD 153950 b is a gas giant orbiting HD 153950, discovered in 2008 by the radial velocity method.
HD 154345 b is a gas giant orbiting HD 154345, discovered in 2006 by the radial velocity method.
HD 156411 b is a gas giant orbiting HD 156411, discovered in 2009 by the radial velocity method.
HD 156668 b is a super-earth orbiting HD 156668, discovered in 2010 by the radial velocity method.
HD 156668 c is a gas giant orbiting HD 156668, discovered in 2021 by the radial velocity method.
HD 158259 b is a terrestrial planet orbiting HD 158259, discovered in 2020 by the radial velocity method.
HD 158259 c is a super-earth orbiting HD 158259, discovered in 2020 by the radial velocity method.
HD 158259 d is a super-earth orbiting HD 158259, discovered in 2020 by the radial velocity method.
HD 158259 e is a super-earth orbiting HD 158259, discovered in 2020 by the radial velocity method.
HD 158259 f is a super-earth orbiting HD 158259, discovered in 2020 by the radial velocity method.
HD 160691 b is an exoplanet orbiting HD 160691, discovered in 2000 by the radial velocity method.
HD 160691 c is an exoplanet orbiting HD 160691, discovered in 2004 by the radial velocity method.
HD 160691 d is a mini-neptune orbiting HD 160691, discovered in 2004 by the radial velocity method.
HD 160691 e is an exoplanet orbiting HD 160691, discovered in 2006 by the radial velocity method.
HD 16175 b is a gas giant orbiting HD 16175, discovered in 2009 by the radial velocity method.
HD 164604 b is a gas giant orbiting HD 164604, discovered in 2009 by the radial velocity method.
HD 164604 c is a gas giant orbiting HD 164604, discovered in 2026 by the radial velocity method.
HD 164922 b is a gas giant orbiting HD 164922, discovered in 2005 by the radial velocity method.
HD 164922 c is a mini-neptune orbiting HD 164922, discovered in 2016 by the radial velocity method.
HD 164922 d is a super-earth orbiting HD 164922, discovered in 2020 by the radial velocity method.
HD 164922 e is a mini-neptune orbiting HD 164922, discovered in 2021 by the radial velocity method.
HD 168746 b is a hot jupiter orbiting HD 168746, discovered in 2002 by the radial velocity method.
HD 169142 b is a gas giant orbiting HD 169142, discovered in 2023 by the direct imaging.
HD 17156 b is a gas giant orbiting HD 17156, discovered in 2007 by the radial velocity method.
HD 173416 b is a gas giant orbiting HD 173416, discovered in 2008 by the radial velocity method.
HD 175541 b is a gas giant orbiting HD 175541, discovered in 2007 by the radial velocity method.
HD 176986 b is an exoplanet orbiting HD 176986, discovered in 2017 by the radial velocity method.
HD 176986 c is an exoplanet orbiting HD 176986, discovered in 2017 by the radial velocity method.
HD 176986 d is a mini-neptune orbiting HD 176986, discovered in 2026 by the radial velocity method.
HD 179949 b is a hot jupiter orbiting HD 179949, discovered in 2000 by the radial velocity method.
HD 180617 b is a mini-neptune orbiting HD 180617, discovered in 2018 by the radial velocity method.
HD 181342 b is a gas giant orbiting HD 181342, discovered in 2009 by the radial velocity method.
HD 181433 b is an exoplanet orbiting HD 181433, discovered in 2008 by the radial velocity method.
HD 181433 c is an exoplanet orbiting HD 181433, discovered in 2008 by the radial velocity method.
HD 181433 d is a gas giant orbiting HD 181433, discovered in 2008 by the radial velocity method.
HD 181720 b is a gas giant orbiting HD 181720, discovered in 2009 by the radial velocity method.
HD 18438 b is a gas giant orbiting HD 18438, discovered in 2023 by the radial velocity method.
HD 18742 b is a gas giant orbiting HD 18742, discovered in 2011 by the radial velocity method.
HD 189567 b is a mini-neptune orbiting HD 189567, discovered in 2021 by the radial velocity method.
HD 189567 c is a mini-neptune orbiting HD 189567, discovered in 2021 by the radial velocity method.
HD 189733 b is a hot jupiter orbiting HD 189733, discovered in 2005 by the radial velocity method.
HD 190007 b is a mini-neptune orbiting HD 190007, discovered in 2020 by the radial velocity method.
HD 190360 b is a gas giant orbiting HD 190360, discovered in 2003 by the radial velocity method.
HD 190360 c is a mini-neptune orbiting HD 190360, discovered in 2005 by the radial velocity method.
HD 191939 b is a mini-neptune orbiting HD 191939, discovered in 2020 by the transit method.
HD 191939 c is a mini-neptune orbiting HD 191939, discovered in 2020 by the transit method.
HD 191939 d is a mini-neptune orbiting HD 191939, discovered in 2020 by the transit method.
HD 191939 e is a gas giant orbiting HD 191939, discovered in 2022 by the radial velocity method.
HD 191939 f is a gas giant orbiting HD 191939, discovered in 2022 by the radial velocity method.
HD 191939 g is a mini-neptune orbiting HD 191939, discovered in 2022 by the radial velocity method.
HD 192263 b is a gas giant orbiting HD 192263, discovered in 1999 by the radial velocity method.
HD 192310 b is a mini-neptune orbiting HD 192310, discovered in 2011 by the radial velocity method.
HD 192310 c is a mini-neptune orbiting HD 192310, discovered in 2011 by the radial velocity method.
HD 192699 b is a gas giant orbiting HD 192699, discovered in 2007 by the radial velocity method.
HD 19994 b is a gas giant orbiting HD 19994, discovered in 2003 by the radial velocity method.
HD 203030 b is a gas giant orbiting HD 203030, discovered in 2006 by the direct imaging.
HD 203387 b is a gas giant orbiting HD 203387, discovered in 2022 by the radial velocity method.
HD 203387 c is a gas giant orbiting HD 203387, discovered in 2022 by the radial velocity method.
HD 204941 b is a gas giant orbiting HD 204941, discovered in 2011 by the radial velocity method.
HD 205739 b is a gas giant orbiting HD 205739, discovered in 2008 by the radial velocity method.
HD 206610 b is a gas giant orbiting HD 206610, discovered in 2009 by the radial velocity method.
HD 206893 b is a gas giant orbiting HD 206893, discovered in 2021 by the direct imaging.
HD 206893 c is a gas giant orbiting HD 206893, discovered in 2022 by the direct imaging.
HD 20781 b is a terrestrial planet orbiting HD 20781, discovered in 2019 by the radial velocity method.
HD 20781 c is a super-earth orbiting HD 20781, discovered in 2019 by the radial velocity method.
HD 20781 d is a mini-neptune orbiting HD 20781, discovered in 2019 by the radial velocity method.
HD 20781 e is a mini-neptune orbiting HD 20781, discovered in 2019 by the radial velocity method.
HD 20782 b is a gas giant orbiting HD 20782, discovered in 2006 by the radial velocity method.
HD 20794 b is a terrestrial planet orbiting HD 20794, discovered in 2011 by the radial velocity method.
HD 20794 d is a super-earth orbiting HD 20794, discovered in 2011 by the radial velocity method.
HD 20794 e is a super-earth orbiting HD 20794, discovered in 2017 by the radial velocity method.
HD 20794 f is a super-earth orbiting HD 20794, discovered in 2025 by the radial velocity method.
HD 208487 b is a gas giant orbiting HD 208487, discovered in 2004 by the radial velocity method.
HD 20868 b is a gas giant orbiting HD 20868, discovered in 2008 by the radial velocity method.
HD 210277 b is a gas giant orbiting HD 210277, discovered in 1998 by the radial velocity method.
HD 211970 b is a mini-neptune orbiting HD 211970, discovered in 2019 by the radial velocity method.
HD 212771 b is a gas giant orbiting HD 212771, discovered in 2009 by the radial velocity method.
HD 215152 b is an exoplanet orbiting HD 215152, discovered in 2018 by the radial velocity method.
HD 215152 c is an exoplanet orbiting HD 215152, discovered in 2018 by the radial velocity method.
HD 215152 d is an exoplanet orbiting HD 215152, discovered in 2018 by the radial velocity method.
HD 215152 e is an exoplanet orbiting HD 215152, discovered in 2018 by the radial velocity method.
HD 217107 b is a hot jupiter orbiting HD 217107, discovered in 1998 by the radial velocity method.
HD 217107 c is a gas giant orbiting HD 217107, discovered in 2005 by the radial velocity method.
HD 218566 b is a gas giant orbiting HD 218566, discovered in 2010 by the radial velocity method.
HD 219077 b is a gas giant orbiting HD 219077, discovered in 2012 by the radial velocity method.
HD 219134 b is a super-earth orbiting HD 219134, discovered in 2015 by the radial velocity method.
HD 219134 c is a terrestrial planet orbiting HD 219134, discovered in 2015 by the radial velocity method.
HD 219134 d is a super-earth orbiting HD 219134, discovered in 2015 by the radial velocity method.
HD 219134 f is a terrestrial planet orbiting HD 219134, discovered in 2015 by the radial velocity method.
HD 219134 g is a mini-neptune orbiting HD 219134, discovered in 2015 by the radial velocity method.
HD 219134 h is a gas giant orbiting HD 219134, discovered in 2015 by the radial velocity method.
HD 221287 b is a gas giant orbiting HD 221287, discovered in 2007 by the radial velocity method.
HD 222237 b is a gas giant orbiting HD 222237, discovered in 2024 by the radial velocity method.
HD 224693 b is a gas giant orbiting HD 224693, discovered in 2006 by the radial velocity method.
HD 22496 b is a super-earth orbiting HD 22496, discovered in 2021 by the radial velocity method.
HD 23079 b is a gas giant orbiting HD 23079, discovered in 2001 by the radial velocity method.
HD 23079 c is a mini-neptune orbiting HD 23079, discovered in 2025 by the radial velocity method.
HD 231701 b is a gas giant orbiting HD 231701, discovered in 2007 by the radial velocity method.
HD 260655 b is a terrestrial planet orbiting HD 260655, discovered in 2022 by the transit method.
HD 260655 c is a terrestrial planet orbiting HD 260655, discovered in 2022 by the transit method.
HD 27442 b is a gas giant orbiting HD 27442, discovered in 2000 by the radial velocity method.
HD 27894 b is a gas giant orbiting HD 27894, discovered in 2005 by the radial velocity method.
HD 27894 c is a gas giant orbiting HD 27894, discovered in 2017 by the radial velocity method.
HD 27894 d is a gas giant orbiting HD 27894, discovered in 2017 by the radial velocity method.
HD 284149 AB b is a gas giant orbiting HD 284149 A, discovered in 2017 by the direct imaging.
HD 285968 b is a mini-neptune orbiting HD 285968, discovered in 2008 by the radial velocity method.
HD 28678 b is a gas giant orbiting HD 28678, discovered in 2011 by the radial velocity method.
HD 30856 b is a gas giant orbiting HD 30856, discovered in 2011 by the radial velocity method.
HD 32518 b is a gas giant orbiting HD 32518, discovered in 2009 by the radial velocity method.
HD 33142 b is a gas giant orbiting HD 33142, discovered in 2011 by the radial velocity method.
HD 33142 c is a gas giant orbiting HD 33142, discovered in 2016 by the radial velocity method.
HD 33142 d is a gas giant orbiting HD 33142, discovered in 2022 by the radial velocity method.
HD 33564 b is a gas giant orbiting HD 33564, discovered in 2005 by the radial velocity method.
HD 34445 b is a gas giant orbiting HD 34445, discovered in 2009 by the radial velocity method.
HD 34445 c is a gas giant orbiting HD 34445, discovered in 2017 by the radial velocity method.
HD 34445 d is a gas giant orbiting HD 34445, discovered in 2017 by the radial velocity method.
HD 34445 e is a mini-neptune orbiting HD 34445, discovered in 2017 by the radial velocity method.
HD 34445 f is a gas giant orbiting HD 34445, discovered in 2017 by the radial velocity method.
HD 34445 g is a gas giant orbiting HD 34445, discovered in 2017 by the radial velocity method.
HD 3651 b is a gas giant orbiting HD 3651, discovered in 2003 by the radial velocity method.
HD 37124 b is a gas giant orbiting HD 37124, discovered in 2002 by the radial velocity method.
HD 37124 c is a gas giant orbiting HD 37124, discovered in 2002 by the radial velocity method.
HD 37124 d is a gas giant orbiting HD 37124, discovered in 2005 by the radial velocity method.
HD 38283 b is a gas giant orbiting HD 38283, discovered in 2010 by the radial velocity method.
HD 39091 b is a gas giant orbiting HD 39091, discovered in 2001 by the radial velocity method.
pi Men c is a super-earth orbiting HD 39091, discovered in 2018 by the transit method.
pi Men d is a mini-neptune orbiting HD 39091, discovered in 2022 by the radial velocity method.
HD 39194 b is a super-earth orbiting HD 39194, discovered in 2021 by the radial velocity method.
HD 39194 c is a mini-neptune orbiting HD 39194, discovered in 2021 by the radial velocity method.
HD 39194 d is a super-earth orbiting HD 39194, discovered in 2021 by the radial velocity method.
HD 40307 b is an exoplanet orbiting HD 40307, discovered in 2009 by the radial velocity method.
HD 40307 c is an exoplanet orbiting HD 40307, discovered in 2009 by the radial velocity method.
HD 40307 d is an exoplanet orbiting HD 40307, discovered in 2009 by the radial velocity method.
HD 40307 f is a super-earth orbiting HD 40307, discovered in 2013 by the radial velocity method.
HD 40307 g is a mini-neptune orbiting HD 40307, discovered in 2013 by the radial velocity method.
HD 4208 b is a gas giant orbiting HD 4208, discovered in 2001 by the radial velocity method.
HD 4308 b is a mini-neptune orbiting HD 4308, discovered in 2005 by the radial velocity method.
HD 43197 b is a gas giant orbiting HD 43197, discovered in 2010 by the radial velocity method.
HD 43197 c is a gas giant orbiting HD 43197, discovered in 2022 by the radial velocity method.
HD 45184 b is a mini-neptune orbiting HD 45184, discovered in 2019 by the radial velocity method.
HD 45184 c is a mini-neptune orbiting HD 45184, discovered in 2019 by the radial velocity method.
HD 45350 b is a gas giant orbiting HD 45350, discovered in 2004 by the radial velocity method.
HD 45652 b is a gas giant orbiting HD 45652, discovered in 2008 by the radial velocity method.
HD 46375 b is a hot jupiter orbiting HD 46375, discovered in 2000 by the radial velocity method.
HD 47536 b is a gas giant orbiting HD 47536, discovered in 2002 by the radial velocity method.
HD 48265 b is a gas giant orbiting HD 48265, discovered in 2008 by the radial velocity method.
HD 48265 c is a gas giant orbiting HD 48265, discovered in 2026 by the radial velocity method.
HD 48948 b is a super-earth orbiting HD 48948, discovered in 2024 by the radial velocity method.
HD 48948 c is a mini-neptune orbiting HD 48948, discovered in 2024 by the radial velocity method.
HD 48948 d is a mini-neptune orbiting HD 48948, discovered in 2024 by the radial velocity method.
HD 49674 b is a hot jupiter orbiting HD 49674, discovered in 2002 by the radial velocity method.
HD 52265 b is a gas giant orbiting HD 52265, discovered in 2000 by the radial velocity method.
HD 60532 b is a gas giant orbiting HD 60532, discovered in 2008 by the radial velocity method.
HD 60532 c is a gas giant orbiting HD 60532, discovered in 2008 by the radial velocity method.
HD 62509 b is a gas giant orbiting HD 62509, discovered in 2006 by the radial velocity method.
HD 63433 b is a super-earth orbiting HD 63433, discovered in 2020 by the transit method.
HD 63433 c is a mini-neptune orbiting HD 63433, discovered in 2020 by the transit method.
HD 63433 d is a terrestrial planet orbiting HD 63433, discovered in 2023 by the transit method.
HD 63454 b is a hot jupiter orbiting HD 63454, discovered in 2005 by the radial velocity method.
HD 63765 b is a gas giant orbiting HD 63765, discovered in 2009 by the radial velocity method.
HD 6434 b is a gas giant orbiting HD 6434, discovered in 2003 by the radial velocity method.
HD 66141 b is a gas giant orbiting HD 66141, discovered in 2012 by the radial velocity method.
HD 68988 b is a hot jupiter orbiting HD 68988, discovered in 2001 by the radial velocity method.
HD 68988 c is a gas giant orbiting HD 68988, discovered in 2021 by the radial velocity method.
HD 69830 b is a mini-neptune orbiting HD 69830, discovered in 2006 by the radial velocity method.
HD 69830 c is a mini-neptune orbiting HD 69830, discovered in 2006 by the radial velocity method.
HD 69830 d is a mini-neptune orbiting HD 69830, discovered in 2006 by the radial velocity method.
HD 7199 b is an exoplanet orbiting HD 7199, discovered in 2011 by the radial velocity method.
HD 73534 b is a gas giant orbiting HD 73534, discovered in 2008 by the radial velocity method.
HD 75289 b is a hot jupiter orbiting HD 75289, discovered in 1999 by the radial velocity method.
HD 75898 b is a gas giant orbiting HD 75898, discovered in 2007 by the radial velocity method.
HD 75898 c is a gas giant orbiting HD 75898, discovered in 2024 by the radial velocity method.
HD 7924 b is an exoplanet orbiting HD 7924, discovered in 2008 by the radial velocity method.
HD 7924 c is an exoplanet orbiting HD 7924, discovered in 2015 by the radial velocity method.
HD 7924 d is an exoplanet orbiting HD 7924, discovered in 2015 by the radial velocity method.
HD 81688 b is a gas giant orbiting HD 81688, discovered in 2007 by the radial velocity method.
HD 81817 b is a gas giant orbiting HD 81817, discovered in 2020 by the radial velocity method.
HD 81817 c is a gas giant orbiting HD 81817, discovered in 2022 by the radial velocity method.
HD 82886 b is a gas giant orbiting HD 82886, discovered in 2011 by the radial velocity method.
HD 82943 b is a gas giant orbiting HD 82943, discovered in 2003 by the radial velocity method.
HD 82943 c is a gas giant orbiting HD 82943, discovered in 2003 by the radial velocity method.
HD 83443 b is a hot jupiter orbiting HD 83443, discovered in 2002 by the radial velocity method.
HD 83443 c is a gas giant orbiting HD 83443, discovered in 2022 by the radial velocity method.
HD 85390 b is a gas giant orbiting HD 85390, discovered in 2009 by the radial velocity method.
HD 8574 b is a gas giant orbiting HD 8574, discovered in 2002 by the radial velocity method.
HD 86081 b is a hot jupiter orbiting HD 86081, discovered in 2006 by the radial velocity method.
HD 86728 b is a mini-neptune orbiting HD 86728, discovered in 2025 by the radial velocity method.
HD 90156 b is a mini-neptune orbiting HD 90156, discovered in 2009 by the radial velocity method.
GJ 1137 c is a super-earth orbiting HD 93083, discovered in 2026 by the radial velocity method.
HD 93083 b is a gas giant orbiting HD 93083, discovered in 2005 by the radial velocity method.
HD 94890 b is a gas giant orbiting HD 94890, discovered in 2025 by the radial velocity method.
HD 94890 c is a gas giant orbiting HD 94890, discovered in 2025 by the radial velocity method.
HD 95086 b is a gas giant orbiting HD 95086, discovered in 2013 by the direct imaging.
HD 96063 b is a gas giant orbiting HD 96063, discovered in 2011 by the radial velocity method.
HD 96700 b is a mini-neptune orbiting HD 96700, discovered in 2021 by the radial velocity method.
HD 96700 c is a super-earth orbiting HD 96700, discovered in 2021 by the radial velocity method.
HD 96700 d is a mini-neptune orbiting HD 96700, discovered in 2021 by the radial velocity method.
HD 97658 b is a super-earth orbiting HD 97658, discovered in 2010 by the radial velocity method.
HD 98219 b is a gas giant orbiting HD 98219, discovered in 2011 by the radial velocity method.
HD 99109 b is a gas giant orbiting HD 99109, discovered in 2005 by the radial velocity method.
HD 99492 b is a mini-neptune orbiting HD 99492, discovered in 2004 by the radial velocity method.
HD 99492 c is a mini-neptune orbiting HD 99492, discovered in 2023 by the radial velocity method.
HIP 12961 b is a gas giant orbiting HIP 12961, discovered in 2010 by the radial velocity method.
HIP 14810 b is a hot jupiter orbiting HIP 14810, discovered in 2005 by the radial velocity method.
HIP 14810 c is a gas giant orbiting HIP 14810, discovered in 2006 by the radial velocity method.
HIP 14810 d is a gas giant orbiting HIP 14810, discovered in 2009 by the radial velocity method.
HIP 21152 b is a gas giant orbiting HIP 21152, discovered in 2022 by the direct imaging.
HIP 39017 b is a gas giant orbiting HIP 39017, discovered in 2024 by the direct imaging.
HIP 41378 b is a mini-neptune orbiting HIP 41378, discovered in 2016 by the transit method.
HIP 41378 c is a mini-neptune orbiting HIP 41378, discovered in 2016 by the transit method.
HIP 41378 d is a mini-neptune orbiting HIP 41378, discovered in 2016 by the transit method.
HIP 41378 e is a mini-neptune orbiting HIP 41378, discovered in 2016 by the transit method.
HIP 41378 f is a gas giant orbiting HIP 41378, discovered in 2016 by the transit method.
HIP 41378 g is a mini-neptune orbiting HIP 41378, discovered in 2025 by the radial velocity method.
HIP 48714 b is a mini-neptune orbiting HIP 48714, discovered in 2020 by the radial velocity method.
HIP 54515 b is a gas giant orbiting HIP 54515, discovered in 2026 by the direct imaging.
HD 101581 b is a terrestrial planet orbiting HIP 56998, discovered in 2025 by the transit method.
HD 101581 c is a terrestrial planet orbiting HIP 56998, discovered in 2025 by the transit method.
HIP 57274 b is an exoplanet orbiting HIP 57274, discovered in 2011 by the radial velocity method.
HIP 57274 c is a gas giant orbiting HIP 57274, discovered in 2011 by the radial velocity method.
HIP 57274 d is a gas giant orbiting HIP 57274, discovered in 2011 by the radial velocity method.
HIP 65426 b is a gas giant orbiting HIP 65426, discovered in 2017 by the direct imaging.
HIP 66074 b is a gas giant orbiting HIP 66074, discovered in 2023 by the astrometry.
HIP 70849 b is a gas giant orbiting HIP 70849, discovered in 2009 by the radial velocity method.
HIP 77900 b is a gas giant orbiting HIP 77900, discovered in 2024 by the direct imaging.
HIP 78530 b is a gas giant orbiting HIP 78530, discovered in 2010 by the direct imaging.
HIP 79098 AB b is a gas giant orbiting HIP 79098 AB, discovered in 2019 by the direct imaging.
HIP 79431 b is a gas giant orbiting HIP 79431, discovered in 2009 by the radial velocity method.
HIP 81208 C b is a gas giant orbiting HIP 81208 C, discovered in 2023 by the direct imaging.
HIP 99770 b is a gas giant orbiting HIP 99770, discovered in 2023 by the direct imaging.
HN Lib b is a super-earth orbiting HN Lib, discovered in 2023 by the radial velocity method.
HN Peg b is a gas giant orbiting HN Peg, discovered in 2006 by the direct imaging.
HR 2562 b is a gas giant orbiting HR 2562, discovered in 2016 by the direct imaging.
HR 810 b is a gas giant orbiting HR 810, discovered in 1999 by the radial velocity method.
HR 8799 b is a gas giant orbiting HR 8799, discovered in 2008 by the direct imaging.
HR 8799 c is a gas giant orbiting HR 8799, discovered in 2008 by the direct imaging.
HR 8799 d is a gas giant orbiting HR 8799, discovered in 2008 by the direct imaging.
HR 8799 e is a gas giant orbiting HR 8799, discovered in 2010 by the direct imaging.
KOINTREAU-3 b is a gas giant orbiting ISO-Oph 96, discovered in 2026 by the direct imaging.
ITG 15 b is a gas giant orbiting ITG 15 A, discovered in 2024 by the direct imaging.
K2-18 b is a super-earth orbiting K2-18, discovered in 2015 by the transit method.
K2-18 c is a mini-neptune orbiting K2-18, discovered in 2017 by the radial velocity method.
kap And b is a gas giant orbiting kap And, discovered in 2012 by the direct imaging.
Kapteyn c is a mini-neptune orbiting Kapteyn, discovered in 2014 by the radial velocity method.
KELT-9 b is a hot jupiter orbiting KELT-9, discovered in 2017 by the transit method.
Kepler-100 b is a terrestrial planet orbiting Kepler-100, discovered in 2014 by the transit method.
Kepler-100 c is a super-earth orbiting Kepler-100, discovered in 2014 by the transit method.
Kepler-100 d is a super-earth orbiting Kepler-100, discovered in 2014 by the transit method.
Kepler-100 e is a mini-neptune orbiting Kepler-100, discovered in 2023 by the radial velocity method.
Kepler-11 b is a super-earth orbiting Kepler-11, discovered in 2010 by the transit method.
Kepler-11 c is a mini-neptune orbiting Kepler-11, discovered in 2010 by the transit method.
Kepler-11 d is a mini-neptune orbiting Kepler-11, discovered in 2010 by the transit method.
Kepler-11 e is a mini-neptune orbiting Kepler-11, discovered in 2010 by the transit method.
Kepler-11 f is a mini-neptune orbiting Kepler-11, discovered in 2010 by the transit method.
Kepler-11 g is a mini-neptune orbiting Kepler-11, discovered in 2010 by the transit method.
Kepler-122 b is a super-earth orbiting Kepler-122, discovered in 2014 by the transit method.
Kepler-122 c is a gas giant orbiting Kepler-122, discovered in 2014 by the transit method.
Kepler-122 d is a super-earth orbiting Kepler-122, discovered in 2014 by the transit method.
Kepler-122 e is a mini-neptune orbiting Kepler-122, discovered in 2014 by the transit method.
Kepler-122 f is a super-earth orbiting Kepler-122, discovered in 2014 by the transit timing variations.
Kepler-138 b is a terrestrial planet orbiting Kepler-138, discovered in 2014 by the transit method.
Kepler-138 c is a terrestrial planet orbiting Kepler-138, discovered in 2014 by the transit method.
Kepler-138 d is a terrestrial planet orbiting Kepler-138, discovered in 2014 by the transit method.
Kepler-138 e is a terrestrial planet orbiting Kepler-138, discovered in 2022 by the transit timing variations.
Kepler-139 b is a mini-neptune orbiting Kepler-139, discovered in 2014 by the transit method.
Kepler-139 c is a mini-neptune orbiting Kepler-139, discovered in 2014 by the transit method.
Kepler-139 d is a super-earth orbiting Kepler-139, discovered in 2023 by the transit method.
Kepler-139 e is a gas giant orbiting Kepler-139, discovered in 2023 by the radial velocity method.
Kepler-139 f is a gas giant orbiting Kepler-139, discovered in 2025 by the transit timing variations.
Kepler-16 b is a gas giant orbiting Kepler-16, discovered in 2011 by the transit method.
Kepler-1649 b is a terrestrial planet orbiting Kepler-1649, discovered in 2017 by the transit method.
Kepler-1649 c is a terrestrial planet orbiting Kepler-1649, discovered in 2020 by the transit method.
Kepler-1660 AB b is a gas giant orbiting Kepler-1660 A, discovered in 2023 by the eclipse timing variations.
Kepler-186 b is a terrestrial planet orbiting Kepler-186, discovered in 2014 by the transit method.
Kepler-186 c is a terrestrial planet orbiting Kepler-186, discovered in 2014 by the transit method.
Kepler-186 d is a terrestrial planet orbiting Kepler-186, discovered in 2014 by the transit method.
Kepler-186 e is a terrestrial planet orbiting Kepler-186, discovered in 2014 by the transit method.
Kepler-19 b is a super-earth orbiting Kepler-19, discovered in 2011 by the transit method.
Kepler-19 c is a mini-neptune orbiting Kepler-19, discovered in 2011 by the transit timing variations.
Kepler-19 d is a mini-neptune orbiting Kepler-19, discovered in 2017 by the radial velocity method.
Kepler-20 b is a super-earth orbiting Kepler-20, discovered in 2011 by the transit method.
Kepler-20 c is a mini-neptune orbiting Kepler-20, discovered in 2011 by the transit method.
Kepler-20 d is a mini-neptune orbiting Kepler-20, discovered in 2011 by the transit method.
Kepler-20 e is a terrestrial planet orbiting Kepler-20, discovered in 2011 by the transit method.
Kepler-20 f is a terrestrial planet orbiting Kepler-20, discovered in 2011 by the transit method.
Kepler-20 g is a mini-neptune orbiting Kepler-20, discovered in 2016 by the radial velocity method.
Kepler-24 b is a super-earth orbiting Kepler-24, discovered in 2011 by the transit method.
Kepler-24 c is a mini-neptune orbiting Kepler-24, discovered in 2011 by the transit method.
Kepler-24 d is a super-earth orbiting Kepler-24, discovered in 2014 by the transit method.
Kepler-24 e is a mini-neptune orbiting Kepler-24, discovered in 2014 by the transit method.
Kepler-26 b is a mini-neptune orbiting Kepler-26, discovered in 2011 by the transit method.
Kepler-26 c is a mini-neptune orbiting Kepler-26, discovered in 2011 by the transit method.
Kepler-26 d is a terrestrial planet orbiting Kepler-26, discovered in 2014 by the transit method.
Kepler-26 e is a mini-neptune orbiting Kepler-26, discovered in 2014 by the transit method.
Kepler-32 b is a super-earth orbiting Kepler-32, discovered in 2011 by the transit method.
Kepler-32 c is a super-earth orbiting Kepler-32, discovered in 2011 by the transit method.
Kepler-32 d is a mini-neptune orbiting Kepler-32, discovered in 2012 by the transit method.
Kepler-32 e is a terrestrial planet orbiting Kepler-32, discovered in 2012 by the transit method.
Kepler-32 f is a terrestrial planet orbiting Kepler-32, discovered in 2012 by the transit method.
Kepler-33 b is a super-earth orbiting Kepler-33, discovered in 2011 by the transit method.
Kepler-33 c is a mini-neptune orbiting Kepler-33, discovered in 2011 by the transit method.
Kepler-33 d is a mini-neptune orbiting Kepler-33, discovered in 2011 by the transit method.
Kepler-33 e is a mini-neptune orbiting Kepler-33, discovered in 2011 by the transit method.
Kepler-33 f is a mini-neptune orbiting Kepler-33, discovered in 2011 by the transit method.
Kepler-338 b is a mini-neptune orbiting Kepler-338, discovered in 2014 by the transit method.
Kepler-338 c is a super-earth orbiting Kepler-338, discovered in 2014 by the transit method.
Kepler-338 d is a mini-neptune orbiting Kepler-338, discovered in 2014 by the transit method.
Kepler-338 e is a terrestrial planet orbiting Kepler-338, discovered in 2014 by the transit timing variations.
Kepler-37 b is a terrestrial planet orbiting Kepler-37, discovered in 2013 by the transit method.
Kepler-37 c is a terrestrial planet orbiting Kepler-37, discovered in 2013 by the transit method.
Kepler-37 d is a super-earth orbiting Kepler-37, discovered in 2013 by the transit method.
Kepler-37 e is a terrestrial planet orbiting Kepler-37, discovered in 2014 by the transit timing variations.
Kepler-411 b is a mini-neptune orbiting Kepler-411, discovered in 2013 by the transit method.
Kepler-411 c is a mini-neptune orbiting Kepler-411, discovered in 2016 by the transit method.
Kepler-411 d is a mini-neptune orbiting Kepler-411, discovered in 2018 by the transit method.
Kepler-411 e is a mini-neptune orbiting Kepler-411, discovered in 2018 by the transit timing variations.
Kepler-416 b is a mini-neptune orbiting Kepler-416, discovered in 2014 by the transit timing variations.
Kepler-416 c is a super-earth orbiting Kepler-416, discovered in 2014 by the transit timing variations.
Kepler-416 d is a super-earth orbiting Kepler-416, discovered in 2023 by the transit method.
Kepler-442 b is a terrestrial planet orbiting Kepler-442, discovered in 2015 by the transit method.
Kepler-452 b is a super-earth orbiting Kepler-452, discovered in 2015 by the transit method.
Kepler-46 b is a gas giant orbiting Kepler-46, discovered in 2012 by the transit method.
Kepler-46 c is a gas giant orbiting Kepler-46, discovered in 2012 by the transit timing variations.
Kepler-46 d is a super-earth orbiting Kepler-46, discovered in 2014 by the transit method.
Kepler-48 b is a super-earth orbiting Kepler-48, discovered in 2012 by the transit method.
Kepler-48 c is a mini-neptune orbiting Kepler-48, discovered in 2012 by the transit method.
Kepler-48 d is a super-earth orbiting Kepler-48, discovered in 2014 by the transit method.
Kepler-48 e is a gas giant orbiting Kepler-48, discovered in 2014 by the radial velocity method.
Kepler-48 f is a gas giant orbiting Kepler-48, discovered in 2023 by the radial velocity method.
Kepler-49 b is a mini-neptune orbiting Kepler-49, discovered in 2012 by the transit method.
Kepler-49 c is a mini-neptune orbiting Kepler-49, discovered in 2012 by the transit method.
Kepler-49 d is a super-earth orbiting Kepler-49, discovered in 2014 by the transit method.
Kepler-49 e is a terrestrial planet orbiting Kepler-49, discovered in 2014 by the transit method.
Kepler-51 b is a gas giant orbiting Kepler-51, discovered in 2012 by the transit method.
Kepler-51 c is a gas giant orbiting Kepler-51, discovered in 2012 by the transit method.
Kepler-51 d is a gas giant orbiting Kepler-51, discovered in 2014 by the transit method.
Kepler-51 e is a super-earth orbiting Kepler-51, discovered in 2024 by the transit timing variations.
Kepler-55 b is a mini-neptune orbiting Kepler-55, discovered in 2012 by the transit method.
Kepler-55 c is a super-earth orbiting Kepler-55, discovered in 2012 by the transit method.
Kepler-55 d is a terrestrial planet orbiting Kepler-55, discovered in 2014 by the transit method.
Kepler-55 e is a terrestrial planet orbiting Kepler-55, discovered in 2014 by the transit method.
Kepler-55 f is a terrestrial planet orbiting Kepler-55, discovered in 2014 by the transit method.
Kepler-58 b is a mini-neptune orbiting Kepler-58, discovered in 2012 by the transit method.
Kepler-58 c is a mini-neptune orbiting Kepler-58, discovered in 2012 by the transit method.
Kepler-58 d is a mini-neptune orbiting Kepler-58, discovered in 2014 by the transit method.
Kepler-58 e is a super-earth orbiting Kepler-58, discovered in 2023 by the transit method.
Kepler-65 b is a terrestrial planet orbiting Kepler-65, discovered in 2012 by the transit method.
Kepler-65 c is a mini-neptune orbiting Kepler-65, discovered in 2012 by the transit method.
Kepler-65 d is a terrestrial planet orbiting Kepler-65, discovered in 2012 by the transit method.
Kepler-65 e is a gas giant orbiting Kepler-65, discovered in 2019 by the radial velocity method.
Kepler-68 b is a super-earth orbiting Kepler-68, discovered in 2013 by the transit method.
Kepler-68 c is a terrestrial planet orbiting Kepler-68, discovered in 2013 by the transit method.
Kepler-68 d is a gas giant orbiting Kepler-68, discovered in 2013 by the radial velocity method.
Kepler-68 e is a gas giant orbiting Kepler-68, discovered in 2023 by the radial velocity method.
Kepler-79 b is a mini-neptune orbiting Kepler-79, discovered in 2012 by the transit method.
Kepler-79 c is a mini-neptune orbiting Kepler-79, discovered in 2012 by the transit method.
Kepler-79 d is a gas giant orbiting Kepler-79, discovered in 2014 by the transit method.
Kepler-79 e is a mini-neptune orbiting Kepler-79, discovered in 2014 by the transit method.
Kepler-80 b is a mini-neptune orbiting Kepler-80, discovered in 2012 by the transit method.
Kepler-80 c is a mini-neptune orbiting Kepler-80, discovered in 2012 by the transit method.
Kepler-80 d is a terrestrial planet orbiting Kepler-80, discovered in 2014 by the transit method.
Kepler-80 e is a super-earth orbiting Kepler-80, discovered in 2014 by the transit method.
Kepler-80 f is a terrestrial planet orbiting Kepler-80, discovered in 2016 by the transit method.
Kepler-80 g is a terrestrial planet orbiting Kepler-80, discovered in 2017 by the transit method.
Kepler-82 b is a mini-neptune orbiting Kepler-82, discovered in 2012 by the transit method.
Kepler-82 c is a mini-neptune orbiting Kepler-82, discovered in 2012 by the transit method.
Kepler-82 d is a super-earth orbiting Kepler-82, discovered in 2014 by the transit method.
Kepler-82 e is a mini-neptune orbiting Kepler-82, discovered in 2014 by the transit method.
Kepler-82 f is a mini-neptune orbiting Kepler-82, discovered in 2019 by the transit timing variations.
Kepler-84 b is a super-earth orbiting Kepler-84, discovered in 2012 by the transit method.
Kepler-84 c is a super-earth orbiting Kepler-84, discovered in 2012 by the transit method.
Kepler-84 d is a terrestrial planet orbiting Kepler-84, discovered in 2014 by the transit method.
Kepler-84 e is a mini-neptune orbiting Kepler-84, discovered in 2014 by the transit method.
Kepler-84 f is a super-earth orbiting Kepler-84, discovered in 2014 by the transit method.
Kepler-85 b is a super-earth orbiting Kepler-85, discovered in 2012 by the transit method.
Kepler-85 c is a super-earth orbiting Kepler-85, discovered in 2012 by the transit method.
Kepler-85 d is a terrestrial planet orbiting Kepler-85, discovered in 2014 by the transit method.
Kepler-85 e is a terrestrial planet orbiting Kepler-85, discovered in 2014 by the transit method.
Kepler-88 d is a gas giant orbiting KOI-142, discovered in 2020 by the radial velocity method.
KOI-142 b is a mini-neptune orbiting KOI-142, discovered in 2013 by the transit method.
KOI-142 c is a gas giant orbiting KOI-142, discovered in 2013 by the transit timing variations.
L 363-38 b is a super-earth orbiting L 363-38, discovered in 2023 by the radial velocity method.
L 98-59 b is a terrestrial planet orbiting L 98-59, discovered in 2019 by the transit method.
L 98-59 c is a terrestrial planet orbiting L 98-59, discovered in 2019 by the transit method.
L 98-59 d is a super-earth orbiting L 98-59, discovered in 2019 by the transit method.
L 98-59 e is a terrestrial planet orbiting L 98-59, discovered in 2021 by the radial velocity method.
L 98-59 f is a terrestrial planet orbiting L 98-59, discovered in 2025 by the radial velocity method.
LHS 1140 b is a super-earth orbiting LHS 1140, discovered in 2017 by the transit method.
LHS 1140 c is a terrestrial planet orbiting LHS 1140, discovered in 2018 by the transit method.
LHS 1678 b is a terrestrial planet orbiting LHS 1678, discovered in 2021 by the transit method.
LHS 1678 c is a terrestrial planet orbiting LHS 1678, discovered in 2021 by the transit method.
LHS 1678 d is a terrestrial planet orbiting LHS 1678, discovered in 2024 by the transit method.
LHS 3844 b is a terrestrial planet orbiting LHS 3844, discovered in 2019 by the transit method.
LHS 475 b is a terrestrial planet orbiting LHS 475, discovered in 2023 by the transit method.
LkCa 15 b is an exoplanet orbiting LkCa 15, discovered in 2015 by the direct imaging.
LkCa 15 c is an exoplanet orbiting LkCa 15, discovered in 2015 by the direct imaging.
LP 261-75 b is a gas giant orbiting LP 261-75 A, discovered in 2006 by the direct imaging.
LP 791-18 b is a terrestrial planet orbiting LP 791-18, discovered in 2019 by the transit method.
LP 791-18 c is a mini-neptune orbiting LP 791-18, discovered in 2019 by the transit method.
LP 791-18 d is a terrestrial planet orbiting LP 791-18, discovered in 2023 by the transit method.
LP 890-9 b is a terrestrial planet orbiting LP 890-9, discovered in 2022 by the transit method.
LP 890-9 c is a terrestrial planet orbiting LP 890-9, discovered in 2022 by the transit method.
LTT 1445 A b is a terrestrial planet orbiting LTT 1445 A, discovered in 2019 by the transit method.
LTT 1445 A c is a terrestrial planet orbiting LTT 1445 A, discovered in 2022 by the transit method.
Luhman 16 b is a gas giant orbiting Luhman 16 A, discovered in 2017 by the direct imaging.
M62H b is an exoplanet orbiting M62H, discovered in 2024 by the pulsar timing.
MOA-2007-BLG-192L b is a mini-neptune orbiting MOA-2007-BLG-192L, discovered in 2008 by the microlensing.
mu Leo b is a gas giant orbiting mu Leo, discovered in 2014 by the radial velocity method.
mu2 Sco b is a gas giant orbiting mu2 Sco, discovered in 2022 by the direct imaging.
MWC 758 c is an exoplanet orbiting MWC 758, discovered in 2023 by the direct imaging.
NN Ser c is a gas giant orbiting NN Ser, discovered in 2010 by the eclipse timing variations.
NN Ser d is a gas giant orbiting NN Ser, discovered in 2010 by the eclipse timing variations.
nu Oph b is a gas giant orbiting nu Oph, discovered in 2012 by the radial velocity method.
nu Oph c is a gas giant orbiting nu Oph, discovered in 2012 by the radial velocity method.
NY Vir b is a gas giant orbiting NY Vir, discovered in 2011 by the eclipse timing variations.
NY Vir c is a gas giant orbiting NY Vir, discovered in 2019 by the eclipse timing variations.
OGLE-2005-BLG-071L b is a gas giant orbiting OGLE-2005-BLG-071L, discovered in 2005 by the microlensing.
OGLE-2005-BLG-390L b is a super-earth orbiting OGLE-2005-BLG-390L, discovered in 2005 by the microlensing.
OGLE-2006-BLG-109L b is a gas giant orbiting OGLE-2006-BLG-109L, discovered in 2008 by the microlensing.
OGLE-2006-BLG-109L c is a gas giant orbiting OGLE-2006-BLG-109L, discovered in 2008 by the microlensing.
OGLE-2007-BLG-368L b is a mini-neptune orbiting OGLE-2007-BLG-368L, discovered in 2009 by the microlensing.
OGLE-2012-BLG-0026L b is a gas giant orbiting OGLE-2012-BLG-0026L, discovered in 2012 by the microlensing.
OGLE-2012-BLG-0026L c is a gas giant orbiting OGLE-2012-BLG-0026L, discovered in 2012 by the microlensing.
Oph 11 b is a gas giant orbiting Oph 11, discovered in 2006 by the direct imaging.
PDS 70 b is a gas giant orbiting PDS 70, discovered in 2018 by the direct imaging.
PDS 70 c is a gas giant orbiting PDS 70, discovered in 2019 by the direct imaging.
Proxima Cen d is a terrestrial planet orbiting Proxima Cen, discovered in 2025 by the radial velocity method.
PSR B0329+54 b is a terrestrial planet orbiting PSR B0329+54, discovered in 2017 by the pulsar timing.
PSR B1257+12 b is a terrestrial planet orbiting PSR B1257+12, discovered in 1994 by the pulsar timing.
PSR B1257+12 c is a super-earth orbiting PSR B1257+12, discovered in 1992 by the pulsar timing.
PSR B1257+12 d is a super-earth orbiting PSR B1257+12, discovered in 1992 by the pulsar timing.
PSR B1620-26 b is a gas giant orbiting PSR B1620-26, discovered in 2003 by the pulsar timing.
PSR J1719-1438 b is an exoplanet orbiting PSR J1719-1438, discovered in 2011 by the pulsar timing.
PSR J2322-2650 b is a hot jupiter orbiting PSR J2322-2650, discovered in 2017 by the pulsar timing.
PZ Tel b is a gas giant orbiting PZ Tel, discovered in 2023 by the direct imaging.
rho CrB b is a gas giant orbiting rho CrB, discovered in 1997 by the radial velocity method.
rho CrB c is a gas giant orbiting rho CrB, discovered in 2016 by the radial velocity method.
rho CrB e is a super-earth orbiting rho CrB, discovered in 2023 by the radial velocity method.
Ross 128 b is a terrestrial planet orbiting Ross 128, discovered in 2017 by the radial velocity method.
Ross 458 c is a gas giant orbiting Ross 458, discovered in 2010 by the direct imaging.
Ross 508 b is a super-earth orbiting Ross 508, discovered in 2022 by the radial velocity method.
ROXs 12 b is a gas giant orbiting ROXs 12, discovered in 2013 by the direct imaging.
ROXs 42 B b is a gas giant orbiting ROXs 42 B, discovered in 2013 by the direct imaging.
RR Cae b is a gas giant orbiting RR Cae, discovered in 2012 by the eclipse timing variations.
SR 12 AB c is a gas giant orbiting SR 12 AB, discovered in 2010 by the direct imaging.
tau Boo b is a hot jupiter orbiting tau Boo, discovered in 1996 by the radial velocity method.
tau Cet f is a super-earth orbiting tau Cet, discovered in 2017 by the radial velocity method.
tau Cet g is a terrestrial planet orbiting tau Cet, discovered in 2017 by the radial velocity method.
tau Cet h is a terrestrial planet orbiting tau Cet, discovered in 2017 by the radial velocity method.
tau Gem b is a gas giant orbiting tau Gem, discovered in 2013 by the radial velocity method.
Teegarden's Star b is a terrestrial planet orbiting Teegarden's Star, discovered in 2019 by the radial velocity method.
Teegarden's Star c is a terrestrial planet orbiting Teegarden's Star, discovered in 2019 by the radial velocity method.
Teegarden's Star d is a terrestrial planet orbiting Teegarden's Star, discovered in 2024 by the radial velocity method.
TOI-1203 b is a terrestrial planet orbiting TOI-1203, discovered in 2025 by the radial velocity method.
TOI-1203 c is a super-earth orbiting TOI-1203, discovered in 2025 by the radial velocity method.
TOI-1203 e is a gas giant orbiting TOI-1203, discovered in 2025 by the radial velocity method.
TOI-1203.01 is a mini-neptune orbiting TOI-1203, discovered in 2021 by the transit method.
TOI-1266 b is a mini-neptune orbiting TOI-1266, discovered in 2020 by the transit method.
TOI-1266 c is a super-earth orbiting TOI-1266, discovered in 2020 by the transit method.
TOI-1266 d is a super-earth orbiting TOI-1266, discovered in 2025 by the transit timing variations.
TOI-201 b is a gas giant orbiting TOI-201, discovered in 2021 by the transit method.
TOI-201 c is a gas giant orbiting TOI-201, discovered in 2025 by the transit timing variations.
TOI-201 d is a terrestrial planet orbiting TOI-201, discovered in 2026 by the transit method.
TOI-2267 b is a terrestrial planet orbiting TOI-2267 A, discovered in 2025 by the transit method.
TOI-2267 c is a terrestrial planet orbiting TOI-2267 A, discovered in 2025 by the transit method.
TOI-2267 d is a super-earth orbiting TOI-2267 B, discovered in 2025 by the transit method.
TOI-270 b is a terrestrial planet orbiting TOI-270, discovered in 2019 by the transit method.
TOI-270 c is a super-earth orbiting TOI-270, discovered in 2019 by the transit method.
TOI-270 d is a super-earth orbiting TOI-270, discovered in 2019 by the transit method.
TOI-4010 b is a mini-neptune orbiting TOI-4010, discovered in 2023 by the transit method.
TOI-4010 c is a hot jupiter orbiting TOI-4010, discovered in 2023 by the transit method.
TOI-4010 d is a gas giant orbiting TOI-4010, discovered in 2023 by the transit method.
TOI-4010 e is a gas giant orbiting TOI-4010, discovered in 2023 by the radial velocity method.
TOI-540 b is a terrestrial planet orbiting TOI-540, discovered in 2020 by the transit method.
TOI-5624 b is a super-earth orbiting TOI-5624, discovered in 2026 by the transit method.
TOI-5624 c is a mini-neptune orbiting TOI-5624, discovered in 2026 by the transit method.
TOI-5624 d is a mini-neptune orbiting TOI-5624, discovered in 2026 by the transit method.
TOI-5624 e is a mini-neptune orbiting TOI-5624, discovered in 2026 by the transit method.
TOI-5624 f is a mini-neptune orbiting TOI-5624, discovered in 2026 by the transit timing variations.
TOI-5789 b is a terrestrial planet orbiting TOI-5789, discovered in 2026 by the radial velocity method.
TOI-5789 c is a mini-neptune orbiting TOI-5789 by the transit method.
TOI-5789 d is a super-earth orbiting TOI-5789, discovered in 2026 by the radial velocity method.
TOI-5789 e is a mini-neptune orbiting TOI-5789, discovered in 2026 by the radial velocity method.
TOI-700 b is a terrestrial planet orbiting TOI-700, discovered in 2020 by the transit method.
TOI-700 c is a mini-neptune orbiting TOI-700, discovered in 2020 by the transit method.
TOI-700 d is a terrestrial planet orbiting TOI-700, discovered in 2020 by the transit method.
TOI-700 e is a terrestrial planet orbiting TOI-700, discovered in 2023 by the transit method.
TOI-771 b is a terrestrial planet orbiting TOI-771, discovered in 2024 by the transit method.
TOI-771 c is a terrestrial planet orbiting TOI-771, discovered in 2025 by the radial velocity method.
TWA 7 b is a gas giant orbiting TWA 7, discovered in 2025 by the direct imaging.
TYC 8998-760-1 b is a gas giant orbiting TYC 8998-760-1, discovered in 2020 by the direct imaging.
TYC 8998-760-1 c is a gas giant orbiting TYC 8998-760-1, discovered in 2020 by the direct imaging.
UCAC3 113-933 b is a gas giant orbiting UCAC3 113-933, discovered in 2024 by the direct imaging.
UCAC4 328-061594 b is a gas giant orbiting UCAC4 328-061594, discovered in 2024 by the direct imaging.
ups And b is a hot jupiter orbiting ups And, discovered in 1996 by the radial velocity method.
ups And c is a gas giant orbiting ups And, discovered in 1999 by the radial velocity method.
ups And d is a gas giant orbiting ups And, discovered in 1999 by the radial velocity method.
USco CTIO 108 b is a gas giant orbiting USco CTIO 108, discovered in 2008 by the direct imaging.
USco1556 b is a gas giant orbiting USco1556 A, discovered in 2019 by the direct imaging.
USco1621 b is a gas giant orbiting USco1621 A, discovered in 2019 by the direct imaging.
V2376 Ori b is a gas giant orbiting V2376 Ori, discovered in 2025 by the direct imaging.
VHS J125601.92-125723.9 b is a gas giant orbiting VHS J125601.92-125723.9, discovered in 2015 by the direct imaging.
WASP-12 b is a hot jupiter orbiting WASP-12, discovered in 2008 by the transit method.
WASP-121 b is a hot jupiter orbiting WASP-121, discovered in 2016 by the transit method.
WASP-17 b is a hot jupiter orbiting WASP-17, discovered in 2009 by the transit method.
WASP-39 b is a hot jupiter orbiting WASP-39, discovered in 2011 by the transit method.
WASP-43 b is a hot jupiter orbiting WASP-43, discovered in 2011 by the transit method.
WASP-76 b is a hot jupiter orbiting WASP-76, discovered in 2016 by the transit method.
WASP-96 b is a hot jupiter orbiting WASP-96, discovered in 2014 by the transit method.
WD 0806-661 b is a gas giant orbiting WD 0806-661, discovered in 2011 by the direct imaging.
WISE J033605.05-014350.4 b is a gas giant orbiting WISE J033605.05-014350.4, discovered in 2023 by the direct imaging.
WISEP J121756.91+162640.2 A b is a gas giant orbiting WISEP J121756.91+162640.2 A, discovered in 2012 by the direct imaging.
WISPIT 1 b is a gas giant orbiting WISPIT 1, discovered in 2025 by the direct imaging.
WISPIT 1 c is a gas giant orbiting WISPIT 1, discovered in 2025 by the direct imaging.
WISPIT 2 b is a gas giant orbiting WISPIT 2, discovered in 2025 by the direct imaging.
WISPIT 2 c is a gas giant orbiting WISPIT 2, discovered in 2026 by the direct imaging.
Wolf 1061 b is a terrestrial planet orbiting Wolf 1061, discovered in 2015 by the radial velocity method.
Wolf 1061 c is a super-earth orbiting Wolf 1061, discovered in 2015 by the radial velocity method.
Wolf 1061 d is a mini-neptune orbiting Wolf 1061, discovered in 2015 by the radial velocity method.
Wolf 1069 b is a terrestrial planet orbiting Wolf 1069, discovered in 2023 by the radial velocity method.
KOINTREAU-1 b is a gas giant orbiting XEST 17-036, discovered in 2026 by the direct imaging.
xi Aql b is a gas giant orbiting xi Aql, discovered in 2007 by the radial velocity method.
XO-2 S b is a gas giant orbiting XO-2 S, discovered in 2014 by the radial velocity method.
XO-2 S c is a gas giant orbiting XO-2 S, discovered in 2014 by the radial velocity method.
XO-2 S d is a gas giant orbiting XO-2 S, discovered in 2024 by the radial velocity method.
YZ Cet b is a terrestrial planet orbiting YZ Cet, discovered in 2017 by the radial velocity method.
YZ Cet c is a terrestrial planet orbiting YZ Cet, discovered in 2017 by the radial velocity method.
YZ Cet d is a terrestrial planet orbiting YZ Cet, discovered in 2017 by the radial velocity method.
14 Her is a K0 star that hosts 2 known exoplanets in this catalogue, about 58 light-years away.
1RXS J160929.1-210524 is a K7 V star that hosts 1 known exoplanet in this catalogue, about 454 light-years away.
2MASS J01033563-5515561 A is a M5.5/M6 star that hosts 1 known exoplanet in this catalogue, about 154 light-years away.
2MASS J01225093-2439505 is a M3.5 V star that hosts 1 known exoplanet in this catalogue, about 110 light-years away.
2MASS J02192210-3925225 is a M6 star that hosts 1 known exoplanet in this catalogue, about 131 light-years away.
2MASS J0249-0557 A is a M6 V star that hosts 1 known exoplanet in this catalogue, about 215 light-years away.
2MASS J03590986+2009361 is a star that hosts 1 known exoplanet in this catalogue, about 383 light-years away.
2MASS J04372171+2651014 is a M V star that hosts 1 known exoplanet in this catalogue, about 419 light-years away.
2MASS J04414489+2301513 is a M8.5 star that hosts 1 known exoplanet in this catalogue, about 393 light-years away.
2MASS J11011926-7732383 is a star that hosts 1 known exoplanet in this catalogue.
2MASS J11550485-7919108 is a star that hosts 1 known exoplanet in this catalogue, about 329 light-years away.
2MASS J12073346-3932539 is a M8 star that hosts 1 known exoplanet in this catalogue, about 210 light-years away.
2MASS J16262785-2625152 is a M4.5 star that hosts 1 known exoplanet in this catalogue, about 474 light-years away.
2MASS J19383260+4603591 is a star that hosts 3 known exoplanets in this catalogue, about 1293 light-years away.
2MASS J21252752-8138278 is a star that hosts 1 known exoplanet in this catalogue, about 111 light-years away.
2MASS J22362452+4751425 is a K7 V star that hosts 1 known exoplanet in this catalogue, about 227 light-years away.
2MASS J22501512+2325342 is a M3 star that hosts 1 known exoplanet in this catalogue, about 187 light-years away.
55 Cnc B is a M4.5 V star that hosts 2 known exoplanets in this catalogue, about 41 light-years away.
AB Aur is a star that hosts 1 known exoplanet in this catalogue, about 529 light-years away.
AB Pic is a K2 V star that hosts 1 known exoplanet in this catalogue, about 163 light-years away.
AF Lep is a F8 star that hosts 1 known exoplanet in this catalogue, about 88 light-years away.
AU Mic is a M1 V star that hosts 4 known exoplanets in this catalogue, about 32 light-years away.
b Cen A is a B2.5 V star that hosts 1 known exoplanet in this catalogue, about 320 light-years away.
BD-06 1339 is a K7/M0 V star that hosts 2 known exoplanets in this catalogue, about 66 light-years away.
BD-11 4672 is a K7V star that hosts 2 known exoplanets in this catalogue, about 89 light-years away.
BD-210397 is a K7 V star that hosts 2 known exoplanets in this catalogue, about 77 light-years away.
BD+60 1417 is a K0 star that hosts 1 known exoplanet in this catalogue, about 147 light-years away.
bet Pic is a A5V star that hosts 2 known exoplanets in this catalogue, about 64 light-years away.
CD Cet is a M5.0 V star that hosts 1 known exoplanet in this catalogue, about 28 light-years away.
CD-35 2722 is a M1 V star that hosts 1 known exoplanet in this catalogue, about 73 light-years away.
CFBDSIR J145829+101343 is a star that hosts 1 known exoplanet in this catalogue, about 75 light-years away.
CFHTWIR-Oph 98 A is a M9-L1 star that hosts 1 known exoplanet in this catalogue.
CHXR 73 is a M3.5 star that hosts 1 known exoplanet in this catalogue, about 621 light-years away.
COCONUTS-2 A is a M3 V star that hosts 1 known exoplanet in this catalogue, about 36 light-years away.
CT Cha is a K5e star that hosts 1 known exoplanet in this catalogue, about 622 light-years away.
CWISEP J193518.59-154620.3 is a Y star that hosts 1 known exoplanet in this catalogue, about 47 light-years away.
DENIS-P J082303.1-491201 is a L1.5 star that hosts 1 known exoplanet in this catalogue, about 68 light-years away.
DH Tau is a M0.5 star that hosts 1 known exoplanet in this catalogue, about 440 light-years away.
DMPP-1 is a F8 V star that hosts 4 known exoplanets in this catalogue, about 204 light-years away.
DP Leo is a star that hosts 1 known exoplanet in this catalogue, about 997 light-years away.
eps Eri is a K2 V star that hosts 1 known exoplanet in this catalogue, about 10 light-years away.
eps Ind A is a K5 V star that hosts 1 known exoplanet in this catalogue, about 12 light-years away.
FU Tau is a M7.25 star that hosts 1 known exoplanet in this catalogue, about 435 light-years away.
G 192-15 is a M5.0 V star that hosts 2 known exoplanets in this catalogue, about 31 light-years away.
G 196-3 is a star that hosts 1 known exoplanet in this catalogue, about 71 light-years away.
G 261-6 is a M5.5 V star that hosts 1 known exoplanet in this catalogue, about 35 light-years away.
Gaia-4 is a star that hosts 1 known exoplanet in this catalogue, about 240 light-years away.
Gaia-5 is a star that hosts 1 known exoplanet in this catalogue, about 134 light-years away.
gam Cep is a K1 III-IV star that hosts 1 known exoplanet in this catalogue, about 46 light-years away.
GJ 1002 is a M5.5 V star that hosts 2 known exoplanets in this catalogue, about 16 light-years away.
GJ 1061 is a M5.5 V star that hosts 3 known exoplanets in this catalogue, about 12 light-years away.
GJ 1132 is a M4.5 V star that hosts 2 known exoplanets in this catalogue, about 41 light-years away.
GJ 1148 is a M5 star that hosts 2 known exoplanets in this catalogue, about 36 light-years away.
GJ 1151 is a M 4.5V star that hosts 1 known exoplanet in this catalogue, about 26 light-years away.
GJ 1265 is a M4.5 V star that hosts 1 known exoplanet in this catalogue, about 33 light-years away.
GJ 1289 is a M4.5 Ve star that hosts 1 known exoplanet in this catalogue, about 27 light-years away.
GJ 15 A is a M1 star that hosts 2 known exoplanets in this catalogue, about 12 light-years away.
GJ 163 is a M star that hosts 3 known exoplanets in this catalogue, about 49 light-years away.
GJ 179 is a M3.5 V star that hosts 1 known exoplanet in this catalogue, about 40 light-years away.
GJ 180 is a M3 star that hosts 3 known exoplanets in this catalogue, about 39 light-years away.
GJ 229 is a M1.5V star that hosts 2 known exoplanets in this catalogue, about 19 light-years away.
GJ 251 is a M3.0 V star that hosts 2 known exoplanets in this catalogue, about 18 light-years away.
GJ 273 is a M3.5 star that hosts 2 known exoplanets in this catalogue, about 19 light-years away.
GJ 3021 is a G6 V star that hosts 1 known exoplanet in this catalogue, about 57 light-years away.
GJ 3138 is a M0 star that hosts 3 known exoplanets in this catalogue, about 93 light-years away.
GJ 317 is a M3.5 V star that hosts 2 known exoplanets in this catalogue, about 50 light-years away.
GJ 328 is a M0.0 star that hosts 2 known exoplanets in this catalogue, about 67 light-years away.
GJ 3293 is a M2.5 star that hosts 4 known exoplanets in this catalogue, about 66 light-years away.
GJ 3323 is a M4 star that hosts 2 known exoplanets in this catalogue, about 18 light-years away.
GJ 3378 is a M4 V star that hosts 1 known exoplanet in this catalogue, about 25 light-years away.
GJ 338 B is a M0 V star that hosts 1 known exoplanet in this catalogue, about 21 light-years away.
GJ 341 is a M1 star that hosts 1 known exoplanet in this catalogue, about 34 light-years away.
GJ 3512 is a M5.5 V star that hosts 2 known exoplanets in this catalogue, about 31 light-years away.
GJ 357 is a M2.5 V star that hosts 3 known exoplanets in this catalogue, about 31 light-years away.
GJ 3634 is a M2.5 star that hosts 1 known exoplanet in this catalogue, about 66 light-years away.
GJ 367 is a M1.0 V star that hosts 3 known exoplanets in this catalogue, about 31 light-years away.
GJ 3779 is a M4.0 V star that hosts 1 known exoplanet in this catalogue, about 45 light-years away.
GJ 393 is a M2.0 V star that hosts 1 known exoplanet in this catalogue, about 23 light-years away.
GJ 3988 is a M4.5 V star that hosts 1 known exoplanet in this catalogue, about 32 light-years away.
GJ 3998 is a M1 star that hosts 3 known exoplanets in this catalogue, about 59 light-years away.
GJ 411 is a M1.5 V star that hosts 2 known exoplanets in this catalogue, about 19 light-years away.
GJ 414 A is a K7 V star that hosts 2 known exoplanets in this catalogue, about 39 light-years away.
GJ 422 is a M3.5 V star that hosts 1 known exoplanet in this catalogue, about 41 light-years away.
GJ 4274 is a M4.5 V star that hosts 2 known exoplanets in this catalogue, about 24 light-years away.
GJ 433 is a M2V star that hosts 3 known exoplanets in this catalogue, about 30 light-years away.
GJ 436 is a M2.5 V star that hosts 1 known exoplanet in this catalogue, about 32 light-years away.
GJ 480 is a M3.5 Ve star that hosts 1 known exoplanet in this catalogue, about 46 light-years away.
GJ 486 is a M3.5 V star that hosts 1 known exoplanet in this catalogue, about 26 light-years away.
GJ 504 is a G0 V star that hosts 1 known exoplanet in this catalogue, about 57 light-years away.
GJ 514 is a M0.5-1.0 V star that hosts 1 known exoplanet in this catalogue, about 25 light-years away.
GJ 536 is a M1 V star that hosts 2 known exoplanets in this catalogue, about 34 light-years away.
GJ 625 is a M2 star that hosts 1 known exoplanet in this catalogue, about 21 light-years away.
GJ 649 is a M1.0 star that hosts 1 known exoplanet in this catalogue, about 34 light-years away.
GJ 667 C is a M1.5 V star that hosts 5 known exoplanets in this catalogue, about 24 light-years away.
GJ 674 is a M2.5 star that hosts 1 known exoplanet in this catalogue, about 15 light-years away.
GJ 676 A is a M0 star that hosts 4 known exoplanets in this catalogue, about 52 light-years away.
GJ 680 is a K5 star that hosts 1 known exoplanet in this catalogue, about 32 light-years away.
GJ 682 is a M3.5 V star that hosts 2 known exoplanets in this catalogue, about 16 light-years away.
GJ 685 is a M0.5 star that hosts 1 known exoplanet in this catalogue, about 47 light-years away.
GJ 687 is a M3.0V star that hosts 2 known exoplanets in this catalogue, about 15 light-years away.
GJ 740 is a M1.0 V star that hosts 1 known exoplanet in this catalogue, about 36 light-years away.
GJ 806 is a M1.5 V star that hosts 2 known exoplanets in this catalogue, about 39 light-years away.
GJ 832 is a M2/3 V star that hosts 1 known exoplanet in this catalogue, about 16 light-years away.
GJ 849 is a M3.5 star that hosts 2 known exoplanets in this catalogue, about 29 light-years away.
GJ 86 is a K1V star that hosts 1 known exoplanet in this catalogue, about 35 light-years away.
GJ 876 is a M2.5V star that hosts 4 known exoplanets in this catalogue, about 15 light-years away.
GJ 887 is a M1 V star that hosts 4 known exoplanets in this catalogue, about 11 light-years away.
GJ 896 A is a M3.5 V star that hosts 1 known exoplanet in this catalogue, about 20 light-years away.
GJ 900 A is a K7 star that hosts 1 known exoplanet in this catalogue, about 68 light-years away.
GJ 9066 is a M5.0 V star that hosts 1 known exoplanet in this catalogue, about 15 light-years away.
GJ 96 is a M2 star that hosts 1 known exoplanet in this catalogue, about 39 light-years away.
GJ 9827 is a K7 V star that hosts 3 known exoplanets in this catalogue, about 97 light-years away.
Gl 378 is a M1 star that hosts 1 known exoplanet in this catalogue, about 49 light-years away.
Gl 410 is a K star that hosts 1 known exoplanet in this catalogue, about 39 light-years away.
Gl 49 is a M1.5 V star that hosts 1 known exoplanet in this catalogue, about 32 light-years away.
Gl 686 is a M1.0 V star that hosts 1 known exoplanet in this catalogue, about 27 light-years away.
Gliese 12 is a M4 V star that hosts 1 known exoplanet in this catalogue, about 40 light-years away.
GQ Lup is a K7e V star that hosts 1 known exoplanet in this catalogue, about 493 light-years away.
GSC 06214-00210 is a K7 star that hosts 1 known exoplanet in this catalogue, about 354 light-years away.
GU Psc is a M3 star that hosts 1 known exoplanet in this catalogue, about 155 light-years away.
HD 100546 is a B9 Vne star that hosts 1 known exoplanet in this catalogue, about 358 light-years away.
HD 10180 is a G1 V star that hosts 6 known exoplanets in this catalogue, about 127 light-years away.
HD 104067 is a K2V star that hosts 2 known exoplanets in this catalogue, about 66 light-years away.
HD 10647 is a F9 V star that hosts 1 known exoplanet in this catalogue, about 57 light-years away.
HD 106906 is a F5 V star that hosts 1 known exoplanet in this catalogue, about 336 light-years away.
HD 111232 is a G8 V star that hosts 2 known exoplanets in this catalogue, about 94 light-years away.
HD 113538 is a K9 V star that hosts 2 known exoplanets in this catalogue, about 53 light-years away.
HD 114386 is a K3 VC star that hosts 2 known exoplanets in this catalogue, about 91 light-years away.
HD 114783 is a K0 star that hosts 2 known exoplanets in this catalogue, about 69 light-years away.
HD 11506 is a G0 V star that hosts 3 known exoplanets in this catalogue, about 167 light-years away.
HD 115404 A is a K2V star that hosts 2 known exoplanets in this catalogue, about 36 light-years away.
HD 125612 is a G3 V star that hosts 3 known exoplanets in this catalogue, about 188 light-years away.
HD 128311 is a K0 star that hosts 2 known exoplanets in this catalogue, about 53 light-years away.
HD 128717 is a star that hosts 1 known exoplanet in this catalogue, about 240 light-years away.
HD 134060 is a G3 IV star that hosts 2 known exoplanets in this catalogue, about 78 light-years away.
HD 134606 is a G5IV star that hosts 5 known exoplanets in this catalogue, about 87 light-years away.
HD 134987 is a G5 V star that hosts 2 known exoplanets in this catalogue, about 85 light-years away.
HD 135344 A is a A0 V star that hosts 1 known exoplanet in this catalogue, about 462 light-years away.
HD 136352 is a G4 V star that hosts 3 known exoplanets in this catalogue, about 48 light-years away.
HD 13808 is a K2 V star that hosts 2 known exoplanets in this catalogue, about 92 light-years away.
HD 141399 is a K0 star that hosts 4 known exoplanets in this catalogue, about 121 light-years away.
HD 142 is a F7V star that hosts 3 known exoplanets in this catalogue, about 85 light-years away.
HD 143811 A is a star that hosts 1 known exoplanet in this catalogue, about 446 light-years away.
HD 1461 is a G0 V star that hosts 2 known exoplanets in this catalogue, about 76 light-years away.
HD 147379 is a M0.0 V star that hosts 1 known exoplanet in this catalogue, about 35 light-years away.
HD 153557 is a K0 star that hosts 3 known exoplanets in this catalogue, about 59 light-years away.
HD 154345 is a G8 star that hosts 1 known exoplanet in this catalogue, about 60 light-years away.
HD 156668 is a K2 star that hosts 2 known exoplanets in this catalogue, about 79 light-years away.
HD 158259 is a G0 star that hosts 5 known exoplanets in this catalogue, about 88 light-years away.
HD 164922 is a G9 V star that hosts 4 known exoplanets in this catalogue, about 72 light-years away.
HD 169142 is a star that hosts 1 known exoplanet in this catalogue, about 371 light-years away.
HD 176986 is a K2.5 V star that hosts 3 known exoplanets in this catalogue, about 91 light-years away.
HD 180617 is a M2.5 V star that hosts 1 known exoplanet in this catalogue, about 19 light-years away.
HD 181433 is a K3 IV star that hosts 3 known exoplanets in this catalogue, about 88 light-years away.
HD 189567 is a G3 V star that hosts 2 known exoplanets in this catalogue, about 58 light-years away.
HD 189733 is a K2 V star that hosts 1 known exoplanet in this catalogue, about 64 light-years away.
HD 190007 is a K4 V star that hosts 1 known exoplanet in this catalogue, about 41 light-years away.
HD 190360 is a G star that hosts 2 known exoplanets in this catalogue, about 52 light-years away.
HD 191939 is a G9 V star that hosts 6 known exoplanets in this catalogue, about 175 light-years away.
HD 192263 is a K2 V star that hosts 1 known exoplanet in this catalogue, about 64 light-years away.
HD 192310 is a K3V star that hosts 2 known exoplanets in this catalogue, about 29 light-years away.
HD 203030 is a G8 V star that hosts 1 known exoplanet in this catalogue, about 128 light-years away.
HD 204941 is a K1/2V star that hosts 1 known exoplanet in this catalogue, about 94 light-years away.
HD 206893 is a F5 V star that hosts 2 known exoplanets in this catalogue, about 133 light-years away.
HD 20781 is a K0 V star that hosts 4 known exoplanets in this catalogue, about 117 light-years away.
HD 20782 is a G1.5 V star that hosts 1 known exoplanet in this catalogue, about 117 light-years away.
HD 210277 is a G0 V star that hosts 1 known exoplanet in this catalogue, about 69 light-years away.
HD 211970 is a K7 V star that hosts 1 known exoplanet in this catalogue, about 43 light-years away.
HD 215152 is a K3 V star that hosts 4 known exoplanets in this catalogue, about 70 light-years away.
HD 217107 is a G star that hosts 2 known exoplanets in this catalogue, about 65 light-years away.
HD 219077 is a G8 V+ star that hosts 1 known exoplanet in this catalogue, about 95 light-years away.
HD 219134 is a K3 V star that hosts 6 known exoplanets in this catalogue, about 21 light-years away.
HD 222237 is a K3 V star that hosts 1 known exoplanet in this catalogue, about 37 light-years away.
HD 22496 is a K5/M0V star that hosts 1 known exoplanet in this catalogue, about 44 light-years away.
HD 260655 is a M0 V star that hosts 2 known exoplanets in this catalogue, about 33 light-years away.
HD 27894 is a K2 V star that hosts 3 known exoplanets in this catalogue, about 143 light-years away.
HD 284149 A is a star that hosts 1 known exoplanet in this catalogue, about 384 light-years away.
HD 285968 is a M2 V star that hosts 1 known exoplanet in this catalogue, about 31 light-years away.
HD 33142 is a K0 III star that hosts 3 known exoplanets in this catalogue, about 396 light-years away.
HD 34445 is a G0 V star that hosts 6 known exoplanets in this catalogue, about 150 light-years away.
HD 3651 is a K0 V star that hosts 1 known exoplanet in this catalogue, about 36 light-years away.
HD 37124 is a G4 V star that hosts 3 known exoplanets in this catalogue, about 103 light-years away.
HD 39091 is a G0 V star that hosts 3 known exoplanets in this catalogue, about 60 light-years away.
HD 39194 is a K0 V star that hosts 3 known exoplanets in this catalogue, about 86 light-years away.
HD 40307 is a K2.5 V star that hosts 5 known exoplanets in this catalogue, about 42 light-years away.
HD 4308 is a G5V star that hosts 1 known exoplanet in this catalogue, about 72 light-years away.
HD 45184 is a G1.5 V star that hosts 2 known exoplanets in this catalogue, about 72 light-years away.
HD 46375 is a K1 IV-V star that hosts 1 known exoplanet in this catalogue, about 96 light-years away.
HD 48948 is a K3 V star that hosts 3 known exoplanets in this catalogue, about 55 light-years away.
HD 62509 is a K0IIIvar star that hosts 1 known exoplanet in this catalogue, about 34 light-years away.
HD 63433 is a G5 V star that hosts 3 known exoplanets in this catalogue, about 73 light-years away.
HD 69830 is a K0V star that hosts 3 known exoplanets in this catalogue, about 41 light-years away.
HD 75289 is a G0 star that hosts 1 known exoplanet in this catalogue, about 95 light-years away.
HD 7924 is a K0.5 V star that hosts 3 known exoplanets in this catalogue, about 55 light-years away.
HD 82943 is a G2/3V star that hosts 2 known exoplanets in this catalogue, about 90 light-years away.
HD 90156 is a G5V star that hosts 1 known exoplanet in this catalogue, about 72 light-years away.
HD 96700 is a G0 V star that hosts 3 known exoplanets in this catalogue, about 83 light-years away.
HD 97658 is a K1 V star that hosts 1 known exoplanet in this catalogue, about 70 light-years away.
HD 99492 is a K2 V star that hosts 2 known exoplanets in this catalogue, about 59 light-years away.
HIP 14810 is a G5 star that hosts 3 known exoplanets in this catalogue, about 165 light-years away.
HIP 21152 is a F5 V star that hosts 1 known exoplanet in this catalogue, about 142 light-years away.
HIP 39017 is a A9/F0 star that hosts 1 known exoplanet in this catalogue, about 216 light-years away.
HIP 41378 is a F6 star that hosts 6 known exoplanets in this catalogue, about 347 light-years away.
HIP 48714 is a M0.5 Ve star that hosts 1 known exoplanet in this catalogue, about 34 light-years away.
HIP 54515 is a A5 V star that hosts 1 known exoplanet in this catalogue, about 270 light-years away.
HIP 56998 is a K4/5V star that hosts 2 known exoplanets in this catalogue, about 42 light-years away.
HIP 57274 is a K4 V star that hosts 3 known exoplanets in this catalogue, about 84 light-years away.
HIP 66074 is a star that hosts 1 known exoplanet in this catalogue, about 116 light-years away.
HIP 70849 is a K7 V star that hosts 1 known exoplanet in this catalogue, about 78 light-years away.
HIP 77900 is a star that hosts 1 known exoplanet in this catalogue, about 492 light-years away.
HIP 78530 is a B9 V star that hosts 1 known exoplanet in this catalogue, about 446 light-years away.
HIP 79098 AB is a B9 V star that hosts 1 known exoplanet in this catalogue, about 476 light-years away.
HIP 81208 C is a M star that hosts 1 known exoplanet in this catalogue, about 481 light-years away.
HN Lib is a M4.0 V star that hosts 1 known exoplanet in this catalogue, about 20 light-years away.
HN Peg is a G0 V star that hosts 1 known exoplanet in this catalogue, about 59 light-years away.
HR 2562 is a F5 V star that hosts 1 known exoplanet in this catalogue, about 111 light-years away.
HR 8799 is a A5 V star that hosts 4 known exoplanets in this catalogue, about 135 light-years away.
ISO-Oph 96 is a K6-M1 star that hosts 1 known exoplanet in this catalogue, about 459 light-years away.
ITG 15 A is a star that hosts 1 known exoplanet in this catalogue, about 445 light-years away.
K2-18 is a M2.5 V star that hosts 2 known exoplanets in this catalogue, about 124 light-years away.
kap And is a B9 IVn star that hosts 1 known exoplanet in this catalogue, about 163 light-years away.
Kapteyn is a M2.0V star that hosts 1 known exoplanet in this catalogue, about 13 light-years away.
KELT-9 is a B9.5-A0 star that hosts 1 known exoplanet in this catalogue, about 667 light-years away.
Kepler-100 is a star that hosts 4 known exoplanets in this catalogue, about 994 light-years away.
Kepler-11 is a star that hosts 6 known exoplanets in this catalogue, about 2108 light-years away.
Kepler-122 is a star that hosts 5 known exoplanets in this catalogue, about 3352 light-years away.
Kepler-138 is a M1 V star that hosts 4 known exoplanets in this catalogue, about 218 light-years away.
Kepler-139 is a star that hosts 5 known exoplanets in this catalogue, about 1276 light-years away.
Kepler-16 is a star that hosts 1 known exoplanet in this catalogue, about 245 light-years away.
Kepler-1649 is a star that hosts 2 known exoplanets in this catalogue, about 301 light-years away.
Kepler-1660 A is a F7 V star that hosts 1 known exoplanet in this catalogue, about 3877 light-years away.
Kepler-19 is a star that hosts 3 known exoplanets in this catalogue, about 713 light-years away.
Kepler-20 is a star that hosts 6 known exoplanets in this catalogue, about 922 light-years away.
Kepler-24 is a star that hosts 4 known exoplanets in this catalogue, about 3774 light-years away.
Kepler-26 is a M0 V star that hosts 4 known exoplanets in this catalogue, about 1094 light-years away.
Kepler-32 is a M1 V star that hosts 5 known exoplanets in this catalogue, about 1056 light-years away.
Kepler-33 is a star that hosts 5 known exoplanets in this catalogue, about 3944 light-years away.
Kepler-338 is a star that hosts 4 known exoplanets in this catalogue, about 1803 light-years away.
Kepler-37 is a star that hosts 4 known exoplanets in this catalogue, about 209 light-years away.
Kepler-411 is a K2 V star that hosts 4 known exoplanets in this catalogue, about 501 light-years away.
Kepler-416 is a star that hosts 3 known exoplanets in this catalogue, about 2253 light-years away.
Kepler-442 is a star that hosts 1 known exoplanet in this catalogue, about 1194 light-years away.
Kepler-452 is a G2 star that hosts 1 known exoplanet in this catalogue, about 1800 light-years away.
Kepler-46 is a star that hosts 3 known exoplanets in this catalogue, about 2535 light-years away.
Kepler-48 is a star that hosts 5 known exoplanets in this catalogue, about 1001 light-years away.
Kepler-49 is a M1 V star that hosts 4 known exoplanets in this catalogue, about 1015 light-years away.
Kepler-51 is a star that hosts 4 known exoplanets in this catalogue, about 2557 light-years away.
Kepler-55 is a star that hosts 5 known exoplanets in this catalogue, about 1888 light-years away.
Kepler-58 is a star that hosts 4 known exoplanets in this catalogue, about 3162 light-years away.
Kepler-65 is a star that hosts 4 known exoplanets in this catalogue, about 991 light-years away.
Kepler-68 is a star that hosts 4 known exoplanets in this catalogue, about 470 light-years away.
Kepler-79 is a star that hosts 4 known exoplanets in this catalogue, about 3330 light-years away.
Kepler-80 is a K5 star that hosts 6 known exoplanets in this catalogue, about 1205 light-years away.
Kepler-82 is a star that hosts 5 known exoplanets in this catalogue, about 2950 light-years away.
Kepler-84 is a star that hosts 5 known exoplanets in this catalogue, about 3340 light-years away.
Kepler-85 is a star that hosts 4 known exoplanets in this catalogue, about 2496 light-years away.
KOI-142 is a G6 V star that hosts 3 known exoplanets in this catalogue, about 1229 light-years away.
L 363-38 is a star that hosts 1 known exoplanet in this catalogue, about 33 light-years away.
L 98-59 is a M3 V star that hosts 5 known exoplanets in this catalogue, about 35 light-years away.
LHS 1140 is a M4.5 V star that hosts 2 known exoplanets in this catalogue, about 49 light-years away.
LHS 1678 is a M2.0 V star that hosts 3 known exoplanets in this catalogue, about 65 light-years away.
LHS 3844 is a M4.5-M5.0 star that hosts 1 known exoplanet in this catalogue, about 49 light-years away.
LHS 475 is a M3.5 V star that hosts 1 known exoplanet in this catalogue, about 41 light-years away.
LkCa 15 is a star that hosts 2 known exoplanets in this catalogue, about 516 light-years away.
LP 261-75 A is a M4.5 V star that hosts 1 known exoplanet in this catalogue, about 111 light-years away.
LP 791-18 is a M(6.1 +/- 0.7) V star that hosts 3 known exoplanets in this catalogue, about 86 light-years away.
LP 890-9 is a M6 V star that hosts 2 known exoplanets in this catalogue, about 106 light-years away.
LTT 1445 A is a M3.0 star that hosts 2 known exoplanets in this catalogue, about 22 light-years away.
Luhman 16 A is a star that hosts 1 known exoplanet in this catalogue.
M62H is a star that hosts 1 known exoplanet in this catalogue.
MOA-2007-BLG-192L is a star that hosts 1 known exoplanet in this catalogue, about 7046 light-years away.
mu2 Sco is a B2 IV star that hosts 1 known exoplanet in this catalogue.
MWC 758 is a A8Ve star that hosts 1 known exoplanet in this catalogue, about 520 light-years away.
NN Ser is a WD star that hosts 2 known exoplanets in this catalogue, about 1683 light-years away.
NY Vir is a star that hosts 2 known exoplanets in this catalogue, about 1775 light-years away.
OGLE-2005-BLG-071L is a star that hosts 1 known exoplanet in this catalogue, about 10438 light-years away.
OGLE-2005-BLG-390L is a star that hosts 1 known exoplanet in this catalogue, about 21529 light-years away.
OGLE-2006-BLG-109L is a star that hosts 2 known exoplanets in this catalogue, about 4926 light-years away.
OGLE-2007-BLG-368L is a star that hosts 1 known exoplanet in this catalogue, about 19246 light-years away.
OGLE-2012-BLG-0026L is a G5 V star that hosts 2 known exoplanets in this catalogue, about 13110 light-years away.
Oph 11 is a M9 star that hosts 1 known exoplanet in this catalogue, about 444 light-years away.
PDS 70 is a K7 star that hosts 2 known exoplanets in this catalogue, about 369 light-years away.
PSR B0329+54 is a star that hosts 1 known exoplanet in this catalogue, about 1647 light-years away.
PSR B1257+12 is a star that hosts 3 known exoplanets in this catalogue, about 1957 light-years away.
PSR B1620-26 is a star that hosts 1 known exoplanet in this catalogue.
PSR J1719-1438 is a star that hosts 1 known exoplanet in this catalogue, about 3914 light-years away.
PSR J2322-2650 is a star that hosts 1 known exoplanet in this catalogue, about 750 light-years away.
PZ Tel is a G9 IV star that hosts 1 known exoplanet in this catalogue, about 154 light-years away.
Ross 458 is a M2 star that hosts 1 known exoplanet in this catalogue, about 38 light-years away.
Ross 508 is a M4.5 V star that hosts 1 known exoplanet in this catalogue, about 37 light-years away.
ROXs 12 is a M0 star that hosts 1 known exoplanet in this catalogue, about 446 light-years away.
ROXs 42 B is a M0 star that hosts 1 known exoplanet in this catalogue, about 468 light-years away.
RR Cae is a M star that hosts 1 known exoplanet in this catalogue, about 69 light-years away.
SR 12 AB is a star that hosts 1 known exoplanet in this catalogue, about 366 light-years away.
Teegarden's Star is a M7.0 V star that hosts 3 known exoplanets in this catalogue, about 12 light-years away.
TOI-1203 is a G3 V star that hosts 4 known exoplanets in this catalogue, about 212 light-years away.
TOI-1266 is a M2 star that hosts 3 known exoplanets in this catalogue, about 117 light-years away.
TOI-201 is a F star that hosts 3 known exoplanets in this catalogue, about 371 light-years away.
TOI-2267 A is a M5 V star that hosts 2 known exoplanets in this catalogue, about 74 light-years away.
TOI-2267 B is a M6 V star that hosts 1 known exoplanet in this catalogue, about 74 light-years away.
TOI-270 is a M3 V star that hosts 3 known exoplanets in this catalogue, about 73 light-years away.
TOI-4010 is a K V star that hosts 4 known exoplanets in this catalogue, about 579 light-years away.
TOI-540 is a M V star that hosts 1 known exoplanet in this catalogue, about 46 light-years away.
TOI-5624 is a star that hosts 5 known exoplanets in this catalogue, about 332 light-years away.
TOI-5789 is a K1 V star that hosts 4 known exoplanets in this catalogue, about 67 light-years away.
TOI-700 is a M2.5 V star that hosts 4 known exoplanets in this catalogue, about 102 light-years away.
TOI-771 is a M3 star that hosts 2 known exoplanets in this catalogue, about 82 light-years away.
TWA 7 is a star that hosts 1 known exoplanet in this catalogue, about 111 light-years away.
TYC 8998-760-1 is a K3 IV star that hosts 2 known exoplanets in this catalogue, about 309 light-years away.
UCAC3 113-933 is a M0 star that hosts 1 known exoplanet in this catalogue, about 172 light-years away.
UCAC4 328-061594 is a DC star that hosts 1 known exoplanet in this catalogue, about 130 light-years away.
ups And is a F8 V star that hosts 3 known exoplanets in this catalogue, about 44 light-years away.
USco CTIO 108 is a M7 star that hosts 1 known exoplanet in this catalogue, about 470 light-years away.
USco1556 A is a M3.0 V star that hosts 1 known exoplanet in this catalogue, about 459 light-years away.
USco1621 A is a M2.5 V star that hosts 1 known exoplanet in this catalogue, about 450 light-years away.
V2376 Ori is a M star that hosts 1 known exoplanet in this catalogue.
VHS J125601.92-125723.9 is a M7.5 star that hosts 1 known exoplanet in this catalogue, about 41 light-years away.
WASP-12 is a star that hosts 1 known exoplanet in this catalogue, about 1394 light-years away.
WASP-121 is a F6 V star that hosts 1 known exoplanet in this catalogue, about 880 light-years away.
WASP-17 is a F4 star that hosts 1 known exoplanet in this catalogue, about 1324 light-years away.
WASP-39 is a star that hosts 1 known exoplanet in this catalogue, about 698 light-years away.
WASP-43 is a K7 V star that hosts 1 known exoplanet in this catalogue, about 283 light-years away.
WASP-76 is a F7 star that hosts 1 known exoplanet in this catalogue, about 634 light-years away.
WASP-96 is a G8 star that hosts 1 known exoplanet in this catalogue, about 1150 light-years away.
WD 0806-661 is a DQ star that hosts 1 known exoplanet in this catalogue, about 63 light-years away.
WISE J033605.05-014350.4 is a star that hosts 1 known exoplanet in this catalogue.
WISEP J121756.91+162640.2 A is a T8.5 star that hosts 1 known exoplanet in this catalogue, about 33 light-years away.
WISPIT 1 is a K4 V star that hosts 2 known exoplanets in this catalogue, about 750 light-years away.
WISPIT 2 is a star that hosts 2 known exoplanets in this catalogue, about 440 light-years away.
Wolf 1069 is a M5.0 V star that hosts 1 known exoplanet in this catalogue, about 31 light-years away.
XEST 17-036 is a M4 star that hosts 1 known exoplanet in this catalogue, about 517 light-years away.
XO-2 S is a G8 V star that hosts 3 known exoplanets in this catalogue, about 494 light-years away.
YZ Cet is a M4.5 V star that hosts 3 known exoplanets in this catalogue, about 12 light-years away.
The 14 Her system is a planetary system with 2 known planets in this catalogue.
The 2MASS J19383260+4603591 system is a planetary system with 3 known planets in this catalogue.
The 47 UMa system is a planetary system with 3 known planets in this catalogue.
The 55 Cnc system is a planetary system with 5 known planets in this catalogue.
The 55 Cnc B system is a planetary system with 2 known planets in this catalogue.
The 61 Vir system is a planetary system with 3 known planets in this catalogue.
The 7 CMa system is a planetary system with 2 known planets in this catalogue.
The 75 Cet system is a planetary system with 2 known planets in this catalogue.
The AU Mic system is a planetary system with 4 known planets in this catalogue.
The Barnard's star system is a planetary system with 4 known planets in this catalogue.
The BD-06 1339 system is a planetary system with 2 known planets in this catalogue.
The BD-11 4672 system is a planetary system with 2 known planets in this catalogue.
The BD-210397 system is a planetary system with 2 known planets in this catalogue.
The bet Pic system is a planetary system with 2 known planets in this catalogue.
The DMPP-1 system is a planetary system with 4 known planets in this catalogue.
The G 192-15 system is a planetary system with 2 known planets in this catalogue.
The GJ 1002 system is a planetary system with 2 known planets in this catalogue.
The GJ 1061 system is a planetary system with 3 known planets in this catalogue.
The GJ 1132 system is a planetary system with 2 known planets in this catalogue.
The GJ 1148 system is a planetary system with 2 known planets in this catalogue.
The GJ 15 A system is a planetary system with 2 known planets in this catalogue.
The GJ 163 system is a planetary system with 3 known planets in this catalogue.
The GJ 180 system is a planetary system with 3 known planets in this catalogue.
The GJ 229 system is a planetary system with 2 known planets in this catalogue.
The GJ 251 system is a planetary system with 2 known planets in this catalogue.
The GJ 273 system is a planetary system with 2 known planets in this catalogue.
The GJ 3138 system is a planetary system with 3 known planets in this catalogue.
The GJ 317 system is a planetary system with 2 known planets in this catalogue.
The GJ 328 system is a planetary system with 2 known planets in this catalogue.
The GJ 3293 system is a planetary system with 4 known planets in this catalogue.
The GJ 3323 system is a planetary system with 2 known planets in this catalogue.
The GJ 3512 system is a planetary system with 2 known planets in this catalogue.
The GJ 357 system is a planetary system with 3 known planets in this catalogue.
The GJ 367 system is a planetary system with 3 known planets in this catalogue.
The GJ 3998 system is a planetary system with 3 known planets in this catalogue.
The GJ 411 system is a planetary system with 2 known planets in this catalogue.
The GJ 414 A system is a planetary system with 2 known planets in this catalogue.
The GJ 4274 system is a planetary system with 2 known planets in this catalogue.
The GJ 433 system is a planetary system with 3 known planets in this catalogue.
The GJ 536 system is a planetary system with 2 known planets in this catalogue.
The GJ 581 system is a planetary system with 3 known planets in this catalogue.
The GJ 667 C system is a planetary system with 5 known planets in this catalogue.
The GJ 676 A system is a planetary system with 4 known planets in this catalogue.
The GJ 682 system is a planetary system with 2 known planets in this catalogue.
The GJ 687 system is a planetary system with 2 known planets in this catalogue.
The GJ 806 system is a planetary system with 2 known planets in this catalogue.
The GJ 849 system is a planetary system with 2 known planets in this catalogue.
The GJ 876 system is a planetary system with 4 known planets in this catalogue.
The GJ 887 system is a planetary system with 4 known planets in this catalogue.
The GJ 9827 system is a planetary system with 3 known planets in this catalogue.
The HD 10180 system is a planetary system with 6 known planets in this catalogue.
The HD 104067 system is a planetary system with 2 known planets in this catalogue.
The HD 111232 system is a planetary system with 2 known planets in this catalogue.
The HD 113538 system is a planetary system with 2 known planets in this catalogue.
The HD 114386 system is a planetary system with 2 known planets in this catalogue.
The HD 114783 system is a planetary system with 2 known planets in this catalogue.
The HD 11506 system is a planetary system with 3 known planets in this catalogue.
The HD 115404 A system is a planetary system with 2 known planets in this catalogue.
The HD 118203 system is a planetary system with 2 known planets in this catalogue.
The HD 125612 system is a planetary system with 3 known planets in this catalogue.
The HD 128311 system is a planetary system with 2 known planets in this catalogue.
The HD 134060 system is a planetary system with 2 known planets in this catalogue.
The HD 134606 system is a planetary system with 5 known planets in this catalogue.
The HD 134987 system is a planetary system with 2 known planets in this catalogue.
The HD 136352 system is a planetary system with 3 known planets in this catalogue.
The HD 13808 system is a planetary system with 2 known planets in this catalogue.
The HD 141399 system is a planetary system with 4 known planets in this catalogue.
The HD 142 system is a planetary system with 3 known planets in this catalogue.
The HD 1461 system is a planetary system with 2 known planets in this catalogue.
The HD 153557 system is a planetary system with 3 known planets in this catalogue.
The HD 156668 system is a planetary system with 2 known planets in this catalogue.
The HD 158259 system is a planetary system with 5 known planets in this catalogue.
The HD 160691 system is a planetary system with 4 known planets in this catalogue.
The HD 164604 system is a planetary system with 2 known planets in this catalogue.
The HD 164922 system is a planetary system with 4 known planets in this catalogue.
The HD 176986 system is a planetary system with 3 known planets in this catalogue.
The HD 181433 system is a planetary system with 3 known planets in this catalogue.
The HD 189567 system is a planetary system with 2 known planets in this catalogue.
The HD 190360 system is a planetary system with 2 known planets in this catalogue.
The HD 191939 system is a planetary system with 6 known planets in this catalogue.
The HD 192310 system is a planetary system with 2 known planets in this catalogue.
The HD 203387 system is a planetary system with 2 known planets in this catalogue.
The HD 206893 system is a planetary system with 2 known planets in this catalogue.
The HD 20781 system is a planetary system with 4 known planets in this catalogue.
The HD 20794 system is a planetary system with 4 known planets in this catalogue.
The HD 215152 system is a planetary system with 4 known planets in this catalogue.
The HD 217107 system is a planetary system with 2 known planets in this catalogue.
The HD 219134 system is a planetary system with 6 known planets in this catalogue.
The HD 23079 system is a planetary system with 2 known planets in this catalogue.
The HD 260655 system is a planetary system with 2 known planets in this catalogue.
The HD 27894 system is a planetary system with 3 known planets in this catalogue.
The HD 33142 system is a planetary system with 3 known planets in this catalogue.
The HD 34445 system is a planetary system with 6 known planets in this catalogue.
The HD 37124 system is a planetary system with 3 known planets in this catalogue.
The HD 39091 system is a planetary system with 3 known planets in this catalogue.
The HD 39194 system is a planetary system with 3 known planets in this catalogue.
The HD 40307 system is a planetary system with 5 known planets in this catalogue.
The HD 43197 system is a planetary system with 2 known planets in this catalogue.
The HD 45184 system is a planetary system with 2 known planets in this catalogue.
The HD 48265 system is a planetary system with 2 known planets in this catalogue.
The HD 48948 system is a planetary system with 3 known planets in this catalogue.
The HD 60532 system is a planetary system with 2 known planets in this catalogue.
The HD 63433 system is a planetary system with 3 known planets in this catalogue.
The HD 68988 system is a planetary system with 2 known planets in this catalogue.
The HD 69830 system is a planetary system with 3 known planets in this catalogue.
The HD 75898 system is a planetary system with 2 known planets in this catalogue.
The HD 7924 system is a planetary system with 3 known planets in this catalogue.
The HD 81817 system is a planetary system with 2 known planets in this catalogue.
The HD 82943 system is a planetary system with 2 known planets in this catalogue.
The HD 83443 system is a planetary system with 2 known planets in this catalogue.
The HD 93083 system is a planetary system with 2 known planets in this catalogue.
The HD 94890 system is a planetary system with 2 known planets in this catalogue.
The HD 96700 system is a planetary system with 3 known planets in this catalogue.
The HD 99492 system is a planetary system with 2 known planets in this catalogue.
The HIP 14810 system is a planetary system with 3 known planets in this catalogue.
The HIP 41378 system is a planetary system with 6 known planets in this catalogue.
The HIP 56998 system is a planetary system with 2 known planets in this catalogue.
The HIP 57274 system is a planetary system with 3 known planets in this catalogue.
The HR 8799 system is a planetary system with 4 known planets in this catalogue.
The K2-18 system is a planetary system with 2 known planets in this catalogue.
The Kepler-100 system is a planetary system with 4 known planets in this catalogue.
The Kepler-11 system is a planetary system with 6 known planets in this catalogue.
The Kepler-122 system is a planetary system with 5 known planets in this catalogue.
The Kepler-138 system is a planetary system with 4 known planets in this catalogue.
The Kepler-139 system is a planetary system with 5 known planets in this catalogue.
The Kepler-1649 system is a planetary system with 2 known planets in this catalogue.
The Kepler-186 system is a planetary system with 5 known planets in this catalogue.
The Kepler-19 system is a planetary system with 3 known planets in this catalogue.
The Kepler-20 system is a planetary system with 6 known planets in this catalogue.
The Kepler-24 system is a planetary system with 4 known planets in this catalogue.
The Kepler-26 system is a planetary system with 4 known planets in this catalogue.
The Kepler-32 system is a planetary system with 5 known planets in this catalogue.
The Kepler-33 system is a planetary system with 5 known planets in this catalogue.
The Kepler-338 system is a planetary system with 4 known planets in this catalogue.
The Kepler-37 system is a planetary system with 4 known planets in this catalogue.
The Kepler-411 system is a planetary system with 4 known planets in this catalogue.
The Kepler-416 system is a planetary system with 3 known planets in this catalogue.
The Kepler-46 system is a planetary system with 3 known planets in this catalogue.
The Kepler-48 system is a planetary system with 5 known planets in this catalogue.
The Kepler-49 system is a planetary system with 4 known planets in this catalogue.
The Kepler-51 system is a planetary system with 4 known planets in this catalogue.
The Kepler-55 system is a planetary system with 5 known planets in this catalogue.
The Kepler-58 system is a planetary system with 4 known planets in this catalogue.
The Kepler-65 system is a planetary system with 4 known planets in this catalogue.
The Kepler-68 system is a planetary system with 4 known planets in this catalogue.
The Kepler-79 system is a planetary system with 4 known planets in this catalogue.
The Kepler-80 system is a planetary system with 6 known planets in this catalogue.
The Kepler-82 system is a planetary system with 5 known planets in this catalogue.
The Kepler-84 system is a planetary system with 5 known planets in this catalogue.
The Kepler-85 system is a planetary system with 4 known planets in this catalogue.
The KOI-142 system is a planetary system with 3 known planets in this catalogue.
The L 98-59 system is a planetary system with 5 known planets in this catalogue.
The LHS 1140 system is a planetary system with 2 known planets in this catalogue.
The LHS 1678 system is a planetary system with 3 known planets in this catalogue.
The LkCa 15 system is a planetary system with 2 known planets in this catalogue.
The LP 791-18 system is a planetary system with 3 known planets in this catalogue.
The LP 890-9 system is a planetary system with 2 known planets in this catalogue.
The LTT 1445 A system is a planetary system with 2 known planets in this catalogue.
The NN Ser system is a planetary system with 2 known planets in this catalogue.
The nu Oph system is a planetary system with 2 known planets in this catalogue.
The NY Vir system is a planetary system with 2 known planets in this catalogue.
The OGLE-2006-BLG-109L system is a planetary system with 2 known planets in this catalogue.
The OGLE-2012-BLG-0026L system is a planetary system with 2 known planets in this catalogue.
The PDS 70 system is a planetary system with 2 known planets in this catalogue.
The Proxima Cen system is a planetary system with 2 known planets in this catalogue.
The PSR B1257+12 system is a planetary system with 3 known planets in this catalogue.
The rho CrB system is a planetary system with 3 known planets in this catalogue.
The tau Cet system is a planetary system with 3 known planets in this catalogue.
The Teegarden's Star system is a planetary system with 3 known planets in this catalogue.
The TOI-1203 system is a planetary system with 4 known planets in this catalogue.
The TOI-1266 system is a planetary system with 3 known planets in this catalogue.
The TOI-201 system is a planetary system with 3 known planets in this catalogue.
The TOI-2267 A system is a planetary system with 2 known planets in this catalogue.
The TOI-270 system is a planetary system with 3 known planets in this catalogue.
The TOI-4010 system is a planetary system with 4 known planets in this catalogue.
The TOI-5624 system is a planetary system with 5 known planets in this catalogue.
The TOI-5789 system is a planetary system with 4 known planets in this catalogue.
The TOI-700 system is a planetary system with 4 known planets in this catalogue.
The TOI-771 system is a planetary system with 2 known planets in this catalogue.
The TRAPPIST-1 system is a planetary system with 7 known planets in this catalogue.
The TYC 8998-760-1 system is a planetary system with 2 known planets in this catalogue.
The ups And system is a planetary system with 3 known planets in this catalogue.
The WISPIT 1 system is a planetary system with 2 known planets in this catalogue.
The WISPIT 2 system is a planetary system with 2 known planets in this catalogue.
The Wolf 1061 system is a planetary system with 3 known planets in this catalogue.
The XO-2 S system is a planetary system with 3 known planets in this catalogue.
The YZ Cet system is a planetary system with 3 known planets in this catalogue.
Detecting the tiny dip in a star's brightness as a planet passes in front of it.
Measuring the gravitational wobble a planet induces in its star.
Taking an actual picture of a planet by blocking its star's glare.
Using a star's gravity as a lens to reveal an unseen planet.
Detecting planets from the gravitational tug they exert on other transiting planets.
Finding planets from shifts in the eclipse times of a binary star.
Measuring the tiny side-to-side wobble of a star on the sky.
Detecting planets from regular changes in a pulsar's precise pulses.
Small, likely rocky planets up to about 1.6 Earth radii.
Planets larger than Earth but smaller than the ice giants, roughly 1.6–2.4 Earth radii.
Planets between super-Earths and Neptune in size, with thick atmospheres, roughly 2.4–5.5 Earth radii.
Large planets dominated by hydrogen and helium, larger than about 5.5 Earth radii.
Gas-giant planets orbiting extremely close to their stars, with short orbital periods.
The NASA Exoplanet Archive is the authoritative catalogue of confirmed exoplanets and their measured parameters.
The habitable zone is the range of orbits around a star where a planet could, in principle, hold liquid water on its surface. Lying in the zone is not a guarantee of habitability.
Aryabhata was the first of the great mathematician-astronomers of classical India.
Al-Battani was among the most influential astronomers of the medieval Islamic world, observing from Raqqa in present-day Syria.
Abd al-Rahman al-Sufi, known in Latin as Azophi, revised Ptolemy's star catalogue against his own observations in his Book of Fixed Stars.
Nasir al-Din al-Tusi built the great observatory at Maragha, one of the most advanced research institutions of its age.
Ulugh Beg was a Timurid ruler and astronomer who built a monumental observatory at Samarkand with an enormous meridian arc.
Christiaan Huygens was a Dutch polymath who built superb telescopes of his own design.
Giovanni Domenico Cassini was the founding director of the Paris Observatory. He discovered four of Saturn's moons and the dark gap in its rings now called the Cassini Division, and his measurement of the parallax of Mars helped fix the…
Isaac Newton united the heavens and the Earth under a single law. His Principia (1687) showed that the same gravity that pulls an apple to the ground holds the Moon in its orbit and shapes the paths of the planets, explaining Kepler's laws…
Charles Messier was a dedicated French comet-hunter who grew tired of mistaking fuzzy, unmoving objects for comets. To avoid the confusion he listed them — galaxies, nebulae, and star clusters — in a catalogue of about 110 entries.
John Herschel, son of William, extended the family's surveys to the southern skies from the Cape of Good Hope. His General Catalogue of nebulae and clusters became the backbone of the later New General Catalogue (NGC).
Henry Draper was an American physician and pioneer of astrophotography. In 1872 he made the first photograph showing the spectral lines of a star, Vega, and in 1880 he captured the first photograph of the Orion Nebula.
Urbain Le Verrier predicted the planet Neptune using mathematics alone. From small irregularities in the orbit of Uranus he calculated where an unseen planet must lie, and on the very night his prediction reached Berlin in 1846 the planet…
Johann Galle was the astronomer at the Berlin Observatory who, on 23 September 1846, pointed his telescope where Urbain Le Verrier's calculations predicted and found Neptune almost at once.
Edward Charles Pickering directed the Harvard College Observatory from 1877 to 1919 and built the program of stellar spectroscopy and photography that produced the Henry Draper Catalogue.
Cecilia Payne-Gaposchkin discovered what stars are made of. Her 1925 doctoral thesis applied new atomic physics to stellar spectra and concluded that the Sun and stars are composed almost entirely of hydrogen and helium — a result so…
Georges Lemaître was a Belgian priest and physicist who, in 1927, derived an expanding universe from general relativity and estimated its rate of expansion — two years before Hubble's observations.
Fritz Zwicky was a brilliant, combative astrophysicist at Caltech. In 1933 he measured the motions of galaxies in the Coma cluster and concluded that vast amounts of invisible 'dark matter' must be holding them together — a finding ignored…
Jocelyn Bell Burnell discovered pulsars as a graduate student at Cambridge in 1967, spotting an impossibly regular radio signal her team nicknamed 'LGM-1'.
Arno Penzias, with Robert Wilson at Bell Labs, detected a faint, uniform microwave hiss coming from every direction in the sky.
Robert Wilson, with Arno Penzias, discovered the cosmic microwave background radiation in 1965 using a sensitive horn antenna at Bell Labs.
Maarten Schmidt cracked the mystery of quasars. In 1963 he realised that the strange spectrum of the radio source 3C 273 was ordinary hydrogen shifted far to the red, placing the object billions of light-years away — and meaning it shone…
Stephen Hawking united general relativity and quantum mechanics at the edge of black holes, predicting in 1974 that they slowly radiate and shrink — Hawking radiation.
Michel Mayor, with his student Didier Queloz, discovered 51 Pegasi b in 1995 — the first planet found orbiting a normal star like the Sun. The unexpected 'hot Jupiter' opened the entire field of exoplanet science.
Didier Queloz was a doctoral student of Michel Mayor when, in 1995, their spectrograph revealed the tell-tale wobble of 51 Pegasi caused by an orbiting giant planet — the first exoplanet around a Sun-like star.
Jane Luu, with David Jewitt, spent five years searching for objects beyond Neptune and in 1992 found the first one, (15760) Albion.
Reinhard Genzel led one of two teams that, over decades, tracked the orbits of stars whipping around the centre of the Milky Way.
Andrea Ghez used the Keck telescopes and adaptive optics to follow stars orbiting the centre of the Milky Way with extraordinary precision.
Saul Perlmutter led the Supernova Cosmology Project, one of two teams using distant Type Ia supernovae as standard candles to measure the history of cosmic expansion.
Brian Schmidt led the High-z Supernova Search Team, which independently found that the expansion of the universe is accelerating.
Adam Riess carried out much of the analysis that revealed cosmic acceleration for the High-z Supernova Search Team in 1998. He has since led precise measurements of the universe's expansion rate that hint at gaps in our cosmological model.
Neil deGrasse Tyson is an astrophysicist and the director of New York's Hayden Planetarium, and the most prominent science communicator of his generation.
Hipparchus discovered that the equinox points slowly drift along the zodiac, completing a circuit in about 26,000 years, by comparing his star positions with older records.
In January 1610 Galileo saw four points of light beside Jupiter that changed position night after night — moons orbiting another world.
Galileo observed that Venus shows a full cycle of phases like the Moon, including a 'full' phase only possible if it orbits the Sun.
Christiaan Huygens discovered Titan, Saturn's largest moon, with a telescope of his own design.
Huygens explained that the strange 'arms' Galileo had seen around Saturn are in fact a thin, flat ring surrounding but not touching the planet. In 1675 Cassini found the gap dividing the rings.
Applying Newton's gravitation, Halley showed that comets recorded in 1531, 1607, and 1682 were one body on a 76-year orbit, and predicted its return in 1758.
William Herschel spotted a slow-moving object that proved to be a new planet far beyond Saturn — the first planet discovered since antiquity.
From tiny irregularities in the orbit of Uranus, Le Verrier (and, independently, John Couch Adams) predicted an unseen planet; Galle found Neptune within a degree of the prediction on 23 September 1846.
Cecilia Payne-Gaposchkin's doctoral thesis applied atomic physics to stellar spectra and concluded that stars are composed overwhelmingly of hydrogen and helium.
Henrietta Leavitt found that the pulsation period of a Cepheid variable star reveals its true luminosity, giving astronomers a 'standard candle' for measuring distance.
Using Cepheid distances and galaxy redshifts, Edwin Hubble showed in 1929 that galaxies recede faster the farther away they are — the universe is expanding, as Lemaître had derived two years earlier.
Fritz Zwicky inferred unseen mass in the Coma cluster in 1933, and from the 1970s Vera Rubin's galaxy rotation curves showed that galaxies are dominated by invisible 'dark matter'.
Maarten Schmidt recognised that the puzzling radio source 3C 273 was extremely redshifted, placing it billions of light-years away and making it astonishingly luminous.
Penzias and Wilson detected a faint microwave glow coming uniformly from every direction — the cooled afterglow of the hot early universe.
Jocelyn Bell Burnell detected a strikingly regular radio pulse that proved to be a rapidly spinning neutron star sweeping a beam past the Earth.
Jane Luu and David Jewitt discovered (15760) Albion, the first body found in the Kuiper Belt beyond Neptune after a five-year search.
The First Exoplanet Around a Sun-like Star
Michel Mayor and Didier Queloz, using the ELODIE spectrograph at the Observatoire de Haute-Provence, detected the wobble of the star 51 Pegasi caused by an orbiting giant planet — the first exoplanet found around a normal, Sun-like star.
Two teams using distant Type Ia supernovae found that the expansion of the universe is speeding up, driven by a mysterious 'dark energy'.
The First Detection of Gravitational Waves
On 14 September 2015 the LIGO observatories recorded a ripple in spacetime from two merging black holes 1.3 billion light-years away — the first direct detection of gravitational waves.
Over three decades, the teams of Reinhard Genzel and Andrea Ghez tracked stars orbiting the centre of the Milky Way, revealing a four-million-solar-mass black hole, Sagittarius A*.
The Event Horizon Telescope, a global network of radio dishes including ALMA, produced the first image of a black hole's shadow — the supermassive black hole at the heart of the galaxy M87.
In July 2022 the James Webb Space Telescope released its first full-colour images, including the deepest and sharpest infrared view of the distant universe ever taken.
Ptolemy's comprehensive treatise on astronomy, presenting the geocentric model with epicycles and a catalogue of more than a thousand stars.
Aryabhata's concise verse treatise on mathematics and astronomy, giving methods for planetary positions and eclipses, a sine table, and the idea that the Earth rotates on its axis.
Al-Sufi's revision of Ptolemy's star catalogue against his own observations, with constellation drawings and corrected magnitudes.
Copernicus's masterwork, 'On the Revolutions of the Heavenly Spheres', setting out the heliocentric system in full. Published in the year of his death, it began the displacement of the Earth from the centre of the cosmos.
Kepler's 'New Astronomy', in which his struggle with the orbit of Mars led him to the first two laws of planetary motion: elliptical orbits and the equal-area law.
Galileo's 'Starry Messenger', the first published account of telescopic astronomy: the four moons of Jupiter, the mountains of the Moon, and the countless stars of the Milky Way.
Kepler's 'Harmony of the World', which presents his third law of planetary motion — relating a planet's orbital period to its distance from the Sun.
Dialogue Concerning the Two Chief World Systems
Galileo's spirited comparison of the Copernican and Ptolemaic systems, written in Italian for a wide audience. Its defence of heliocentrism led to his trial and condemnation by the Inquisition in 1633.
Philosophiæ Naturalis Principia Mathematica
Newton's 'Mathematical Principles of Natural Philosophy', perhaps the most important scientific book ever written.
Carl Sagan's book and accompanying television series, which traced the history of science and the scale of the universe for a global audience and became one of the most influential works of science communication ever made.
Stephen Hawking's best-selling account of cosmology — from the Big Bang to black holes and the nature of time — which brought the deepest questions of the universe to millions of readers.
The model, codified by Ptolemy, in which the Earth sits motionless at the centre of the cosmos while the Sun, Moon, planets, and stars revolve around it on a system of circles and epicycles.
The model placing the Sun at the centre of the planetary system, with the Earth a planet that both spins on its axis and orbits the Sun.
Three laws describing how planets move: orbits are ellipses with the Sun at one focus; a line from the Sun to a planet sweeps out equal areas in equal times; and the square of a planet's orbital period is proportional to the cube of its…
Newton's law that every mass attracts every other with a force proportional to their masses and inversely proportional to the square of the distance between them.
Einstein's theory of gravity as the curvature of spacetime by mass and energy. Published in 1915, it predicted the bending of starlight, the precession of Mercury's orbit, black holes, an expanding universe, and gravitational waves —…
The theory that the universe expanded from an extremely hot, dense early state, first proposed by Georges Lemaître as the 'primeval atom'.
The star catalogue embedded in Ptolemy's Almagest, listing over a thousand stars in 48 constellations with positions and magnitudes. It built on Hipparchus's earlier catalogue and defined the classical sky for centuries.
Ulugh Beg's star catalogue, compiled at the Samarkand observatory, giving fresh naked-eye positions for over a thousand stars. It was the most accurate star catalogue produced between Ptolemy and Tycho Brahe.
The planetary tables completed by Johannes Kepler from Tycho Brahe's observations, named for Emperor Rudolf II. Built on elliptical orbits, they were far more accurate than any predecessor and remained in use for over a century.
The two Index Catalogues (1895 and 1908), compiled by J. L. E. Dreyer as supplements to the New General Catalogue, adding thousands of nebulae and clusters discovered with photography and larger telescopes.
A vast catalogue of stellar spectra produced at Harvard, with classifications largely by Annie Jump Cannon. Named in memory of astrophotography pioneer Henry Draper, it gave the 'HD' designations still used for stars today.
The system that orders stars by the appearance of their spectra into the temperature sequence O B A F G K M, developed at Harvard under Edward Pickering and brought to its final form by Annie Jump Cannon.
The two-dimensional classification developed by Morgan, Keenan, and Kellman at Yerkes Observatory, adding a luminosity class (I–V) to the Harvard temperature type.
The catalogue produced by ESA's Hipparcos mission, the first space astrometry survey, giving high-precision parallaxes, positions, and magnitudes. It established the modern distance scale of the nearby Galaxy.
The catalogues from ESA's Gaia mission, mapping the positions, distances, motions, and brightnesses of nearly two billion stars.
The earliest systematic sky-watching, when farming and religious calendars were tied to the motions of the Sun, Moon, and stars.
The astronomers of Mesopotamia kept centuries of meticulous observational records on clay tablets, developed arithmetical methods to predict lunar and planetary positions, and bequeathed the sexagesimal (base-60) system that still divides…
Ancient Egyptian sky-watchers used the heliacal rising of Sirius to anticipate the Nile flood, organised a 365-day civil calendar, and aligned temples and pyramids to the stars and cardinal directions.
Greek thinkers transformed astronomy into a geometric science, seeking physical and mathematical models of the heavens.
Under Roman rule, astronomy flourished above all at Alexandria, where Ptolemy compiled the Almagest. The Romans reformed the calendar into the Julian system and preserved and transmitted Greek astronomical learning.
Astronomers across the medieval Islamic world preserved, corrected, and extended Greek and Indian astronomy.
Chinese court astronomers kept among the longest continuous observational records in history, documenting eclipses, comets, and 'guest stars' — including the supernova of 1054 that formed the Crab Nebula — for calendrical and imperial…
The Indian astronomical tradition produced sophisticated mathematical astronomy in Sanskrit treatises (siddhantas). Aryabhata and his successors modelled planetary motion, computed eclipses, and proposed that the Earth rotates on its axis.
Maya astronomers tracked the Sun, Moon, and especially Venus with remarkable precision, encoding their cycles in the Dresden Codex and in calendars that governed ritual and agriculture across the Classic period.
The European Renaissance reopened astronomy to bold reform. Copernicus placed the Sun at the centre of the planetary system, and Tycho Brahe's unprecedentedly accurate measurements set the stage for a new physics of the heavens.
In little more than a century, astronomy was remade. The telescope opened the sky, Kepler found that planets move in ellipses, Galileo turned observation into evidence, and Newton's universal gravitation united the heavens and the Earth…
Spectroscopy and photography turned telescopes into instruments of astrophysics, revealing what stars are made of.
The launch of Sputnik opened astronomy to the whole electromagnetic spectrum from above the atmosphere.
Twenty-first-century astronomy works in many messengers at once — light, gravitational waves, and particles.
The refracting telescope appeared in the Netherlands in 1608, with the spectacle-maker Hans Lippershey filing the first known patent application.
Founding of the Royal Observatory, Greenwich
King Charles II founded the Royal Observatory at Greenwich in 1675 to improve navigation by mapping the stars and the Moon. It gave its name to the Greenwich Meridian and Greenwich Mean Time and shaped positional astronomy for centuries.
Founding of the International Astronomical Union
The International Astronomical Union was founded in 1919 to coordinate astronomy worldwide.
In 1920 Harlow Shapley and Heber Curtis debated the scale of the universe: whether the spiral nebulae lie within the Milky Way or are separate 'island universes'.
The premier international award in physics, awarded by the Royal Swedish Academy of Sciences since 1901.
Breakthrough Prize in Fundamental Physics
A major science award founded in 2012. Its Special Breakthrough Prize has honoured discoveries including the detection of gravitational waves and, for Jocelyn Bell Burnell, the discovery of pulsars.
The hot, dense early state from which the observable Universe has been expanding for about 13.8 billion years.
A hypothesised burst of exponential expansion in the first fraction of a second that would explain the Universe's uniformity and flatness.
The production of the light elements — hydrogen, helium, and traces of lithium — in the first few minutes of the Universe.
The moment the cooling Universe let electrons and protons combine into neutral atoms, allowing light to travel freely for the first time.
The period after recombination and before the first stars, when the Universe was filled with neutral gas and no sources of light.
The era when the first stars and galaxies formed and began to light up the Universe.
The era when radiation from the first stars and galaxies re-ionized the neutral hydrogen filling the Universe.
The gravitational growth of tiny early density variations into the galaxies, clusters, and cosmic web we see today.
The Universe today: expanding, accelerating, and dominated by dark energy and dark matter.
The observed stretching of space itself, which carries galaxies apart at rates proportional to their distance.
The stretching of light to longer (redder) wavelengths as it travels through expanding space.
The law that a galaxy's recession velocity is proportional to its distance: v = H₀ × d.
The present-day rate of expansion of the Universe, denoted H₀.
The unresolved disagreement between measurements of the Hubble constant from the early and the local Universe.
The time elapsed since the Big Bang, measured to be about 13.8 billion years.
The region of the Universe from which light has had time to reach us since the Big Bang.
The boundary beyond which light has not had time to reach us — the edge of the observable Universe.
The faint, uniform microwave glow left over from recombination — the oldest light in the Universe.
A preferred ~500-million-light-year separation in the clustering of galaxies, frozen in from sound waves in the early Universe.
An unseen form of matter, detected only through its gravity, that outweighs ordinary matter roughly five to one.
The unknown component driving the accelerating expansion of the Universe, making up roughly 68% of it.
A constant energy density of empty space, Einstein's Λ, the simplest candidate for dark energy.
The vast network of filaments and voids into which galaxies and dark matter are organised on the largest scales.
The statistical distribution of matter across the Universe on the largest scales.
The universal attraction between masses that governs the motion of everything from apples to galaxies.
The four-dimensional fabric of space and time that mass and energy curve to produce gravity.
Einstein's 1905 theory that the laws of physics and the speed of light are the same for all inertial observers.
The sought-after theory that would unify general relativity with quantum mechanics.
The boundary around a black hole beyond which nothing, not even light, can escape.
A point predicted by general relativity where density becomes infinite and the theory breaks down.
Faint thermal radiation predicted to be emitted by black holes due to quantum effects at the horizon.
A rotating disk of gas spiralling into a compact object, heated until it glows brightly.
The radius to which a mass must be compressed for its escape velocity to reach the speed of light — the size of a non-rotating black hole's event horizon.
The minimum speed needed to break free of a body's gravity without further propulsion.
A measure of disorder that, on cosmic scales, only increases — giving time its direction.
Ripples in spacetime produced by accelerating masses, such as merging black holes.
The theory describing the known elementary particles and three of the four fundamental forces.
The standard model of cosmology: a flat, expanding Universe dominated by a cosmological constant (Λ) and cold dark matter (CDM).
An alternative proposal that modifies the law of gravity at very low accelerations instead of invoking dark matter.
The hypothesis that our observable Universe is one of many, or of infinitely many, universes.
Models in which the Universe undergoes repeated cycles of expansion and contraction, or a 'bounce' instead of a singular beginning.
A region of spacetime where gravity is so strong that nothing, not even light, can escape.
A black hole of millions to billions of solar masses, found at the centre of most large galaxies.
A black hole between about 100 and 100,000 solar masses — the elusive middle range.
A black hole of a few to a few dozen solar masses, formed when a massive star collapses.
A hypothesised black hole formed from density fluctuations in the very early Universe rather than from a star.
The ultra-dense collapsed core of a massive star, packing more than the Sun's mass into a city-sized sphere.
A neutron star with an extraordinarily powerful magnetic field, the strongest known in the Universe.
The dense, Earth-sized remnant left when a low- or medium-mass star sheds its outer layers.
A 'failed star' too massive to be a planet but too light to sustain hydrogen fusion.
The extremely luminous core of a distant galaxy powered by a feeding supermassive black hole.
An active galactic nucleus whose relativistic jet points almost directly at Earth.
A galaxy centre made unusually luminous by matter accreting onto a supermassive black hole.
An extended, roughly spherical cloud of dark matter within which a galaxy or cluster is embedded.
A gravitationally bound collection of hundreds to thousands of galaxies — the largest such structures.
A vast grouping of galaxy clusters and groups, among the largest structures in the Universe.
A thread of galaxies and dark matter stretching between clusters, forming the strands of the cosmic web.
An enormous, nearly empty region of space between the filaments of the cosmic web.
NASA's Cosmic Background Explorer, which measured the spectrum and first mapped the anisotropy of the cosmic microwave background.
WMAP (Wilkinson Microwave Anisotropy Probe)
NASA's Wilkinson Microwave Anisotropy Probe, which mapped the CMB in detail and pinned down the cosmological parameters.
DESI (Dark Energy Spectroscopic Instrument)
A spectroscopic survey measuring the redshifts of tens of millions of galaxies to map cosmic expansion and dark energy.
A Japanese underground, cryogenic gravitational-wave detector, the fourth major observatory in the global network.
A planet-scale network of radio telescopes that images the shadows of supermassive black holes.
Albert Einstein reshaped our understanding of space, time, and gravity. His 1905 theory of special relativity and 1915 theory of general relativity form the foundation of modern cosmology, predicting the expansion of the Universe, black…
Webb's first deep field — the galaxy cluster SMACS 0723 — the deepest, sharpest infrared image of the distant universe at the time of its release.
The 'Cosmic Cliffs' — the edge of a star-forming region in the Carina Nebula, revealed by Webb in infrared.
The Southern Ring Nebula — a planetary nebula of gas shed by a dying star — shown in two Webb infrared views.
Stephan's Quintet — a compact group of galaxies, four of which are locked in a cosmic dance.
The 'Pillars of Creation' — towers of gas and dust in the Eagle Nebula, one of Hubble's most iconic images.
The Hubble Ultra Deep Field — around ten thousand galaxies in a patch of sky a tenth the width of the full Moon.
The first image of a black hole: the shadow of the supermassive black hole at the centre of the galaxy M87, released in 2019.
Sagittarius A* — The Milky Way's Black Hole
The Event Horizon Telescope's 2022 image of Sagittarius A*, the supermassive black hole at the centre of our own Galaxy.
'Earthrise' — Earth seen rising over the Moon, photographed by astronaut William Anders during Apollo 8 on 24 December 1968.
'The Blue Marble' — a fully illuminated Earth photographed by the crew of Apollo 17 on their way to the Moon in 1972.
'Pale Blue Dot' — Earth as a single pixel, photographed by Voyager 1 from about 6 billion kilometres away in 1990.
Saturn backlit by the Sun, with Earth visible as a distant point of light — Cassini's 'The Day the Earth Smiled'.
The Sombrero Galaxy — an edge-on spiral with a brilliant nucleus and a prominent dust lane.
The Crab Nebula — the expanding remnant of a supernova recorded by astronomers in 1054.
The floor of Jezero Crater on Mars, imaged by NASA's Perseverance rover after its 2021 landing.
The layered lower slopes of Mount Sharp in Gale Crater, imaged by NASA's Curiosity rover.
The active Sun in extreme ultraviolet, showing hot plasma tracing magnetic loops above the surface.
Webb's near-infrared view of Jupiter, revealing auroras at both poles, high-altitude hazes, and the planet's faint rings.
The Milky Way arching over ESO's Very Large Telescope at Paranal, Chile — one of the darkest skies on Earth.
The International Space Station in orbit, photographed by a departing crew spacecraft.
The 'Family Portrait' — the first mosaic of the Solar System, taken by Voyager 1 from beyond Neptune in 1990.
The first full-colour science images from the James Webb Space Telescope, released in July 2022.
Long exposures that reveal thousands of distant galaxies in a tiny patch of sky.
Direct horizon-scale images of supermassive black holes.
Clouds of gas and dust where stars are born and where they end their lives.
Island universes of stars, from the Milky Way to the deep field.
Worlds of our own Sun — planets, moons, and the Sun itself.
The Red Planet, seen from orbit and from its surface.
The largest planet and its dynamic atmosphere.
Our star across the electromagnetic spectrum.
Our home world seen from the Moon, from orbit, and from billions of kilometres away.
Images from the Apollo missions to the Moon.
Images from the twin Voyager probes on their grand tour and beyond.
Images from the Cassini mission to Saturn.
Works produced by US federal agencies (NASA, JPL, USNO) are generally not subject to copyright and are free to use. A credit line is still requested and always shown here.
Creative Commons Attribution 4.0 International
Free to share and adapt with attribution. Used by ESA/Hubble, ESA/Webb, ESO, and the Event Horizon Telescope Collaboration. (Wikimedia Commons files may instead be CC BY-SA 4.0; each is verified individually.)
NASA's official public-domain image archive.
US Hubble image archive from the Space Telescope Science Institute.
European Hubble image archive; CC BY 4.0.
The Event Horizon Telescope Collaboration's released imagery; CC BY 4.0.
US ground-based optical/infrared image archive; CC BY 4.0.
Media repository; each file's license (public domain or Creative Commons) is verified individually.
NASA's family of heavy- and super-heavy-lift rockets developed for the Apollo program — the Saturn I, Saturn IB, and the Moon-launching Saturn V.
A long-running U.S. launch-vehicle family that evolved from an early ICBM into the modern Atlas V operated by United Launch Alliance.
A prolific U.S. launch-vehicle family spanning six decades, from the Thor-derived Delta through the Delta II and the hydrogen-fueled Delta IV, retired in 2024.
A U.S. family derived from the Titan ICBM — the crewed Titan II of Gemini, and the hypergolic Titan III and Titan IV heavy launchers for national-security and planetary missions.
SpaceX's family of RP-1/LOX rockets — the retired Falcon 1, the reusable Falcon 9, and the Falcon Heavy — that made orbital-class booster reuse routine.
NASA's super-heavy-lift family for the Artemis program, planned in progressively more capable Block 1, Block 1B, and Block 2 configurations.
Europe's flagship launch-vehicle family, from the Ariane 1 of 1979 through the heavy-lift Ariane 5 and the current Ariane 6.
The most-launched rocket lineage in history — descended from the R-7, the world's first ICBM (1957), and continued today by the crew-carrying Soyuz.
China's principal launch-vehicle family, spanning small to heavy lift — from the early hypergolic Long March 2/3/4 to the modern cryogenic Long March 5/6/7/8.
Japan's family of liquid-hydrogen launch vehicles — the H-I, H-II, H-IIA/H-IIB, and the current H3 — developed by JAXA and Mitsubishi Heavy Industries.
NASA's first heavy-lift rocket and the first designed for spaceflight rather than as a missile; it flight-tested Apollo hardware and clustered eight engines in its first stage.
NASA's partially reusable crewed launch system — a winged orbiter with an external tank and two solid rocket boosters — that flew 135 missions building the ISS and servicing Hubble.
A highly reliable medium-lift workhorse that launched GPS satellites and many NASA planetary missions, including the Mars rovers Spirit and Opportunity and the Kepler telescope.
The human-rated Titan II Gemini Launch Vehicle, adapted from an ICBM to carry the two-person Gemini spacecraft into orbit.
The largest and last of the Titan family — a heavy-lift launcher for large U.S. national-security satellites and the Cassini–Huygens mission to Saturn.
SpaceX's first rocket and the first privately developed liquid-fueled launcher to reach orbit, in 2008 — the proving ground for the Merlin engine.
A medium-lift rocket operated by Northrop Grumman that launched Cygnus cargo spacecraft to the ISS; the flown Antares 230+ retired in 2023 after its Russian/Ukrainian first-stage supply was cut, pending the U.S.-built Antares 330.
An air-launched, three-stage solid-fueled small rocket dropped from a carrier aircraft to place small satellites into low Earth orbit.
A family of solid-fueled small launchers built from surplus Minuteman and Peacekeeper missile motors for U.S. government payloads.
Rocket Lab's reusable medium-lift methane/LOX rocket in development, with a reusable first stage and integrated fairing.
Blue Origin's fully reusable suborbital vehicle for research payloads and crewed flights above the Kármán line; it lands its booster propulsively.
Relativity Space's reusable heavy-lift methane/LOX rocket, built largely by large-scale additive manufacturing.
A small-to-medium-lift two-stage rocket operated by Firefly Aerospace for dedicated small-satellite launches.
Europe's first launcher, which established independent access to space and orbited the Giotto probe to Halley's Comet.
An uprated single-payload development of Ariane 1 with a more powerful third stage.
An Ariane variant adding two solid strap-on boosters and dual-payload capability for commercial satellites.
A highly successful and flexible Ariane variant with multiple booster configurations that dominated the commercial launch market in the 1990s.
Europe's small-lift launcher with three solid stages and a liquid upper stage, for small scientific and Earth-observation satellites.
An upgraded, more capable Vega with larger solid motors and a common booster shared with Ariane 6.
The world's first intercontinental ballistic missile, which in 1957 launched Sputnik 1 and founded the most prolific rocket lineage in history.
Russia's modular heavy-lift launcher built from common URM core boosters and burning kerosene/LOX, intended to replace the Proton.
The Soviet super heavy-lift rocket that launched the uncrewed Buran shuttle, flying only twice before the program ended.
A Ukrainian-designed medium-lift kerosene/LOX rocket whose first stage traces to the Energia boosters, flown from Baikonur and the Sea Launch ocean platform.
The Soviet super heavy-lift Moon rocket; all four launch attempts (1969–1972) failed and the program was cancelled. The flown vehicle used Kuznetsov NK-15 engines; the improved NK-33 (for the never-flown N1F) flew decades later on other rockets.
China's only human-rated launch vehicle, which carries the Shenzhou spacecraft with crews to the Tiangong space station.
A modern kerosene/LOX medium-lift Long March that launches the Tianzhou cargo spacecraft to the Tiangong station.
A super heavy-lift launch vehicle in development for China's planned crewed lunar and deep-space missions.
Japan's first entirely domestically developed launch vehicle, using cryogenic LH2/LOX stages.
JAXA's new-generation launch vehicle with the expander-bleed LE-9 engine, designed for lower cost and higher flexibility than the H-IIA.
A Japanese solid-fueled small-lift rocket derived from the H-IIA's booster technology, launched from the Uchinoura Space Center for small scientific satellites.
ISRO's most powerful operational rocket, which launched Chandrayaan-2 and Chandrayaan-3 and is being human-rated for the Gaganyaan program.
ISRO's small-satellite launch vehicle, designed for low-cost, on-demand launches of small payloads to low Earth orbit.
A small-lift two-stage rocket developed by Germany's Isar Aerospace for the European small-satellite market.
PLD Space's orbital small-lift rocket in development, following the suborbital Miura 1, with plans to recover the first stage.
An air-launched, two-stage small rocket released from a modified Boeing 747; it reached orbit before Virgin Orbit ceased operations in 2023.
The Saturn V first stage, powered by five F-1 engines burning RP-1 and liquid oxygen — the stage that generated the Saturn V's ~34 MN of liftoff thrust.
The Saturn V second stage, powered by five J-2 engines burning liquid hydrogen and liquid oxygen.
The restartable single-J-2 upper stage used as the Saturn V third stage and the Saturn IB second stage; its restart performed trans-lunar injection for Apollo.
The pair of reusable solid rocket boosters that provided most of the Space Shuttle's liftoff thrust before being recovered from the ocean by parachute.
The SLS core stage, powered by four RS-25 engines (repurposed Space Shuttle main engines) burning liquid hydrogen and liquid oxygen.
The pair of five-segment solid rocket boosters, derived from the Shuttle SRBs, that provide most of the SLS's liftoff thrust.
The reusable Falcon 9 first stage, powered by nine Merlin 1D engines and recovered by propulsive landing on a droneship or landing pad.
The expendable Falcon 9 upper stage, powered by a single vacuum-optimized Merlin engine.
The Ariane 5 cryogenic main stage (Étage Principal Cryotechnique), powered by a single Vulcain 2 engine burning liquid hydrogen and liquid oxygen.
The pair of large solid rocket boosters (Étage d'Accélération à Poudre) that provide most of Ariane 5's liftoff thrust.
The RP-1/LOX engine of the Saturn V first stage — five clustered F-1s remain the most powerful single-chamber liquid engines ever flown, lifting Apollo off the pad.
The restartable LH2/LOX engine of the Saturn V second and third stages and the Saturn IB second stage; its S-IVB restart sent Apollo crews toward the Moon.
A reusable fuel-rich staged-combustion LH2/LOX engine developed for the Space Shuttle (as the SSME) and now expended on the SLS core stage; among the highest-efficiency hydrogen engines flown.
A large LH2/LOX gas-generator engine developed for the Delta IV; designed for lower cost than the SSME, it powered the Delta IV and Delta IV Heavy cores.
A long-serving expander-cycle LH2/LOX upper-stage engine (first flown in the 1960s) that powers the Centaur and DCSS upper stages and continues on Vulcan Centaur.
SpaceX's reusable RP-1/LOX gas-generator engine; nine power each Falcon 9 first stage and twenty-seven power the Falcon Heavy, with a vacuum variant on the upper stage.
SpaceX's methane/LOX full-flow staged-combustion engine for Starship and its Super Heavy booster — one of very few full-flow engines ever flown, designed for rapid reuse. Thrust has risen across versions.
A Russian two-chamber oxidizer-rich staged-combustion RP-1/LOX engine (derived from the RD-170) that powered the Atlas V first stage.
The most powerful liquid-propellant rocket engine ever flown — a four-chamber oxidizer-rich staged-combustion RP-1/LOX engine used on the Energia boosters and (as the RD-171) the Zenit first stage.
The RP-1/LOX gas-generator engines of the R-7/Soyuz core and strap-on boosters — first flown in 1957 and, in evolved form, still launching crews to orbit.
The Kuznetsov oxidizer-rich staged-combustion RP-1/LOX engine that powered the Soviet N1 Moon rocket — thirty on the first stage alone — across its four failed launches.
A lightweight high-performance oxidizer-rich staged-combustion RP-1/LOX engine developed in the Soviet N1 program for the upgraded (never-flown) N1F; refurbished units later flew (as the AJ-26) on the first-generation Antares.
The LH2/LOX gas-generator core engine of Ariane 5 (and, as Vulcain 2.1, of the Ariane 6 core stage).
A restartable closed-expander-cycle LH2/LOX upper-stage engine developed for Ariane 6, enabling multiple burns for complex mission profiles.
A LH2/LOX upper-stage engine that powered the cryogenic upper stage (ESC-A) of Ariane 5 and earlier Ariane vehicles.
Rocket Lab's small RP-1/LOX engine — the first electric-pump-fed (battery-driven turbopump) engine to reach orbit; nine power the Electron first stage and one the second stage.
Blue Origin's methane/LOX oxidizer-rich staged-combustion engine, which powers both the ULA Vulcan Centaur first stage and Blue Origin's own New Glenn booster.
Blue Origin's LH2/LOX engine — a combustion-tap-off variant (BE-3PM) powers the reusable New Shepard suborbital vehicle, and an upper-stage variant (BE-3U) flies on New Glenn.
China's kerosene/LOX oxidizer-rich staged-combustion engine, used in the boosters of Long March 5 and the cores of Long March 6/7.
China's first large LH2/LOX engine, two of which power the Long March 5 core stage.
A LH2/LOX staged-combustion engine that powers the first stage of Japan's H-IIA and H-IIB launch vehicles.
A large LH2/LOX expander-bleed-cycle engine developed for the first stage of Japan's H3 rocket, chosen for reliability and lower cost.
ISRO's storable-propellant (UDMH/N2O4) engine, used across the PSLV, GSLV, and LVM3 liquid stages and strap-on boosters.
ISRO's indigenous LH2/LOX cryogenic upper-stage engine, which powers the C25 upper stage of the LVM3 (GSLV Mk III).
The hypergolic (Aerozine 50 / N2O4) first- and second-stage engines (LR-87 / LR-91) of the Titan II, III, and IV families, valued for storable-propellant readiness on ICBM-derived launchers.
A restartable pressure-fed engine burning the storable hypergolic combination MMH/N2O4, used on the Ariane 5 EPS storable upper stage for precise orbit insertion.
A refined-kerosene fuel burned with liquid oxygen. Dense and room-temperature-storable fuel with a cryogenic oxidizer; the workhorse first-stage combination from the Saturn V's F-1 to SpaceX's Merlin.
Liquid hydrogen burned with liquid oxygen — the highest-performing chemical propellant by specific impulse, but low-density and deeply cryogenic. Used by the RS-25, RL10, Vulcain, and LE-7/LE-9.
Liquid methane burned with liquid oxygen. A modern choice balancing performance, density, and reusability (clean-burning, in-situ producible on Mars); used by Raptor, BE-4, and Vulcain-class successors.
A storable hypergolic combination that ignites on contact without an igniter. Long the mainstay of the Proton and early Long March vehicles; toxic and being phased out for new designs.
A storable hypergolic combination used in upper stages and orbital-maneuvering systems where reliable restart matters, such as the Ariane 5 storable upper stage.
A hypergolic blend of UDMH and hydrazine with N2O4 oxidizer, used by the Titan family and various upper stages during the 20th century.
A cast solid propellant of ammonium-perchlorate oxidizer, aluminium fuel, and a rubber binder. High thrust and simplicity, but not throttleable or shut-down-able once lit; used in the Shuttle/SLS boosters, Vega, and many strap-on boosters.
The historic Kennedy Space Center pad that launched the Apollo 11 Saturn V and many Space Shuttle flights, now leased to SpaceX for Falcon 9, Falcon Heavy, and Starship operations.
A Kennedy Space Center pad used for Apollo, Skylab, and Shuttle launches and rebuilt as a clean-pad for NASA's Space Launch System.
A Cape Canaveral complex that launched Saturn IB flights and later served the Delta IV and Delta IV Heavy.
A Cape Canaveral complex used for Titan launches and now the home pad of United Launch Alliance's Atlas V and Vulcan Centaur.
A Cape Canaveral complex long used by the Delta family, including the Delta II that launched NASA's Mars rovers.
SpaceX's primary Falcon 9 pad at Cape Canaveral — the workhorse complex for most Falcon 9 launches.
The SpaceX Falcon 9 pad at Vandenberg for polar and Sun-synchronous launches on the U.S. West Coast.
The Mid-Atlantic Regional Spaceport pad at Wallops used by Northrop Grumman's Antares to launch Cygnus cargo missions.
The first Ariane launch complex at the Guiana Space Centre, used by the early Ariane 1–3 vehicles.
The Guiana Space Centre complex that launched every Ariane 5 mission.
The Guiana Space Centre complex built as the new launch pad for Ariane 6.
The Guiana Space Centre complex for the Vega and Vega-C small launchers, on the site of the former Ariane 1 pad.
The historic Baikonur pad that launched Sputnik 1 and Yuri Gagarin, and for decades the departure point for Soyuz crews to orbit.
A Baikonur complex used for Proton heavy-lift launches.
The Baikonur complex built for the Zenit launch vehicle.
The Plesetsk complex used for Angara launches in northern Russia.
The Jiuquan complex for China's human-rated Long March 2F, launching Shenzhou crews to the Tiangong station.
A Xichang complex widely used for Long March 3B launches to geostationary transfer orbit.
The coastal Wenchang complex for the heavy-lift Long March 5.
The Wenchang complex for the Long March 7, which launches Tianzhou cargo missions.
The Tanegashima complex for Japan's large liquid launch vehicles — the H-II, H-IIA/H-IIB, and H3.
The first ISRO pad at Sriharikota, used for the PSLV and SSLV.
The second ISRO pad at Sriharikota, used for the GSLV and LVM3, including the Chandrayaan and Gaganyaan missions.
SpaceX's orbital launch and catch complex at Starbase for the fully reusable Starship and Super Heavy.
The aerospace manufacturer whose lineage (the Martin Company → Martin Marietta → Lockheed Martin) built and operated the Titan family of launch vehicles.
The aerospace company (via the former Orbital Sciences / Orbital ATK) that operates the Antares, Pegasus, and Minotaur launch vehicles.
A launch company developing the medium-lift, reusable Terran R using large-scale additive manufacturing (3D printing).
A launch and space company operating the small-to-medium-lift Firefly Alpha rocket.
A German launch startup developing the small-lift Spectrum rocket.
A Spanish launch company developing the Miura family, including the suborbital Miura 1 and orbital Miura 5.
A now-defunct air-launch company that operated LauncherOne, released from a modified Boeing 747 carrier aircraft.
The circumpolar northern constellations around the Great Bear, including Ursa Minor, Draco, Boötes, Canes Venatici, Coma Berenices, Corona Borealis, Camelopardalis, Lynx, and Leo Minor.
The twelve constellations of the zodiac, through which the Sun, Moon, and planets appear to move along the ecliptic.
The mythological group of the Perseus–Andromeda legend — Cassiopeia, Cepheus, Andromeda, Perseus, Pegasus, Cetus, Auriga, Lacerta, and Triangulum.
The largest family, centred on Hercules and including the Milky Way constellations Aquila, Lyra, Cygnus, Sagitta, Vulpecula, Ophiuchus, Serpens, Scutum, Hydra, Corvus, Crater, Sextans, Centaurus, Lupus, Corona Australis, Ara, Triangulum Australe, and Crux.
The bright winter constellations around the Hunter — Orion, Canis Major, Canis Minor, Lepus, and Monoceros.
A watery grouping including the ship Argo Navis (now Carina, Puppis, Vela, Pyxis) plus Delphinus, Equuleus, Eridanus, Piscis Austrinus, and Columba.
Southern constellations introduced from Johann Bayer's 1603 Uranometria — Apus, Chamaeleon, Dorado, Grus, Hydrus, Indus, Musca, Pavo, Phoenix, Tucana, and Volans.
The far-southern constellations named by Nicolas-Louis de Lacaille in the 1750s, mostly after scientific instruments — Antlia, Caelum, Circinus, Fornax, Horologium, Mensa, Microscopium, Norma, Octans, Pictor, Reticulum, Sculptor, and Telescopium.
Seven bright stars of Ursa Major forming a dipper (the Plough in Britain) — the most familiar star pattern of the northern sky, and a signpost to Polaris.
The main pattern of Ursa Minor, whose handle ends at Polaris, the North Star.
A large triangle of three first-magnitude stars — Vega, Deneb, and Altair — spanning Lyra, Cygnus, and Aquila; the defining pattern of the northern summer sky.
An equilateral triangle of Sirius, Procyon, and Betelgeuse, straddling Canis Major, Canis Minor, and Orion.
A great ring of brilliant winter stars — Rigel, Aldebaran, Capella, Pollux, Procyon, and Sirius — enclosing much of the northern winter sky.
A large near-square of stars marking the body of Pegasus, with its northeastern corner shared by Andromeda — a key autumn signpost.
The cross-shaped main pattern of Cygnus, laid along the summer Milky Way with Deneb at its head.
The brightest stars of Sagittarius form a teapot whose spout points toward the Galactic Center, where the summer Milky Way is richest.
A backwards-question-mark of stars marking the head and mane of Leo, anchored by Regulus.
A lopsided quadrilateral forming the torso of Hercules; the great globular cluster M13 lies along its western side.
A chance line of six stars with a hook (also called Brocchi's Cluster) in Vulpecula, a fine binocular target.
A cross of four stars spanning Carina and Vela, often mistaken for the true Southern Cross (Crux).
The brilliant northern winter evening sky, dominated by Orion and the bright stars of the Winter Hexagon — Sirius, Rigel, Aldebaran, Capella, Pollux, and Procyon.
The northern spring evening sky, when Leo, Virgo, and Boötes ride high and the great galaxy fields of the Virgo and Coma clusters are best placed.
The northern summer evening sky, when the Milky Way arches overhead through the Summer Triangle (Vega, Deneb, Altair) toward the rich star clouds of Sagittarius and the Galactic Center.
The northern autumn evening sky of the Perseus–Andromeda legend — the Great Square of Pegasus, Andromeda and its galaxy, Cassiopeia, Cepheus, and Perseus.
The region of space from roughly 160 to 2,000 km altitude, where a satellite circles the Earth in about 90 minutes. Low latency and easy access make it the busiest orbital regime.
The band of orbits between low Earth orbit and the geostationary altitude. Its multi-hour periods and wide coverage make it ideal for navigation constellations, typically near 20,000 km.
A circular orbit 35,786 km above the equator where a satellite's period matches Earth's rotation, so it appears fixed in the sky. The workhorse orbit for communications and weather monitoring.
A near-polar low orbit whose plane precesses to keep a constant angle to the Sun, so a satellite passes over each location at the same local solar time — ideal for consistent-illumination Earth imaging.
A low orbit inclined close to 90° that passes over (or near) both poles, letting a satellite eventually observe the whole planet as the Earth turns underneath it.
An elongated orbit with a low perigee and a very high apogee (as in the Molniya and Tundra orbits). The satellite moves slowly near apogee, dwelling for hours over high latitudes that geostationary orbit cannot serve.
An elliptical transfer orbit with perigee in low Earth orbit and apogee at the geostationary altitude, used to carry a satellite most of the way to GEO before its own engine circularises the orbit.
The U.S. agency operating the GOES geostationary and JPSS/POES polar weather satellites.
The U.S. Geological Survey, which operates the Landsat archive jointly with NASA.
The U.S. military service that operates the GPS navigation constellation.
The European organisation for the exploitation of meteorological satellites, operator of the Meteosat and Metop fleets.
The operator of the Iridium (and Iridium NEXT) low-Earth-orbit voice and data communications constellation.
The operator of the OneWeb low-Earth-orbit broadband communications constellation.
A major satellite operator running geostationary and medium-Earth-orbit (O3b) communications fleets.
One of the oldest and largest commercial geostationary communications satellite operators, operator of the first commercial GEO comsat, Early Bird.
A commercial Earth-imaging company operating the large Dove (Flock) and SkySat constellations.
A commercial operator of very-high-resolution Earth-imaging satellites, including the WorldView series.
A commercial operator of a low-Earth-orbit constellation for rapid-revisit Earth imaging.
SpaceX's low-Earth-orbit broadband internet constellation, the largest ever built, delivering global high-speed connectivity.
A low-Earth-orbit broadband constellation providing global connectivity, focused on enterprise, government, and maritime users.
The second-generation Iridium constellation of 66 cross-linked low-Earth-orbit satellites providing pole-to-pole voice and data coverage.
A low-Earth-orbit satellite-phone and data constellation serving voice, messaging, and IoT connectivity.
SES's medium-Earth-orbit broadband constellation delivering low-latency connectivity to telecom, maritime, and enterprise customers between the tropics and beyond.
The United States' global navigation satellite system, providing worldwide positioning, navigation, and timing from medium Earth orbit.
Europe's civil global navigation satellite system — owned by the EU and operated through EUSPA, with ESA as the design and procurement agent — offering high-accuracy positioning independent of GPS.
Russia's global navigation satellite system, providing worldwide positioning and timing from medium Earth orbit.
China's global navigation satellite system, using a mix of medium-Earth, geostationary, and inclined geosynchronous orbits.
Planet Labs' fleet of shoebox-sized Dove CubeSats that image the entire land surface of the Earth daily at medium resolution.
A commercial low-Earth-orbit constellation delivering rapid-revisit, high-cadence Earth imagery.
NASA's international array of giant radio antennas — at Goldstone (California), Madrid, and Canberra — that communicates with interplanetary spacecraft and distant satellites, spaced around the globe for continuous coverage.
NASA's network of ground stations and relay satellites (formerly the Space Network's TDRSS and the Ground Network) that supports missions in Earth orbit and near-Earth space.
The European Space Agency's global network of ground tracking stations that communicates with ESA's Earth-orbiting and deep-space missions.
The first satellite launched by the United States, in 1958, whose radiation detector discovered the Van Allen radiation belts. Built by JPL and launched by the U.S. Army — NASA did not yet exist.
An early U.S. technology and science satellite — the oldest human-made object still in orbit, and the first satellite to use solar cells.
The first active communications satellite, which relayed the first transatlantic television signals in 1962.
The first successful weather satellite, which returned the first television images of Earth's cloud cover in 1960 and founded operational meteorology from space.
The first commercial communications satellite in geostationary orbit, which began regular transatlantic telecommunications service in 1965.
A long-running series of Soviet communications satellites that gave their name to the Molniya orbit — a highly elliptical orbit whose slow apogee high over the northern latitudes provided the coverage that geostationary satellites could not reach at high latitudes.
The first satellite of the Landsat program, which began the longest continuous record of Earth's land surface from space.
A NASA/USGS Landsat satellite carrying the Operational Land Imager and Thermal Infrared Sensor, continuing the multi-decade land-imaging record.
The latest Landsat satellite, launched in 2021 to work in tandem with Landsat 8 for an eight-day global revisit of the land surface.
A Copernicus radar-imaging mission providing all-weather, day-and-night synthetic-aperture radar imagery of land and ocean.
A Copernicus optical-imaging mission delivering high-resolution multispectral imagery for land monitoring, agriculture, and disaster response.
A Copernicus mission monitoring ocean and land surface temperature, colour, and topography for climate and marine services.
NASA's flagship Earth Observing System morning satellite, carrying instruments including MODIS and ASTER to study land, ocean, and atmosphere.
NASA's Earth Observing System afternoon satellite, focused on the water cycle — precipitation, evaporation, clouds, and ocean properties.
Japan's greenhouse-gases observing satellite — the first satellite dedicated to monitoring atmospheric carbon dioxide and methane from space — operated by JAXA with Japan's National Institute for Environmental Studies.
A NASA–CNES mission surveying the height of Earth's surface water — oceans, lakes, and rivers — with unprecedented resolution.
A NASA laser-altimetry mission measuring the elevation of ice sheets, glaciers, sea ice, and vegetation to track a changing planet.
A radar-altimetry mission continuing the decades-long record of global sea-surface height for oceanography and climate monitoring.
A Maxar very-high-resolution commercial Earth-imaging satellite used for mapping, defence, and analytics.
The first of NOAA's advanced GOES-R geostationary weather satellites, imaging the Western Hemisphere every few minutes for forecasting and storm tracking.
EUMETSAT's geostationary weather satellites imaging Europe, Africa, and the Atlantic to support European weather forecasting.
A Japanese geostationary weather satellite operated by the Japan Meteorological Agency, providing high-frequency full-disk imaging of East Asia and the western Pacific.
The first satellite of NOAA's Joint Polar Satellite System, providing global polar-orbiting weather and environmental observations.
A twin-satellite mission that mapped tiny variations in Earth's gravity field to track the movement of water, ice, and mass around the planet.
The follow-on mission to GRACE, continuing the record of Earth's changing gravity field and the redistribution of water and ice.
A NASA mission mapping the moisture in Earth's surface soil to improve weather and climate models and monitor drought and floods.
A NASA mission carrying a cloud-profiling radar that measured the vertical structure of clouds to study their role in climate.
A NASA–CNES mission using a space lidar to profile aerosols and thin clouds in Earth's atmosphere, flying in the A-Train formation.
ESA's pioneering astrometry satellite, which precisely measured the positions, distances, and motions of over 100,000 stars — the forerunner of Gaia. An apogee-motor failure left it in a highly elliptical orbit, yet it still delivered landmark astrometric catalogues.
A crowdfunded CubeSat that demonstrated controlled solar sailing in Earth orbit, raising its orbit using only the pressure of sunlight.
One of the largest main-belt asteroids, a dark, primitive carbonaceous body.
One of the largest carbonaceous main-belt asteroids — not to be confused with Jupiter's moon Europa.
One of the largest main-belt asteroids, a dark carbonaceous body.
A large outer-main-belt asteroid and the first asteroid found to have two moons — Romulus and Remus — making it the first known triple asteroid system.
One of the largest asteroids, on a highly inclined orbit, the namesake of the Euphrosyne family.
The third asteroid ever discovered, a large stony main-belt body — one of the historic first four minor planets.
The largest stony (S-type) asteroid and the parent of the Eunomia family in the intermediate main belt.
A large carbonaceous outer-main-belt asteroid, parent of the Themis family, on whose surface water ice has been detected.
The parent body of the Eos family, a large K-type asteroid in the outer main belt.
The parent of the large Flora family of stony asteroids in the inner main belt.
The namesake of the Hungaria group — a dense cluster of small, high-inclination asteroids at the inner edge of the main belt.
The namesake of the Hilda group, whose members orbit in a 3:2 mean-motion resonance with Jupiter in the outer main belt.
The first Centaur discovered, orbiting between Saturn and Uranus and showing cometary activity — so it carries both an asteroid and a comet designation.
A large, extremely distant detached trans-Neptunian object on one of the most elongated known orbits, far beyond the Kuiper Belt.
The first Mars-crossing asteroid discovered — its orbit crosses that of Mars.
The first Jupiter Trojan discovered, leading Jupiter at the L4 Lagrange point in the 'Greek camp'.
A binary Jupiter Trojan trailing Jupiter at the L5 'Trojan camp', and the final flyby target of NASA's Lucy mission.
A near-Earth binary asteroid whose small moon, Dimorphos, was struck by NASA's DART in 2022 — humanity's first test of asteroid deflection.
The small moon of the near-Earth asteroid Didymos and the impact target of NASA's DART mission — the first object whose orbit humans deliberately changed. ESA's Hera will survey the aftermath.
An elongated near-Earth asteroid in a chaotic, tumbling rotation, flown past by China's Chang'e 2 in 2012; it crosses both Earth's and Mars's orbits.
One of the most elongated known asteroids, a near-Earth Apollo object well characterised by radar.
A small near-Earth Apollo asteroid on which the Yarkovsky effect — the tiny orbital push from re-radiated sunlight — was first directly measured by radar.
The prototype of the Atira class — near-Earth asteroids whose orbits lie entirely inside Earth's orbit — and itself a binary system.
Basaltic fragments blasted from the giant south-polar impact basin of 4 Vesta — the source of the HED meteorites found on Earth.
A large family of dark, carbonaceous asteroids in the outer main belt, named for its largest member, 10 Hygiea.
A family of stony asteroids in the outer main belt, one of whose members, 243 Ida, was imaged by the Galileo spacecraft.
A prominent family of stony asteroids in the intermediate main belt, dominated by its largest member, 15 Eunomia.
An old family of carbonaceous asteroids in the outer main belt, some of whose members show signs of water ice and cometary activity.
A large family of K-type asteroids in the outer main belt, named for its parent body, 221 Eos.
A very large, ancient family of stony asteroids in the inner main belt, a candidate source of some ordinary-chondrite meteorites.
The main asteroid belt between Mars and Jupiter, home to the great majority of known asteroids — from the dwarf planet Ceres down to countless small bodies.
Asteroids on orbits that cross the path of Mars, dynamically linked to the inner edge of the main belt.
A distinct group of small, high-inclination asteroids just inside the main belt, named for 434 Hungaria.
A group of outer-belt asteroids held in a 3:2 orbital resonance with Jupiter, tracing a distinctive triangular pattern over time.
Icy small bodies orbiting between Jupiter and Neptune on unstable orbits — transitional objects between the Kuiper Belt and the comets, some of which show cometary activity.
The broad ring of icy bodies beyond Neptune, home to Pluto and the other classical trans-Neptunian objects.
A sparse population of distant icy bodies on eccentric, inclined orbits, gravitationally scattered outward by Neptune — the likely source of many short-period comets.
Trans-Neptunian objects on distant orbits detached from Neptune's gravitational influence, such as Sedna — the innermost members may belong to the inner Oort cloud.
The largest class of near-Earth asteroids — Earth-crossers with orbits mostly larger than Earth's, named after 1862 Apollo.
Near-Earth asteroids with orbits mostly inside Earth's but reaching out to cross it, named after 2062 Aten.
Near-Earth asteroids that approach Earth's orbit from the outside without crossing it, often crossing the orbit of Mars — named after 1221 Amor.
The rarest near-Earth class, with orbits contained entirely within Earth's — hard to detect because they never appear far from the Sun. Named after 163693 Atira.
The vast swarm of asteroids sharing Jupiter's orbit in a 1:1 resonance, split between the leading Greek camp and the trailing Trojan camp — the target population of NASA's Lucy mission.
The Jupiter Trojans leading the planet at the L4 Lagrange point, traditionally named after Greek heroes of the Trojan War — led by 588 Achilles.
The Jupiter Trojans trailing the planet at the L5 Lagrange point, traditionally named after Trojan heroes — including the binary 617 Patroclus.
Minor planets sharing Neptune's orbit in a 1:1 resonance at its L4 and L5 points — a population thought to rival the Jupiter Trojans in number.
A mean-motion resonance in which a body completes three orbits for every two of Jupiter's, stabilising the Hilda group in the outer main belt.
The co-orbital resonance that traps the Jupiter Trojans at the planet's L4 and L5 Lagrange points, sharing Jupiter's orbital period.
The resonance in which a body completes two orbits for every three of Neptune's — the home of the 'plutinos', including Pluto itself.
The co-orbital resonance that holds the Neptune Trojans at the planet's Lagrange points.
The impact of a ~10-kilometre asteroid that formed the Chicxulub crater and is widely linked to the Cretaceous–Paleogene mass extinction, including the end of the non-avian dinosaurs.
A large airburst over remote Siberia that flattened roughly 2,000 square kilometres of forest without leaving an impact crater — the largest asteroid or comet impact in recorded history.
The airburst of a ~20-metre near-Earth object over Russia, whose shock wave shattered windows and injured around 1,500 people — the most damaging modern impact event, and a spur to planetary-defense efforts.
NASA's Near Earth Asteroid Rendezvous mission, the first spacecraft to orbit an asteroid (433 Eros, 2000) and the first to soft-land on one (2001).
ESA's planetary-defense mission to the Didymos–Dimorphos binary, launched in 2024 to survey the aftermath of NASA's DART impact in detail.
The comet with the shortest known orbital period (about 3.3 years) and the parent of the Taurid meteor stream.
The parent comet of the Leonid meteor shower, whose 33-year returns produce the periodic Leonid storms.
A Jupiter-family comet, parent of the Draconid meteor shower, and the first comet ever visited by a spacecraft — NASA's ICE probe flew through its tail in 1985.
A Jupiter-family comet visited by ESA's Giotto in 1992 during its extended mission, after Giotto's earlier encounter with Halley.
A Jupiter-family comet that began fragmenting in 1995 and has since broken into dozens of pieces — a rare chance to watch a comet disintegrate over successive returns.
A small, hyperactive Jupiter-family comet flown past by NASA's EPOXI mission (the repurposed Deep Impact spacecraft) in 2010.
The 'Great Comet of 2007', the brightest comet in decades, whose vast fanned dust tail was a spectacular sight from the Southern Hemisphere.
A Kreutz sungrazing comet that unexpectedly survived a passage through the Sun's corona in December 2011, emerging to display a bright tail.
One of the brightest comets of the past thousand years — a Kreutz sungrazer that became visible in daylight near the Sun in October 1965.
A long-period comet that made an exceptionally close pass of Mars in October 2014, observed up close by the fleet of Mars orbiters and rovers.
A long-period comet on a roughly 415-year orbit, the parent body of the Lyrid meteor shower seen each April.
The most numerous class of periodic comets, whose orbits are shepherded by Jupiter and which originate in the scattered disc beyond Neptune.
Periodic comets with orbits of decades to a couple of centuries, named for their prototype, Halley's Comet.
Comets on enormous orbits reaching deep into the outer Solar System, arriving from the Oort cloud after millions of years — the source of most great comets.
Comets whose orbits carry them through the Sun's outer atmosphere; most disintegrate, though a few survive. Many belong to the Kreutz family and are discovered by solar observatories.
Objects that orbit within the asteroid belt yet develop tails or comae — a blurring of the traditional line between asteroids and comets, and a possible reservoir of water.
A family of sungrazing comets on very similar orbits, thought to be the fragments of a single giant comet that broke apart many centuries ago. They include some of the brightest comets in history and are discovered in large numbers by solar spacecraft.
A hypothesised spherical cloud of trillions of icy bodies at the outermost edge of the Sun's gravitational influence — the reservoir from which long-period and Halley-type comets are nudged inward.
The dense inner region of the Oort cloud, whose existence is inferred from detached objects like Sedna whose orbits are too distant to be shaped by Neptune.
A near-Earth asteroid that brightens and sheds dust as it passes very close to the Sun — a 'rock comet' — and the parent body of the Geminid meteor shower, unusual for a shower whose source is an asteroid rather than a comet.
The prototype main-belt comet — an object on an ordinary asteroid-belt orbit that repeatedly develops a comet-like tail, carrying both an asteroid number and a comet designation.
A large near-Earth object on a comet-like orbit long suspected to be a dormant comet; faint carbon-dioxide activity was detected in 2013, suggesting it is not fully extinct.
An asteroid on a short-period, comet-like orbit believed to be a dormant or extinct comet nucleus — the parent body of the sharp, brief Quadrantid meteor shower.
ESA's mission to Halley's Comet, which flew through the comet's coma in 1986 and returned the first close-up images of a cometary nucleus, later re-targeted to comet Grigg–Skjellerup.
NASA's mission that fired a 370-kg impactor into comet Tempel 1 in 2005 to excavate and study the material beneath a comet's surface.
NASA's sample-return mission that captured dust from the coma of comet Wild 2 and returned it to Earth in 2006, and later flew past Tempel 1 as Stardust-NExT.
NASA's ion-propulsion technology demonstrator that flew past comet Borrelly in 2001, returning detailed images of its nucleus.
The extended mission of the Deep Impact spacecraft, which flew past the small, hyperactive comet Hartley 2 in 2010.
The largest carbonaceous chondrite found on Earth, which fell in 1969 and became the most-studied meteorite in history — its calcium–aluminium inclusions are among the oldest solid material in the Solar System.
A carbonaceous chondrite that fell in 1969 and was found to contain a rich suite of amino acids and other organic compounds — key evidence that the building blocks of life exist in space.
A rare, extremely primitive CI carbonaceous chondrite whose composition closely matches that of the Sun — a benchmark for the bulk composition of the Solar System.
An exceptionally pristine carbonaceous meteorite recovered frozen from a lake in 2000, preserving organic material with minimal terrestrial contamination.
A CM2 carbonaceous chondrite that fell in 2019, rapidly recovered and rich in organic compounds — sometimes called a 'second Murchison'.
A carbonaceous chondrite whose 2021 fall was captured by camera networks, allowing its orbit to be traced and the sample to be recovered within days — one of the most pristine falls ever studied.
The recovered stones from the 2013 Chelyabinsk airburst, an ordinary chondrite whose spectacular entry — filmed by countless dashcams — was the most damaging meteor event in modern history.
An ordinary chondrite whose 1992 fall was videotaped as a brilliant fireball across the eastern United States before it struck and damaged a parked car in Peekskill, New York.
A large enstatite chondrite that fell in 1952 — a rare, highly reduced meteorite type thought to have formed in the innermost, oxygen-poor part of the solar nebula.
The largest known intact meteorite and the largest naturally-occurring piece of iron near the Earth's surface, an ~60-tonne slab still lying where it was found in Namibia.
One of the largest observed iron meteorite falls, which broke apart over the Sikhote-Alin mountains in 1947 and scattered thousands of fragments, many with dramatic regmaglypt thumbprint textures, across a strewn field.
An ancient field of large iron meteorites in Argentina, known to indigenous peoples for millennia, whose fragments include some of the heaviest single meteorite masses ever recovered.
The largest meteorite ever found in the United States, an ~15-tonne iron sacred to the Clackamas people of the Willamette Valley.
The iron meteorite responsible for Barringer Crater (Meteor Crater) in Arizona; fragments are scattered around the rim of the crater it formed some 50,000 years ago.
A pallasite strewn field in Kansas — pallasites are among the most beautiful meteorites, with olive-green olivine crystals suspended in a matrix of nickel-iron.
A large mesosiderite that fell in 1879 — a stony-iron meteorite mixing metal with silicate fragments, thought to record a violent collision between differentiated asteroids.
A eucrite whose fall was witnessed in October 1960 (the stones recovered in the following years) — one of the HED meteorites, basaltic rocks blasted from the surface of the asteroid Vesta, whose spectra they match.
Nicknamed 'Black Beauty', a Martian breccia containing the most water of any Mars meteorite and some of the oldest Martian crust yet sampled.
A Martian meteorite recovered from Antarctica in 1984 and made famous in 1996 by a disputed claim that microscopic structures within it might be evidence of ancient Martian microbial life.
The first meteorite recognised as a piece of the Moon, recovered from Antarctica in 1982 — its match to Apollo samples proved that lunar rocks can be delivered to Earth as meteorites.
The most common meteorites: primitive, undifferentiated stony rocks that preserve material from the birth of the Solar System, subdivided into carbonaceous, ordinary, and enstatite groups.
Stony meteorites from bodies that melted and differentiated — including basalts from the asteroid Vesta and rocks blasted off Mars and the Moon.
Dense meteorites of nickel-iron alloy, thought to be fragments of the metallic cores of asteroids that were shattered by collisions — the source of the largest meteorites found on Earth.
Rare meteorites blending rock and metal in roughly equal measure — the pallasites (olivine in metal) and mesosiderites (breccias of metal and silicate).
Dark, primitive chondrites carrying carbon, water-bearing minerals, and complex organics — the closest samples we have to the raw ingredients of the Solar System, and to what asteroids like Bennu and Ryugu are made of.
By far the most common meteorites to fall, these stony chondrites come from ordinary silicate asteroids in the inner belt.
Rare, chemically reduced chondrites that formed in the innermost, oxygen-starved region of the solar nebula — a possible source of much of Earth's own building material.
The howardite–eucrite–diogenite clan of basaltic achondrites, whose spectra match the asteroid Vesta so closely that they are considered pieces of its crust, delivered to Earth after impacts.
Rocks ejected from Mars by large impacts and later swept up by Earth — identified by trapped gases matching the composition measured in the Martian atmosphere by landers.
Pieces of the Moon flung to Earth by impacts, whose mineralogy matches the samples returned by the Apollo and Luna missions — a free supply of lunar rock from unsampled regions.
The most striking meteorites, in which gem-quality green olivine crystals are suspended in a lattice of nickel-iron — probably formed at the core–mantle boundary of a shattered asteroid.
Chaotic stony-iron breccias mixing crustal silicates with metallic core material — thought to record the catastrophic disruption and re-assembly of a differentiated asteroid.
A brilliant green fireball that crossed the eastern United States in October 1992, filmed by at least 16 people, before a fragment struck a parked car in Peekskill, New York — one of the best-documented fireball-to-meteorite events.
A powerful bolide that exploded over the Bering Sea in December 2018 with roughly ten times the energy of the Hiroshima bomb — the largest airburst since Chelyabinsk, unnoticed at the time because it occurred over the remote ocean.
The best-preserved impact crater on Earth, gouged out ~50,000 years ago by the Canyon Diablo iron meteorite — the site where the impact origin of craters was first firmly established.
The largest confirmed impact structure on Earth, the deeply eroded remnant of a crater formed roughly two billion years ago by one of the largest impacts in the planet's history.
One of the oldest and largest known impact structures, whose ancient impact melt hosts some of the world's richest nickel and copper ore deposits.
A well-studied mid-sized impact crater in Germany whose shocked minerals and impact glass were used by Apollo astronauts as a training ground for recognising impact features on the Moon.
The strewn field left by the 1947 Sikhote-Alin iron meteorite fall, where thousands of fragments and impact pits were scattered across the taiga of the Russian Far East.
A field of craters and large iron masses in northern Argentina, formed by an ancient fall and known to local peoples for thousands of years — the source of some of the heaviest meteorite masses on Earth.
The first confirmed interstellar object, detected in October 2017 on its way out of the Solar System. Its strongly hyperbolic orbit (eccentricity about 1.2) showed it was never bound to the Sun. It displayed no visible coma, is highly elongated, and showed a slight non-gravitational acceleration — features that drew wide attention, though the scientific consensus is that it is a natural body.
The second confirmed interstellar object and the first that was unmistakably a comet, discovered in August 2019 by amateur astronomer Gennadiy Borisov. Its eccentricity of about 3.4 made its interstellar origin certain. Unlike 1I/ʻOumuamua it showed an active dust coma and tail, letting astronomers study the chemistry of a comet formed around another star; it proved unusually rich in carbon monoxide.
The third confirmed interstellar object, discovered on 1 July 2025 by the ATLAS survey in Chile. Its orbit is the most strongly hyperbolic of the three found so far, with an eccentricity of roughly 6, and it showed cometary activity as it passed through the inner Solar System in late 2025. Some physical parameters remain preliminary, but its interstellar origin is established by the trajectory.
A bright meteor (bolide) that entered Earth's atmosphere near Papua New Guinea on 8 January 2014, recorded in NASA CNEOS's fireball database. From the reported high velocity it was proposed in 2019 to have originated outside the Solar System, which would make it a candidate interstellar meteor. The claim is disputed: the underlying velocity data come from US Government sensors whose uncertainties are not public, and the interstellar interpretation is not accepted by the wider community. It is not a confirmed interstellar object.
A long-period comet that a close encounter with Jupiter in 1980 flung onto a clearly hyperbolic orbit (eccentricity about 1.06). It is now leaving the Solar System, but — unlike a true interstellar object — it formed here; the hyperbolic orbit is the result of a planetary slingshot, not an origin around another star.
A near-parabolic long-period comet from the Oort cloud, famous for disintegrating completely near perihelion in July 2000 — one of the best-observed comet break-ups. Its orbit was close to the parabolic boundary (eccentricity near 1), the hallmark of a first-time visitor from the distant Solar System, not from interstellar space.
A long-period comet discovered by Andrea Boattini through the Mount Lemmon Survey, on a near-parabolic orbit with an eccentricity extremely close to 1. Like the other long-period comets here it is a distant Solar-System visitor, not an interstellar object: its original orbit is bound and it is not being ejected from the Solar System — the tiny excess over a parabola is an epoch-dependent, perturbed value.
A dynamically new, near-parabolic long-period comet discovered by Pan-STARRS in 2017 and notable for showing activity at a record distance — a coma was detected beyond Saturn's orbit, on the comet's first passage in from the Oort cloud. Its near-parabolic orbit marks it as a distant Solar-System visitor, not an interstellar object.
The primary signature of an interstellar object: its speed relative to the Sun exceeds the local escape velocity by enough that the orbit is strongly hyperbolic (eccentricity well above 1). A large hyperbolic excess velocity (v∞) cannot be produced by planetary perturbations, so it points to an origin outside the Solar System. A small excess, by contrast, can come from a planetary slingshot and does not by itself prove an interstellar origin.
Determining an object's orbit from astrometry and tracing its path backward. An unbound, strongly hyperbolic incoming trajectory — arriving from interstellar space rather than from the planetary region — establishes that the object was not on a closed Solar orbit. The direction it came from (its radiant) can also be identified, though no specific parent star has been pinned down for any interstellar object.
Taking spectra and colours of a visitor to characterise its surface or coma chemistry and compare it with Solar-System comets and asteroids. Spectroscopy does not by itself prove an interstellar origin — the orbit does that — but it reveals what a body from another planetary system is made of, as with the carbon-monoxide-rich coma of 2I/Borisov.
An orbit with eccentricity below 1: the object is gravitationally bound to the Sun and returns. Planets, asteroids, and periodic comets all follow bound elliptical orbits. A bound orbit is the baseline against which unbound, hyperbolic trajectories are recognised.
An orbit with eccentricity very close to 1 — the boundary between bound and unbound. Long-period comets falling in from the Oort cloud on their first passage follow near-parabolic orbits. A near-parabolic orbit signals a distant Solar-System origin, not an interstellar one.
An orbit with eccentricity just above 1, produced when a Solar-System comet is perturbed by a planet (usually Jupiter) onto an escape trajectory. The object is leaving the Solar System, but it formed here — the small excess over e = 1 is a slingshot effect, not evidence of an interstellar origin.
A strongly hyperbolic trajectory — eccentricity well above 1 with a large excess velocity relative to the Sun — that cannot be produced by planetary perturbations. This is the signature of an interstellar object: a body that entered the Solar System already unbound, from another star system, and will leave on the same path. 1I/ʻOumuamua, 2I/Borisov, and 3I/ATLAS all follow such trajectories.
The Asteroid Terrestrial-impact Last Alert System — a NASA-funded network of small survey telescopes, operated by the University of Hawaiʻi, that scans the whole visible sky nightly for moving objects and impact hazards. Its Chilean telescope discovered the third interstellar object, 3I/ATLAS, in 2025.
A NASA-funded near-Earth-object survey based at the University of Arizona, using telescopes on Mount Lemmon and Mount Bigelow. It is a prolific discoverer of comets and near-Earth asteroids, including the hyperbolic long-period comet C/2007 W1 (Boattini).
The International Astronomical Union's clearinghouse for the astrometry, orbits, and designations of small Solar-System bodies — and of interstellar objects, to which it assigns the special "I" (interstellar) designations such as 1I, 2I, and 3I. It is operated under the auspices of the IAU.
NASA's Center for Near-Earth Object Studies, at the Jet Propulsion Laboratory, which computes near-Earth-object orbits and impact risk and maintains the public fireball database. Its reported velocity for the 2014-01-08 bolide is the basis of a debated — and unconfirmed — claim of an interstellar meteor.
JAXA's planned mission to the moons of Mars — it will study Phobos and Deimos and return a sample of Phobos to Earth, testing whether the Martian moons are captured asteroids or debris from a giant impact.
An ESA (with JAXA) fast-class mission that will wait at the Sun–Earth L2 point for a suitable target, then fly by a pristine, dynamically-new comet — ideally one entering the inner Solar System for the first time, or even an interstellar object.
A JAXA technology-demonstration and flyby mission that will test advanced ion propulsion en route to a flyby of 3200 Phaethon — the rock-comet source of the Geminid meteor shower — studying its dust.
A NASA New Frontiers proposal to return a sample from comet 67P/Churyumov–Gerasimenko — the comet Rosetta explored. It was a finalist in the New Frontiers 4 competition but was not selected (Dragonfly was chosen instead).
An early-2000s ESA planetary-defense concept — a two-spacecraft study in which an impactor (Hidalgo) would strike an asteroid while an orbiter (Sancho) measured the deflection. It was never built, but it prefigured the AIDA/DART–Hera approach.
A NASA SIMPLEx pair of small spacecraft designed to fly by binary asteroids. Built to share Psyche's launch, the twins were left without a viable trajectory when Psyche slipped by a year, and the mission was cancelled with the spacecraft put into storage.
ESA's Asteroid Impact Mission — the original European orbiter half of the AIDA collaboration, meant to observe the DART impact in real time. It was not funded in 2016, but its science was largely revived and reshaped as the Hera mission.
A spacecraft that passes a small body once at high speed, gathering images and data during a brief encounter. Flybys are the cheapest way to reach a new target — Giotto at Halley, Deep Space 1 at Borrelly, Lucy at the Trojans.
A spacecraft that matches a small body's orbit and stays with it for an extended study, rather than flying past. Rendezvous enables detailed mapping and, often, orbiting or landing.
A spacecraft that enters orbit around a small body to map it globally over time — NEAR at Eros, Dawn at Vesta and Ceres, Rosetta at comet 67P.
A spacecraft (or a deployed element) that touches down on a small body's surface — Philae on comet 67P, NEAR on Eros, and the touchdown sampling of Hayabusa and Hayabusa2.
A spacecraft (or a released projectile) that deliberately strikes a small body — to excavate subsurface material (Deep Impact) or to deflect it (DART).
A mission that collects material from a small body and brings it back to Earth for laboratory study — Hayabusa (Itokawa), Hayabusa2 (Ryugu), OSIRIS-REx (Bennu), and Stardust (comet Wild 2).
More than 1,500 microscopic grains from the S-type asteroid 25143 Itokawa, returned by Hayabusa in 2010 — the first sample ever returned from an asteroid. The grains tied ordinary (LL) chondrite meteorites to S-type asteroids and showed signs of space weathering.
5.4 grams of surface and subsurface material from the carbonaceous asteroid 162173 Ryugu, returned by Hayabusa2 in 2020. The pristine, water- and organic-bearing grains contain amino acids and predate the Solar System's planets.
121.6 grams of dust and rock from the carbonaceous near-Earth asteroid 101955 Bennu, returned by OSIRIS-REx in 2023 — the largest asteroid sample yet returned. Early analysis shows abundant carbon and water-bearing clay minerals.
Thousands of cometary dust particles captured in aerogel as Stardust flew through the coma of comet 81P/Wild 2, returned in 2006 — the first cometary material and the first sample from beyond the Moon. The grains revealed high-temperature minerals and the amino acid glycine.
The small heat-shielded capsule that carried Hayabusa's Itokawa grains back through the atmosphere, separating from the spacecraft (which burned up) and landing by parachute in the Australian outback.
The reentry capsule that returned Hayabusa2's 5.4 g of Ryugu material, recovered in the Australian desert while the spacecraft continued on to an extended mission.
The capsule that delivered 121.6 g of asteroid Bennu to Earth, released by OSIRIS-REx on a flyby before the spacecraft diverted toward Apophis.
The capsule that returned Stardust's aerogel trays of comet Wild 2 dust — the first sample-return capsule to bring material back from beyond the Moon.
The launch and the long interplanetary cruise to the target, often using gravity assists or ion propulsion to reach a distant small body.
The final approach, when the target grows from a point of light into a resolved world and the spacecraft measures its shape, spin, and gravity to plan operations.
Extended operations close to the body — global mapping, orbiting, and selecting sites for a landing, sampling, or impact.
The critical interaction with the surface — a touchdown, a landing, a sample-collection manoeuvre, or a deliberate impact.
For sample-return missions, the journey home and the high-speed atmospheric reentry of the capsule to a recovery site — the phase that delivers the science to Earth.
The Asteroid Impact and Deflection Assessment — an international collaboration to test and characterise asteroid deflection at the Didymos–Dimorphos binary. NASA's DART performed the kinetic impact in 2022; ESA's Hera will survey the result in detail, together turning a one-off experiment into a repeatable, well-understood technique.
China's deep-space tracking network, operated for CNSA, with large antennas at Jiamusi (66 m) and Kashgar (35 m) in China and a station in Argentina. It supports China's lunar (Chang'e) and planetary (Tianwen) missions.
Russia's deep-space communication facilities, operated by Roscosmos, with large antennas at Ussuriysk in the Far East and historically at Bear Lakes and Yevpatoria (Crimea). It descends from the Soviet deep-space network that supported the Luna, Venera, and Mars probes.
ISRO's deep-space network, centred on the 32 m and 18 m antennas at Byalalu near Bengaluru. It provided tracking and communication for the Chandrayaan lunar missions and the Mars Orbiter Mission (Mangalyaan).
Japan's deep-space tracking network, run by JAXA/ISAS, centred on the Usuda Deep Space Center in Nagano (a 64 m antenna) and the newer 54 m Misasa antenna. It supported the Hayabusa asteroid missions and Japan's other deep-space probes.
A growing set of commercial providers — such as KSAT, SSC, and Goonhilly — that offer deep-space and near-Earth ground-station support on a service basis, augmenting the government networks as mission traffic grows. NASA's Near Space Network increasingly buys commercial services alongside its own antennas.
Goldstone Deep Space Communications Complex
The US complex of NASA's Deep Space Network, in California's Mojave Desert. Its 70 m antenna (DSS-14, the 'Mars' dish) and a cluster of 34 m beam-waveguide antennas track spacecraft across the Solar System.
Madrid Deep Space Communications Complex
The European complex of NASA's Deep Space Network, outside Madrid. With Goldstone and Canberra it forms the three-station ring that keeps deep-space missions continuously in view.
Canberra Deep Space Communication Complex
The southern-hemisphere complex of NASA's Deep Space Network, in Australia. Its 70 m antenna (DSS-43) is the only one able to command Voyager 2 on its southward interstellar trajectory.
ESA's first deep-space antenna (DSA 1), a 35 m dish in Western Australia, supporting Estrack's interplanetary missions.
ESA's second deep-space antenna (DSA 2), a 35 m dish in central Spain.
ESA's third deep-space antenna (DSA 3), a 35 m dish in Argentina — the southern-hemisphere member of Estrack's deep-space trio.
An Estrack ground station in the Canary Islands, used for launch and early-orbit support and near-Earth tracking.
China's 66 m deep-space antenna in the northeast, a principal station of the Chinese Deep Space Network for lunar and planetary missions.
China's western deep-space station, with a cluster of 35 m antennas, part of the Chinese Deep Space Network.
A Russian deep-space tracking station in the Far East, part of the network that descends from the Soviet-era deep-space facilities.
ISRO's Indian Deep Space Network station near Bengaluru, whose 32 m antenna supported the Chandrayaan and Mars Orbiter missions.
JAXA's 64 m deep-space antenna in Nagano, which supported the Hayabusa asteroid missions and Japan's other deep-space probes.
NASA's primary ground terminal for the TDRS relay satellites, in New Mexico. Nearly all Space Network traffic — including from the ISS and Hubble — passes through White Sands.
A high-latitude ground station at 78°N able to see every pass of a polar-orbiting satellite. Operated commercially by KSAT and used by NASA's Near Space Network.
A high-latitude ground station in Fairbanks, part of NASA's Near Space Network, heavily used for polar-orbiting Earth-observation satellites.
A NASA Near Space Network ground station on the US east coast, providing tracking and data services for near-Earth missions (distinct from the co-located Wallops launch range).
The largest and most sensitive dishes of the Deep Space Network — one at each complex (Goldstone, Madrid, Canberra). Their huge collecting area is reserved for the most distant or weakest spacecraft, such as the Voyagers, and for radar astronomy.
The modern workhorse antennas of the Deep Space Network. A beam-waveguide design routes the signal through mirrors to equipment in a shielded room below, allowing several to be arrayed and supporting X- and Ka-band.
An earlier generation of 34 m Deep Space Network antenna with the feed at the dish, being gradually retired in favour of the beam-waveguide design.
Instead of one large dish, many smaller antennas whose signals are combined electronically to act as a single larger aperture. Arraying is a future direction for the Deep Space Network, offering flexible, scalable collecting area.
The main dish on a spacecraft, which focuses its signal into a narrow, high-gain beam that must be pointed accurately at Earth. It carries the high-rate science downlink — for example Voyager's 3.7 m dish.
A spacecraft antenna with a broader beam than the high-gain dish, trading data rate for easier pointing — useful during manoeuvres or as a backup.
A near-omnidirectional spacecraft antenna that needs no accurate pointing, used for command and low-rate telemetry — the safety-net link that works even when a spacecraft has lost attitude control.
An optical (laser) communication terminal that transmits data on an infrared beam rather than radio. NASA's Deep Space Optical Communications terminal flew on the Psyche spacecraft and set deep-space data-rate records.
A lower-frequency microwave band long used for spacecraft command and low-rate telemetry, and for near-Earth links. Robust and less affected by weather than higher bands, but limited in data rate.
The workhorse band of deep-space communication and radiometric navigation. Most interplanetary missions send their science data and are tracked on X-band, which balances data rate against antenna size and weather losses.
A higher-frequency band that carries much more data than X-band for the same antenna, at the cost of greater sensitivity to rain and pointing. Increasingly used for high-rate science downlink from deep space.
An ultra-high-frequency band used for short-range proximity links — for example between a Mars rover and an orbiter that relays the data to Earth — rather than for direct deep-space communication.
Laser communication encodes data on an infrared beam instead of radio waves. Its far shorter wavelength packs data into a tighter beam, promising data rates 10–100× higher than radio — the frontier of deep-space communication, demonstrated by DSOC on the Psyche spacecraft.
Measuring a spacecraft's distance and velocity from its radio signal — range from the round-trip signal time, and line-of-sight velocity from the Doppler shift. Combined over time from the ground stations, these fix a spacecraft's trajectory across the Solar System.
A precise angular-position technique: two widely separated stations record the spacecraft's signal and that of a distant quasar, and the tiny difference in arrival times pins down the spacecraft's position on the sky to a few nanoradians — vital for accurate planetary arrivals.
Using a spacecraft's own camera images of a target body against the background stars to determine its position relative to that body — essential in the final approach to an asteroid, comet, or moon, where ground tracking alone is not precise enough.
Onboard software that processes optical-navigation images in real time and steers the spacecraft itself, without waiting for commands from Earth. It was pioneered by Deep Space 1 and used for terminal guidance in fast flybys and the DART impact.
A small camera that identifies star patterns to determine which way a spacecraft is pointed, to a fraction of an arcsecond. Star trackers give the precise attitude a spacecraft needs to aim its high-gain antenna at Earth and its instruments at a target.
Gyroscopes and accelerometers in an inertial measurement unit that sense a spacecraft's rotation and acceleration, propagating its orientation between star-tracker updates and through manoeuvres when other references are unavailable.
A miniaturised, ultra-stable atomic clock small enough to fly on a spacecraft. By putting precise timekeeping onboard, it enables one-way radiometric navigation — the spacecraft can determine its own position without the round-trip to a ground clock — a technology demonstrated in Earth orbit.
A continuous atomic timescale kept by hundreds of atomic clocks worldwide — the stable foundation from which civil time is derived. TAI never inserts leap seconds, making it ideal for measuring precise intervals.
The civil time standard, derived from International Atomic Time but kept within a second of the Earth's rotation by occasional leap seconds. Deep-space tracking tags its measurements in UTC.
The continuous timescale of the Global Positioning System, offset from TAI by a fixed number of seconds and widely used to synchronise ground equipment.
The onboard counter that timestamps a spacecraft's data. Because it drifts relative to ground time, mission teams maintain a correlation (SCLK-to-ground time) using the tracking network so that events can be placed on a common timescale.
Deep Space Optical Communications (DSOC)
NASA's technology demonstration of laser communication from deep space, flying as a rider on the Psyche spacecraft. It transmitted data over tens of millions of kilometres at rates far beyond radio, proving optical links for future missions.
Laser Communications Relay Demonstration (LCRD)
A NASA optical-communication relay in geostationary orbit that demonstrates two-way laser links between ground stations and spacecraft, a stepping stone toward operational optical relays in the Near Space Network.
Tracking and Data Relay Satellite System (TDRS)
A fleet of geostationary relay satellites that give near-Earth spacecraft — including the ISS and Hubble — near-continuous contact with the ground, instead of only during the few minutes of a ground-station pass. TDRS is the space-based half of NASA's Near Space Network.
The end-to-end function every mission depends on: downlinking telemetry (spacecraft health and science), measuring the signal for tracking and navigation, and uplinking commands. The deep-space and near-Earth networks exist to provide TT&C.
The continuous stream of charged particles — mostly protons and electrons — that flows outward from the Sun's corona at hundreds of kilometres per second, filling the Solar System and shaping planetary magnetospheres.
A sudden, intense burst of radiation from the Sun's surface, released when magnetic energy in the corona is explosively reconfigured. The X-rays arrive in minutes and can ionise Earth's upper atmosphere, causing radio blackouts.
An enormous eruption of magnetised plasma from the Sun's corona, launching billions of tonnes of material into space. When aimed at Earth, a CME can drive the largest geomagnetic storms one to three days later.
A temporary disturbance of Earth's magnetosphere, driven by the arrival of a fast solar wind or a coronal mass ejection. Strong storms can disrupt satellites, power grids, and navigation, and drive bright auroras.
The glow produced when energetic particles from the magnetosphere spiral down Earth's magnetic-field lines and excite gases in the upper atmosphere — the visible signature of space weather over the polar regions.
The region around a planet dominated by its magnetic field, which deflects the solar wind and traps charged particles. Earth's magnetosphere shields the surface from most space radiation.
The vast bubble of solar wind and magnetic field that surrounds the entire Solar System, carving out a cavity in the surrounding interstellar medium and shielding the planets from a fraction of the galactic cosmic rays.
The outer boundary of the heliosphere, where the outward pressure of the solar wind balances the pressure of the interstellar medium — the edge of the Sun's domain, crossed by the two Voyager spacecraft.
High-energy charged particles that stream through space near the speed of light. They come from the Sun (solar energetic particles) and from beyond the Solar System (galactic cosmic rays), and are a primary radiation hazard for astronauts.
Extremely energetic charged particles from outside the Solar System — the remnants of supernovae and other violent events. They pervade deep space, are hard to shield against, and pose the dominant long-term radiation risk on missions to Mars.
Bursts of high-energy particles accelerated by solar flares and coronal mass ejections. Unlike the steady galactic cosmic rays, SEP events are sudden and can deliver a dangerous radiation dose to astronauts within hours.
Two (sometimes more) doughnut-shaped zones of energetic charged particles trapped by Earth's magnetic field. Spacecraft crossing the belts — and those in orbits within them — must be hardened against the intense radiation.
Defunct satellites, spent rocket stages, and fragments left in Earth orbit. Travelling at kilometres per second, even a small piece can destroy a working spacecraft, and collisions create more debris — a growing hazard in low Earth orbit.
Tiny natural particles — grains of comet and asteroid dust — moving at tens of kilometres per second. They erode surfaces and can puncture spacecraft; together with orbital debris they define the impact hazard for spacecraft.
The build-up of electric charge on a spacecraft as it moves through the space plasma, especially during geomagnetic storms. A sudden discharge can damage electronics — a leading cause of space-weather-related spacecraft anomalies.
Single oxygen atoms that dominate the thin atmosphere of low Earth orbit. Highly reactive, atomic oxygen slowly erodes exposed spacecraft materials, a design concern for anything operating for long periods in LEO.
The ionised gas that pervades near-Earth space, from the ionosphere out through the magnetosphere. Its density and energy govern spacecraft charging, radio propagation, and the behaviour of the radiation belts.
A global index of geomagnetic activity, derived from magnetometer readings and reported every three hours on a scale of 0 (quiet) to 9 (extreme storm). Kp is the standard measure used to forecast auroras and satellite disturbances.
The Disturbance storm-time index, which tracks the strength of the equatorial ring current and so measures the intensity of a geomagnetic storm — the more negative the Dst, the stronger the storm.
NOAA's five-level scale for the severity of geomagnetic storms, from G1 (minor) to G5 (extreme), describing the expected effects on power grids, satellites, and navigation.
NOAA's five-level scale for solar radiation (energetic-particle) storms, from S1 to S5, describing the radiation hazard to astronauts, high-altitude flights, and spacecraft.
NOAA's five-level scale for radio blackouts caused by solar-flare X-rays ionising the dayside upper atmosphere, from R1 (minor) to R5 (extreme).
SOHO (Solar and Heliospheric Observatory)
A joint ESA/NASA solar observatory at the Sun–Earth L1 point, operating since 1995. Its coronagraphs image coronal mass ejections and it is a workhorse of space-weather monitoring (and a prolific comet discoverer).
A NASA mission that images the Sun in many ultraviolet wavelengths at high cadence, studying solar activity, flares, and the magnetic field that drives space weather.
A NASA mission at the Sun–Earth L1 point that measures the solar wind and energetic particles upstream of Earth, giving roughly an hour of warning before disturbances reach the planet.
A NOAA/NASA mission at the Sun–Earth L1 point that provides real-time solar-wind measurements for operational space-weather forecasting, along with full-disc images of Earth.
NOAA's official source of space-weather forecasts, watches, and warnings — the operational centre that issues the Kp, G-, S-, and R-scale alerts used to protect power grids, satellites, and aviation.
JPL Space Flight Operations Facility (SFOF)
NASA's nerve centre for deep-space missions, at the Jet Propulsion Laboratory in Pasadena. From the SFOF, controllers command and monitor spacecraft across the Solar System through the Deep Space Network.
NASA's Goddard Space Flight Center in Maryland operates many Earth-orbiting and astrophysics missions and hosts the Near Space Network's control functions.
NASA's iconic human-spaceflight control room at the Johnson Space Center in Houston, which has directed crewed missions from Gemini and Apollo to the International Space Station.
ESA's mission-control centre in Darmstadt, Germany, from which the agency operates its scientific and interplanetary spacecraft through the Estrack network.
JAXA operates its science and deep-space missions from centres including the Sagamihara campus (ISAS) and the Tsukuba Space Center, working with the Usuda deep-space antenna.
ISTRAC (ISRO Telemetry, Tracking and Command Network)
ISRO's network and operations organisation, headquartered in Bengaluru, which provides tracking and mission operations for India's Earth-orbiting and deep-space missions.
Roscosmos's Mission Control Center in Korolyov, near Moscow, which directs Russian human spaceflight and the Russian segment of the International Space Station.
China's principal mission-control centre in Beijing, which directs the country's human-spaceflight, lunar (Chang'e), and planetary (Tianwen) missions.
The team and facility that command and monitor a spacecraft in real time — the heart of mission operations, staffed by controllers each responsible for a subsystem.
The discipline of determining and predicting a spacecraft's orbit and attitude, and computing the manoeuvres needed to keep it on its planned trajectory.
Estimating a spacecraft's precise position and velocity from tracking data (ranging, Doppler, and angles) — the input to every manoeuvre and every science observation.
The operational process of guiding a spacecraft to its target — combining orbit determination with manoeuvre design, using the deep-space network's radiometric tracking.
Receiving, decoding, and displaying the stream of engineering and science data a spacecraft downlinks, so controllers can assess its health and scientists can use its measurements.
Building and validating the time-ordered lists of commands a spacecraft executes, often days or weeks in advance, and uplinking them through the ground network.
Turning a mission's science and engineering goals into a detailed, resource-constrained plan of activities — what the spacecraft will do, when, and within its power, data, and pointing limits.
The pre-agreed decision rules that tell a control team how to respond to situations, so that time-critical calls are made consistently and safely rather than improvised.
Continuously watching a spacecraft's telemetry against expected limits to catch anomalies early — the routine vigilance that keeps a mission alive.
The onboard and ground logic that detects failures and responds automatically to keep a spacecraft safe when the ground cannot react in time — vital across the long light-time to deep space.
A protective state a spacecraft autonomously enters when it detects a serious problem — pointing its solar arrays at the Sun and its antenna toward Earth, and waiting for instructions.
Software that automates routine operations — from pass scheduling and telemetry screening to onboard sequence execution — reducing workload and enabling operations at deep-space distances.
The operations phase spanning launch and the critical early days — acquiring the spacecraft, checking it out, and getting it onto its planned trajectory (Launch and Early Orbit Phase, LEOP).
The long interplanetary-cruise phase — keeping the spacecraft healthy, performing trajectory-correction manoeuvres, and preparing for arrival.
The prime phase in which the spacecraft carries out its science — planning observations, commanding the instruments, and returning the data that is the point of the mission.
The final phase — safely disposing of a spacecraft (a controlled re-entry, a graveyard orbit, or a deliberate impact) and preserving its data — closing out the mission responsibly.
The mechanical skeleton of a spacecraft — the load-bearing frame that holds everything together and survives the violence of launch, plus the mechanisms that deploy solar arrays, antennas, and instruments once in space.
The subsystem that keeps every part of a spacecraft within its allowable temperature range, radiating away waste heat and insulating against the extreme cold of space and the heat of the Sun.
The subsystem that generates, stores, and distributes electricity — from solar arrays or radioisotope generators, through batteries, to every instrument and heater on board.
The subsystem that changes a spacecraft's velocity — for orbit insertion, trajectory corrections, and station-keeping — using chemical, electric, or cold-gas thrusters.
The subsystem that determines and controls which way a spacecraft points — sensing its orientation with star trackers and gyroscopes, and turning it with reaction wheels or thrusters.
The spacecraft's onboard computing — the flight computer, software, and memory that execute commands, run the spacecraft autonomously, and manage faults across the long light-time to deep space.
The subsystem that carries commands up and telemetry and science data down — the spacecraft's radios and antennas, working with the ground network.
The subsystem — and the few dramatic minutes — that gets a spacecraft from the top of an atmosphere to a safe landing: a heat shield to survive entry, a parachute or thrusters to slow down, and legs or airbags to touch down.
The robotic arms and manipulators that let spacecraft build, service, sample, and move cargo — from the Space Shuttle and station arms to the sampling arms of planetary landers.
For crewed spacecraft, the systems that keep people alive and let vehicles join up — environmental control and life support (ECLSS) and the docking mechanisms that connect spacecraft.
Panels of photovoltaic cells that convert sunlight into electricity — the primary power source for most spacecraft in the inner Solar System. Beyond Jupiter, sunlight becomes too weak and other sources are needed.
Rechargeable batteries store energy from the solar arrays to power a spacecraft through eclipse, at night, or during peak demand. Lithium-ion has largely replaced older nickel chemistries.
Radioisotope Thermoelectric Generator (RTG)
A nuclear power source that converts the heat of decaying plutonium-238 directly into electricity. RTGs let missions operate far from the Sun or through the lunar night — powering Voyager, Cassini, and the nuclear Mars rovers Curiosity and Perseverance (the earlier rovers were solar-powered).
A device that generates electricity by combining hydrogen and oxygen, producing water as a by-product. Fuel cells powered the Apollo and Space Shuttle missions, useful for short crewed flights needing high power.
Thrusters and engines that burn propellants for high thrust — the standard means of orbit insertion and large manoeuvres, using monopropellants (hydrazine) or bipropellants.
A gridded electrostatic thruster that ionises a propellant (usually xenon) and accelerates it with electric-field grids to very high exhaust velocity. It delivers tiny thrust but sips fuel, enabling missions like Deep Space 1 and Dawn.
A type of electric propulsion that traps electrons in a magnetic field to ionise and accelerate propellant. Widely used for satellite station-keeping and, increasingly, for deep-space missions — NASA's Psyche is the first to fly Hall-effect thrusters beyond lunar orbit.
The simplest thruster — it just releases a stored, pressurised gas through a nozzle. Low-performance but reliable, used for fine attitude control and on small spacecraft.
A propulsion concept that heats a propellant with a nuclear reactor for high thrust and efficiency. Long studied and tested on the ground, it is a candidate for future fast crewed trips to Mars.
A set of small thrusters arranged around a spacecraft for precise control of orientation and small translations — used for pointing, docking, and stabilisation.
A spinning flywheel that a spacecraft speeds up or slows down to rotate itself, by conservation of angular momentum, without using any propellant — the workhorse of precise pointing.
A spinning gyroscope whose axis is tilted to produce large control torques efficiently — used on big, agile spacecraft such as the International Space Station and Earth-imaging satellites.
The central processor that runs a spacecraft — executing command sequences, controlling subsystems, and reacting to faults. Deep-space computers are radiation-hardened and modest by consumer standards, prizing reliability over speed.
The programs that fly the spacecraft — running the control loops, sequences, and autonomy. Flight software is exhaustively tested, because a bug billions of kilometres away cannot be fixed by hand.
Memory and electronics designed to withstand the charged particles of space, which can flip bits or damage circuits. Error-correcting codes and hardened parts keep the computer trustworthy.
The onboard logic that detects, isolates, and recovers from failures autonomously — putting the spacecraft into a safe state and calling home when it cannot resolve a problem itself.
A surface that sheds a spacecraft's waste heat into space by infrared radiation — the only way to cool in a vacuum, where there is no air to carry heat away.
The shiny, quilted blankets that wrap most spacecraft — many thin reflective layers that block radiative heat transfer, insulating against both the Sun's heat and the cold of space.
Electric heaters and passive heat pipes that keep components — propellant lines, batteries, instruments — above their minimum temperatures, moving heat from where it is made to where it is needed or shed.
The main load-bearing frame of the spacecraft, which carries the launch loads and provides the rigid backbone to which everything else is mounted.
The hinges, booms, and release devices that unfold solar arrays, antennas, and instrument booms after launch — single-use mechanisms that must work the first time.
The ablative or reusable shield that protects a spacecraft from the searing heat of atmospheric entry, where air violently compressed ahead of the vehicle's bow shock can reach thousands of degrees (the heating is dominated by shock compression, not friction). Ablative shields char and carry heat away as they erode.
The decelerator that slows a spacecraft in an atmosphere after the heat shield has done its work — from the supersonic parachutes of Mars landers to the splashdown chutes of crew capsules.
The thrusters, legs, or airbags that manage the final touchdown — from the sky-crane of the Mars rovers to the propulsive landings of crew and booster vehicles.
A jointed manipulator used to move cargo, service hardware, capture spacecraft, or collect samples. The Shuttle's Canadarm helped assemble the Space Station and the permanently-installed Canadarm2 services it; planetary landers carry smaller sampling arms.
An imaging instrument that records visible (and often near-infrared or ultraviolet) light — the eyes of a spacecraft, from wide-angle context cameras to high-resolution narrow-angle telescopes.
An instrument that captures both an image and a spectrum for every pixel, mapping the composition of a surface or atmosphere by the wavelengths of light it reflects or emits.
An instrument that splits light into its component wavelengths to reveal composition, temperature, and motion — the workhorse of remote sensing, spanning ultraviolet, visible, infrared, X-ray, and gamma-ray bands.
An instrument that sorts atoms and molecules by mass, identifying the chemical and isotopic makeup of a sample of gas or dust — essential for atmospheres, plumes, and returned samples.
An instrument that measures magnetic fields, revealing a planet's internal dynamo, a moon's hidden ocean, or the structure of the solar wind and magnetospheres.
An instrument that counts and characterises the electrons, ions, and cosmic rays of space plasmas — mapping radiation belts, the solar wind, and energetic-particle events.
An instrument that detects the tiny dust grains of space — from cometary and interplanetary dust to the particles of planetary rings — measuring their speed, mass, and sometimes composition.
An active instrument that transmits radio waves and analyses the echoes to map surfaces through cloud and darkness, or to probe beneath the surface. Synthetic-aperture radar (SAR) achieves high resolution from orbit.
An active instrument that fires laser pulses and times their return to measure distance precisely — mapping the topography of a planet, moon, or asteroid with height accuracy of metres.
An instrument that senses the tiny ground motions of quakes and impacts, probing the interior structure of a world by how seismic waves travel through it — as InSight did for Mars.
An instrument that measures the gamma rays and neutrons emitted by a surface under cosmic-ray bombardment, revealing elemental composition — and, through neutrons, the presence of water or ice.
A technique that uses the spacecraft's own radio signal as an instrument — tracking tiny frequency shifts to weigh a planet, map its gravity field, and probe its atmosphere and rings by how they bend the signal.
LORRI (Long Range Reconnaissance Imager)
New Horizons's high-resolution narrow-angle telescope camera, which returned the first detailed images of Pluto and the Kuiper Belt object Arrokoth.
New Horizons's ultraviolet imaging spectrometer, which probed the composition and structure of Pluto's atmosphere as the spacecraft flew through its shadow.
Juno's wide-angle visible-light camera, included partly for public engagement, which has returned spectacular images of Jupiter's turbulent poles and cloud bands.
Cassini's wide- and narrow-angle cameras, which imaged Saturn, its rings, and its moons in unprecedented detail over thirteen years.
Cassini's magnetometer, which mapped Saturn's magnetic field and detected the field perturbation that first revealed Enceladus's dynamic atmosphere and plumes, prompting the closer flybys.
The Voyager cameras, which returned the first close-up images of the outer planets and their moons, and the 'Pale Blue Dot' portrait of Earth.
OSIRIS-REx's camera suite, which mapped the asteroid Bennu in detail and documented the touch-and-go sample collection.
SEIS (Seismic Experiment for Interior Structure)
InSight's ultra-sensitive seismometer, which detected hundreds of marsquakes and, for the first time, revealed the internal structure of Mars.
Magellan's imaging radar, which pierced Venus's thick clouds to map 98% of the planet's surface at high resolution.
MESSENGER Gamma-Ray & Neutron Spectrometer
MESSENGER's spectrometer, which measured the elemental composition of Mercury's surface and helped confirm water ice in its permanently shadowed polar craters.
Dawn's camera, which mapped the giant asteroid Vesta and the dwarf planet Ceres, including the bright carbonate deposits of Ceres's Occator crater.
Galileo Near-Infrared Mapping Spectrometer (NIMS)
Galileo's imaging spectrometer, which mapped the composition of Jupiter's moons and found evidence for salts and a subsurface ocean on Europa.
The Voyager cosmic-ray detectors, whose measurements of the sudden change in particle counts marked each spacecraft's crossing of the heliopause into interstellar space.
Cassini's dust detector, which sampled the grains of Saturn's rings and the ice particles of Enceladus's plume, measuring their composition and revealing the moon's subsurface ocean.
MESSENGER's laser altimeter, which measured the topography of Mercury's northern hemisphere and helped confirm water ice in its permanently shadowed polar craters.
Cassini's radio-science experiment, which used the spacecraft's radio link — tracking tiny frequency shifts and radio occultations — to weigh Saturn, map its gravity field, and probe the structure of its rings and atmosphere.
A bowl-shaped depression blasted out when an asteroid or comet strikes a solid surface. Craters are the most common landform in the Solar System, and their density is used to date surfaces — the more craters, the older the terrain.
An enormous impact structure, hundreds to thousands of kilometres across, formed by a giant early impact — often multi-ringed and later flooded by lava, as with the lunar maria.
A broad, gently-sloping volcano built by fluid lava flows. On Mars, low gravity and a stationary crust let shield volcanoes grow to enormous size — Olympus Mons is the tallest in the Solar System.
An 'ice volcano' that erupts water, ammonia, or methane instead of molten rock, resurfacing the frozen worlds of the outer Solar System — from Ceres's Ahuna Mons to the plumes of Enceladus.
A broad, dark plain of solidified lava. The lunar maria — the 'seas' — are vast basalt flows that filled ancient impact basins; similar plains cover much of Venus and Mars.
The ancient, heavily-cratered high terrain of a world, older and more rugged than the smooth plains — like the bright lunar highlands or the tessera terrain of Venus.
A deep, steep-sided valley cut by tectonics or water. Mars's Valles Marineris is a canyon system so large it would stretch across the entire United States.
A cliff formed where the crust has broken and one side has risen relative to the other. Mercury is covered in long lobate scarps produced as the planet cooled and shrank.
A chain or massif of mountains, whether uplifted by tectonics, thrown up around an impact basin, or built by volcanism — from Venus's Maxwell Montes to the water-ice mountains of Pluto.
Complex, intensely deformed 'tile' terrain unique to Venus — the planet's oldest and most tectonically tortured surface, ridged and grooved in intersecting directions.
A large circular volcanic-tectonic feature, ringed by fractures, thought to form where hot material rises and pushes up the crust — a signature landform of Venus.
Bright bands of parallel ridges and grooves that cut across the dark, ancient surface of Ganymede — young, tectonically-resurfaced ice.
A field of wind-blown dunes, showing that a world has an atmosphere and mobile sediment — from the basaltic-sand dunes of Mars to the hydrocarbon-sand dunes of Titan.
A giant channel carved by catastrophic floods of water in the distant past, evidence that liquid water once flowed across the surface of Mars.
A fan of sediment deposited where an ancient river entered a standing body of water — a prime target in the search for past life, as at Jezero crater on Mars.
A broad plain or flowing sheet of ice. On Pluto, the nitrogen-ice glaciers of Sputnik Planitia churn and flow; on Mars and the icy moons, water ice shapes the surface.
A jumble of broken, tilted blocks of crust, often where a surface has been disrupted from below — as on Europa, where it may mark places the ice shell interacts with the ocean beneath.
A lake or sea of liquid methane and ethane — found only on Titan, the one other world in the Solar System with stable liquid on its surface.
A chain of three vast shield volcanoes on the Tharsis rise, a bulge so large it may have tilted the whole planet. Tharsis dominates the western hemisphere of Mars.
One of the largest visible impact basins in the Solar System and the lowest point on Mars, deep enough that the atmospheric pressure at its floor can allow liquid water briefly.
A 154 km impact crater with a central mountain (Aeolis Mons / Mount Sharp) of layered sediments. The Curiosity rover has climbed it, reading a history of ancient lakes.
A crater that once held a lake, with a well-preserved river delta at its rim. The Perseverance rover is caching samples here in the search for signs of ancient life.
One of the largest outflow channels on Mars, carved by catastrophic floods of water that burst from the Tharsis region billions of years ago.
The vast lava-filled 'Sea of Showers', one of the largest lunar maria, occupying a giant ancient impact basin on the Moon's near side.
A young, prominent lunar impact crater with terraced walls and bright rays of ejecta, a classic example of a complex crater.
One of the largest impact basins in the Solar System, on Mercury, so violent that its antipode is marked by chaotic 'weird terrain' shaken up by the focused seismic waves.
A great lobate cliff on Mercury, formed as the planet's interior cooled and its crust contracted, thrusting one block of terrain over another.
The highest mountains on Venus, rising about 11 km above the mean surface in the northern highlands of Ishtar Terra — higher than Everest above sea level.
A continent-sized highland region straddling Venus's equator, roughly the size of Africa, cut by deep rifts and dotted with volcanic features.
The largest corona on Venus — a vast circular volcano-tectonic feature ringed by fractures, marking where hot material welled up beneath the crust.
One of the first-recognised tessera regions on Venus — a patch of the planet's oldest, most intensely deformed 'tile' terrain, ridged and grooved by ancient tectonics.
A vast field of dark, wind-blown dunes wrapping around the north polar ice cap of Mars — one of the largest dune fields on the planet.
A crater on the dwarf planet Ceres famous for its bright deposits — salts left behind by briny water that reached the surface, hinting at a subsurface reservoir.
A steep, isolated mountain on Ceres interpreted as a cryovolcano — a dome built by icy, briny material erupting from within the dwarf planet.
An enormous impact basin covering much of the south pole of the asteroid Vesta, with a central peak among the tallest in the Solar System. Its excavation launched the HED meteorites.
A region of Europa where the icy crust has broken into a jumble of tilted blocks 'rafts' set in refrozen slush — evidence that the surface interacts with the ocean below.
A swath of the bright, grooved terrain that covers much of Ganymede — younger ice, tectonically resurfaced into parallel ridges and troughs.
A giant multi-ring impact structure on Callisto — concentric rings of ridges rippling out from a bright central plain across the most heavily-cratered surface in the Solar System.
Four parallel fractures across the south pole of Enceladus from which giant plumes of water vapour and ice erupt into space — fed by the moon's subsurface ocean.
The largest known sea of liquid methane and ethane on Titan, near the north pole — the largest body of surface liquid in the Solar System beyond Earth.
The largest lake in Titan's southern hemisphere, a shallow methane-ethane lake whose shoreline changes with the moon's seasons.
The strange, dimpled surface of Neptune's moon Triton, resembling the skin of a cantaloupe — a young, resurfaced landscape unlike anywhere else, imaged by Voyager 2.
The vast nitrogen-ice plain that forms the western lobe of Pluto's bright 'heart'. Its ice slowly churns in convection cells and flows like a glacier, keeping the surface young.
Jagged mountains of water ice rising several kilometres along the edge of Sputnik Planitia on Pluto — water ice is rigid enough at Pluto's temperatures to hold up mountains.
A national or multinational government body that funds, directs, and carries out a country's space program — from human spaceflight and robotic exploration to Earth observation and launch. NASA, ESA, JAXA, ISRO, Roscosmos, and CNSA are the largest.
A specialised research and operations centre of a space agency, each focused on a distinct role — building spacecraft, training astronauts, running mission control, testing engines, or launching rockets. NASA and ESA each run a family of them.
A laboratory that designs, builds, and operates spacecraft and instruments, often as a federally-funded centre managed for an agency by a university. JPL and the Johns Hopkins Applied Physics Laboratory have built many of the great robotic missions.
An independent institute that leads scientific research, operates a mission's science operations, or curates its data archives — from the Space Telescope Science Institute to independent research bodies that lead planetary missions.
A private company that develops launch vehicles, spacecraft, or satellites — increasingly under contract to space agencies. SpaceX, Blue Origin, Rocket Lab, and the established aerospace primes span the field.
An organization that operates ground-based observatories and telescopes and supports the astronomical community — such as the European Southern Observatory, NSF NOIRLab, and the national astronomical observatories.
NASA's largest centre for Earth and space science, in Greenbelt, Maryland. Goddard builds and operates robotic science missions and manages flagship observatories including Hubble and the James Webb Space Telescope, whose science operations are run by the Space Telescope Science Institute.
NASA's centre for human spaceflight, in Houston, Texas. Johnson is home to the astronaut corps and to Mission Control, which has directed crewed flights from Gemini and Apollo to the Space Shuttle and the International Space Station.
NASA's centre for propulsion and launch vehicles, in Huntsville, Alabama. Marshall developed the Saturn V, elements of the Space Shuttle, and the Space Launch System, and manages many science payloads.
NASA's primary launch centre, on Merritt Island, Florida, beside Cape Canaveral. Kennedy processes and launches crewed and robotic missions and is NASA's gateway for human spaceflight.
A NASA research centre in California's Silicon Valley focused on aeronautics, astrobiology, entry systems, small spacecraft, and supercomputing. Ames led the Kepler exoplanet mission's science.
NASA's oldest field centre, in Hampton, Virginia, founded for aeronautics research. Langley works on atmospheric science, materials, and the entry, descent, and landing systems that deliver spacecraft to other worlds.
NASA's centre for aerospace propulsion, power, and communications, in Cleveland, Ohio. Glenn develops electric propulsion, space power systems, and the technologies that keep spacecraft running.
NASA's principal rocket-engine test centre, in southern Mississippi. Stennis has tested the engines of the Saturn V, the Space Shuttle, and the Space Launch System.
NASA's centre for atmospheric flight research, at Edwards Air Force Base in California. Armstrong flies experimental and research aircraft and supported the Space Shuttle's landings and approach tests.
A NASA launch range on Virginia's eastern shore, managed by Goddard. Wallops flies sounding rockets, scientific balloons, and small orbital launches, and hosts a mid-Atlantic commercial launch pad.
European Space Research and Technology Centre
ESA's largest establishment and technical heart, in Noordwijk, the Netherlands. ESTEC designs and tests almost every ESA spacecraft and instrument before flight.
ESA's establishment for Earth observation, in Frascati, Italy. ESRIN acquires, processes, and distributes data from Europe's Earth-observation satellites and hosts ESA's Living Planet programme.
ESA's centre for space science operations and archives, near Madrid, Spain. ESAC runs the science operations and data archives for ESA's astronomy and planetary missions, from Gaia and XMM-Newton to Mars Express.
ESA's centre for the European astronaut corps, in Cologne, Germany. EAC trains ESA astronauts for missions to the International Space Station and prepares them for exploration beyond low Earth orbit.
JAXA's central hub, in Tsukuba Science City, Japan. Tsukuba develops and tests satellites and rockets, trains Japanese astronauts, and operates the Kibo module on the International Space Station.
Johns Hopkins University Applied Physics Laboratory
A university-affiliated research laboratory in Laurel, Maryland, that designs, builds, and operates robotic spacecraft. APL built New Horizons, MESSENGER, the Parker Solar Probe, and the DART planetary-defence mission.
An independent, non-profit research institute headquartered in San Antonio, Texas. SwRI leads the science of NASA missions including Juno, New Horizons, and Lucy, and builds spacecraft instruments.
A non-profit research institute in Mountain View, California, dedicated to understanding the origin and nature of life in the universe, including the search for extraterrestrial intelligence and astrobiology research.
The opening of the space age, from the launch of Sputnik 1 to the first probes toward the Moon — the moment humanity's machines first left the Earth.
The Cold-War contest between the Soviet Union and the United States that carried the first humans into orbit and on to the Moon, culminating in the Apollo landings and the détente of Apollo–Soyuz.
The decades in which robotic probes first reached every planet — Mariner, Pioneer, Viking, and the two Voyagers that toured the outer Solar System and reached its edge.
Thirty years of the reusable Space Shuttle — building space stations, launching and repairing great observatories, and marked by the losses of Challenger and Columbia.
The era of continuous human presence in orbit aboard the International Space Station — the largest structure ever built in space and a laboratory for living and working off Earth.
The modern era of spaceflight — reusable and commercial rockets carrying cargo and crew to orbit, alongside a new generation of robotic explorers reaching Mars, the comets, Pluto, and interstellar space.
The return to the Moon — NASA's Artemis program and its international and commercial partners working to land the next humans on the lunar surface and build a sustained presence.
The Soviet Union launches Sputnik 1, the first artificial satellite, opening the space age and stunning the world with its steady radio beep from orbit.
The first successful United States satellite, Explorer 1, carries a Geiger counter that discovers the belts of trapped radiation now named for James Van Allen.
The Soviet Luna 2 becomes the first spacecraft to reach the surface of another world, impacting the Moon.
Gagarin Becomes the First Human in Space
Yuri Gagarin orbits the Earth once aboard Vostok 1, becoming the first human in space and the first to orbit the planet.
Shepard Becomes the First American in Space
Alan Shepard flies a 15-minute suborbital hop aboard Freedom 7, becoming the first American in space three weeks after Gagarin.
Glenn Becomes the First American to Orbit the Earth
John Glenn circles the Earth three times aboard Friendship 7, the first American to orbit the planet.
Tereshkova Becomes the First Woman in Space
Valentina Tereshkova spends nearly three days in orbit aboard Vostok 6, the first woman to fly in space.
Alexei Leonov leaves his Voskhod 2 capsule for about twelve minutes, the first human to walk in space.
Luna 9 Makes the First Soft Landing on the Moon
The Soviet Luna 9 makes the first soft landing on the Moon and returns the first pictures from its surface.
The crew of Apollo 8 become the first humans to leave Earth orbit and circle the Moon, returning the famous Earthrise photograph.
Apollo 11 Lands the First Humans on the Moon
Neil Armstrong and Buzz Aldrin walk on the Moon while Michael Collins orbits above — the first humans to set foot on another world.
An oxygen tank explodes on the way to the Moon; the crew and mission control improvise a safe return, turning a near-disaster into a triumph of ingenuity.
The Soviet Venera 7 transmits from the surface of Venus, the first successful landing on another planet.
The Soviet Union launches Salyut 1, the world's first space station, beginning the long human effort to live and work in orbit.
The final Apollo landing; Eugene Cernan is, to date, the last person to walk on the Moon, and geologist Harrison Schmitt the only scientist to do so.
The United States launches Skylab, its first space station, where crews study the Sun and the effects of long-duration spaceflight on the human body.
Viking 1 becomes the first spacecraft to operate successfully on the surface of Mars, returning the first pictures from the Martian ground and searching for life.
Voyager 1 and Voyager 2 launch on a grand tour of the outer Solar System, exploiting a rare planetary alignment to visit the giant planets.
Voyager 2 sweeps past Neptune, the first and only spacecraft to visit the ice giant, completing the reconnaissance of every planet from Mercury to Neptune.
Columbia lifts off on STS-1, the first flight of the Space Shuttle — the first reusable crewed spacecraft, twenty years to the day after Gagarin's flight.
Sally Ride, First American Woman in Space
Aboard Challenger, Sally Ride becomes the first American woman in space.
The Space Shuttle Challenger breaks apart 73 seconds after launch, killing all seven crew and grounding the shuttle fleet for nearly three years — a turning point for spaceflight safety.
The Space Shuttle deploys the Hubble Space Telescope; after a famous repair mission corrected its mirror, Hubble transformed astronomy and public views of the cosmos.
Galileo becomes the first spacecraft to orbit Jupiter and drops a probe into its atmosphere, beginning years of study of the giant planet and its moons.
Mars Pathfinder lands using airbags and deploys Sojourner, the first successful rover on another planet, proving a low-cost path back to the Martian surface.
The Zarya module launches, the first piece of the International Space Station — the largest structure ever assembled in space, built by fifteen nations.
The Space Shuttle Columbia breaks apart during re-entry, killing all seven crew and leading to the decision to retire the shuttle fleet.
Cassini enters orbit around Saturn and later delivers the Huygens probe to Titan, beginning thirteen years of discovery in the Saturn system.
Deep Impact fires a projectile into comet Tempel 1, excavating fresh material to reveal what a comet is made of.
Japan's Hayabusa touches down on the asteroid Itokawa; despite great difficulties it returns to Earth in 2010 with the first samples ever collected from an asteroid.
Atlantis flies STS-135, the 135th and final Space Shuttle mission, ending thirty years of shuttle flight and beginning a gap in American crewed launch.
The car-sized Curiosity rover lands in Gale Crater using the daring sky-crane manoeuvre, beginning a long study of Mars's ancient habitability.
Voyager 1 crosses the heliopause and becomes the first human-made object to enter interstellar space, still returning data from beyond the Sun's bubble.
ESA's Rosetta becomes the first spacecraft to orbit a comet and, with its Philae lander, the first to soft-land on one — comet Churyumov–Gerasimenko.
After a nine-year journey, New Horizons sweeps past Pluto, revealing an astonishingly varied world and completing the first reconnaissance of the classical Solar System.
SpaceX's Crew Dragon Demo-2 carries astronauts to the ISS, the first crewed orbital flight launched by a private company and the return of crewed launch to American soil.
OSIRIS-REx and Hayabusa2 Sample Asteroids
Within months of each other, Japan's Hayabusa2 delivers samples of asteroid Ryugu to Earth and NASA's OSIRIS-REx collects a sample from asteroid Bennu, opening a new age of asteroid sample return.
Launch of the James Webb Space Telescope
The James Webb Space Telescope launches and unfolds a giant segmented mirror a million miles from Earth, opening the infrared universe and the era of studying the first galaxies.
Ingenuity Makes the First Powered Flight on Another World
The tiny Ingenuity helicopter, carried by the Perseverance rover, lifts off from the surface of Mars — the first powered, controlled flight on another planet.
NASA's DART deliberately crashes into the moonlet Dimorphos and measurably changes its orbit — the first demonstration that humanity could deflect an asteroid.
The uncrewed Artemis I sends the Orion spacecraft around the Moon and back on the first flight of NASA's program to return humans to the lunar surface.
Chandrayaan-3 Lands Near the Lunar South Pole
India's Chandrayaan-3 makes a soft landing near the Moon's south pole, making India the fourth nation to land on the Moon and the first near the south-polar region.
Sputnik 1 was the first human-made object placed in orbit around the Earth, opening the space age.
Yuri Gagarin was the first person to travel into space and orbit the Earth, aboard Vostok 1.
Valentina Tereshkova was the first woman to fly in space, aboard Vostok 6.
Alexei Leonov made the first extravehicular activity, floating outside his Voskhod 2 capsule.
Apollo 11 landed Neil Armstrong and Buzz Aldrin on the Moon, the first humans to walk on another world.
Salyut 1 was the first space station, the beginning of humans living and working in orbit.
Venera 7 returned data from the surface of Venus, the first successful landing on another planet.
Viking 1 was the first spacecraft to land and operate successfully on the surface of Mars.
Sojourner, delivered by Mars Pathfinder, was the first wheeled rover to operate on another planet.
The Space Shuttle was the first crewed spacecraft designed to fly to orbit and return to be flown again.
Rosetta's Philae lander made the first soft landing on the nucleus of a comet.
Hayabusa returned the first samples ever collected from an asteroid, from Itokawa, to Earth.
SpaceX's Crew Dragon Demo-2 was the first crewed orbital spaceflight launched by a private company.
The Ingenuity helicopter made the first powered, controlled flight by an aircraft on another planet.
DART was the first mission to change the orbit of an asteroid, demonstrating a technique for planetary defence.
Voyager 1 is the most distant human-made object from Earth, over 24 billion kilometres away and still receding, having crossed into interstellar space in 2012.
The Parker Solar Probe is the fastest human-made object, reaching speeds of hundreds of thousands of kilometres per hour as the Sun's gravity accelerates it through its closest approaches.
First Object to Reach Interstellar Space
Voyager 1 was the first spacecraft to cross the heliopause and enter interstellar space, the region between the stars.
The longest single spaceflight was flown by cosmonaut Valeri Polyakov, who spent about 437 days continuously aboard the Mir space station in 1994–1995.
The crew of Apollo 13 travelled farther from Earth than any humans before or since, swinging around the far side of the Moon on a free-return trajectory after their spacecraft was crippled.
Longest Continuous Human Presence in Space
The International Space Station has been continuously inhabited since November 2000, the longest unbroken human presence in space.
Longest-Operating Interplanetary Spacecraft
The two Voyager spacecraft, launched in 1977, are the longest-operating interplanetary spacecraft, still returning data from beyond the planets after more than four decades.
The medical discipline concerned with keeping astronauts healthy before, during, and after spaceflight — studying how microgravity changes the body and how to protect it on long missions to the ISS, the Moon, and Mars.
The study of how the radiation of space — galactic cosmic rays and solar energetic particles — affects living tissue, and how crews can be protected beyond the shelter of Earth's magnetic field.
The behavioural health and human-factors discipline — how isolation, confinement, altered day–night cycles, and workload affect crews, and how habitats and schedules are designed around human needs.
The engineering that keeps a crew alive — generating oxygen, scrubbing carbon dioxide, recovering water, managing waste, and controlling the atmosphere. These technologies make up the Environmental Control and Life Support System.
Life support that uses living systems — plants and microbes — to recycle air, water, and waste and to grow food, moving toward the closed ecosystems that long missions far from Earth will need.
The heart and blood vessels adapt to weightlessness, and the heart can weaken without the constant work of pumping against gravity. Crews often experience orthostatic intolerance — dizziness on standing — when they return to gravity.
In the first days of flight, the conflict between the eyes and the balance organs of the inner ear causes disorientation and nausea as the brain adapts to weightlessness; a mirror-image readaptation occurs on return to gravity.
Spaceflight alters the immune system — some functions are dampened while latent viruses can reactivate — a concern for crew health on long missions far from medical care.
On the ISS the crew sees sixteen sunrises a day, and mission schedules can shift sleep times; the resulting disruption of the body clock degrades sleep, alertness, and performance.
Long missions in a confined habitat, far from family and unable to leave, place real psychological demands on crews — from mood and interpersonal tension to the cognitive effects of monotony — that grow with distance and duration.
Systems that produce breathable oxygen in a closed cabin, typically by splitting recovered water into oxygen and hydrogen through electrolysis, so a crew is not wholly dependent on tanks brought from Earth.
The carbon dioxide a crew exhales must be continuously removed from the cabin air. Systems use regenerable sorbents or amine beds to scrub it out, and increasingly to recover its oxygen rather than venting it overboard.
On the ISS, most of the crew's water is recycled — reclaimed from humidity, hygiene water, and urine and purified back to drinking quality. Closing the water loop is essential to missions too far to resupply.
Systems for collecting and processing human waste and trash in weightlessness — from the spacecraft toilet to the handling of solid waste — protecting crew health and, increasingly, recovering water and resources.
Life support must hold the cabin at a comfortable, safe temperature and humidity, removing the heat and moisture that crew and equipment add and preventing condensation that could damage systems or grow microbes.
Sensors continuously track the cabin's oxygen, carbon dioxide, pressure, and trace contaminants, so that the life-support system can respond and the crew is warned of any hazardous change in their air.
The engineered system that feeds a crew — shelf-stable, nutritious food packaged for weightlessness, planned to sustain health and morale over long missions where resupply is limited or impossible.
Growing plants in space — for fresh food, for recycling air and water, and for crew morale. Experiments aboard the ISS have grown and eaten space-grown crops, a step toward the farms that Moon and Mars crews will need.
The goal of a fully regenerative life-support system, in which plants and microbes recycle essentially all of the air, water, and waste — the closed ecosystem that a self-sufficient Mars base would require. Ground experiments such as BIOS-3 and MELiSSA have pursued it.
Weightlifting in orbit. Devices such as the ISS's Advanced Resistive Exercise Device let crews load their bones and muscles against a resistance in place of gravity — the single most important countermeasure against bone and muscle loss.
Crews run on a harness-tethered treadmill and pedal a cycle ergometer for hours each week to keep the heart and muscles conditioned against the deconditioning of weightlessness.
Carefully planned diet and supplementation — adequate energy, protein, vitamin D, and controlled sodium — works together with exercise to protect bone and muscle and to support overall crew health.
Medications used to protect crew health — bone-preserving drugs studied against spaceflight osteopenia, and medicines that manage space motion sickness, sleep, and other conditions in flight.
A device that applies suction to the lower body, pulling fluids back toward the legs as gravity would. It is studied as a countermeasure to the headward fluid shift and the eye changes of SANS.
Spinning a spacecraft or a short-radius centrifuge to create an outward force that mimics gravity. A long-studied but not yet operational countermeasure that could address many effects of weightlessness at once.
Protecting crews from space radiation with mass — hydrogen-rich materials, water, or regolith — and with mission design, such as storm shelters for solar particle events and limits on time beyond the magnetosphere.
Tunable LED lighting that shifts colour and intensity through the day to reinforce the body clock, helping crews sleep and stay alert despite sixteen orbital sunrises a day.
The measures that sustain crew mental health — private family conferences, care packages, meaningful scheduling and rest, and ground-based behavioural health teams — increasingly important the farther a crew travels from Earth.
The biomedical sensors, health checks, and ground-linked telemedicine that watch over crew health in flight. On missions to Mars, where help is minutes-to-hours away by radio, crews will need to be far more medically autonomous.
Using the materials found on the Moon, Mars, and asteroids — water ice, regolith, and metals — instead of launching everything from Earth. ISRU is the key to affordable, sustained exploration beyond low Earth orbit.
Making and assembling things in space — 3D-printing parts on a station, building large structures on orbit, and servicing spacecraft — rather than launching everything fully formed inside a rocket fairing.
The persistent facilities that a spacefaring economy needs — propellant depots, habitats, and surface bases — and the megastructure concepts, from space elevators to mass drivers, that would transform access to space.
Generating power in space and beaming it where it is needed — from the arrays that power a station to the concept of space solar-power satellites that would collect sunlight in orbit and send it to Earth.
Moving cargo and spacecraft around in space — orbital tugs, in-space refuelling, and reusable transfer vehicles — the transport layer of an in-space economy.
Mining and extracting water and volatiles — from the permanently-shadowed craters at the lunar poles and from water-bearing carbonaceous asteroids such as Bennu. Water is the keystone resource: it provides drinking water, breathable oxygen, radiation shielding, and rocket propellant.
Producing breathable oxygen and oxidiser from local materials — from the carbon dioxide of the Martian atmosphere or from oxygen-bearing lunar regolith. NASA's MOXIE experiment on the Perseverance rover demonstrated making oxygen on Mars.
Working the loose surface soil of the Moon and Mars — sintering or melting it into building material, extracting metals and oxygen, and using it for radiation shielding — turning the ground itself into a resource.
Extracting metals — iron, nickel, and precious metals — from asteroids and from lunar and Martian regolith, to build structures in space without lifting the mass from Earth. Metal-rich M-type asteroids such as Psyche are studied as future resources.
Making rocket propellant in space — splitting water into hydrogen and oxygen, or combining Martian carbon dioxide with hydrogen to make methane and oxygen — so a return vehicle can be fuelled at its destination instead of carrying all its propellant from Earth.
3D-printing parts and tools in orbit, layer by layer. A 3D printer has operated aboard the ISS since 2014, printing tools and spares on demand and pointing toward a future where spacecraft parts are made in space rather than launched.
Building large structures in space from parts, rather than folding a finished structure into a rocket fairing. In-space assembly would allow telescopes, antennas, and stations far larger than any launch vehicle could carry whole.
Repairing, refuelling, and upgrading spacecraft in orbit instead of discarding them — extending mission life and reducing debris. Robotic servicing missions have already docked with and relocated satellites.
Using robots to build and maintain infrastructure in space and on other worlds with little or no human presence — laying landing pads, assembling habitats, and constructing solar farms before crews arrive.
An orbiting fuel station that stores propellant so spacecraft can refuel in space. A depot would let missions launch 'dry' and top up on orbit, breaking the tyranny of carrying all their propellant from the ground.
Keeping cryogenic propellants — liquid hydrogen and oxygen — cold enough not to boil away over long missions. Cryogenic fluid management is a key enabling technology for depots and for deep-space transfer stages.
Privately-built and operated space stations intended to succeed the ISS as destinations in low Earth orbit — for research, manufacturing, and tourism. Axiom Station is being assembled to begin attached to the ISS before flying free.
Habitats that launch compact and expand in space, giving far more volume per kilogram than rigid modules. The Genesis demonstrators and the BEAM module on the ISS have proven the concept in orbit.
A sustained human outpost on the Moon — habitats, power, and ISRU plants supporting long stays — the surface counterpart of the Gateway station, and a proving ground for the technologies of a Mars base.
A cable anchored to the ground and reaching beyond geostationary orbit, up which vehicles would climb to space without rockets. It remains theoretical: no known material has the strength-to-weight needed to build the tether on Earth.
An electromagnetic catapult that accelerates payloads to high speed along a track — proposed especially on the Moon, where the low gravity and airlessness would let a mass driver launch mined material into space without rockets.
A large satellite that collects sunlight in orbit — where the Sun always shines — and beams the energy to receivers on the ground as microwaves. Small-scale power-beaming has been demonstrated; a full system remains a concept.
Compact nuclear reactors to power a Moon or Mars base through the long lunar night and the dim Martian winter, when solar power is not enough. NASA's KRUSTY test demonstrated the underlying Kilopower reactor technology on the ground.
A reusable vehicle that moves other spacecraft between orbits — delivering satellites to their final orbit, boosting or de-orbiting them, and ferrying cargo — a workhorse of an in-space transport network.
Transferring propellant between spacecraft in orbit, so a vehicle can be refuelled rather than replaced. Refuelling a large in-space stage is central to plans for crewed missions to the Moon and Mars.
Cargo spacecraft that resupply stations and return payloads, increasingly designed to be reused. Commercial cargo vehicles routinely deliver supplies to the ISS, and reusable capsules now return and fly again.
The return of humans to the Moon and the build-out of a sustained presence — the Artemis crewed missions and the Gateway station in lunar orbit.
The next steps at Mars — returning the samples now being cached by Perseverance, studying the moons of Mars, and preparing for human missions.
A renaissance at Venus — a fleet of new missions to map its surface, sound its atmosphere, and understand why Earth's twin became a hell-world.
The search for habitable environments in the outer Solar System — the subsurface oceans of Europa and the seas and organic chemistry of Titan.
Future missions to asteroids and comets — for science and for planetary defence, including surveys to find the hazardous near-Earth objects before they find us.
The great observatories of the coming decades — surveying dark energy, imaging habitable worlds, and opening the low-frequency gravitational-wave and X-ray skies.
Reaching the least-explored worlds — an orbiter for an ice giant, and a probe designed to travel deliberately beyond the heliosphere into interstellar space.
The first crewed flight of NASA's Artemis program — a crew of four flying around the Moon and back aboard Orion, the first humans beyond low Earth orbit since 1972.
The mission intended to return humans to the surface of the Moon — the first crewed lunar landing since Apollo 17, targeting the water-ice-bearing south-polar region.
A NASA Discovery mission to drop a probe through the atmosphere of Venus, measuring its chemistry and origins layer by layer, and imaging the surface as it descends.
A NASA Discovery orbiter to map Venus in fine detail with radar — its topography, geology, and any active volcanism — revealing how the planet evolved so differently from Earth.
ESA's Venus orbiter, working alongside the NASA Venus missions to understand why Earth's near-twin became so inhospitable — studying the planet as a whole system.
A NASA New Frontiers rotorcraft that will fly across the dunes and impact craters of Saturn's moon Titan, sampling a world with a thick atmosphere and a rich organic chemistry.
A NASA infrared space telescope dedicated to planetary defence — hunting for the near-Earth objects that are hard to spot from the ground, to find hazards decades before any possible impact.
NASA's next flagship space telescope, recommended by the astronomy decadal survey — designed to directly image potentially habitable planets around other stars and search their atmospheres for signs of life.
ESA's next great X-ray observatory — designed to study the hot, energetic universe, from the gas that binds galaxy clusters to the black holes that shaped galaxies, at far higher sensitivity than today's X-ray telescopes.
A space-based gravitational-wave observatory — three spacecraft forming a giant laser interferometer to hear the low-frequency ripples in spacetime that ground detectors cannot, from the mergers of the largest black holes.
The flagship mission recommended to become the next great outer-planets endeavour — a first dedicated orbiter for an ice giant, to explore Uranus, its tilted magnetosphere, its rings, and its moons.
A concept for a purpose-built successor to the Voyagers — a spacecraft designed from the start to reach deep interstellar space and study the boundary between the Sun's influence and the galaxy beyond.
Measuring the precise positions and motions of the stars — parallax, proper motion, and the space astrometry that has mapped over a billion stars. The foundation on which distances across the galaxy are built.
Measuring how bright things are and resolving their fine detail — the magnitude system, precision photometry, and the interferometry and adaptive optics that sharpen the view.
Splitting light into its spectrum to read the composition, temperature, motion, and magnetic fields of distant objects — and classifying stars by what their spectra reveal.
How astronomers measure distances across the universe — a ladder from parallax to standard candles to redshift, each rung calibrating the next, reaching from nearby stars to the edge of the observable universe.
The techniques that find and weigh planets around other stars — from the tiny dimming of a transit to the wobble of radial velocity — most of them modelled already in the exoplanet encyclopedia.
Watching how things change with time — the oscillations that let us sound the interiors of the Sun and stars, the occultations that reveal sizes, and the study of the variable and transient sky.
Astronomy beyond light — the bending of light by gravity, the direct detection of gravitational waves and cosmic neutrinos, and the combined multi-messenger view of the most violent events.
How raw measurements become knowledge — deriving the properties of stars and galaxies, weighing black holes, mapping dark matter through rotation curves, and the calibration, error analysis, and honest uncertainty that make a measurement science.
The apparent shift of a nearby star against distant background stars as the Earth orbits the Sun. The size of that shift gives the star's distance by simple geometry — the first and most fundamental rung of the distance ladder.
The slow drift of a star across the sky over years, as it and the Sun move through the galaxy. Combined with radial velocity and distance, it yields a star's true motion through space.
Measuring stellar positions, distances, and motions from space at extraordinary precision. ESA's Hipparcos and then Gaia have charted more than a billion stars, transforming our three-dimensional map of the galaxy.
The precise measurement of the brightness of a star or galaxy, in one or more filters. Photometry over time reveals variable stars, transiting planets, and supernovae; photometry in different colours reveals temperature.
Astronomy's logarithmic, backwards brightness scale, in which smaller numbers are brighter. Apparent magnitude is how bright an object looks; absolute magnitude is how bright it truly is — and the difference gives its distance.
Combining the light of separate telescopes so they act as one much larger instrument, achieving resolution impossible for a single dish. Radio interferometry links antennas across continents; it produced the first images of black-hole shadows.
Deformable mirrors that flex hundreds of times a second to cancel the blurring of Earth's turbulent atmosphere, giving ground telescopes near space-quality sharpness.
Spreading light into its spectrum to read the fingerprints of the elements. Spectral lines reveal what an object is made of, how hot it is, how it moves (through the Doppler shift), and the strength of its magnetic fields — the single most powerful tool in astronomy.
Sorting stars by the lines in their spectra into the sequence O, B, A, F, G, K, M — a classification that turned out to be an ordering by temperature, and the basis of the Hertzsprung–Russell diagram.
Measuring the polarisation of light, which carries information no brightness or spectrum can — magnetic-field geometry, scattering by dust and grains, and the physics of everything from stellar surfaces to the cosmic microwave background.
Objects whose true brightness is known, so that how faint they appear gives their distance. Cepheid variables and Type Ia supernovae are the great standard candles that carry the distance ladder out into the universe.
Cepheid variable stars pulse with a period that depends on their true luminosity — Henrietta Leavitt's discovery. Measure the period, know the luminosity, and the apparent brightness gives the distance. Cepheids calibrated the scale of the galaxy and beyond.
For distant galaxies, the expansion of the universe stretches their light to longer, redder wavelengths in proportion to their distance. Measure the redshift, apply the Hubble–Lemaître law, and you have the distance — the top rung of the ladder.
The chain of methods, each calibrating the next, that measures the universe: geometric parallax for nearby stars, standard candles for nearby galaxies, and redshift for the far reaches. The mismatch between its rungs is at the heart of today's Hubble tension.
Reading the Sun's interior from the oscillations that ripple across its surface, as seismologists read the Earth from earthquakes. Helioseismology has mapped the Sun's internal rotation and the depth of its convection zone.
Applying the same idea to other stars — measuring their tiny brightness oscillations to determine their internal structure, mass, radius, and age. Space photometry from Kepler and TESS turned it into a precision tool.
Watching a star wink out as a foreground body passes in front of it. The timing reveals the size and shape of asteroids, the rings of the giant planets, and the atmospheres of distant worlds — even Pluto's.
Gravity bends light, so massive foreground objects magnify and distort background ones — strongly, into arcs and multiple images, or weakly, subtly shearing distant galaxies. Lensing weighs matter directly, mapping dark matter that emits no light.
Detecting the minute stretching and squeezing of space as gravitational waves pass, using kilometre-scale laser interferometers. Since 2015, detectors have heard the mergers of black holes and neutron stars, opening a new sense for astronomy.
Catching the ghostly neutrinos that stream from the Sun, from supernovae, and from the most energetic events in the universe. Neutrinos pass through matter almost untouched, carrying information from places light cannot escape.
Combining light, gravitational waves, neutrinos, and cosmic rays from the same event to learn what no single messenger could tell. The 2017 neutron-star merger, seen in gravitational waves and across the spectrum, was its landmark.
Mapping the faint microwave afterglow of the Big Bang and its minute temperature and polarisation ripples. Their statistics — including the baryon acoustic oscillations frozen into them — pin down the composition, geometry, and age of the universe.
How the measurable — brightness, colour, spectrum, motion — becomes the physical: a star's temperature, luminosity, mass, radius, chemical composition (metallicity), and age, mostly inferred through models rather than measured directly.
Measuring how fast a galaxy rotates at each radius, usually from the Doppler shift of its gas. The stars orbit far faster than the visible matter can explain — the classic evidence that galaxies are embedded in halos of dark matter.
Weighing a black hole by the motion of what orbits it — stars near the galactic centre, gas in a disk, or the gravitational waves of a merger. The masses range from a few Suns to billions.
The discipline that makes a number science: calibrating instruments against known standards, tying measurements to common reference frames, propagating uncertainties, and stating the statistical confidence of a result. In astronomy, a measurement without an error bar is not a measurement.
The thermonuclear detonation of a white dwarf that has been pushed over a critical mass. Their remarkably uniform peak brightness makes them the standard candles that measured the accelerating expansion of the universe.
The catastrophic collapse of the core of a massive star, which rebounds into an explosion and leaves a neutron star or black hole. Most of the energy escapes as neutrinos — first detected from SN 1987A — making these among the earliest multi-messenger sources.
An exceptionally energetic core-collapse explosion of a very massive star, releasing far more kinetic energy than an ordinary supernova. Hypernovae from rapidly-rotating collapsars are thought to power the long gamma-ray bursts.
A thermonuclear runaway on the surface of a white dwarf that is accreting matter from a companion star. Unlike a supernova, the white dwarf survives, and the outburst can recur.
The most luminous electromagnetic events in the universe — brief, intense flashes of gamma rays. Long bursts come from the collapse of massive stars; short bursts from the mergers of neutron stars. Each is followed by a fading multi-wavelength afterglow.
Sudden, intense bursts of gamma and X-rays from magnetars — neutron stars with the strongest magnetic fields known. Their giant flares are so bright they can be detected across the galaxy, and are now linked to some fast radio bursts.
The optical and infrared glow that follows the merger of two neutron stars, powered by the radioactive decay of the heavy elements forged in the merger. The 2017 event GW170817, seen in gravitational waves and light, was the landmark of multi-messenger astronomy.
The inspiral and merger of two compact objects — black holes or neutron stars — radiating a chirp of gravitational waves. Since 2015 these have been heard routinely; neutron-star mergers also shine as kilonovae.
The flare produced when a star wanders too close to a supermassive black hole and is torn apart by tides, some of its debris blazing as it falls in. TDEs light up otherwise-quiet galactic nuclei for months.
Millisecond flashes of radio waves from far across the universe, immensely energetic for their brevity. At least some come from magnetars; most are one-off, though a few repeat. Their dispersion probes the matter between the galaxies.
A close binary in which a white dwarf accretes matter from a companion through a disk, producing recurrent outbursts as the disk brightens — the dwarf novae and related variables of the time-domain sky.
Stars whose brightness changes irregularly through eruptions and flares — from the giant eruptions of luminous blue variables to the flares of young and magnetically-active stars.
NASA's network for the rapid distribution of alerts about transient events — gamma-ray bursts, gravitational-wave triggers, and neutrino detections — so that telescopes around the world can slew to a fresh event within seconds.
The Virtual Observatory's standard machine-readable format for reporting a transient celestial event — what, where, when, and how confident — so that alerts flow automatically between observatories, brokers, and robotic telescopes.
The official IAU registry that assigns the discovery names of supernovae and other transients, and collects the reports and classifications that establish who found what, and when.
A short-notice publication service for rapidly announcing and commenting on new astronomical observations, widely used to share follow-up of transients within hours.
The torrent of alerts the Vera C. Rubin Observatory will issue — millions per night — as it scans the whole southern sky every few nights, feeding community brokers that filter the deluge into the events worth chasing.
A wide-field survey images the sky repeatedly and flags anything that has changed — a new point of light, or one that has brightened or moved. The candidate is issued as an alert within seconds.
Other telescopes turn to the candidate to gather more data — deeper images, colours, and the first spectra — often within minutes to hours, before a fast-fading event disappears.
The candidate is verified as a real astrophysical transient — not an instrument artefact, asteroid, or known variable — and registered with an official discovery name.
A spectrum reveals what the transient is — the type of supernova, the redshift of a burst, the nature of the source — placing it in its class and distance.
The result is shared with the community and the scientific record — as a rapid telegram, a circular, and ultimately a peer-reviewed paper — so that the event contributes to the wider science.
A flattened, rotating disk of stars, gas, and dust wound into spiral arms, with a central bulge. The arms are where new stars form, tracing waves of star formation sweeping through the disk.
A spiral galaxy whose arms wind out from the ends of a straight bar of stars crossing the centre. The bar channels gas inward, feeding star formation and the central black hole. The Milky Way is one.
A smooth, featureless ellipsoid of mostly old stars, with little gas and little ongoing star formation. The largest ellipticals sit at the centres of galaxy clusters and are thought to be built by mergers.
A disk galaxy with a prominent bulge but no spiral arms — a transitional form between spirals and ellipticals, with an old stellar population and little cold gas left to form stars.
A galaxy with no regular spiral or elliptical structure, often small and gas-rich with vigorous star formation. Many are shaped by the gravitational pull of larger neighbours, like the Magellanic Clouds beside the Milky Way.
A galaxy with a bright ring of stars and gas around a comparatively empty centre, usually formed when a smaller galaxy plunges through the disk of a larger one, sending a wave of star formation outward.
A small galaxy with far fewer stars than a giant like the Milky Way. Dwarfs are by far the most numerous galaxies, and many orbit larger ones as satellites; they are dominated by dark matter.
A galaxy distorted from any regular form — by a close encounter, an ongoing merger, or an active nucleus. The tidal tails and bridges of interacting pairs, like the Antennae, are the clearest signs of galaxies in collision.
A spiral galaxy with a bright, compact active nucleus whose spectrum shows broad or narrow emission lines from gas swirling near the central black hole — a relatively low-luminosity active galactic nucleus in an otherwise normal-looking galaxy.
A galactic nucleus whose spectrum is dominated by emission from weakly-ionized gas. LINERs are the most common type of active nucleus, though whether they are all powered by a black hole or partly by hot old stars is still debated.
A galaxy — usually a giant elliptical — that pours enormous energy into twin jets and lobes of radio-emitting plasma, launched by its central black hole and reaching far beyond the visible galaxy. Centaurus A is the nearest.
A blazar seen looking almost straight down its jet, so its light is dominated by the rapidly-variable, featureless glow of the jet itself rather than by emission lines — one of the most extreme, fast-varying kinds of active nucleus.
The framework that the many types of active galactic nucleus — Seyferts, quasars, radio galaxies, blazars — are largely the same underlying object, a supermassive black hole accreting through a disk and torus, seen from different angles and at different luminosities. A model that explains the types, rather than a type itself.
How galaxies grow and change over cosmic time — assembling from smaller pieces, forming stars, exhausting or losing their gas, and transforming from blue, star-forming disks into red, quiescent ellipticals.
The collision and coalescence of two galaxies. Mergers trigger bursts of star formation, funnel gas to the central black hole, and can turn two spirals into a single elliptical — a driving force of galaxy evolution.
The gravitational give-and-take of galaxies passing close without fully merging — drawing out tidal tails and bridges, triggering star formation, and, in a direct hit, punching out a ring galaxy.
The way an active central black hole regulates its galaxy — its winds and jets heating and expelling gas, quenching star formation, and explaining the tight link between a galaxy's black-hole mass and its bulge.
A phase of exceptionally intense star formation, forming stars far faster than a galaxy can sustain — often triggered by a merger or interaction and driving powerful galactic winds. M82 is the archetype.
The shutdown of star formation in a galaxy, as it loses or is stripped of its cold gas, or has it heated by feedback — leaving a red, passively-evolving elliptical or lenticular of ageing stars.
The gravitationally-bound group of galaxies the Milky Way belongs to — dominated by the Milky Way and Andromeda, with the Triangulum galaxy and dozens of dwarfs. Andromeda and the Milky Way are approaching, and will merge in a few billion years.
The nearest large galaxy cluster, over a thousand galaxies bound together and centred on the giant elliptical M87. Its gravity draws the Local Group toward it, and it anchors our corner of the local supercluster.
A rich, dense cluster of over a thousand galaxies. In 1933 Fritz Zwicky found its galaxies moving far too fast to be held together by their visible mass — the first evidence for dark matter.
The vast supercluster the Milky Way belongs to, defined in 2014 by the flows of galaxies toward a common gravitational focus. It contains around a hundred thousand galaxies across half a billion light-years.
One of the largest known structures in the universe — an immense wall of galaxies stretching over a billion light-years, mapped by the Sloan Digital Sky Survey, part of the filamentary cosmic web.
One of the largest known voids — an enormous, nearly-empty region of space containing very few galaxies, a vast bubble between the filaments and walls of the cosmic web.
The study of how life began — the chemistry that turned simple molecules into self-replicating systems on the early Earth, and whether the same steps could happen elsewhere. A question that frames the entire search for life beyond Earth.
What makes a world able to host life — liquid water, an energy source, the chemical building blocks, and a stable enough environment for long enough. Habitability is judged by these factors, not by any detection of life.
The search for signs of life — atmospheric gases, surface features, and chemical patterns that life could produce — and the rigorous work of telling a true biosignature from a false positive made by non-living processes.
The search for signs of technology — radio and optical signals, and other technosignatures — carried out by the SETI Institute and programs like Breakthrough Listen. A search for intelligence, distinct from the search for microbial life.
The icy moons with liquid-water oceans beneath their shells — Europa, Enceladus, and Titan — now the most promising places to search for life in the Solar System, targets of the Europa Clipper and Dragonfly missions.
The discipline of preventing contamination — protecting other worlds from Earth microbes carried by spacecraft (forward contamination), and protecting Earth from any material returned from them (backward contamination), so the search for life is not fooled and no harm is done.
Gases in a planet's atmosphere that life could produce and maintain — especially a chemical disequilibrium, like oxygen and methane together, that non-living chemistry would quickly erase. Detected by the spectroscopy of a planet's light.
Signs of life on a surface — pigments, the 'red edge' reflectance of vegetation, or patterns and textures a biosphere leaves behind — sought both on exoplanets and on the surface of Mars.
Chemical fingerprints of life in rock or ice — the isotopic ratios life prefers, the handedness (chirality) of its molecules, and specific organic byproducts — the kind of evidence the Perseverance rover seeks and caches on Mars.
Structures preserved in rock that life can build — layered stromatolites, biominerals, and microfossils. Perseverance is exploring an ancient Martian river delta where such signs might be preserved.
A sign not of life but of technology — a radio or optical signal, an artificial light, an industrial pollutant, or a megastructure. The search for technosignatures is the search for intelligence, led by SETI and Breakthrough Listen.
A signal that mimics life but is made by non-living processes — abiotic oxygen from water splitting, geological methane, or a mis-measured spectral feature. Ruling out false positives is the hardest and most important part of any claim of life; the Venus phosphine debate is a recent lesson.
The one requirement every known form of life shares — a liquid solvent for its chemistry. The habitable zone is defined by where a planet could hold liquid water on its surface, but subsurface oceans extend the possibilities far beyond it.
Life needs a source of energy to drive its chemistry — sunlight for photosynthesis, or chemical and thermal energy where the Sun cannot reach. Tidal heating warms the interiors of the icy moons, powering hydrothermal vents like those that may nourish life on Earth.
The elements and molecules life is built from — carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur, and complex organic chemistry. Titan has a rich organic chemistry, and Enceladus's plumes carry organic molecules from its ocean.
Earth organisms that thrive in extremes — searing vents, acid, salt, cold, and intense radiation — that once seemed impossible for life. They vastly widen where life might survive, and are the closest analogs for what an ocean-world biosphere might be.
A layer of liquid water beneath an icy shell, kept warm by tidal heating and in contact with a rocky seafloor. Europa and Enceladus have them; they are the leading places to look for life beyond Earth, and the target of the Europa Clipper mission.
The risk of carrying Earth microbes to another world on a spacecraft, which could harm any native biosphere or, worse, be mistaken for alien life. Missions to Mars and the ocean worlds are cleaned and sterilised to strict standards to prevent it.
The risk of bringing potentially hazardous material back to Earth in a returned sample. Sample-return missions are designed to contain their cargo as strictly as the most dangerous pathogens, so nothing escapes before it is shown to be safe.
The careful containment, quarantine, and curation of returned samples in specialised facilities — keeping them pristine for science while keeping Earth safe, and preserving them for study by instruments not yet invented.
Dedicated survey telescopes scan the sky night after night for moving points of light — the near-Earth asteroids and comets. Catalina, Pan-STARRS, and ATLAS lead the search from the ground, and the Rubin Observatory will transform it.
A newly-found object's observations are reported to the Minor Planet Center, which links them into a single orbit. The more observations over a longer arc, the more precisely the future path is known.
Determining what an object is — its size, shape, spin, and composition — from light curves, radar, spectra, and, for a few, spacecraft visits. Hera is en route to survey the asteroid DART struck, to learn how a deflection actually worked.
Automatic systems at CNEOS and ESA continuously propagate every known orbit forward for a century or more, flagging any that could approach Earth. Apophis was tracked this way until observations ruled out an impact for the next century.
Judging how serious a possible impact is — its probability, the object's size and energy, and the time until the encounter — and expressing it on the Torino and Palermo scales so the risk can be understood and compared.
Explaining a risk to decision-makers and the public accurately and without alarm — including retracting a warning when better data clears an object, as happened with Apophis. Clear communication is itself part of planetary defence.
If an object were found on a collision course with enough warning, agencies and governments would decide on a response — and plan the reconnaissance and deflection mission it would require. NEO Surveyor is being built to give that warning decades ahead.
The last stage — actually changing an asteroid's orbit so it misses the Earth. DART showed a kinetic impactor works; a gravity tractor, ion beam, or, as a last resort, a nuclear device are other options, chosen by how much warning time is available.
A 0–10 scale, like a hazard traffic light, for communicating the risk of a near-Earth object to the public — combining impact probability and energy into a single colour-coded number. Apophis briefly reached level 4, the highest ever, before further observations returned it to zero.
A more technical, logarithmic scale used by specialists to rank impact hazards against the background risk of a random impact of the same size over the same time. Values below zero mean a threat less than the everyday background; above zero warrants attention.
Crashing a spacecraft into an asteroid at high speed to nudge its orbit — and getting an extra push from the plume of debris thrown off. NASA's DART did exactly this to the moonlet Dimorphos in 2022, measurably shortening its orbit; ESA's Hera is on its way to study the result up close, arriving in late 2026.
A spacecraft that hovers near an asteroid for years, its own tiny gravity slowly towing the asteroid onto a new path. Very slow, but precise and controllable — best used with decades of warning, and often after a kinetic impact to fine-tune the result.
A spacecraft that points a stream of ions at an asteroid, the gentle continuous thrust pushing it aside over a long time — a slow, controllable method related to the gravity tractor, still at the concept stage.
Detonating a nuclear device near an asteroid — not to blow it apart, but to vaporise a layer of its surface, the escaping material shoving it onto a new course. Studied only as a last resort for the largest objects or the shortest warning times; it has never been tested and remains theoretical.
NASA's archive for the data of its optical, ultraviolet, and near-infrared space telescopes — Hubble, JWST, TESS, Kepler, and more — operated by the Space Telescope Science Institute. One of the most-used archives in astronomy.
ESA's science-data archives, hosted at the European Space Astronomy Centre, holding the observations of Europe's astronomy and planetary missions — from Gaia and XMM-Newton to Mars Express and Euclid.
NASA's archive for infrared and submillimetre astronomy — the data of Spitzer, WISE, 2MASS, and Herschel among others — operated by IPAC at Caltech.
NASA's archive for high-energy astrophysics — the X-ray and gamma-ray data of missions like Chandra, Swift, and Fermi — a central resource for the study of the most energetic objects in the universe.
A database that gathers everything known about objects beyond the Milky Way — positions, redshifts, images, and the literature — cross-linking millions of galaxies and quasars across all the surveys that have observed them.
The Strasbourg astronomical Data Centre, a cornerstone of open astronomy that operates the SIMBAD and VizieR services and helped build the Virtual Observatory, tying the world's catalogues and object databases together.
A database of astronomical objects beyond the Solar System, collecting the names, identifiers, measurements, and references for millions of stars and galaxies so that any object can be looked up and cross-identified across the literature.
The most complete library of published astronomical catalogues, letting anyone query tens of thousands of catalogues and data tables in a uniform way — the reference source for catalogue data.
The archive of the European Southern Observatory, holding the data of its ground-based telescopes in Chile — the Very Large Telescope and its partners — for reuse by astronomers worldwide.
The archive of the Atacama Large Millimeter/submillimeter Array, the great international millimetre-wave observatory, preserving its observations of cold gas, dust, and the discs where planets form.
The universal file format of astronomy — a self-describing container for images, tables, and spectra with a human-readable header of metadata. In use since the 1980s and still the standard way astronomical data is stored and shared.
The Virtual Observatory's XML standard for exchanging tabular data — catalogues and query results — between archives, tools, and services, so tables flow between systems without custom parsing.
A modern, human-readable data format developed by the astronomy community as a successor to FITS for complex data — used by the James Webb Space Telescope for its calibration and world-coordinate metadata and adopted as the primary data format of the Roman mission.
The framework of standards, coordinated by the International Virtual Observatory Alliance, that lets the world's archives be searched and combined as if they were one — so an astronomer can query every telescope's data at once. TAP, Cone Search, VOEvent, and VOTable are among its standards.
A Virtual Observatory protocol for running database queries against an archive's catalogues over the web, returning the results as VOTables — the standard way to ask an archive a precise question about its tables.
The simplest Virtual Observatory query — 'give me every object within this radius of this position' — a standard that any catalogue service can answer, used constantly to find what is known around a point on the sky.
A Virtual Observatory protocol for finding and retrieving images of a region of sky from an archive, regardless of which telescope took them — the image counterpart of the cone search.
A Virtual Observatory protocol for finding and retrieving spectra of a target from an archive, bringing the spectroscopy of many instruments into a single uniform search.
The automated processing that turns raw telescope readouts into calibrated, science-ready data — removing instrument signatures, correcting for the atmosphere or detector, and attaching the metadata and error estimates that make the data usable by anyone.
Identifying the same object across different catalogues and wavelengths — matching a source in an infrared survey to its optical and X-ray counterparts — so that all that is known about an object can be brought together despite different names and positions.
NASA's Astrophysics Data System, the digital library of astronomy — indexing essentially the entire research literature and linking every paper to the data, catalogues, and objects it uses, so the literature and the data are one connected web.
The stable, unique names that make science findable and creditable — DOIs for datasets and papers, ORCID iDs for researchers, and bibcodes for the literature — so a result can be cited, retrieved, and attributed unambiguously years later.
The principles that make science trustworthy and reusable — data that is Findable, Accessible, Interoperable, and Reusable (FAIR), open archives, documented pipelines, and citable datasets — so that a result can be checked and built upon by anyone.
A next-generation optical and near-infrared telescope under construction at Las Campanas Observatory in Chile, using seven 8.4-metre mirror segments to form a single light-collecting surface with a resolving power far beyond today's largest telescopes. One of the extremely large telescopes of the coming decade, alongside the ELT and TMT.
A proposed radio interferometer, designed as the successor to the Very Large Array and a complement to ALMA, that would observe the centimetre-to-millimetre sky with far greater sensitivity and resolution — imaging planet-forming discs, molecular gas, and the distant universe. Led by the U.S. National Radio Astronomy Observatory.
The next-generation ground-based observatory for very-high-energy gamma rays, an array of imaging atmospheric Cherenkov telescopes being built across two sites — one in the northern hemisphere on La Palma and one in the southern hemisphere in Chile — to catch the faint blue flashes that gamma rays make in the atmosphere. The largest such observatory ever built.
An artificial star created by shining a laser into the upper atmosphere, exciting sodium atoms ~90 km up to glow. It gives adaptive optics a bright reference point anywhere on the sky — not just near a real bright star — so the shape of the atmosphere's blur can be measured and corrected.
The eye of an adaptive-optics system — it measures, hundreds or thousands of times a second, exactly how the atmosphere has distorted the incoming light, so a correction can be computed and applied. Common designs are the Shack–Hartmann and pyramid sensors.
A thin mirror whose surface is reshaped hundreds or thousands of times a second by an array of actuators, cancelling the distortion the atmosphere imposes on starlight in real time. The active heart of adaptive optics — the ELT's M4 is one of the largest ever built.
A high-resolution spectrograph that uses a coarse, steeply-ruled grating (an échelle) to spread light into many overlapping orders, then a second disperser to separate them — packing very high spectral resolution onto a single detector. The workhorse of precision radial-velocity and stellar-abundance work; HIRES is a classic example.
A spectrograph that records a full spectrum at every point in a two-dimensional field of view at once, producing a 'data cube' of the sky — an image where every pixel is a spectrum. It maps how motion and composition vary across a galaxy or nebula in a single exposure; MUSE on the VLT is a leading example.
An instrument that blocks the overwhelming light of a star so the far fainter objects beside it — a planet, a disc, the solar corona — can be seen. First built by Bernard Lyot to study the Sun, it is now central to directly imaging exoplanets; SPHERE on the VLT is a modern example.
A concept for blocking a star's light not inside the instrument but far in front of the telescope — a large, precisely-shaped screen flown tens of thousands of kilometres away, casting a deep shadow so an orbiting planet stands clear. A proposed external alternative to the coronagraph for future exoplanet-imaging missions.
The charge-coupled device, the detector that transformed optical astronomy — a silicon chip that converts light into electric charge with high efficiency and low noise, read out pixel by pixel. It replaced photographic plates and remains the standard optical detector; Rubin's camera is built from a mosaic of them.
A detector in which each pixel has its own amplifier, allowing very fast, low-power readout. Increasingly used in astronomy for high-speed imaging and for techniques that need many frames per second, and ubiquitous in consumer cameras.
A superconducting detector that records not just the arrival of a photon but its energy and precise time, with no read noise. Operating at temperatures near absolute zero, MKIDs are a frontier technology for the millimetre, submillimetre, and optical sky, and scale to large arrays.
A detector that measures light by the tiny rise in temperature it causes in an absorbing element — the standard way to detect the faint millimetre and submillimetre sky, including the cosmic microwave background. Cooled to a fraction of a degree above absolute zero; the South Pole Telescope's cameras use large bolometer arrays.
The broad family of detectors that must be cooled to cryogenic temperatures — sometimes thousandths of a degree above absolute zero — so that thermal noise does not swamp the faint astronomical signal. Bolometers and MKIDs are cryogenic detectors; the technique is essential across the infrared, millimetre, and X-ray.
Linking many radio dishes so that they act together as one telescope as large as their separation, giving radio astronomy its sharpest images. Arrays like the VLA and ALMA correlate the signals from every pair of antennas to reconstruct the sky.
The technique, developed by Martin Ryle, of building up an image from an interferometer by combining measurements taken as the Earth's rotation carries the antennas to different orientations — synthesising the resolution of a single huge aperture from many small ones. The basis of modern radio imaging.
Radio interferometry stretched across continents — antennas thousands of kilometres apart record the sky independently with precise atomic clocks, and the data are combined later. It achieves the finest angular resolution in all of astronomy; a global VLBI network imaged the shadow of a black hole.
Combining the light of separate optical or infrared telescopes to reach angular resolutions no single telescope could — far harder than in the radio because the light waves must be kept in step to a fraction of their wavelength. The VLT's four unit telescopes can be combined this way.
Taking a rapid burst of very short exposures and keeping only the few sharpest — the lucky moments when the atmosphere happens to be still — then combining them. A simple way to reach near-diffraction-limited resolution on modest telescopes without full adaptive optics.
Recovering fine detail from the fleeting speckle pattern that the atmosphere breaks a star's image into, by taking many very short exposures and reconstructing the true image statistically. It resolves close double stars and fine structure below the atmospheric blur.
Combining many exposures of the same field to build up signal and average down noise, reaching far fainter objects than any single frame — the foundation of deep imaging, from amateur astrophotography to the deepest survey fields.
The real-time control that keeps the interference fringes of an optical interferometer stable against the atmosphere's constantly-changing path lengths, so faint targets can be observed for longer. Without it, the fringes wash out in a fraction of a second.
Old, pulsating horizontal-branch stars with a well-defined luminosity, especially tight when measured in the infrared. Abundant in globular clusters and the haloes of galaxies, they are a standard candle for old stellar populations and, like the Cepheids, are calibrated directly by parallax.
The sharp, near-constant peak brightness that red giant stars reach just before the helium flash — a robust standard candle that can be measured in a galaxy's halo, away from crowding and dust. It provides an independent route to calibrating Type Ia supernovae, and its Hubble-constant value sits between the Cepheid and CMB results.
A distance method that uses the graininess of a galaxy's light: because a nearer galaxy resolves into fewer, brighter patches of unresolved stars per pixel, the amount of pixel-to-pixel fluctuation measures distance. Best suited to smooth elliptical galaxies and the bulges of spirals.
An empirical relation for spiral galaxies between how fast they rotate and how luminous they are — the faster the rotation, the brighter the galaxy. Measuring the rotation (from the width of the 21-cm line) then gives the luminosity, and comparing with the apparent brightness gives the distance.
The elliptical-galaxy counterpart of the Tully–Fisher relation: a link between a galaxy's luminosity and the velocity dispersion of its stars. It is one projection of the tighter Fundamental Plane of elliptical galaxies, which is used as a distance indicator.
A direct, geometric distance measured from water masers orbiting in the accretion disc around a galaxy's central black hole. By tracking their motion and acceleration, the physical size of the disc is found and compared with its angular size — a one-step distance that anchors the ladder without relying on standard candles.
Gravitational-wave sources whose distance can be read directly from the shape of the waveform, with no calibration ladder at all — the gravitational analogue of a standard candle. A merging neutron-star pair with an electromagnetic counterpart yielded the first standard-siren measurement of the Hubble constant.
The fraction of the universe's total energy density that is in matter — dark matter plus ordinary baryonic matter — today. Together with the dark-energy density it sets the geometry and the fate of the universe; it is measured most precisely from the cosmic microwave background.
The fraction of the universe's total energy density carried by dark energy — the component driving the accelerating expansion. In the standard model it is the cosmological constant Λ, and it makes up the majority of the present-day energy budget.
A measure of how clumpy the universe is — the amplitude of matter-density fluctuations averaged over spheres of 8 megaparsecs. It links the smooth early universe to today's web of galaxies, and a mild disagreement between its early-universe and weak-lensing determinations — usually quantified through the related combination S8 — is known as the S8 tension.
The 'tilt' of the spectrum of primordial density fluctuations laid down by inflation — whether fluctuations have slightly more or less power on large scales than on small. A value just below one is a key prediction of, and constraint on, inflationary models, and is measured from the CMB.
The programme that measures the Hubble constant from the local distance ladder — anchoring Cepheids with parallax, using them to calibrate Type Ia supernovae, and reading the expansion rate from supernovae in the smooth Hubble flow. Its value comes out consistently higher than the one inferred from the early universe, and that gap is the Hubble tension.
A proposed but unconfirmed resolution of the Hubble tension in which a small, transient dark-energy-like component acts in the early universe around the time of recombination, shrinking the sound horizon and so raising the Hubble constant inferred from the CMB toward the local value. It is one of several competing ideas — alongside extra relativistic species and modified gravity — and none is yet established.
The roughly eleven-year rise and fall of the Sun's activity, traced by the number of sunspots from solar minimum to solar maximum and back. Its underlying magnetic cycle takes about twenty-two years, as the Sun's polarity flips and returns. Activity — flares, CMEs, and storms — peaks near solar maximum.
Dark, cooler patches on the Sun's visible surface where intense magnetic fields suppress the flow of heat from below. Their number rises and falls with the solar cycle, and they mark the magnetically active regions from which flares and CMEs erupt.
Areas of strong, complex magnetic field on the Sun, usually marked by sunspots, where magnetic energy builds up and is released. Active regions are the launch sites of the largest solar flares and coronal mass ejections, and are watched closely for space-weather forecasting.
Regions of the Sun's corona where the magnetic field opens out into space rather than looping back, appearing dark in X-ray and ultraviolet images. They are the source of the fast solar wind, and the high-speed streams they send out drive recurring geomagnetic activity.
The ionised layer of Earth's upper atmosphere, created by solar ultraviolet and X-ray radiation. It reflects and refracts radio waves — enabling long-distance HF communication — but solar flares and geomagnetic storms disturb it, causing radio blackouts and errors in satellite navigation.
Spacecraft are exposed to the full force of space weather: energetic particles charge their surfaces and interiors and flip bits in their electronics, while geomagnetic storms heat and expand the upper atmosphere, increasing drag and pulling low-orbit satellites down faster.
Satellite navigation signals pass through the ionosphere, and when solar flares and geomagnetic storms disturb it the signals are delayed and scattered, degrading positioning accuracy — a serious concern for aviation, surveying, and precision agriculture.
Aircraft on polar routes can lose high-frequency radio contact during solar radio blackouts and are exposed to raised radiation levels during solar particle events, sometimes forcing flights to divert to lower latitudes.
Radiation is one of the central hazards of human spaceflight. A large solar particle event can deliver a dangerous dose to astronauts, especially beyond the protection of Earth's magnetic field, and crews may need to shelter in more shielded parts of a spacecraft.
Geomagnetic storms drive currents in the ground that flow into long transmission lines — geomagnetically induced currents — which can saturate and damage transformers and, in severe cases, cause regional blackouts. The 1989 Québec blackout is the classic example.
The X-rays from a solar flare suddenly increase the ionisation of the day-side ionosphere, absorbing high-frequency radio waves and causing radio blackouts across the sunlit Earth — the effect measured by NOAA's R-scale.
The operational space-weather arm of the European Space Agency's Space Safety programme, delivering forecasts, warnings, and data products — on solar activity, the near-Earth environment, and the ionosphere — to European operators of satellites, power grids, aviation, and navigation. The European counterpart to NOAA's Space Weather Prediction Center.
Assigning objects to discrete categories from their measured features — star or galaxy, supernova type, real detection or artefact. It is the workhorse of survey astronomy, sorting the millions of objects a modern survey finds into kinds a human never could review one by one.
Predicting a continuous quantity from an object's features — a galaxy's redshift, a star's temperature or age — rather than a discrete label. Regression turns cheap, plentiful measurements into estimates of quantities that would otherwise need expensive follow-up.
Grouping objects by similarity without being told the categories in advance — letting the structure in the data reveal itself. It is used to find natural classes of objects and to organise catalogues too large to label by hand.
Learning a compact, informative summary — an 'embedding' — of a complex object like an image or a light curve, so that similar objects sit near each other. Good representations make every downstream task, from classification to search, easier and more accurate.
Training a model on unlabelled data by inventing a task it can grade itself on — predicting a hidden part of an image, or telling two views of the same object apart. It is powerful in astronomy, where raw data is abundant but expert labels are scarce.
Large models pre-trained on broad data that can then be adapted to many specific tasks with little extra training. In astronomy they are an emerging approach to building a single model that understands images, spectra, or light curves across many problems at once.
Finding the rare objects that do not fit any known pattern — the outliers that may be the next new class of transient or a genuinely unexpected discovery. As surveys outgrow human inspection, anomaly detection is how the strangest objects get noticed at all.
Sorting galaxies by their shape — spiral, elliptical, irregular, merging — from survey images. One of the earliest large-scale meetings of astronomy and machine learning, building on the labels gathered by citizen-science projects like Galaxy Zoo to train automatic classifiers for surveys too large to inspect by eye.
Deciding what kind of exploding star a transient is — often from its light curve alone, before or without a spectrum. Fast, automatic classification is essential when a survey finds thousands of supernovae a night and only a few can be followed up in detail.
Estimating how far away a galaxy is from its brightness in a few broad colour bands, without taking a full spectrum. It is far less precise than a spectroscopic redshift but can be done for the hundreds of millions of galaxies in an imaging survey, underpinning weak-lensing and large-scale-structure cosmology.
Picking the tiny, periodic dips of an exoplanet transit out of a noisy stellar light curve — and telling a real planet from the many kinds of false positive. Machine learning now helps sift the enormous light-curve archives of transit surveys for the faintest candidates.
Searching survey images for the rare, distinctive arcs and rings of strong gravitational lensing — where a foreground mass bends the light of a background galaxy. The lenses are rare enough, and the images numerous enough, that automated finders are the only way to build large samples.
Finding and measuring the individual stars and galaxies in an astronomical image, and separating real sources from noise and artefacts — the first step of nearly every imaging pipeline. Machine-learning methods increasingly complement the classical algorithms, especially in crowded or blended fields.
Classifying the flood of alerts that a survey like Rubin issues — millions each night when something on the sky changes — quickly enough to catch the fleeting events worth following up. It is the problem the community alert brokers exist to solve.
The labelled examples a model learns from. Their size, coverage, and biases largely determine how well a model works and where it fails — a classifier only knows the kinds of object it was shown, and inherits any selection effects in how those examples were gathered.
Standard, shared datasets on which different methods are compared on equal footing — like the Galaxy Zoo morphology labels or the PLAsTiCC transient-classification challenge. They let the field measure real progress rather than incomparable claims.
Turning raw data into the informative quantities a model uses — statistics of a light curve, cut-outs around a source, colours from photometry. Well-chosen features can make a simple model succeed; increasingly, representation learning discovers them automatically.
Measuring honestly how well a model performs — its accuracy, completeness, and purity, whether its confidences are calibrated, and how it behaves on data unlike its training set. Careful evaluation is what separates a genuinely useful model from one that has merely memorised its examples.
A community alert broker, led from Chile, that ingests a survey's alert stream and classifies its transients and variable objects in real time with machine learning — first for the Zwicky Transient Facility and, in the era ahead, for Rubin.
NOIRLab's alert broker for time-domain astronomy, which filters and annotates survey alert streams to surface the events most worth following up. One of the community brokers selected to process the full Rubin alert stream.
A community alert broker built to process the alert streams of ZTF and Rubin, adding machine-learning classifications and value-added information so that astronomers can select the transients and variables they care about from millions of nightly alerts.
A UK-led community alert broker for the ZTF and Rubin alert streams, letting astronomers query, filter, and cross-match the live stream of changing objects on the sky.
The largest platform for people-powered research, where hundreds of thousands of volunteers help classify and analyse data across astronomy and many other sciences. It grew out of Galaxy Zoo and now hosts dozens of projects that turn human pattern-recognition into published results.
The project that asked the public to sort galaxies by shape from survey images — and found volunteers could do it as well as experts, at enormous scale. Its classifications became a landmark dataset and the training labels for the machine-learning classifiers that followed.
A project inviting the public to search stellar light curves for the tiny dips of a transiting planet — finding candidates, including unusual ones, that automated pipelines had missed. A demonstration that human eyes still catch things algorithms overlook.
A worldwide campaign to measure light pollution by having people compare the faintest stars they can see — often in Orion — against a set of star charts, and report what they see. The result is a global, year-on-year map of the brightening night sky.
A project that crowdsources real-time reports and photographs of the aurora from the public, improving where and when auroral displays are forecast — turning sky-watchers into a distributed sensor network for space weather.
A project in which volunteers scanned microscope images of the aerogel flown on NASA's Stardust mission, hunting for the microscopic tracks of interstellar dust grains — a needle-in-a-haystack search that distributed human attention could solve.
Watching the night sky from home with the naked eye, binoculars, or a small telescope — learning the constellations, following the Moon and planets, and hunting bright deep-sky objects. The foundation of the hobby, and where almost every astronomer begins.
Monitoring stars that change in brightness and reporting careful estimates over months and years. Coordinated by organisations like the AAVSO, amateur variable-star observers build long-term light curves that professionals rely on — one of the clearest cases of amateurs doing lasting science.
Measuring the positions and brightness of asteroids, and timing the moments they pass in front of stars. From these occultation timings, amateurs reconstruct asteroid shapes and sizes to a precision that rivals spacecraft flybys.
Following comets as they brighten, grow tails, and fade — estimating their brightness and sketching or photographing their changing structure. Amateurs have a long tradition of discovering comets, and their brightness estimates track how these unpredictable visitors evolve.
Precisely recording the instant a star winks out and reappears as the Moon or an asteroid passes in front of it. Combined across many observers, these timings reveal lunar-limb profiles and the shapes and sizes of asteroids — a niche where amateurs produce genuinely professional data.
Counting and recording meteors during a shower — their number, brightness, and paths — to measure the shower's strength and structure. Coordinated worldwide by the International Meteor Organization, it is a science anyone can do with nothing but their eyes and patience.
The most-recommended first instrument in astronomy — wide-field, portable, and forgiving. A modest pair shows the craters of the Moon, the moons of Jupiter, star clusters, and the brighter galaxies and nebulae, and teaches the sky better than any telescope rushed into too soon.
A large reflecting telescope on a simple, stable, inexpensive alt-azimuth mount — the design that put big apertures within reach of ordinary observers. It offers more light-gathering power per unit cost than anything else, and is the classic instrument for deep-sky observing.
A telescope mount tilted to align with Earth's rotation axis, so that a single, steady motion cancels the turning of the sky. It keeps an object centred as the Earth spins, which is what makes long-exposure astrophotography possible.
A small, portable motorised mount that slowly turns a camera to follow the stars, so that long exposures capture faint detail without the stars trailing into streaks. It has made wide-field astrophotography of the Milky Way accessible to anyone with a camera.
From a standard camera to a cooled, dedicated astronomical one, the imaging heart of the hobby. Stacking many long exposures, an amateur camera reveals colour and faint structure in nebulae and galaxies far beyond what the eye can see at the eyepiece.
A filter that blocks unwanted light — the orange glow of light pollution, or all but a single emission line such as hydrogen-alpha — so that faint nebulae stand out against the background. Filters let observers under city skies see what would otherwise be washed out.
A gathering where amateur astronomers bring their telescopes to share the sky — with each other and with the public. From a few people in a car park to thousands under a desert sky, star parties are the social heart of the hobby and many people's first look through a telescope.
An observatory open to the public for viewing nights, talks, and hands-on astronomy — often run by universities, clubs, or planetariums. It gives people a chance to look through a real research-grade telescope and meet the people who use them.
A place formally protected for the darkness of its night sky, kept free of light pollution and certified by DarkSky International. Dark-sky parks preserve the vanishing experience of a truly dark sky — and protect the wildlife and human health that artificial light disrupts.
Teaching and public engagement with astronomy — in classrooms, planetariums, science centres, and online — that turns a glance at the stars into understanding. Modern education draws directly on open data archives and survey imagery, letting anyone explore real observations.
The American Association of Variable Star Observers — for more than a century, the organisation that gathers variable-star observations from amateurs worldwide into a single database that professional astronomers draw on. The model for how amateur and professional astronomy work together.
The global body that coordinates amateur meteor observation, collecting counts from observers around the world to measure the strength and structure of meteor showers and to study the streams of debris that cause them.
The Association of Lunar and Planetary Observers, which coordinates amateur observation of the Moon, the planets, comets, and asteroids — organising observing programmes and archiving the results so that amateur monitoring of the Solar System adds up to something lasting.
A German–British gravitational-wave detector near Hannover with 600-metre arms. Smaller than LIGO or Virgo, it works as a technology testbed — pioneering the squeezed-light and other techniques the larger detectors adopt — and observes as part of the international network.
A proposed European third-generation gravitational-wave observatory, to be built underground in a triangle of ten-kilometre arms. Its far greater sensitivity would detect compact-binary mergers across most of the observable universe.
A proposed United States third-generation gravitational-wave observatory with arms up to forty kilometres long — a scaled-up successor to LIGO that, with the Einstein Telescope, would open the distant gravitational-wave universe.
A proposed Japanese space-based gravitational-wave observatory designed for the decihertz band, between the low frequencies LISA will observe and the high frequencies of the ground detectors — a range no other instrument covers.
A proposed Chinese space-based gravitational-wave mission, similar in concept to LISA, that would fly a triangle of spacecraft to detect low-frequency gravitational waves from massive black-hole binaries.
A proposed Chinese space-based gravitational-wave detector of three spacecraft in high geocentric orbit, targeting low-frequency sources such as compact binaries in the Milky Way and merging massive black holes.
The technique behind the ground-based detectors: a laser beam is split down two perpendicular kilometre-scale arms and recombined, and a passing gravitational wave stretches one arm and squeezes the other by a fraction of a proton's width, shifting the interference pattern. LIGO, Virgo, and KAGRA all work this way.
Laser interferometry carried out between spacecraft millions of kilometres apart, free of the ground noise that limits Earth-based detectors. It opens the low-frequency gravitational-wave band — the mergers of massive black holes and the whir of compact binaries — that the ground detectors cannot reach. LISA is the leading example.
Using an array of millisecond pulsars — nature's most precise clocks — as a galaxy-sized gravitational-wave detector. A passing nanohertz gravitational wave subtly shifts the arrival times of the pulsars' pulses in a correlated way; timing arrays have found evidence for a background of such waves from supermassive black-hole binaries.
The merger of two black holes spiralling together — the most common gravitational-wave source detected, and usually a purely gravitational event with no light. The first ever direct detection, in 2015, was of such a merger over a billion light-years away.
The merger of two neutron stars — a gravitational-wave source that also lights up across the electromagnetic spectrum, producing a short gamma-ray burst and a kilonova. The 2017 event GW170817 was seen in both gravitational waves and light, founding multi-messenger astronomy with gravitational waves.
The merger of a black hole with a neutron star — the third class of compact-binary merger, first confidently detected in gravitational waves in early 2020. Whether it produces light depends on whether the black hole tears the neutron star apart before swallowing it.
The public alert system of the LIGO–Virgo–KAGRA collaboration, which issues automated notices — within seconds to minutes — whenever the detectors flag a candidate gravitational-wave event, so that telescopes around the world can begin the hunt for a counterpart. The alerts are distributed through GCN.
An open cyberinfrastructure project building the tools and networks — including the Hopskotch streaming system — to carry the flood of multi-messenger alerts between gravitational-wave, neutrino, and electromagnetic observatories quickly and reliably.
Observing a source in both gravitational waves and electromagnetic light — the channel that transformed astronomy when GW170817 was caught in both, pinning down where a kilonova came from and confirming that neutron-star mergers forge heavy elements.
Searching for neutrinos in coincidence with a gravitational-wave event. Both messengers escape from deep inside cataclysms that light cannot penetrate, so a joint detection would probe the engines of mergers and collapses directly.
The pairing of a gravitational-wave chirp with a short gamma-ray burst. Their near-simultaneous arrival from GW170817 confirmed that neutron-star mergers cause short gamma-ray bursts, and that gravitational waves travel at the speed of light.
Following a gravitational-wave source into the radio, where the slow afterglow of a merger's jet ploughing into surrounding gas unfolds over weeks to months, revealing the geometry and energetics of the outflow.
The optical hunt for a gravitational-wave counterpart — the wide-field survey campaign that finds and follows the fading glow of a kilonova, measuring how a merger's freshly-made heavy elements light up and cool.
Working out where on the sky a gravitational-wave source lies, from the tiny differences in when and how strongly each detector in the network registers the wave. With only two or three detectors the region can be huge — hundreds of square degrees — which is what makes the counterpart search so hard.
The race to find the electromagnetic counterpart of a gravitational-wave event — wide-field telescopes tiling the large localization region, imaging it repeatedly to catch the one new point of light that is the merger's afterglow among millions of unrelated sources.
The time-critical mobilisation of telescopes within minutes to hours of a gravitational-wave alert. A kilonova fades in days and the earliest light carries the most information, so automated systems and rapid human decisions decide whether the counterpart is caught at all.
The probability map of where a gravitational-wave source lies on the sky, released with each alert. Rather than a single point it is a spread of probability — often a long banana-shaped arc — that observers use to plan which patches of sky to search first.
The signal itself — the rising chirp of a compact binary as it spirals in, merges, and rings down. Matching the observed waveform against banks of theoretical templates is how a real signal is dug out of the detector noise and how its source is identified.
Inferring the properties of a gravitational-wave source — the masses and spins of the merging objects, the distance, the orientation — by comparing the waveform against models. It is how a chirp becomes a measurement, including the standard-siren distance that probes the expansion of the universe.
The cumulative catalogue of confident gravitational-wave detections from the LIGO–Virgo–KAGRA observing runs — the growing census of compact-binary mergers, released as open data, from which the population of black holes and neutron stars across cosmic time is reconstructed.
The dense central region of a planet or moon, typically the heaviest material that sank inward as the body formed. In the terrestrial planets it is largely iron; where it is partly molten and convecting, as in Earth, it can generate a global magnetic field.
The thick layer between core and crust, made of hot rock that, though solid, flows over geological time. Its slow convection carries heat outward and drives the tectonics and volcanism that resurface a planet.
The thin, rigid outermost solid layer of a rocky planet or moon — the product of differentiation and volcanism, and the surface on which its geological history is written.
The separation of a young, molten planet into layers by density — the heaviest metal sinking to form a core, the lightest material rising to form a crust. It sets the deep structure every other process then acts on.
The slow motion of a planet's rigid surface plates over its convecting mantle, continually creating and recycling crust. Earth is the only body where plate tectonics is known to operate today, and it is deeply tied to Earth's long-term climate and habitability.
The eruption of molten rock from a planet's interior onto its surface — from Earth's volcanoes to the relentless silicate volcanism of Jupiter's moon Io, the most volcanically active body in the Solar System, whose surface and plumes are painted with sulphur and sulphur-dioxide frosts.
'Ice volcanism' — the eruption not of molten rock but of water, ammonia, or methane from the interior of a cold, icy world. Enceladus jets plumes of water ice into space, and Triton has erupting geysers; the erupted material is these worlds' equivalent of lava.
The gradual loss of a planet's atmosphere to space — light gases escaping thermally, the solar wind stripping the air from an unmagnetised planet, or impacts blasting it away. It is why Mars, which lost its magnetic field, also lost most of its once-thick atmosphere.
How a planet's climate changes over billions of years — the runaway greenhouse that turned Venus into a furnace, the slow drying and cooling of Mars, and the feedbacks that have kept Earth habitable. Comparing the three is the key to understanding what makes a climate stable.
The warming of a planet's surface by an atmosphere that lets sunlight in but traps the outgoing heat. Modest and life-enabling on Earth, it is extreme on Venus, whose thick carbon-dioxide atmosphere makes it the hottest planet in the Solar System.
The global movement of a planet's atmosphere, driven by uneven heating and the planet's rotation — the banded jets and great storms of the gas giants, the super-rotating winds of Venus that lap the planet in days, and the planet-wide dust storms of Mars.
The protection a planet's magnetic field gives its atmosphere by deflecting the solar wind around it. Earth's magnetosphere shields its air; Mars, having lost its global field billions of years ago, was left exposed to the stripping that thinned its atmosphere.
The record of impacts written across a planet's surface, and the way it is read: because craters accumulate over time, a more heavily cratered surface is older. Counting craters is the main way the ages of surfaces across the Solar System are estimated.
A world with a large body of liquid water — most securely the global oceans hidden beneath the ice of moons like Europa and Enceladus, and possibly some water-rich exoplanets. Ocean worlds are among the most promising places to search for life beyond Earth.
A rocky exoplanet orbiting so close to its star that its day side is hot enough to melt rock, covering it in a global magma ocean. Several known super-Earths, such as 55 Cancri e, are thought to be lava worlds, offering a natural laboratory for molten-rock chemistry.
A proposed class of exoplanet — a hot world with a hydrogen-rich atmosphere over a planet-wide ocean. If they exist, hycean planets would offer a much wider habitable zone than rocky worlds and be easier to study, but the class is hypothetical and its habitability unconfirmed.
The thin, warm, mostly atomic gas that fills the space between the stars, laced with dust that reddens the light passing through it. Even here, exposed to starlight, the first simple molecules form — the beginning of cosmic chemistry.
Cold, dense clouds of molecular hydrogen and dust, dark and shielded from starlight, where nearly all the interstellar molecules reside and where stars are born. They are the richest chemical factories in the galaxy, mapped in the millimetre and submillimetre.
The dense cores of molecular clouds where gravity pulls gas together into new stars, and where the heat and radiation of those young stars drive a burst of chemistry. The Orion Nebula is the nearest region of massive star formation and the most-studied example.
The disks of gas and dust that surround young stars, out of which planets, moons, and comets form. Their chemistry — imaged in exquisite detail by ALMA — sets the raw ingredients that new planets and their atmospheres are built from.
The tiny grains of silicate and carbon — often coated in mantles of ice — that pervade the interstellar medium. They redden and dim starlight, radiate in the infrared, and, crucially, provide the surfaces on which many molecules are built.
One of the most abundant molecules in the universe, present as gas, as ice frozen onto dust grains, and in the disks where planets form. Tracing where water is inherited from the interstellar medium versus made in disks is central to understanding how worlds get their oceans.
After molecular hydrogen, the most abundant molecule in space — and, because hydrogen is hard to see directly in cold gas, the workhorse tracer astronomers use to map molecular clouds and measure how much gas is available to form stars.
A common component of the icy mantles that coat interstellar dust grains, detected by the infrared absorption its ice produces against background starlight. Its abundance in ices records the chemistry and radiation history of a cloud.
One of the first polyatomic molecules found in space, and a sensitive thermometer of dense cloud cores: the relative strengths of its radio lines reveal the temperature of the cold gas about to collapse into stars.
A simple nitrogen-bearing molecule widespread in space and central to prebiotic chemistry — many proposed routes to the building blocks of life pass through hydrogen cyanide and its relatives.
A key complex organic molecule that forms not in the gas but on the icy surfaces of dust grains, by the step-by-step addition of hydrogen to frozen carbon monoxide. It is a stepping stone toward the larger organic molecules found around young stars.
Large, flat molecules of linked carbon rings that pervade the galaxy, glowing in a distinctive set of infrared bands and locking up a large share of interstellar carbon. The James Webb Space Telescope maps their emission across galaxies.
The molecular building blocks from which amino acids can form — some detected in space and in the ices of comets, and amino acids themselves found in meteorites such as Murchison. They link the chemistry of the interstellar medium to the origin of life.
Chemistry that happens in the gas between grains, driven especially by fast ion–molecule reactions that proceed even at the frigid temperatures of interstellar clouds. It builds many of the simple molecules seen in space.
Chemistry that happens on the icy mantles of dust grains, where atoms and molecules land, wander, and meet. It makes molecules the gas phase cannot — water and methanol among them — and is the source of much of space's complex organic chemistry.
Chemistry driven by ultraviolet starlight, which breaks molecules apart and ionises atoms at the illuminated edges of clouds and the surfaces of disks — both destroying molecules and opening new reaction pathways.
Chemistry triggered when gas is suddenly heated and compressed — by the outflows of newborn stars or the blast waves of supernovae. Shocks sputter material off dust grains and power reactions that need high temperatures, changing a cloud's chemistry.
The astrochemistry of molecules relevant to the origin of life — how the building blocks of biology can be assembled in interstellar clouds, on icy grains, and in the young Solar System, and delivered to a planet's surface.
The chemistry of protoplanetary disks that decides what new planets are made of — where ices freeze out, which molecules end up in comets and which in planetary atmospheres, and how much water and organic material a world inherits.
The record of the early Solar System's chemistry preserved in comets and meteorites — the amino acids in the Murchison meteorite, the ancient inclusions of Allende, and the ices of comets — a frozen archive of the material that built the planets.
The founding treaty of international space law, opened for signature in 1967. It declares space free for exploration and use by all nations, forbids any state from claiming sovereignty over the Moon or other bodies, bans weapons of mass destruction in orbit, and makes states responsible for their national space activities — governmental or private.
A 1972 convention that elaborates the Outer Space Treaty's liability principle: a launching state is absolutely liable for damage its space objects cause on the Earth's surface or to aircraft, and liable for fault for damage caused in space.
A 1975 convention, in force from 1976, requiring states to register the objects they launch into space with the United Nations, so that space objects can be identified — the basis of the UN register of space objects that UNOOSA maintains.
A 1979 agreement declaring the Moon and its natural resources the common heritage of mankind and calling for an international regime to govern their exploitation. It has been ratified by only a handful of states, none of them major spacefaring powers, which limits its force.
A set of principles for cooperative, peaceful, and transparent exploration of the Moon and beyond, established in 2020 and led by NASA, and signed by a growing number of nations. They interpret the Outer Space Treaty for a new era of lunar activity, including the use of space resources.
The growing population of defunct satellites, spent rocket stages, and fragments of past collisions and explosions that circle the Earth. Travelling at kilometres per second, even a small piece can destroy an operational spacecraft, and there are millions of untracked fragments.
The scenario, named for Donald Kessler, in which the density of objects in orbit becomes high enough that collisions cascade — each impact creating more debris that causes further impacts — potentially making some orbits unusable for generations.
The tracking and cataloguing of the tens of thousands of objects in orbit, and the prediction of close approaches, so that operators can be warned and collisions avoided. It is the sensing foundation on which any traffic management must rest.
The coordination of spacecraft operations — who moves, when, and how — to prevent collisions as orbits grow crowded. Unlike air or sea traffic, space has no established global authority to direct it, making it an urgent and unsolved governance problem.
The guidelines and practices meant to limit the creation of new debris — deorbiting satellites at end of life, venting spent rocket stages so they cannot explode, and clearing valuable orbits within a set number of years after a mission ends.
The deployment of constellations of thousands of satellites in low Earth orbit to provide global broadband. They transform the economics of space but sharply raise concerns over orbital traffic, collision risk, radio-frequency use, and the brightness of the night sky for astronomy.
The regulatory approval a national authority requires before a launch, covering public safety, liability insurance, and environmental review. It is the gate through which every launch must pass, and a major point of national space governance.
The international coordination of the radio-frequency spectrum satellites use and the orbital slots they occupy — especially the crowded geostationary arc — managed through the International Telecommunication Union to prevent interference.
The regulation of space technologies that have both civilian and military uses — rockets, sensors, and satellites — controlling their transfer across borders. It shapes who can build and buy space hardware, and is a persistent tension in the global space industry.
The unsettled question of who may extract and own resources from the Moon and asteroids, and under what rules. The Outer Space Treaty forbids claiming territory, but says little about mining, and nations are now enacting their own laws — a live and contested frontier of space law.
The international policy framework — coordinated by COSPAR — that keeps missions from contaminating other worlds with terrestrial microbes, and Earth from any hazard in returned samples. It turns the science of planetary protection into binding mission requirements.
The private launch industry that has driven the cost of reaching orbit down by an order of magnitude — through reusable rockets and competition — and opened space to companies, universities, and nations that could never before afford it.
The largest part of the space economy — the industry built on satellites for communications, navigation, and Earth observation, whose services underpin the modern economy on the ground, from banking timestamps to weather forecasts to global positioning.
The specialised insurance market that underwrites the risk of launching and operating satellites — covering the moments when a rocket can fail and the years a satellite must survive the hazards of space. It is a small but essential enabler of commercial space.
The whole economic system of space activity — launch, satellites, ground systems, services, and the emerging markets in resources and on-orbit servicing — and the far larger value it creates on Earth. Increasingly it is driven by private capital as much as by governments.
The United Nations Office for Outer Space Affairs, which promotes international cooperation in the peaceful use of space, supports the development of space law, and maintains the United Nations register of objects launched into space.
The Committee on Space Research, an international scientific body that coordinates space research across nations and maintains the planetary-protection policy that keeps missions from contaminating other worlds and Earth from returned samples.
The United Nations agency that allocates the global radio-frequency spectrum and the geostationary and other orbital slots that satellites use, coordinating between nations and operators to prevent harmful interference.
A global space-advocacy organisation that connects space agencies, companies, and societies worldwide and runs the annual International Astronautical Congress, the largest gathering of the space community.
The cycle of observation, hypothesis, prediction, and test that turned the study of the heavens from stargazing and myth into a science — and the reason astronomy's claims can be checked, challenged, and improved rather than merely believed.
The deep changes in how a field sees the world, as described by the philosopher Thomas Kuhn — moments when one framework of assumptions gives way to another, as when the Earth-centred cosmos was replaced by a Sun-centred one.
The episodes in which accumulated anomalies — observations that will not fit the old picture — build until the framework breaks and a new one takes its place. Astronomy has driven several of the largest revolutions in all of science.
The recurring pattern by which a new instrument opens a new window on the universe and a wave of discovery follows — the telescope, the spectroscope, the photographic plate, the radio dish, the gravitational-wave detector each launching a new astronomy.
The systematic ways instruments and selection effects skew what astronomers find — brighter objects being easier to see, for instance, biasing a sample. Recognising and correcting these biases is as much a part of a result as the measurement itself.
The interplay between prediction and measurement that drives astronomy forward — sometimes theory leads and observation confirms (the prediction of Neptune, of gravitational waves), and sometimes observation surprises and theory must catch up (the accelerating universe).
The modern era of vast, collaborative, and expensive instruments — the great space observatories, the kilometre-scale gravitational-wave detectors, the all-sky surveys — that no single scientist could build or fund, run instead by international collaborations of thousands.
The transformation of astronomy into a data science, in which surveys now produce far more data than any team could inspect by hand, and machine learning is used to classify, discover, and even find what no one thought to look for.
The view that our best scientific theories describe a real world — that atoms, black holes, and dark matter are not merely convenient fictions but things that actually exist, even when they cannot be seen directly. It is the working assumption of most astronomers, and a live question in philosophy.
The criterion, associated with the philosopher Karl Popper, that a scientific claim must be testable and capable in principle of being proven wrong. It is one influential attempt to mark the boundary between science and non-science.
What counts as evidence in a science where controlled experiments are rarely possible and the universe cannot be put in a laboratory. Astronomy must infer from what it is shown — the light and particles that happen to arrive — which makes the careful weighing of evidence central.
Every astronomical measurement carries an uncertainty — statistical scatter and systematic error — and understanding it is inseparable from the result. A number without its error bar is not yet a measurement, and disputes in astronomy are often disputes about uncertainty.
The demand that a result stand up when others repeat the analysis on the same or new data — a cornerstone of scientific trust, and a growing concern as analyses become more complex and depend on large software pipelines.
The movement to make the data, code, and methods behind a result openly available, so that science can be checked, reused, and built upon by anyone. In astronomy, with its open archives and shared surveys, it is both a philosophy and a well-developed practice.
The shift from an Earth-centred to a Sun-centred cosmos — from Copernicus's heliocentric proposal, through Galileo's telescopic evidence and Kepler's laws of planetary motion, to Newton's gravity that explained them all. The founding revolution of modern astronomy, and the archetype of a scientific revolution.
From Galileo first turning a spyglass on the sky in 1609 — finding craters on the Moon and moons around Jupiter — through William Herschel's reflecting telescopes, one of which discovered Uranus, to the segmented giants and space telescopes of today. Each leap in aperture opened new depths of the universe.
How splitting starlight into its colours revealed what the stars are made of — the dark lines in the spectrum betraying the elements present. It was the birth of astrophysics, the moment astronomy became not just where and when but what and how.
How Karl Jansky's chance detection of radio waves from the Milky Way in the 1930s opened an entirely new window on the universe — leading in time to pulsars, quasars, the cosmic microwave background, and the imaging of a black hole.
From Hubble's discovery that the universe is expanding, through the Big Bang and the detection of its afterglow, to the surprise of the accelerating cosmos and the tensions in today's precision measurements. A century in which cosmology became a science.
From the first confirmed planet around another Sun-like star in 1995 — found by the radial-velocity wobble it induced — to the thousands now known, many by the transit method, a field that went in a generation from speculation to a central pursuit of astronomy, driven by ever more sensitive detection methods.
From Einstein's 1916 prediction that mass in motion should ripple spacetime, through a century of doubt about whether they could ever be detected, to the first direct detection of a black-hole merger in 2015 — and a new way of observing the universe.
From a strange mathematical solution that many thought unphysical, through the theoretical work that made them respectable and the observations that made them real, to the imaging of a black hole's shadow and the star orbits that prove one lurks at the Milky Way's heart.
The motion of a small body under the gravity of two larger ones orbiting each other. It has no general closed-form solution, yet its study yields the Lagrange points, the concept of orbital stability, and much of modern spacecraft trajectory design.
The gravitational motion of many bodies at once. Beyond two bodies there is no general closed-form solution, so the positions of the planets and moons are found by integrating the equations of motion numerically — the basis of modern ephemerides.
The five points in a two-body system where a small third body can remain fixed relative to the two, its motion balanced by their combined gravity. The James Webb Space Telescope orbits the Sun–Earth L2 point, and the Trojan asteroids sit at Jupiter's L4 and L5.
The region around a body within which its own gravity dominates over that of the more massive body it orbits. It sets how far out moons and rings can stably orbit a planet — anything beyond a planet's Hill sphere is pulled away by the Sun.
The distance within which a body held together only by its own gravity is pulled apart by the tidal forces of the body it orbits. It is why planetary rings lie close in — where a moon could not survive — and why comets passing too close to a planet break into fragments.
The small departures of a real orbit from a perfect two-body ellipse — caused by the pull of other bodies, a planet's equatorial bulge, atmospheric drag, and radiation. They accumulate over time, which is why orbits must be tracked and recomputed continually.
When the orbital periods of two bodies form a simple whole-number ratio, their repeated close alignments deliver gravitational kicks that add up. Such resonances carve the Kirkwood gaps in the asteroid belt and lock Jupiter's inner moons into a precise chain.
A slow resonance not between orbital periods but between the rates at which orbits themselves precess. Acting over millions of years, secular resonances reshape the eccentricities and inclinations of orbits and help clear certain regions of the Solar System.
The slow change of orbits and rotations caused by tidal friction. It is why the Moon is receding from the Earth and the day is lengthening, and why close-in moons and planets end up rotating in step with their orbits.
The locking of a body's rotation to its orbit by tides. The Moon keeps one face toward the Earth in a 1:1 lock, while Mercury rotates three times for every two orbits of the Sun — a 3:2 spin–orbit resonance.
The set of numbers — typically six — that fully specify an orbit and a body's position along it: its size and shape, its orientation in space, and where the body is at a given time. They are the compact language in which every ephemeris and mission trajectory is expressed.
The International Celestial Reference System
The modern, fixed reference frame for the sky, defined by the positions of hundreds of distant quasars whose motion is undetectable. It replaced frames tied to the slowly-shifting equinox with one anchored to some of the most distant objects known — the standard to which all precise astronomical positions are now referred.
The Barycentric Celestial Reference System
The reference system centred on the barycentre — the balance point — of the Solar System, used to describe the motion of the planets and the propagation of light across the Solar System. It is the frame in which planetary ephemerides are computed.
The Geocentric Celestial Reference System
The reference system centred on the Earth, aligned with the barycentric frame but following the Earth in its orbit. It is the natural frame for the motion of satellites and for observations made from the ground.
The plane of the Earth's orbit around the Sun, and the equinox where it crosses the celestial equator. For millennia the equinox was the origin of celestial coordinates — but because it slowly precesses, modern frames are fixed to the stars instead.
The standard reference epoch of modern astronomy — noon on 1 January 2000, in Terrestrial Time. Because the sky's apparent frame drifts with precession, coordinates and orbital elements are stated for a fixed epoch, and J2000.0 is the one in near-universal use.
The older standard epoch, defined by the beginning of the Besselian year 1950, to which many historical star catalogues and coordinates are referred. Converting between B1950 and J2000 positions is a routine but necessary step when using older data.
The series of numerically-integrated ephemerides, produced by NASA's Jet Propulsion Laboratory, that give the positions and velocities of the planets, the Moon, and the Sun to high precision over long spans. The DE ephemerides are the standard reference for precise Solar System calculations.
NASA's information system and software toolkit for computing the geometry of spacecraft and Solar System bodies — where a spacecraft is, where it is pointing, and what it can see. Its shared data files (kernels) are a de facto standard across planetary missions.
JPL's online ephemeris service, which generates highly accurate positions, distances, and other quantities for Solar System bodies and spacecraft, for any observer and time. It is the go-to tool for planning observations and checking where a body will be.
The idealised time on the Earth's surface used as the time axis for astronomical events and geocentric ephemerides. It runs at the same rate as International Atomic Time but is offset ahead of it by a fixed 32.184 seconds, for continuity with the older ephemeris time.
The time coordinate of the Solar System barycentre, used as the independent variable of the planetary ephemerides. It differs from Terrestrial Time only by small periodic terms arising from the Earth's motion around the Sun, never drifting by more than a couple of milliseconds.
The form of Universal Time tied to the actual rotation of the Earth, measured from the positions of distant sources. Because the Earth's spin is slightly irregular and slowly slowing, UT1 drifts against the steady beat of atomic time.
The extra second occasionally inserted into Coordinated Universal Time to keep it within 0.9 seconds of UT1, so that civil clocks stay in step with the turning of the Earth. As atomic time and Earth rotation drift apart, leap seconds bridge the gap — a practice now being reconsidered.
Time kept by the stars rather than the Sun — it measures the Earth's rotation relative to the fixed sky. A sidereal day is about four minutes shorter than a solar day, because the Earth must turn a little further each day to face the Sun again as it moves along its orbit.
Time kept by the real Sun, as a sundial shows it — noon is the moment the Sun crosses the meridian. Because the Earth's orbit is elliptical and tilted, the Sun runs fast or slow through the year, so clocks keep mean solar time instead, differing by up to about a quarter of an hour.
Stars are born when the densest cores of a giant molecular cloud become unable to support themselves against their own gravity and collapse. As a core falls inward it heats, spins up into a disc, and grows a central protostar — a process that can be triggered by the shock of a nearby supernova or the squeeze of a spiral arm.
The stage between a protostar and a fully-fledged star. Still contracting and drawing energy from gravity rather than fusion, the young star — a T Tauri star at low mass, a Herbig Ae/Be star at higher mass — is wrapped in an accretion disc and drives energetic jets, until its core grows hot enough to ignite hydrogen.
The long, stable middle age of a star, during which it fuses hydrogen into helium in its core. This is where stars spend most of their lives — the Sun for roughly ten billion years — and a star's mass fixes where it sits along the main sequence, how brightly it burns, and how long it lasts.
When a star exhausts the hydrogen in its core, fusion moves to a shell around an inert helium core. The envelope swells enormously and cools to a red glow, and the star climbs the red-giant branch — brightening as it ascends until helium ignites at its tip.
In stars below about two solar masses, the helium core becomes so dense that it is held up by electron degeneracy pressure. When helium finally ignites, the degenerate gas cannot expand to regulate itself, so fusion runs away in a brief, violent flash — over in minutes, and hidden deep inside the star.
After helium ignites, a low-mass star settles into a stable phase of quiet core helium burning, sitting on the horizontal branch of the colour–magnitude diagram at roughly constant luminosity. Stars crossing the instability strip here pulsate as RR Lyrae variables.
Late in a low- or intermediate-mass star's life, both a hydrogen shell and a helium shell burn around a carbon–oxygen core. Recurring thermal pulses dredge freshly-made elements to the surface and drive heavy mass loss, as the star climbs the asymptotic giant branch toward the ejection of its envelope.
At the end of the asymptotic giant branch a dying star sheds its outer layers into space, exposing the hot stellar core beneath. The core's ultraviolet light lights up the expanding shell as a glowing planetary nebula — a name from the eighteenth century that has nothing to do with planets — before it fades to a white dwarf.
Throughout their lives, and especially near the end, stars shed mass in winds — driven by radiation pressure on spectral lines in hot, luminous stars, and on dust grains in cool giants and supergiants. Mass loss reshapes a star's fate, stripping envelopes and returning enriched gas to the interstellar medium.
A star born with more than roughly eight solar masses fuses ever-heavier elements until it builds an inert iron core. Iron cannot release energy by fusing, so once the core exceeds its stability limit it collapses in under a second, rebounds, and blows the star apart as a core-collapse supernova, leaving a neutron star or a black hole.
Stars spin, and how fast they spin shapes their lives. Rotation mixes fresh fuel into the core, flattens the star, powers magnetic dynamos, and drives mass loss; it can be measured from the broadening of spectral lines and, for the internal rotation hidden beneath the surface, from asteroseismology.
A star's rotation and convection together drive a magnetic dynamo, giving rise to starspots, flares, and hot outer atmospheres, often waxing and waning in activity cycles. The Sun is the star whose magnetic activity we can watch in closest detail, but the same physics operates across the cool stars.
The dominant way low-mass stars like the Sun turn hydrogen into helium: through a chain of steps, four protons are fused into a single helium-4 nucleus, releasing energy and neutrinos. It powers the cores of the coolest main-sequence stars, where temperatures are too low for the competing CNO cycle.
A second route from hydrogen to helium, in which carbon, nitrogen, and oxygen act as catalysts that are used and regenerated. Because it is extremely temperature-sensitive, the CNO cycle dominates hydrogen burning in stars more massive than roughly 1.3 solar masses, whose cores are hotter than the Sun's.
How stars make carbon: three helium-4 nuclei (alpha particles) combine into carbon-12. It requires temperatures around a hundred million kelvin and proceeds through a finely-tuned nuclear resonance, so it only switches on in the helium-burning cores of evolved giant stars.
The slow capture of neutrons that builds about half the elements heavier than iron, up to lead and bismuth. Neutrons are added one at a time, slowly enough that unstable nuclei usually decay before catching the next — a process that unfolds over thousands of years in the interiors of asymptotic-giant-branch stars.
The rapid capture of neutrons that forges the heaviest elements — gold, platinum, the lanthanides, and uranium. It demands an intense flood of neutrons in a fraction of a second, conditions found when two neutron stars merge, an origin confirmed by the kilonova that followed the 2017 gravitational-wave event GW170817.
In the final phase of a massive star, the core burns successively heavier fuels — carbon, neon, oxygen, and silicon — each stage faster than the last, building an onion-like structure of shells. Silicon burning yields iron, which cannot release energy by fusing, ending the sequence and setting the stage for core collapse.
The single most important diagram in stellar astrophysics: a plot of stars' luminosities against their surface temperatures. Stars are not scattered at random but fall into distinct regions — the diagonal main sequence, the giant and supergiant branches, and the faint white-dwarf sequence — that trace the arc of stellar evolution.
A star is a self-regulating sphere of plasma in which the inward pull of gravity is balanced at every depth by the outward push of pressure — hydrostatic equilibrium. Energy generated by fusion in the core is carried outward by radiation and by convection, and a handful of coupled equations capture the whole structure.
A quantum-mechanical pressure that arises because electrons, by the Pauli exclusion principle, resist being packed too closely — independent of temperature. It supports white dwarfs against gravity, but only up to the Chandrasekhar limit of about 1.4 solar masses, beyond which even degeneracy fails and the star collapses further.
The distribution of masses with which stars are born. Nature makes far more low-mass stars than high-mass ones — a steep decline first quantified by Salpeter — so faint red dwarfs vastly outnumber brilliant massive stars. The initial mass function shapes how galaxies light up, enrich, and evolve.
To an astronomer, every element heavier than helium is a "metal." A star's metallicity records the enrichment of the gas from which it formed, since the Big Bang made essentially only hydrogen and helium and successive generations of stars forged the rest. It is usually expressed as [Fe/H], the iron-to-hydrogen ratio relative to the Sun.
Stars fall into broad populations: metal-rich Population I stars in the disc, like the Sun; old, metal-poor Population II stars in the halo and globular clusters; and a hypothesised first generation of metal-free Population III stars, not yet directly observed. Star clusters — young open clusters and ancient globulars — are coeval populations that serve as the great testing grounds of stellar-evolution theory.
A star's spectrum reveals not only its temperature but its size. The Yerkes system adds a luminosity class — from I for supergiants down through III for giants, V for main-sequence dwarfs, to VII for white dwarfs — to the Harvard spectral type. Together they place a star precisely: the Sun, for instance, is a G2V dwarf.
Most stars are not alone. Pairs bound by gravity — seen as visual, spectroscopic, or eclipsing binaries — let astronomers weigh stars directly from their orbits. When the stars are close enough, one can spill matter across its Roche lobe onto the other, driving novae, X-ray binaries, and the Type Ia supernovae that light up the distant universe.
The flattened, rotating layer that holds most of the Milky Way's stars, gas, and dust, and where stars are still being born today. Only a few hundred parsecs thick but tens of thousands across, it contains the spiral arms and the young, metal-rich stars of the Galactic disc — the Sun among them.
A more extended, puffed-up disc of older, more metal-poor stars that envelops the thin disk. Its stars move on hotter orbits and formed early in the Galaxy's history, making the thick disk a fossil record of a more turbulent youth — perhaps heated by an ancient merger.
The dense, roughly spheroidal concentration of mostly old stars at the heart of the Milky Way. Boxy and peanut-shaped when seen edge-on, the bulge is intimately tied to the central bar and holds clues to how the inner Galaxy assembled.
An elongated bar of stars spanning the central few kiloparsecs, which makes the Milky Way a barred spiral galaxy. The bar funnels gas inward, drives the boxy bulge, and sets up resonances that shape the orbits of disc stars far from the centre.
A vast, sparse, roughly spherical cloud of the Galaxy's oldest and most metal-poor stars, together with its globular clusters, reaching far beyond the disc. Built largely from the shredded remains of smaller galaxies, the stellar halo is the Milky Way's deep archaeological archive.
The bright lanes that wind through the disc, marked out by gas, dust, and freshly-formed luminous stars. The arms are thought to be density waves — regions where orbits crowd together and trigger star formation — rather than fixed structures, so stars drift in and out of them over time.
The outer disc of the Milky Way is not flat but bent, curving up on one side and down on the other like a vinyl record left in the sun. This warp, traced by gas and by young stars, is likely stirred by the gravitational tug of the Magellanic Clouds and the dark-matter halo.
The crowded, dust-shrouded core of the Milky Way, about 26,000 light-years away, home to a dense star cluster and the four-million-solar-mass black hole Sagittarius A*. Hidden at optical wavelengths, it is studied in radio, infrared, and X-rays, and its stars' orbits weigh the central black hole directly.
The reservoir of dense molecular gas within a few hundred parsecs of the Galactic Centre — a fraction of the Galaxy's volume that holds a large share of its molecular material. Turbulent, magnetised, and forming stars under extreme conditions, it is a nearby laboratory for the hearts of other galaxies.
An enormous halo of tenuous, million-degree gas that surrounds the Milky Way, detectable in X-rays and in absorption against distant sources. This hot corona is a reservoir of baryons and the medium through which fresh gas accretes onto the Galaxy and enriched gas is expelled.
The Sun's local patch of the Galaxy — the stars, gas, and structure within a few hundred light-years. It includes the Local Bubble, a cavity of hot, thin gas blown by ancient supernovae, and it is the vantage point from which we map the entire Milky Way, orbiting the Galactic Centre once every roughly 230 million years.
The Milky Way's disc does not turn as a solid body: inner and outer stars complete their orbits at different rates. Yet the orbital speed stays surprisingly flat far from the centre instead of falling off, one of the clearest signs that the visible Galaxy is embedded in a massive halo of unseen dark matter.
Ribbons of stars strung out across the halo, torn from dwarf galaxies and globular clusters as the Milky Way's tides pull them apart. The great Sagittarius stream wraps entirely around the Galaxy; mapped in their dozens by Gaia, these streams trace the shape of the dark-matter halo and record the Galaxy's past meals.
The reconstruction of how the Milky Way formed by reading the ages, chemistry, and motions of its stars, which preserve the imprint of their birth. Gaia's precise positions and velocities for over a billion stars have turned this into a precision science, revealing ancient mergers frozen into the halo.
Stars do not stay at the galactocentric radius where they were born. Resonances with the spiral arms and the bar can shuffle a star inward or outward across the disc without heating its orbit, mixing the disc's chemistry over billions of years and complicating any attempt to read history from composition alone.
A large-scale magnetic field of a few microgauss threads the Milky Way, ordered along the spiral arms and tangled on smaller scales. Weak though it is, it guides cosmic rays, shapes the interstellar medium, and helps regulate star formation; it is traced through synchrotron radiation, Faraday rotation, and polarised starlight and dust.
A proposed — and much-debated — region of the Galaxy thought to be most favourable to complex life: far enough from the crowded, radiation-soaked centre yet metal-rich enough to build planets. Whether such a zone is truly well-defined remains an open question, and it is offered as a hypothesis rather than an established boundary.
The Milky Way is orbited by dozens of smaller galaxies, the brightest being the Large and Small Magellanic Clouds. In the hierarchical picture of galaxy formation, big galaxies grow by swallowing small ones, and the Milky Way is still feeding — its halo and streams are the debris of satellites consumed long ago.
The Milky Way and the Andromeda Galaxy are approaching each other and are predicted to merge into a single elliptical galaxy in roughly four to five billion years, though the exact timing and geometry remain uncertain. Stars will almost never collide, but both discs will be transformed as the two giants of the Local Group become one.
Star formation and supernovae blow hot gas out of the disc, which cools, condenses, and rains back down as clouds — a continual circulation between the disc and the halo. This galactic fountain recycles and mixes gas, and helps deliver the fresh material that keeps the Milky Way forming stars.
The open-source foundation of modern astronomical computing: the Python language together with NumPy for array mathematics, SciPy for scientific algorithms, and pandas for tabular data. Free and community-built, it has become the common language in which most astronomical analysis is now written.
The community-developed core package for astronomy in Python, providing the shared building blocks the field relies on: physical units and constants, celestial coordinate transformations, time scales, cosmological calculations, and reading and writing of FITS and other data formats. A large ecosystem of affiliated packages builds on its foundation.
The community package for solar physics in Python, the solar counterpart to Astropy. It provides the data structures, coordinate frames, and access to solar observatory archives that let researchers analyse images and time series of the Sun within the same open scientific-Python ecosystem.
Interactive documents that weave together live code, results, plots, and narrative text in one place. Notebooks have become the default medium for exploratory analysis, teaching, and sharing reproducible research in astronomy, and they sit at the heart of the cloud-based science platforms now serving the largest surveys.
An Astropy-affiliated package that lets researchers query the major astronomical archives and databases directly from code. Instead of clicking through web forms, a scientist can pull catalogues and images from MAST, VizieR, SIMBAD, and dozens of other services programmatically, making analyses scriptable and repeatable.
The tools and craft of turning data into images that reveal structure — from the ubiquitous Matplotlib plots to interactive and three-dimensional renderings of simulations and surveys. Visualisation is both how astronomers explore their data and how they communicate discoveries.
The supercomputers on which astronomers run the largest cosmological simulations and process survey data at scale. By dividing a problem across thousands of tightly-coupled processors, high-performance computing makes it possible to model the growth of cosmic structure or the collision of neutron stars from first principles.
Graphics processing units, originally built for rendering, excel at the massively parallel arithmetic that powers modern simulation and machine learning. Astronomy uses them to accelerate everything from N-body dynamics and radiative transfer to the training of the large neural networks now applied to survey data.
Elastic, on-demand computing rented from remote data centres. Rather than moving petabytes of survey data to a researcher's own machine, cloud computing lets the analysis run next to the data, a shift that underpins the science platforms being built for the next generation of surveys.
Spreading a computation across many loosely-coupled machines so that datasets far too large for one computer can be processed in parallel. Frameworks for distributed data processing let astronomers cross-match billion-row catalogues and reduce survey images across clusters of ordinary servers.
Integrated, cloud-based environments that bring the analysis tools to the data. Platforms such as the Rubin Science Platform give researchers notebooks, catalogue databases, and image access alongside a survey's archive, so that discovery no longer requires downloading the data at all.
Containerisation & Reproducible Environments
Packaging software together with its exact dependencies into a portable container, so that an analysis runs identically on a laptop, a supercomputer, or the cloud. Containers have become a cornerstone of reproducible research, freezing the computational environment in which a result was produced.
The orchestration of a multi-step analysis — each stage's inputs, outputs, and dependencies made explicit — so that a whole computation can be re-run automatically and at scale. Workflow systems turn a tangle of scripts into a repeatable pipeline, the backbone of processing survey data through many stages.
The recorded lineage of a data product: which raw observations, software versions, and processing steps produced it. Provenance lets a result be traced back to its origins and trusted or reproduced — distinct from a persistent identifier, which names the product, provenance describes how it came to be.
The Astronomical Data Query Language, a dialect of SQL extended with the geometry of the sky, lets astronomers ask precise questions of enormous catalogues — every source within a region, or every object matching a set of criteria. It is the language that the Virtual Observatory's Table Access Protocol serves.
Modern surveys have turned astronomy into a data-intensive science. Gaia charts over a billion stars, the Rubin Observatory's LSST will image the whole southern sky every few nights, and the Square Kilometre Array will generate data faster than any prior instrument — forcing new ways to store, move, and analyse information at petabyte scale.
The vision of an integrated, online ecosystem where data, software, and computing come together — the Virtual Observatory's interoperable archives joined to cloud science platforms and shared notebooks. In such an environment a researcher can find, access, and analyse data from many facilities without ever leaving the browser.
The recognition that scientific software deserves the same care as any other research output: version control, testing, documentation, code review, and open licensing. As astronomy has grown more computational, sustaining and citing the software behind results has become a discipline in its own right.
The strategy of returning to the Moon first, and using it as a proving ground for the systems and skills needed to send crews to Mars. Under this integrated approach the Artemis missions and the Lunar Gateway are steps toward a longer campaign, testing habitats, life support, and surface operations close to home before the far harder journey to Mars.
A crewed outpost on Mars, the long-term goal of human deep-space exploration. Separated from Earth by months of travel and up to twenty minutes of communication delay, a Mars base must make its own propellant, water, and oxygen from local resources and sustain its crew with little hope of rescue.
The spacecraft in which a crew lives during the months-long cruise between worlds. Cut off from resupply and beyond the protection of Earth's magnetic field, a transit habitat must recycle nearly all its air and water, shield its crew from radiation, and keep them healthy and sane across interplanetary distances.
The electricity that keeps a surface base alive — running life support, recharging rovers, and driving the machines that extract local resources. Solar arrays serve where the Sun shines, but through the long lunar night and the dust of a Martian winter a compact fission reactor offers steady power independent of sunlight.
How crews range across a world beyond the walking distance of their habitat — from unpressurised buggies for short trips to pressurised rovers that serve as mobile homes for days-long expeditions. Mobility multiplies the science a surface mission can do, turning a single landing site into a region to explore.
Building shelter on another world rather than carrying it there. Concepts range from covering habitats with bagged regolith for radiation shielding to three-dimensional printing of structures from local soil, so that the mass launched from Earth shrinks and the base can grow using what is already on the ground.
Getting a crew to Mars quickly enough to limit their exposure to weightlessness and radiation. Chemical rockets are proven but heavy on propellant; nuclear-thermal and nuclear-electric propulsion promise shorter transits, while solar-electric tugs can pre-position cargo ahead of the crew.
The problem of setting a heavy crewed vehicle down safely on Mars. The atmosphere is thick enough to fiercely heat an incoming craft yet too thin to slow a massive lander by parachute alone, so landing humans will demand a combination of heat shields, retropropulsion, and technologies well beyond those that delivered the robotic rovers.
Beyond the shelter of Earth's magnetic field, crews are exposed to a steady sleet of galactic cosmic rays and the sudden violence of solar particle events. This radiation raises long-term cancer risk and can damage the nervous system, and shielding against the most energetic particles is one of the hardest unsolved problems of sending humans to Mars.
Radio signals travel at the speed of light, but the distances are vast: a message to a crew at Mars can take as much as about twenty minutes each way, so a real-time conversation with Earth is impossible. The delay forces crews to handle emergencies themselves and reshapes how missions far from home are commanded and supported.
Close to Earth, mission control and a waiting ambulance are never far away; at Mars, a crew is largely on its own. Deep-space missions must be able to diagnose and treat illness, repair their own systems, and make decisions without waiting for Earth — a shift from ground-controlled operations toward genuine self-sufficiency.
On the Space Station, water and air can be topped up from Earth; on a multi-year voyage to Mars there is no resupply. Life support must therefore recycle almost everything — reclaiming water from every source and regenerating oxygen — and may ultimately grow food, closing the loop far more tightly than any system flown so far.
A small crew confined together for years, far from family and the ordinary world, faces real psychological strain — isolation, monotony, and the friction of close quarters. Keeping a team healthy, motivated, and working well together is as vital to a Mars mission as any piece of hardware, and far less forgiving of failure.
Planetary Protection for Crewed Missions
A human crew cannot be sterilised the way a robotic lander can, so people inevitably carry microbes with them. Protecting Mars from Earthly contamination — which could confuse the search for native life — while also guarding the crew against any possible Martian biology is a difficult balance unique to sending humans to another world.
The dust of the Moon and Mars is not the smooth sand of Earth but sharp, clinging, and chemically reactive. Lunar dust abraded the Apollo astronauts' suits and equipment and irritated their lungs, and Martian soil holds toxic perchlorates — so managing dust is essential to keeping crews, seals, and machinery working on any planetary surface.
A whole-sky chart plotting every catalogued star at its real right ascension and declination, sized by apparent magnitude. Rendered as scalable vector graphics directly from the star catalogue's measured coordinates — nothing is invented; a star appears only where the data places it.
The eighty-eight official constellations, each mapped by the real positions of its brightest stars. A gateway from the familiar patterns of the night sky into the stars, myths, and deep-sky objects each region holds.
A chart of the Messier objects — the nebulae, clusters, and galaxies of Charles Messier's eighteenth-century catalogue — each placed at its real celestial coordinates and sized by its apparent extent. The classic target list for a first tour of the deep sky.
A map of the catalogued deep-sky objects — galaxies, nebulae, and star clusters — drawn from their measured right ascension and declination, with symbols scaled by angular size. The wider sky beyond the naked-eye stars.
A naked-eye view of the sky showing only the brightest stars, ranked by apparent magnitude. The stars that anchor the constellations and guide the eye across the night.
An explorer of the Sun's family — the planets, their moons, and the small bodies between them. The data model carries each body's real orbital and physical parameters and is prepared for a future interactive three-dimensional scene; today it presents the ordered, to-scale structure of the system.
An explorer of the structure of our own Galaxy — its discs, bulge, bar, spiral arms, and halo, and the Sun's place within them. Prepared for a three-dimensional rendering of galactic structure; today it maps the anatomy of the Milky Way onto its components.
An explorer of our galactic neighbourhood — the Milky Way, Andromeda, Triangulum, the Magellanic Clouds, and the dozens of dwarf galaxies bound with them into the Local Group. Prepared for a three-dimensional map of the nearby universe.
A browsable index of catalogued galaxies — spirals, ellipticals, and irregulars — organised by morphology and distance. The building blocks of cosmic structure, each linked to its place in the knowledge graph.
An explorer of the planets — their sizes, orbits, atmospheres, and moons, drawn from measured planetary data. From Mercury's scorched rock to the ice giants of the outer system.
An explorer of the moons of the Solar System — from Earth's Moon to the ocean worlds of Jupiter and Saturn — organised by their host planet and physical character.
An explorer of the confirmed planets beyond the Solar System, drawn from the measured exoplanet catalogue — organised by host star, detection method, size, and orbit. The worlds of other suns.
An explorer of the New General Catalogue and its deep-sky objects, organised by type, constellation, and catalogue. The deep sky beyond the Messier list.
An explorer of cosmic distance and scale — from the nearest stars to the edge of the observable universe — built on the rungs of the cosmic distance ladder. Prepared to visualise the vast, logarithmic reach of the cosmos honestly, with distances drawn only from measured indicators.
The familiar stick-figure lines that join a constellation's stars, drawn between the real stellar positions to make the ancient patterns legible on the star map.
A layer showing which part of the sky is above the horizon for an observer at a given place and time. Computed from the observer's location and the clock — no observing conditions are assumed or invented, and location stays on the device.
A layer marking the positions of objects observed by the James Webb Space Telescope, linking each region of the deep-sky map to the science it has enabled.
A layer marking the positions of famous Hubble Space Telescope targets across the deep-sky map, from the Deep Fields to the great nebulae.
A layer representing the all-sky astrometric coverage of the Gaia mission, whose measured positions and parallaxes underpin the modern star catalogue that the atlas draws.
A layer showing the angular field of view of a chosen telescope or instrument against the sky, so a target's real angular size can be compared with what an instrument can frame in a single pointing.
The minimum speed an object needs to break free of a body's gravity, ignoring drag. Set by the body's mass and radius alone.
The speed of a body on a circular orbit at a given distance from a central mass. The Earth circles the Sun at about 29.8 km/s.
Kepler's third law: the time to complete one orbit, from the semi-major axis and the central mass. A planet at 1 AU around the Sun takes one year.
The gravitational acceleration at a body's surface, from its mass and radius. Earth's is about 9.8 m/s².
The radius of the event horizon of a non-rotating black hole of a given mass — the size to which that mass must be compressed to become one. The Sun's is just under three kilometres.
The average density of a body from its mass and radius — a clue to its composition. Earth's ~5510 kg/m³ points to a rock-and-iron world; the giant planets are far less dense.
The radius within which a body's gravity dominates over the larger body it orbits — the region where its moons can hold. Earth's Hill sphere reaches about 1.5 million kilometres.
The distance within which a fluid satellite held together only by gravity is pulled apart by tides. Inside the Earth–Moon fluid Roche limit — about 18,000 km — a Moon-like body could not survive.
How often two orbiting bodies return to the same relative alignment — the interval between successive oppositions, say. Earth and Mars line up about every 2.14 years.
A star's total power output, from its radius and surface temperature by the Stefan–Boltzmann law. Doubling the temperature raises luminosity sixteenfold.
The power radiated per square metre by a blackbody at a given temperature. The Sun's photosphere emits about 63 megawatts per square metre.
The wavelength at which a blackbody radiates most intensely, by Wien's displacement law. The Sun peaks in green light at about 502 nm; hotter stars peak bluer, cooler stars redder.
The steep relation between a main-sequence star's mass and its luminosity: a star twice the Sun's mass shines roughly eleven times as bright. An approximation (exponent ~3.5) valid across the middle main sequence.
Roughly how long a star burns hydrogen in its core, scaled from the Sun's ~10 billion years. Massive stars are prodigal — a two-solar-mass star lasts under two billion years — while red dwarfs last far longer than the present age of the universe.
A star's intrinsic brightness — the apparent magnitude it would have at a standard distance of 10 parsecs. Removes distance so stars can be compared on equal footing.
The difference between apparent and absolute magnitude, which encodes distance. A modulus of five corresponds to 100 parsecs; each five magnitudes multiply the distance tenfold.
The most direct distance measurement: a star's distance in parsecs is the reciprocal of its annual parallax in arcseconds. A parallax of one arcsecond defines one parsec — but no star is that close.
How large an object of known size appears at a given distance. The Moon and the Sun span almost exactly the same half-degree from Earth — the coincidence that makes total solar eclipses possible.
The angle on the sky between two positions given by their right ascension and declination — the great-circle distance between two points on the celestial sphere.
The temperature a planet settles at from the balance of starlight absorbed and heat radiated, before any greenhouse warming. Earth's is about 255 K (−18 °C); its atmosphere lifts the surface to habitable warmth.
The orbital distance at which a planet receives the same starlight per square metre as Earth does from the Sun — a first anchor for the habitable zone. It scales with the square root of the star's luminosity.
The geometric chance that a planet's orbit is aligned edge-on enough for it to transit its star as seen from Earth. Only about one in 215 for an Earth-like orbit — which is why transit surveys must watch so many stars at once.
The recession velocity implied by a small cosmological redshift, v ≈ cz. This linear form holds only for low redshift; at large z the full relativistic and cosmological treatment is required and this approximation overstates the speed.
The distance to a galaxy from its recession velocity and the Hubble constant, by Hubble's law. Because the measured value of H₀ is itself contested — the Hubble tension — it is left as an input rather than fixed.
The finest detail a telescope can resolve, set by diffraction at its aperture — the Rayleigh criterion. Bigger apertures see finer detail; a 100 mm telescope resolves about 1.4 arcseconds in green light.
The magnification of a telescope–eyepiece pair — the ratio of their focal lengths. Useful magnification is capped by the aperture and the atmosphere, not by the eyepiece alone.
How much sky each camera pixel covers, from the pixel size and focal length. Matching the image scale to the seeing (roughly 1–2″ per pixel) is the key to sharp astrophotography.
The angular extent of sky a camera frames, from the sensor size and focal length. A shorter focal length or a larger sensor takes in more sky.
A rule-of-thumb estimate of the faintest star an aperture can show under dark skies. Approximate — real limits depend on sky brightness, magnification, and the observer — so it is offered as a guide, not a guarantee.
The best signal-to-noise achievable when the only noise is the Poisson statistics of the photons themselves — the shot-noise limit. To double the signal-to-noise you must collect four times as many photons.
What is worth observing tonight from a given place, drawn together from the platform's computed twilight, Moon, and planet positions. The plan updates with the observer's clock and location, which stay on the device.
When and whether a target clears the horizon and the twilight for a given night, from its coordinates and the observer's latitude. Built on the computed rise, set, and twilight times.
Builds an observing list from the graph's real objects — stars, deep-sky objects, planets — and checks each against the night's visibility. A bridge from the catalogue to the eyepiece.
The Moon's phase, illumination, and rise and set for a chosen night — the single biggest factor in deep-sky observing. Computed, not assumed.
Which planets are visible tonight and where, from the platform's computed planetary positions and their altitudes through the night. Jupiter and Saturn to Mercury's fleeting apparitions.
Plans a tour of galaxies, nebulae, and clusters by season, constellation, and difficulty, matched against the night's darkness and the target's altitude. The deep sky, night by night.
What each season brings — the constellations overhead, the meteor showers, and the signature deep-sky objects — so a year of observing can be planned in advance.
The civil, nautical, and astronomical twilight times for a given place and date — when true darkness begins and ends. Computed from the Sun's position.
The window of real darkness on a given night — after astronomical twilight ends and while the Moon is down. The hours that matter most for faint targets.
How high a target rides through the night — its altitude against time — so an observer can catch it near the meridian, above the murk of the horizon.
When a target crosses the meridian — its highest, sharpest point in the sky — the ideal moment to observe or image it. Computed from its right ascension and the local sidereal time.
Matches targets to gear — which objects suit binoculars, a small refractor, or a large Dobsonian — using the platform's real equipment catalogue and the target's brightness and size.
Plans an imaging session — the target's framing against the sensor, the Moon and darkness windows, and the capture technique — reusing the real camera, mount, and image-stacking entities.
Assembles a full observing session — an ordered list of targets timed to their best moments through a single night — from the visibility, altitude, and darkness plans. Exportable as a calendar or a printable plan.
An architecture-ready interface for local weather forecasts — the first thing that decides whether a session happens. The interface is defined and wired into the session planner, but no forecast is shown until a weather provider is connected; nothing is assumed.
An architecture-ready interface for atmospheric seeing — the steadiness of the air that sets how fine a detail a night can show. Wired into the astrophotography planner; seeing values appear only from a connected forecast source, never invented.
An architecture-ready interface for sky transparency — how much haze and moisture dim faint objects. Wired into the deep-sky planner; transparency is reported only from a connected source.
An architecture-ready interface for cloud-cover forecasts and satellite cloud maps. Wired into the tonight planner; cloud data is shown only when a provider is connected.
An architecture-ready interface for light-pollution and Bortle-class sky-brightness data by location — which sets how faint an object a site can reach. Wired into the deep-sky planner; a site's darkness is reported only from a connected light-pollution source.
The knowledge graph in numbers, counted live from the real data: how many entities and relations it holds, how they split across science, culture, and astrology, which entity types are largest, and which entities are the most connected hubs.
Deeper measures of the graph's structure — the average number of links per entity, the distribution of connectivity, and the hubs that hold the network together. The shape of the knowledge, not just its size.
A browsable index of every entity in the graph, organised by type and domain, each a gateway into its neighbourhood and its place in the wider web of knowledge.
The verbs of the graph — the relation types that connect entities, from 'orbits' and 'discovered by' to 'associated with' — and how often each is used. The grammar of the knowledge.
The immediate and extended neighbourhood of any entity, expanded breadth-first over the real relations. Start at a star and watch its constellations, catalogues, and physics unfold around it.
The shortest chain of relations connecting any two entities, found by breadth-first search over the real graph. Every link in the path is a genuine relation — a demonstration of how tightly the knowledge is woven together.
The graph's schema laid bare — the entity types and how they connect to one another, from stars and galaxies to missions and methods. The scaffolding on which every entity hangs.
The relations that reach across the graph's domains — where the science of the sky meets its cultural and historical meaning, as when a constellation joins its stars to its myths. The threads that make the graph one whole rather than three.
A node-link visualisation in which entities repel and relations pull, so the graph settles into a shape that reveals its clusters and hubs. A rendering mode over the real neighbourhood data.
A layered layout that arranges entities by level — a taxonomy from the top down, or a dependency chain from cause to effect. A rendering mode for the graph's hierarchical structure.
A grouping of the graph into its natural communities — the tightly-linked clusters of related entities, such as a mission and its instruments, or a star and its planets. A rendering mode over the real link structure.
The web around a single mission — its instruments, targets, discoveries, and the institutions behind it — drawn from the real relations. A lens that turns a mission from a name into a network.
The reach of a research institution across the graph — the missions it runs, the facilities it operates, and the discoveries it has enabled — traced through the real relations.
A discovery set in its web of context — the people who made it, the instruments that enabled it, the objects it revealed, and the ideas it changed. The story of a discovery as a graph.
The intellectual lineage running through the graph — how an astronomer's work connects to the theories, laws, and later discoveries that built on it. The descent of ideas, traced through the real relations.
A direct search across every entity in the graph by name — the fastest way from a word to a node and its neighbourhood.
A live, read-only REST API over the whole knowledge graph — entities, relations, neighbourhoods, and paths — served at /api/v0/entities so other tools can build on the knowledge. Now realised as the Open Platform's public Graph API.
Semantic, scientific search across every entity in the knowledge graph — a direct route from a question to the real objects, concepts, missions, and people that answer it. Grounded in the graph; it returns only what is really there.
A grounded explanation of any entity — what it is, how it connects to the rest of the graph, and where the knowledge comes from — assembled entirely from the entity's own description, its relations, and its cited sources.
Compares two concepts by the real common ground between them — the entities they both connect to in the graph. Mars and Venus, for instance, share atmospheric escape, climate evolution, and their place in the Solar System. A comparison built from relations, not rhetoric.
Explains how two entities are related by naming the real relations that link them — 'discovered by', 'orbits', 'is a kind of' — so a connection is never asserted without the graph edge that backs it.
Traces the chain of real relations connecting a claim to its supporting entities — for example, from Edwin Hubble through the expansion of the universe to dark energy. Every link in the chain is a genuine edge in the graph, so the reasoning can be followed and checked.
Every grounded answer carries the provenance of the entities it draws on — the sources cited on each, and the review status of the knowledge — so the reader can weigh how far to trust it. No answer without its provenance.
Answers linked back to the literature and catalogues behind them, through the platform's persistent identifiers and the ADS literature service. A grounded assistant that shows its references.
Suggests the concepts most closely related to any entity — its real neighbours in the graph. Ask about the main sequence and it surfaces the CNO cycle, the HR diagram, and stellar structure, because those are the entities it actually connects to.
Recommends what to read next from the platform's own entries, following the real relations outward from where a reader is — a grounded path deeper into a subject.
Concise summaries assembled from the entities' own curated descriptions and their key relations — a faithful digest of what the graph holds, with nothing added.
Assembles a learning path through a subject from the platform's curated paths and the real dependencies between concepts — a grounded curriculum drawn from the graph, ordered from foundations to frontier.
Reasons across the graph's domains — following a constellation from its stars to the myths named for it — using the real relations that bridge science, culture, and history. Connections across domains, never invented.
The design principle beneath the assistant: it surfaces only facts already in the knowledge graph, each with its provenance and a traceable chain of relations. A future language model would phrase these grounded facts, never add to them — so an answer can always be checked against the graph.
An architecture-ready interface for tuning the depth of an answer to its audience — an educational mode for newcomers, a research mode for depth, an expert mode for concision. The modes are defined; a language-model layer would realise them over the same grounded facts.
The grounded retrieval — search, neighbourhoods, evidence chains — is exposed as a retrieval-augmented-generation interface, so a future language model can ground every response in the real graph. The retrieval is real today; the generation is future work.
An architecture-ready layer for orchestrating a language model over the grounded retrieval — deciding what to fetch, in what order, and how to assemble it. Defined as an interface; no model is wired in yet.
An architecture-ready interface for remembering the thread of a conversation — the entities discussed, the questions asked — so follow-ups stay in context. The interface is prepared; memory stays on the device, private-first, and holds only references into the graph.
The seam where a language model would join — phrasing the grounded facts the retrieval layer supplies, always constrained to what the graph can back. The interface is defined; the model is future work, and when it comes it will explain, never invent.
The United States' official source for space-weather forecasts and alerts — solar wind, the planetary K-index, the geomagnetic storm scale, and radio-blackout and radiation warnings. Modelled here as a real provider with an honest status; no value is shown until it is connected.
NASA's open database of solar and space-weather events — flares, coronal mass ejections, solar energetic particle events, and interplanetary shocks — served through a public API. Modelled as a real provider with an honest status; no event is shown until it is connected.
The IAU's clearing house for asteroid and comet observations, designations, and orbits, including near-Earth-object close approaches. Modelled as a real provider with an honest status; no close-approach data is shown until it is connected.
NASA JPL's Center for Near-Earth Object Studies computes close-approach tables and impact-risk (Sentry) summaries for asteroids and comets, served through the Solar System Dynamics APIs. Modelled as a real provider with an honest status; no approach distance or date is shown until it is connected.
CelesTrak publishes two-line orbital elements for the ISS and thousands of satellites, from which passes over an observer can be computed by SGP4 propagation. The source and pipeline are modelled here as architecture-ready; neither the live feed nor the propagation is wired, and no pass time is fabricated.
The local conditions that decide whether an observing night happens — weather, atmospheric seeing, sky transparency, cloud cover, and Bortle sky brightness. No licence-safe open provider is connected; the interfaces are defined and await one, and no condition is ever fabricated.
An interactive, to-scale model of the Sun's planetary system. Each orbit ring is drawn at the planet's real semi-major axis, so the true structure of the system — the crowded inner planets and the vast reaches of the outer ones — is genuine. Drag to rotate the system, scroll to zoom.
The nearest stars to the Sun, plotted at their true three-dimensional positions from measured parallax distances. This is the view a two-dimensional star chart cannot give: not just where a star lies on the sky, but how far away it truly is. Drag to fly around the neighbourhood; the Sun sits at the centre.
The stars of a constellation shown by their real directions on the celestial sphere — the pattern as it appears from Earth. Turn on the true-distance figures in the table and a striking fact appears: the stars of a constellation lie at wildly different distances and are not physically connected at all. The familiar shape is a line-of-sight illusion.
Our home galaxy and the Sun's place within it. The measured part of this picture — the local stellar neighbourhood — is the real 3D star field; the wider structure of the Galaxy (its disc, bulge, bar, spiral arms, halo, and centre) is presented from the galactic-structure catalogue as described components, because numeric galaxy-scale positions are not part of the data.
Our galactic neighbourhood — the Milky Way, Andromeda, Triangulum, the Magellanic Clouds, and the dozens of dwarf galaxies bound with them. The members and their relationships are drawn from the graph; their separations are given by the catalogue's descriptive scale labels, because numeric inter-galactic distances and positions are not part of the data.
Bookmark any entity in the knowledge graph — a planet, star, mission, galaxy, method — to your own workspace with a single click. Saved entities are stored only in your browser and are the raw material of collections, notes, and citations. Nothing is sent to a server.
Organise saved entities into named collections — a research theme, a set of targets, a topic to revisit. Collections live in your browser and can be exported or printed. A collection references entities by id; it never copies or alters the underlying data.
An ordered reading list — a path through the encyclopedia you intend to follow. A reading list is a collection whose order is meaningful, so you can sequence a study plan. Stored locally; nothing is tracked about what you read.
Gather the objects you plan to observe into an observation project — a set of targets you can pair with the observing planners and the live-sky tools. An observation project is a local collection of real targets; it computes nothing and fabricates no ephemeris.
Write your own notes and attach them to a saved entity or keep them free-standing — questions, observations, connections you have spotted. Notes are yours alone, held only in your browser, and are included in exports and the printable packet.
Collect the citations behind the entities you study into a citation folder, and export them in APA, Chicago, MLA, Harvard, BibTeX, or RIS. It REUSES the platform's citation engine over real, source-backed references — every field comes from a verifiable citation record; none is invented.
Export your whole workspace — saved entities, collections, notes, and citations — to JSON, Markdown, BibTeX, or CSV, or print a clean research packet. Exports are generated in your browser from your local data; nothing is uploaded, and JSON can be re-imported to move your workspace between devices yourself.
The workspace is private by construction. It stores everything in your browser's localStorage under a single key, holds no account, sets no cookie, makes no network request, and records no analytics. Your data never leaves your device, and a single control erases all of it. This is a guarantee of the design, not a policy promise.
A read-only, deterministic REST API over the whole knowledge graph — list and fetch entities, list relationships, search, and traverse neighbourhoods and shortest paths. Every response carries a provenance envelope (version, source, licence, attribution). No auth, no rate limits, no write endpoints.
The graph query surface: breadth-first neighbourhood traversal and shortest evidence paths between two entities, cycle-safe and bounded. The same real algorithms behind the graph explorer and the grounded assistant, exposed as an API.
A machine-readable OpenAPI 3.1 description of every implemented endpoint, generated from the endpoint registry — so a client, a code generator, or an agent can discover the API automatically.
The registry of authoritative sources behind the platform — every source's name, organisation, canonical URL, licence, and scope — served as a public endpoint, so the provenance of any cited fact can be resolved programmatically.
The real, source-backed citations behind entities, served as an API and exportable in APA, Chicago, MLA, Harvard, BibTeX, and RIS through the platform's citation engine. Every field comes from a verifiable citation record; none is invented.
The complete typed graph — every entity and relation — as a single JSON document, generated from the real graph. The exact bytes served back the download manifest's size and checksum.
The graph as JSON-LD — an RDF-compatible, SPARQL-ready document with a resolvable @id per node and relations as predicates. The linked-data foundation the SPARQL and federation layers are built to sit on.
Every curated dataset — from named stars to live-provider status to 3D scenes — exportable as JSON and CSV with real record counts, licences, and provenance. A focused slice of the graph for a specific need.
The full graph exports offered as bulk downloads, each with a REAL byte size and SHA-256 checksum computed from the exact bytes served, plus its licence and release. No download is fabricated — the checksum can be verified against the file.
The graph and its schema carry versions, surfaced in every API response's provenance envelope, in the OpenAPI description, and on every export — so a consumer can pin a release and know when entities or the schema change.
A clear matrix of the licences that apply — the platform's own CC BY-SA 4.0 for the graph and API, and the individual terms of each upstream source (NASA, ESA, IAU, and the rest) — so reuse obligations are never in doubt.
A hosted SPARQL query endpoint over the graph's RDF. The linked-data shape is live in the JSON-LD export; a queryable SPARQL service is the architecture-ready next step and is not yet hosted — no endpoint is advertised as live.
A GraphQL surface over the same graph, letting a client request exactly the entities, fields, and relations it needs in one query. The schema maps cleanly onto the typed graph; the resolver layer is architecture-ready and not yet served.
Citable, DOI-minted snapshots of the graph, so a specific release can be referenced in the literature. The versioning and checksummed exports that a DOI release needs are live; minting DOIs through a registration agency is architecture-ready.
A Python client over the public API — typed models for entities and relations, and helpers for search, traversal, and export. The API and its OpenAPI description are live, so a client can be generated today; a curated, published package is architecture-ready.
A typed JavaScript/TypeScript client over the public API, for the browser or Node. As with the Python SDK, the OpenAPI description makes a client generatable today; a curated, published package is architecture-ready.
Every entity already carries a resolvable IRI in the JSON-LD export, the foundation for federating the graph with other linked-data sources. A published federation manifest and cross-dataset link set are architecture-ready.
An interface prepared for the International Virtual Observatory Alliance protocols — a TAP service answering ADQL queries over the tabular catalogues (stars, deep-sky, exoplanets). The catalogues carry the real measured columns; a TAP/ADQL service over them is architecture-ready.
The innermost region of the Sun, out to about a quarter of its radius, where nuclear fusion powers the star. At roughly 15 million kelvin and immense density, hydrogen fuses to helium mainly through the proton–proton chain, releasing the energy that slowly works its way outward. Almost all of the Sun's luminosity is generated here.
The layer surrounding the core, from about a quarter to seven-tenths of the solar radius, where energy travels outward as radiation. Photons are absorbed and re-emitted so many times that a single packet of energy can take on the order of a hundred thousand years to cross it. The plasma here rotates almost as a rigid body.
The thin shear layer near seven-tenths of the solar radius, where the rigidly rotating radiative interior meets the differentially rotating convection zone. This velocity shear is widely thought to be where the Sun's large-scale magnetic field is generated — the seat of the solar dynamo.
The outer third of the solar interior, where energy is carried by convection — hot plasma rises, cools, and sinks, like a pot of boiling water. This churning is visible at the surface as granulation and drives the magnetic activity of the Sun. It sits above the tachocline and below the photosphere.
The visible surface of the Sun — the layer from which sunlight escapes — with an effective temperature near 5,772 kelvin and a thickness of only a few hundred kilometres. Sunspots, granulation, and the limb darkening seen in white-light images all belong to the photosphere. It is the reference surface for the Sun's radius.
The reddish layer of the solar atmosphere just above the photosphere, a few thousand kilometres thick, briefly visible as a rosy rim at the start and end of a total eclipse. Its temperature rises with height, and it is threaded by spicules, filaments, and plages. Above it lies the thin transition region.
The thin, irregular layer between the chromosphere and the corona where the temperature climbs steeply — from around ten thousand to a million kelvin over only a few hundred kilometres. It radiates mostly in the extreme ultraviolet and is central to the still-open question of how the corona is heated.
The Sun's outermost atmosphere — a tenuous, million-degree plasma extending millions of kilometres into space, visible to the eye only during a total solar eclipse or with a coronagraph. Far hotter than the surface beneath it, it is shaped by magnetic fields into loops, holes, and streamers, and it continually expands outward as the solar wind.
The mottled, cellular pattern covering the photosphere — the tops of convection cells about a thousand kilometres across, each lasting only minutes. Bright centres are hot plasma rising, dark lanes are cooler plasma sinking. Granulation is the direct visible signature of the convection zone beneath.
A larger-scale convective pattern, with cells around thirty thousand kilometres across that persist for roughly a day. Supergranule flows sweep magnetic field to their edges, building the chromospheric network. It was discovered through Doppler measurements of the surface flows.
A large, relatively cool and dense structure of plasma suspended above the solar surface by magnetic fields, extending into the hot corona. Seen at the limb against the dark sky it appears as a bright arch; quiescent prominences can last for months, while eruptive ones can launch a coronal mass ejection.
The same structure as a prominence, but seen against the bright solar disk rather than at the limb, where it appears as a dark, thread-like channel. A filament is cool plasma along a magnetic boundary; its sudden eruption is a common trigger of a coronal mass ejection.
A bright region of the chromosphere associated with an active region, where concentrated magnetic field heats the plasma above a group of sunspots. Plages are conspicuous in the light of hydrogen and calcium and mark magnetically active areas even as the sunspots themselves come and go.
A short-lived jet of plasma, a few hundred kilometres across, that shoots up from the chromosphere at tens of kilometres per second and falls back within minutes. Millions cover the Sun at any moment, giving the chromospheric limb a grassy appearance; they may contribute to the mass and energy budget of the corona.
An arch of hot, glowing plasma tracing a magnetic field line rooted in the photosphere, the basic building block of the closed corona above active regions. Coronal loops shine brightly in the extreme ultraviolet and X-rays and are central to studies of how the corona is structured and heated.
A large, pointed structure in the corona, seen in eclipse and coronagraph images as bright rays extending outward above the streamer belt. Helmet streamers cap closed magnetic regions and are the source of the slow solar wind; their shape changes over the solar cycle.
A thin, ray-like structure of denser plasma rooted in the Sun's polar regions and extending into a polar coronal hole. Plumes trace open magnetic field lines from which fast solar wind flows, and appear as delicate streaks in images of the poles.
The mechanism that generates and regenerates the Sun's magnetic field, converting the energy of plasma motions — differential rotation and convection — into magnetic energy. The dynamo drives the roughly eleven-year sunspot cycle and the reversal of the Sun's polarity; the details, especially the role of the tachocline, remain an active research problem.
The process by which oppositely directed magnetic field lines break and reconnect, converting stored magnetic energy explosively into heat, light, and fast particles. Reconnection powers solar flares and helps launch coronal mass ejections, and is a fundamental plasma process seen throughout the Universe.
The Sun does not rotate as a solid body: its equator completes a turn in about twenty-five days while the polar regions take around thirty-five. This shearing of the plasma winds up the magnetic field and is a key ingredient of the solar dynamo. It is measured from tracking sunspots and from helioseismology.
One of the central open questions in solar physics: why the corona, at a million or more kelvin, is hundreds of times hotter than the photosphere below it. Leading candidate mechanisms include heating by many tiny reconnection events (nanoflares) and by magnetic waves; missions such as Parker Solar Probe and Solar Orbiter are testing them. No single answer is yet established.
A proposed solution to the coronal heating problem, put forward by Eugene Parker: the corona is heated by a vast number of tiny reconnection events — nanoflares — each far too small to see on its own, but collectively enough to keep the corona hot. It is one of several candidate mechanisms still being tested against observations.
A plot of the latitudes at which sunspots appear over time, first drawn by the Maunders. Across each roughly eleven-year cycle, spots emerge first at mid-latitudes and then closer to the equator, so successive cycles trace wing-shaped patterns. It is the clearest visual summary of the solar activity cycle.
A roughly seventy-year span in the seventeenth and early eighteenth centuries when sunspots almost vanished from the record. It overlapped part of the cooler period known as the Little Ice Age, though the size of any climate link is debated. It is the archetype of a grand solar minimum.
A period of low but not absent solar activity around the turn of the nineteenth century, less deep than the Maunder Minimum. Like other grand minima it is reconstructed from sunspot counts and from cosmogenic isotopes recorded in ice cores and tree rings.
The total energy the Sun radiates varies slightly over the activity cycle — by about a tenth of a percent between solar maximum and minimum — as dark sunspots and bright faculae come and go. Measured continuously from space since the late 1970s, these variations are a key input to studies of the Sun's influence on climate.
The steady, high-speed stream of the solar wind — around seven to eight hundred kilometres per second — that flows out along open magnetic field lines from coronal holes, especially over the poles at solar minimum. It is smoother and less dense than the slow wind.
The denser, more variable component of the solar wind — around three to five hundred kilometres per second — associated with the streamer belt near the solar equator. Its exact sources and release mechanisms are still being pinned down by close-in missions.
The spiral shape the Sun's magnetic field takes as it is carried outward by the solar wind while the Sun rotates, like water from a spinning sprinkler. Predicted by Eugene Parker in 1958 and since confirmed by spacecraft, the Parker spiral sets the geometry of the interplanetary magnetic field and how solar storms reach the planets.
The boundary where the supersonic solar wind abruptly slows as it runs into the pressure of the interstellar medium, roughly ninety astronomical units from the Sun. Voyager 1 crossed it in 2004 and Voyager 2 in 2007 — the first direct measurements of this shock.
The turbulent outer region of the heliosphere, between the termination shock and the heliopause, where the slowed solar wind piles up and is deflected by the interstellar medium. Both Voyager spacecraft spent years traversing it before reaching interstellar space.
The disturbance ahead of the heliosphere as it moves through the surrounding interstellar cloud. Earlier work expected a sharp bow shock, but measurements from IBEX and the Voyagers suggest the Sun moves too slowly through the local medium for a strong shock — a gentler bow wave instead. The exact nature of the boundary is still being studied.
The region just outside the event horizon of a rotating (Kerr) black hole where spacetime itself is dragged around so fast that nothing can stay still relative to the distant stars. Energy can, in principle, be extracted from a black hole's rotation here through the Penrose process. A non-rotating black hole has no ergosphere.
The radius around a non-rotating black hole — one and a half Schwarzschild radii — at which gravity bends light so strongly that photons can orbit in unstable circles. It sets the size of the black hole's 'shadow' and the bright ring seen in the Event Horizon Telescope images of M87* and Sgr A*.
The closest orbit around a black hole in which matter can circle stably — at three Schwarzschild radii for a non-spinning black hole, and closer for a rapidly spinning one. Inside it, matter spirals inevitably inward. The ISCO sets the inner edge of an accretion disk and thus how much energy accretion can release.
The result that a black hole in equilibrium is fully described by just three numbers — its mass, its spin, and its electric charge — and retains no other detail of whatever formed it. All the complexity of the collapsing matter is lost to the outside universe, hidden behind the event horizon with the central singularity, giving black holes a remarkable simplicity.
The twisting of spacetime by a rotating mass, which drags nearby matter and light around with it. Extreme near a spinning black hole, it creates the ergosphere; it is tiny near the Earth, where it was measured by the Gravity Probe B and LAGEOS satellite experiments — a direct confirmation of a subtle prediction of general relativity.
The stretching of light to longer wavelengths as it climbs out of a gravitational well, a prediction of general relativity. It is extreme near a black hole's event horizon, where light is redshifted without limit, and has been measured for the Sun, for white dwarfs, and even for atomic clocks at different heights on Earth.
The stretching of an object into a long, thin shape by the difference in a black hole's gravity between its near and far sides. Around a small stellar black hole the tidal force is lethal well outside the horizon; around a supermassive black hole it is gentle at the horizon, so an infalling object could cross without being torn apart.
A narrow beam of plasma launched at nearly the speed of light from the vicinity of an accreting black hole — from stellar black holes in binaries and from the supermassive black holes powering active galaxies. Jets can span from light-years to millions of light-years and are thought to be powered by the black hole's spin and magnetic fields.
The leading explanation for how relativistic jets are powered: magnetic field lines threading a spinning black hole extract its rotational energy and fling plasma outward. Proposed by Roger Blandford and Roman Znajek in 1977, it lets a black hole act as a cosmic engine, converting spin into the enormous power of a jet.
A near-regular flickering in the X-ray brightness of matter orbiting a black hole or neutron star, revealed in the power spectrum as a broad peak rather than a sharp tone. QPOs probe the innermost accretion flow, close to the innermost stable circular orbit, and are used to study strong gravity — though their exact origin is still debated.
The idealised, spherically symmetric capture of surrounding gas by a compact object, worked out by Hermann Bondi in 1952. It sets a benchmark rate at which a black hole or neutron star can swallow the gas around it, and underlies estimates of how quiescent supermassive black holes such as Sgr A* are fed.
The quantum pressure — arising from the Pauli exclusion principle acting on densely packed neutrons — that holds a neutron star up against its own gravity. It is far stronger than the electron degeneracy pressure that supports a white dwarf, but it too has a limit: above roughly two to three solar masses, no known pressure can prevent collapse into a black hole.
The still-uncertain relationship between pressure and density inside a neutron star, which decides how compressible its ultra-dense matter is and therefore the star's radius and maximum mass. Pinning it down — from radius measurements by NICER, from massive pulsars, and from the tidal signature in neutron-star mergers — is a central goal of modern astrophysics.
How a pulsar pulses: a rapidly rotating, strongly magnetised neutron star beams radiation from its magnetic poles, and if a beam sweeps across the Earth we see a regular pulse once per rotation, like a lighthouse. The precise physics of how the beam is generated in the star's magnetosphere is still not fully understood.
A sudden, tiny speed-up in a pulsar's otherwise steadily slowing rotation, followed by a gradual relaxation. Glitches are thought to be caused by the sudden transfer of angular momentum from a superfluid deep inside the neutron star to its solid crust, giving a rare window onto matter at supernuclear density.
The most powerful magnetic fields known in the Universe — around a hundred trillion to a quadrillion gauss — carried by magnetars, a class of young neutron star. The decay of this colossal field powers their X-ray and gamma-ray flares, including the giant flares bright enough to be detected across the Galaxy and beyond.
A rapidly rotating, magnetised neutron star observed as a source of regular pulses of radiation, usually in radio. The first was found in 1967 by Jocelyn Bell Burnell and Antony Hewish; thousands are now known, with periods from milliseconds to seconds. Pulsars are precise cosmic clocks used to test gravity and to search for gravitational waves.
An old pulsar spun up to hundreds of rotations per second by accreting matter from a companion star — 'recycled' to spin periods of only a few milliseconds. Their extraordinary rotational stability makes them the most precise clocks known and the basis of pulsar-timing arrays searching for low-frequency gravitational waves.
A neutron star in a binary system that pulls gas from its companion; the gas is funnelled by the star's magnetic field onto its poles, where it heats up and shines in pulsed X-rays as the star rotates. X-ray pulsars are how many neutron stars are weighed, and how millisecond pulsars are recycled.
A pulsar whose radiation is powered by the gradual loss of its rotational energy as it slowly spins down — the classic young pulsar, of which the Crab is the archetype. This is distinct from an accretion-powered X-ray pulsar, which draws its energy from infalling matter rather than from its own spin.
The compact object of Cygnus X-1 — the first widely accepted black hole. A bright X-ray source in Cygnus discovered in 1964, it is a stellar-mass black hole of roughly twenty-one solar masses pulling gas from its blue-supergiant donor star (HD 226868). It was the subject of a famous bet between Stephen Hawking and Kip Thorne, which Hawking conceded in 1990.
A stellar-mass black hole of about nine solar masses in a binary system in Cygnus, and one of the nearest black holes with a precisely measured distance from radio parallax. Normally quiet, it erupted in a dramatic X-ray and radio outburst in June 2015 — a nearby microquasar caught devouring gas from its companion.
The young neutron star at the heart of the Crab Nebula, formed in the supernova recorded by observers in 1054. It spins about thirty times a second and is the archetypal rotation-powered pulsar, its wind lighting up the surrounding nebula across the spectrum, from radio to gamma rays.
A young, bright pulsar in the Vela supernova remnant, spinning about eleven times a second. It is the classic glitching pulsar — famous for sudden small speed-ups in its rotation that reveal the superfluid interior of a neutron star — and one of the brightest gamma-ray sources in the sky.
The first pulsar ever discovered, found by Jocelyn Bell Burnell and Antony Hewish in 1967 as a startlingly regular radio signal once labelled 'LGM-1' for Little Green Men. Its 1.337-second pulses opened the study of neutron stars; the discovery is commemorated on the cover of Joy Division's album Unknown Pleasures.
One of the most massive neutron stars known, at about 2.08 solar masses, weighed through the Shapiro delay of its pulses. Its radius has been measured by NASA's NICER X-ray telescope, and together the mass and radius are among the tightest constraints on the neutron-star equation of state and how dense matter behaves.
The mathematical object that captures everything knowable about a quantum system; its squared magnitude gives the probability of finding a particle in a given state. Wave functions underlie the discrete energy levels of atoms — and therefore the spectral lines that let astronomers read the composition, temperature, and motion of distant stars and gas.
The principle that a quantum system can exist in a combination of states at once until it is measured, when a single outcome is realised. It is the heart of quantum weirdness and of quantum computing, and it is the reason atomic transitions and particle interactions must be described in probabilities rather than certainties.
A deep correlation between quantum particles such that measuring one instantly fixes the state of the other, however far apart they are — what Einstein called 'spooky action at a distance.' Confirmed in ever-more-stringent experiments, it does not allow faster-than-light signalling and is a foundation of quantum information science.
The fundamental limit that a particle's position and momentum cannot both be known with arbitrary precision — a property of quantum nature itself, not of imperfect instruments. Together with the Pauli exclusion principle it sets the scale of the degeneracy pressure — the resistance of fermions such as electrons and neutrons to being crowded together — that holds up white dwarfs and neutron stars against gravity.
The finding that light and matter each behave as both waves and particles depending on how they are observed — light as photons in the photoelectric effect, electrons as interfering waves in a double slit. It reconciled centuries of debate about the nature of light and underlies how detectors count the photons that carry astronomy's information.
An intrinsic form of angular momentum carried by particles, quantised in units of the reduced Planck constant and unrelated to any literal spinning. Spin divides particles into fermions and bosons and, through the Pauli exclusion principle, into the electron shells of atoms; the spin-flip of hydrogen produces the 21-centimetre radio line that maps neutral gas across the Galaxy.
The quantum ability of a particle to cross an energy barrier it classically could not surmount. Tunnelling lets protons in the Sun's core fuse despite their electrical repulsion — without it the Sun could not shine — and it is central to the theory of how radiation escapes a black hole.
The lowest possible energy of a quantum system, which is never zero — even empty space seethes with quantum fluctuations. This vacuum energy is a real, measured effect (the Casimir force), and its possible connection to the accelerating expansion of the Universe is one of the deepest open problems in physics.
The process by which a quantum system loses its delicate superposition through unavoidable interaction with its environment, giving rise to the definite, classical world we observe. Decoherence explains why quantum weirdness is hard to see at everyday scales and is a central challenge for building quantum computers.
The fundamental constituents of matter and force in the Standard Model — the quarks and leptons that make up matter, and the force-carrying bosons. Everything from a star to a galaxy is built from a handful of these particles, and understanding them connects the physics of the very small to the structure of the whole Universe.
The four basic interactions of nature — gravity, electromagnetism, and the strong and weak nuclear forces. Together they govern everything from the fusion that powers stars to the collapse of a massive core, and unifying them, especially gravity with the quantum forces, remains a central goal of physics.
The particle associated with the Higgs field, which gives many elementary particles their mass. Predicted in the 1960s and discovered at CERN's Large Hadron Collider in 2012, it completed the Standard Model; the origin of mass it explains is fundamental to why matter — and therefore stars and galaxies — exists as it does.
A tiny, electrically neutral particle that interacts only very weakly and so streams almost unimpeded through matter — trillions pass through you each second. Neutrinos are produced in the Sun's core, in supernovae, and by cosmic rays, and detecting them opens a window onto processes hidden from light, a pillar of multi-messenger astronomy.
The quantum phenomenon in which a neutrino changes flavour — electron, muon, or tau — as it travels. Its discovery proved that neutrinos have a small mass, resolved the decades-old 'solar neutrino problem' of the Sun apparently producing too few, and was recognised with the 2015 Nobel Prize in Physics.
Matter's mirror image — particles with the same mass but opposite charge, such as the positron discovered in cosmic rays in 1932. When matter and antimatter meet they annihilate into pure energy. Antiparticles are produced in high-energy astrophysical environments and are detected in cosmic rays reaching the Earth.
The unexplained fact that the Universe is made almost entirely of matter, even though the Big Bang should have produced matter and antimatter in equal amounts, which would have annihilated completely. Why a tiny excess of matter survived — the problem of baryogenesis — is one of the great open questions in physics and cosmology.
Einstein's result that mass and energy are two forms of the same thing, related by the speed of light squared. It is the accounting behind starlight: fusing hydrogen into helium in the Sun's core converts about four million tonnes of mass into energy every second, and it governs the annihilation of matter with antimatter.
The relativistic effect by which time runs slower for fast-moving observers and deeper in a gravitational field. It is measured every day — GPS satellites must correct for it — and it steepens near neutron stars and black holes, where clocks near the horizon crawl relative to distant ones. Even distant supernovae are seen to fade in slow motion as the Universe expands.
The relativistic shortening of an object along its direction of motion as seen by an observer it moves past, becoming dramatic near the speed of light. It is the companion of time dilation, and it explains how short-lived muons created high in the atmosphere by cosmic rays still reach the ground.
The principle that gravitational and inertial mass are identical, so that being in free fall is locally indistinguishable from floating in empty space. This insight led Einstein from special to general relativity, recasting gravity as the curvature of spacetime; it is tested to extraordinary precision by lunar laser ranging and dedicated satellites.
Fleeting, unavoidable variations in the energy of a field, permitted by the uncertainty principle. Stretched to astronomical size during cosmic inflation, tiny quantum fluctuations are believed to have seeded the density variations we now see imprinted on the cosmic microwave background and grown into galaxies and clusters.
The energy that fills empty space even in the absence of matter or radiation, arising from quantum fields in their lowest state. Vacuum energy is a leading candidate for the dark energy driving cosmic acceleration and is closely tied to the cosmological constant in Einstein's equations.
The vast mismatch between the tiny dark-energy density measured in the Universe and the enormous vacuum energy that naive quantum theory predicts — a discrepancy of many tens of orders of magnitude. Often called the worst prediction in physics, it remains one of the deepest unsolved problems where quantum theory meets gravity.
A sea of relic neutrinos released about one second after the Big Bang, when the young Universe became transparent to them — the neutrino analogue of the cosmic microwave background. Its existence is strongly supported by its imprint on primordial element abundances and the microwave background, though the neutrinos themselves are far too low in energy to have been detected directly.
A theoretical ceiling on the energy of cosmic-ray protons that reach us from far away: above roughly 5×10¹⁹ electronvolts they collide with cosmic-microwave-background photons and lose energy, so the highest-energy cosmic rays must originate relatively nearby. Observatories studying the ultra-high-energy sky test this predicted cutoff.
A family of thrusters that accelerate propellant using electrical energy rather than combustion, reaching exhaust velocities several times higher than chemical rockets. The trade is thrust: forces are gentle — millinewtons to newtons — so electric propulsion excels at station-keeping and patient deep-space cruises, as NASA's Dawn demonstrated in reaching both Vesta and Ceres.
An architecture that pairs a space nuclear reactor with electric thrusters: the reactor generates electricity, which drives ion or Hall thrusters. Unlike solar-electric propulsion it is independent of distance from the Sun, making it a candidate for crewed missions to Mars and the outer Solar System. No nuclear-electric system has yet flown; it remains a design and technology-development goal.
An electric-propulsion concept that heats propellant to a plasma with radio waves and confines and exhausts it with magnetic fields, in principle allowing the exhaust velocity to be tuned in flight. It has been tested on the ground but has not flown in space, and operating it at useful power levels would require an electrical source far beyond today's spacecraft.
An electrothermal thruster that passes propellant through an electric arc, heating it far beyond what a chemical reaction alone allows before it expands through a nozzle. Arcjets have flown operationally for satellite station-keeping, offering higher exhaust velocity than cold-gas or simple resistojet systems.
The simplest electric thruster: propellant is warmed by flowing over an electrically heated element and then expelled through a nozzle. Modest but reliable, resistojets have long been used for satellite attitude control and station-keeping, bridging cold-gas systems and higher-performance electric propulsion.
Propulsion with no propellant at all: a large, lightweight reflective sail is pushed by the momentum of sunlight itself. The thrust is minute but continuous and free, building up large velocity changes over time. Japan's IKAROS proved the principle in interplanetary space in 2010, and The Planetary Society's LightSail 2 demonstrated sail-raised orbits around Earth.
A simple chemical system in which a single propellant — classically hydrazine — is decomposed over a catalyst bed to produce hot gas, needing no separate oxidiser or ignition. Monopropellant thrusters are workhorses for spacecraft attitude control and small maneuvers, valued for their simplicity and quick, repeatable pulses.
A chemical system that burns a separate fuel and oxidiser, releasing far more energy than a monopropellant and delivering higher exhaust velocity. Bipropellant engines — from hypergolic storable combinations to cryogenic hydrogen–oxygen — power launch vehicles, orbit-insertion burns, and deep-space main engines.
A high-efficiency rocket-engine power cycle in which propellant burned in a preburner drives the turbopumps and is then routed into the main chamber, so almost none is wasted. It is harder to build than the simpler gas-generator cycle but yields higher performance; the Space Shuttle's RS-25 used it, and SpaceX's Raptor uses the even more demanding full-flow staged-combustion variant.
The founding relation of astronautics, derived by Konstantin Tsiolkovsky in 1903: the velocity change a rocket can achieve equals its exhaust velocity times the natural logarithm of the ratio of its starting mass to its empty mass. Because the mass ratio enters logarithmically, reaching high Δv demands either very high exhaust velocity or an impractically large fraction of propellant — the 'tyranny' that shapes every mission design.
The standard measure of a rocket's fuel efficiency: the thrust produced per unit weight-flow of propellant, expressed in seconds. Higher specific impulse means more velocity change from the same propellant. Chemical engines reach roughly 300–450 seconds; electric thrusters, trading thrust for efficiency, reach thousands.
The ratio of an engine's or vehicle's thrust to its weight. To lift off, a launch vehicle's thrust must exceed its weight — a thrust-to-weight ratio above one — while efficient upper-stage and in-space engines can operate well below one. It is the counterpoint to specific impulse: high-thrust engines often trade away efficiency, and vice versa.
An accounting of every velocity change a mission requires — launch to orbit, orbital transfers, planetary capture, landing, and margins — summed into a total 'delta-v budget' that the propulsion system must deliver. Comparing the budget against what the rocket equation allows is the central feasibility check of mission design.
The practice of discarding spent tanks and engines during ascent so the rocket no longer has to accelerate empty mass. Staging sidesteps the rocket equation's steep penalty on mass ratio and is how essentially every orbital launch vehicle reaches space — from the Saturn V's three stages to the Falcon 9's two.
Steering a rocket by aiming its thrust — most often by gimballing the engines on hydraulic or electric actuators, and sometimes with vanes or differential throttling. Because a climbing rocket is aerodynamically unstable, thrust vector control is what keeps it pointed and on course from liftoff through staging.
The guided approach of two spacecraft to the same orbit and position so they can dock or berth — a delicate dance governed by orbital mechanics, where firing to speed up raises the orbit and paradoxically slows the chase down on a target ahead, while slowing down drops into a lower, faster orbit that catches up. First achieved by Gemini in 1965, rendezvous is the foundation of space-station crew and cargo flights and of in-space assembly.
The small, regular maneuvers that hold a spacecraft in its intended orbit or slot against perturbations — atmospheric drag, the Moon and Sun's pull, and the Earth's uneven gravity. Geostationary satellites, for instance, must be nudged north–south and east–west to stay on station, a task increasingly handed to efficient electric thrusters.
Using repeated shallow passes through the upper fringe of a planet's atmosphere to shed orbital energy through drag, gradually shrinking a large capture orbit into the desired one — trading time for a large saving in propellant. NASA's Mars orbiters, including Mars Global Surveyor and Mars Reconnaissance Orbiter, used months of aerobraking to reach their science orbits.
A single, deep pass through a planet's atmosphere to slow a spacecraft enough for orbital capture in one stroke, behind a heat shield — far faster than aerobraking but far more demanding, requiring precise guidance and thermal protection. It has been studied and validated in analysis but has not yet been used on a planetary mission.
The efficient launch trajectory in which a rocket pitches over slightly after liftoff and then lets gravity gradually bend its path toward the horizontal, keeping the vehicle aligned with its velocity to minimise aerodynamic loads and steering losses. Nearly every orbital launch follows a gravity-turn profile from the pad to orbit.
The workhorse of exoplanet atmospheres: as a planet transits its star, a sliver of starlight filters through the ring of atmosphere at its edge, and the gases there imprint absorption features that vary with wavelength. Comparing the planet's apparent size across a spectrum reveals which molecules — water, carbon dioxide, methane — are present. JWST has made this a routine, high-precision technique.
Measuring the light a planet itself emits — usually its thermal glow — to probe the temperature structure and composition of its dayside. Because the planet's emission is measured against the star, it is easiest for hot planets, and it reveals whether temperature rises or falls with altitude in ways transmission spectra cannot.
The moment a planet passes behind its star. The dip in the system's combined light equals the light the planet was contributing, so subtracting the two isolates the planet's thermal emission and reflected light — the basis of emission spectroscopy and dayside temperature measurements.
Tracking a planet's brightness through its whole orbit as its illuminated fraction changes, like the phases of the Moon. The shape of the curve reveals the temperature difference between day and night sides and how efficiently winds carry heat around the planet — a direct window onto atmospheric circulation.
The statistical machinery that turns a spectrum into numbers: models of an atmosphere are compared against the data, usually with Bayesian inference, to find the mix of gases, temperatures, and clouds that best explains it — along with honest uncertainties. Retrieval is how a wiggly spectrum becomes a measured abundance.
High-Resolution Cross-Correlation Spectroscopy
A ground-based technique that resolves thousands of individual spectral lines and uses the planet's changing Doppler shift along its orbit to separate its light from the star's and the Earth's atmosphere. Cross-correlating against molecular templates detects specific gases and even measures atmospheric winds; it is a headline science case for the coming extremely large telescopes.
A spectroscopic signature seen during transit: as the planet crosses the face of its rotating star, it blocks first the approaching then the receding limb, distorting the star's measured velocity. The shape of that distortion reveals whether the planet's orbit is aligned with the star's spin — a key clue to how the system formed and migrated.
Condensate clouds and photochemically produced hazes are common in exoplanet atmospheres, and they matter for observers: high-altitude aerosols mute or flatten the features in a transmission spectrum, masking the gases below. Distinguishing a genuinely cloudy atmosphere from a clear one is a central challenge of characterization.
A layer in which temperature rises with altitude rather than falling, created when high-altitude absorbers soak up starlight — the exoplanet analogue of Earth's ozone stratosphere. On the hottest giant planets, absorbers such as titanium oxide or metals can drive inversions, which flip molecular features in an emission spectrum from absorption to emission.
The temperature a planet would settle at if it simply balanced the starlight it absorbs against the heat it radiates, set by the star's output, the orbital distance, and the planet's reflectivity. It is a first estimate — real atmospheres shift it through greenhouse warming and heat redistribution — but it frames where a world sits relative to the habitable zone.
The enrichment of an atmosphere in elements heavier than hydrogen and helium, and the ratio of carbon to oxygen within it. These quantities are more than bookkeeping: because different ices and gases condense at different distances in the disk, a planet's measured metallicity and C/O ratio carry a fingerprint of where and how it formed.
The leading model of planet formation: dust in a protoplanetary disk sticks into ever-larger bodies until a solid core grows massive enough — roughly ten Earth masses — to pull in a thick envelope of gas, becoming a giant planet. It naturally explains rocky planets, ice giants, and gas giants as a sequence, though building cores fast enough before the gas disperses is a live problem.
An alternative route to giant planets in which a massive, cool region of a protoplanetary disk becomes gravitationally unstable and fragments directly into a bound clump of gas, skipping the slow core-building step. It may account for massive planets on wide orbits that are hard to make by core accretion within the disk's lifetime.
Planets do not necessarily stay where they form: gravitational interaction with the gas disk, or later with other bodies, can move them inward or outward over time. Migration is the standard explanation for hot Jupiters — giant planets on scorching close-in orbits where they could not have formed — and shapes the architecture of whole systems.
The distance from a young star beyond which it is cold enough for a volatile such as water to freeze into ice. Past the snow line the supply of solid material jumps, favouring the rapid growth of massive cores — one reason the Solar System's giant planets lie beyond it — and its location leaves an imprint on a planet's later atmospheric composition.
A mechanism that helps solve core accretion's timing problem: centimetre-sized 'pebbles' drifting inward through the disk are efficiently swept up by a growing embryo, letting cores reach giant-planet mass far faster than by collisions of larger bodies alone. It has become a central ingredient in modern planet-formation theory.
The European Space Agency's Ariel is the first mission dedicated to surveying the atmospheres of a large, diverse sample of known exoplanets — around a thousand — chiefly by transmission and emission spectroscopy at infrared wavelengths. Selected as ESA's fourth medium-class mission and planned for launch in 2029, it aims to link atmospheric composition to how and where planets form.
PLATO is a European Space Agency mission that will hunt for terrestrial planets in the habitable zones of bright, Sun-like stars using an array of small telescopes to watch for transits, while asteroseismology of the host stars pins down their ages and sizes. Selected as ESA's third medium-class mission, it is planned for launch in 2026.
A list of 109 bright deep-sky objects compiled by the British amateur astronomer Sir Patrick Moore to complement the Messier Catalogue, which it deliberately avoids duplicating. Ordered by declination and spanning both hemispheres, it gathers showpiece galaxies, clusters, and nebulae — such as the Hyades and NGC 869/884 — that Messier omitted. Objects carry a 'C' number.
The first systematic catalogue of dark nebulae, compiled by Edward Emerson Barnard from his pioneering photographs of the Milky Way. The 1919 list of 182 objects was later extended to 370; each 'B' object is a cloud of interstellar dust silhouetted against the star fields behind it, such as B33, the Horsehead Nebula.
A catalogue of HII regions — clouds of ionised hydrogen glowing around hot young stars — compiled by Stewart Sharpless. Its second edition (Sh2, 1959) lists 313 emission nebulae across the northern Milky Way, including many of the sky's great star-forming complexes. Objects carry an 'Sh2' number.
Two catalogues compiled by George Abell. The 1958 catalogue of rich clusters of galaxies — later extended southward — became the standard reference for galaxy clusters, listing thousands of the densest concentrations in the Universe. Separately, Abell catalogued 86 large, faint planetary nebulae. Objects carry an 'Abell' number in both.
A comprehensive catalogue of galaxies begun by Paturel and collaborators, providing a unique 'PGC' identifier, position, and basic parameters for tens of thousands of galaxies. It forms the backbone of the HyperLEDA database, and its PGC numbers are widely used as a standard cross-reference for galaxies lacking a common name.
Uppsala General Catalogue of Galaxies (UGC)
A catalogue of 12,921 galaxies north of declination −02°30′, compiled by Peter Nilson at Uppsala from the Palomar Sky Survey. Selected mainly by apparent size, it was for decades the most complete catalogue of nearby northern galaxies and remains a common cross-reference; objects carry a 'UGC' number.
The standard catalogue of stars in the immediate solar neighbourhood, begun by Wilhelm Gliese and later extended with Hartmut Jahreiß. It lists the stars known to lie within about 25 parsecs of the Sun, with distances and motions; its 'GJ' (or older 'Gl') numbers are the usual designations for nearby red dwarfs and other close stars.
An astrometric and photometric catalogue of about 2.5 million of the brightest stars, derived from the star-mapper data of ESA's Hipparcos satellite. Named in honour of Tycho Brahe, it provides positions, proper motions, and two-colour photometry, and its 'TYC' identifiers are a standard reference for stars fainter than the main Hipparcos catalogue.
A catalogue of 258,997 stars compiled by the Smithsonian Astrophysical Observatory, combining earlier positional catalogues to support satellite tracking. Its dense, uniform coverage and widely printed star atlas made 'SAO' numbers a long-standing standard designation for stars down to about ninth magnitude.
General Catalogue of Variable Stars (GCVS)
The authoritative catalogue of variable stars, first published in Moscow in 1948 and maintained since at the Sternberg Astronomical Institute. It assigns official variable-star designations and records variability type, period, and amplitude for tens of thousands of stars, serving as the reference for the naming of newly confirmed variables.
The principal database of double and multiple stars, maintained by the United States Naval Observatory. It gathers positions, separations, position angles, and magnitudes for well over a hundred thousand pairs from centuries of measurements, and its 'WDS' identifiers are the standard reference for binary and multiple systems.
A catalogue of stars with large proper motions — at least half an arcsecond per year — compiled by Willem Luyten from decades of photographic plate comparisons. Because high proper motion usually signals a nearby star, the 'LHS' catalogue is a rich hunting ground for the Sun's closest neighbours, including many faint red and white dwarfs.
Wolf Catalogue of High-Proper-Motion Stars
An early catalogue of high-proper-motion stars assembled by Max Wolf, a pioneer of astrophotography, from his survey of moving stars. Its 'Wolf' numbers survive as designations for several well-known nearby stars — most famously Wolf 359, one of the closest stars to the Sun.
The great pre-photographic survey of the northern sky, carried out under Friedrich Argelander at Bonn and published from 1863. It recorded positions and magnitudes for about 325,000 stars to roughly ninth magnitude — the most comprehensive star catalogue of its era — and its 'BD' designations remain in use for naked-eye and telescopic stars today.
The catalogues of bright deep-sky showpieces made for the eye and the small telescope — Charles Messier's eighteenth-century list of 'objects to avoid' when comet-hunting, and Patrick Moore's later Caldwell Catalogue that gathers the bright objects Messier passed over.
The New General Catalogue and its two Index Catalogue supplements, compiled by J. L. E. Dreyer from the visual discoveries of the Herschels and their successors. Together the NGC and IC number nearly 13,000 galaxies, clusters, and nebulae and remain the most widely used designations for deep-sky objects.
The specialist catalogues of interstellar clouds — Sharpless's HII regions glowing around young stars, Barnard's dark dust clouds silhouetted against the Milky Way, and Abell's large, faint planetary nebulae. Together they map the gas and dust between the stars.
The great reference catalogues of galaxies — the Uppsala General Catalogue's size-selected northern galaxies and the Principal Galaxies Catalogue that underpins the HyperLEDA database, providing standard identifiers for galaxies far beyond those with common names.
The positional catalogues that pin down where the stars are — from Argelander's pre-photographic Bonner Durchmusterung and the Smithsonian's SAO catalogue to the space-based precision of Hipparcos, Tycho-2, and Gaia.
The catalogues that map the Sun's immediate neighbourhood — Gliese's census of stars within about 25 parsecs, and the high-proper-motion catalogues of Luyten (LHS) and Max Wolf, whose fast-moving stars are usually the closest ones.
The catalogues of stars that change and stars that come in pairs — the General Catalogue of Variable Stars, which names and classifies variables, and the Washington Double Star Catalog, the master reference for binary and multiple systems.
The system introduced by Johann Bayer in his 1603 atlas Uranometria, labelling the bright stars of each constellation with a Greek letter followed by the Latin genitive of the constellation's name — so α Orionis is Betelgeuse, even though Rigel (β Orionis) is usually the brighter of the two, a reminder that the ordering is only approximate. Roughly in order of brightness, Bayer letters remain the most familiar designations for naked-eye stars.
A numbering scheme drawn from John Flamsteed's star catalogue, published posthumously in 1725, that labels the stars of each constellation with a number in order of increasing right ascension — so 61 Cygni is the sixty-first Flamsteed star of Cygnus. Flamsteed numbers name many stars that have no Bayer letter.
The scheme for naming variable stars, formalised in the General Catalogue of Variable Stars. Within each constellation the first variables take the letters R through Z, then two-letter combinations RR through ZZ and AA through QZ, and thereafter V335, V336, and so on — a system that grew from a handful of early discoveries into a labelling scheme for tens of thousands of variables.
A catch-all term for any object beyond the Solar System that is neither a single star nor a planet — the star clusters, nebulae, and galaxies that fill catalogues from Messier to the NGC. Deep-sky objects are the classic targets of the amateur telescope and the workhorses of stellar and galactic astrophysics.
A loose, irregular group of a few dozen to a few thousand stars born together from the same molecular cloud, found in the disk of the Galaxy. Their stars share an age and composition, making open clusters key laboratories for stellar evolution; because they are only weakly bound, they gradually disperse over hundreds of millions of years.
A dense, roughly spherical swarm of tens of thousands to millions of very old stars, tightly bound by gravity and orbiting in the halo of a galaxy. Globular clusters are among the oldest structures in the Universe, and their tightly packed, coeval stars make them benchmarks for stellar ages and the early history of the Galaxy.
A loose grouping of young, massive stars that formed together but are not gravitationally bound, so they drift apart over tens of millions of years. OB associations trace the sites of recent star formation along a galaxy's spiral arms and are often still embedded in the gas of their parent clouds.
A cloud of interstellar gas that glows with its own light, ionised by the ultraviolet radiation of nearby hot stars so that it re-emits in characteristic lines — most famously the red of hydrogen. Emission nebulae mark regions of active star formation and include the great HII regions of the Galaxy.
A large cloud of ionised atomic hydrogen (H II) surrounding one or more hot O- and B-type stars, whose ultraviolet light strips the electrons from the surrounding gas. HII regions are the glowing signposts of massive-star formation, and their sizes and spectra are used to trace star formation across galaxies.
A cloud of interstellar dust that shines not by its own emission but by scattering the light of nearby stars. Because fine dust scatters blue light most efficiently, reflection nebulae typically appear blue — as in the wisps of nebulosity draped around the Pleiades.
A dense cloud of interstellar dust so opaque that it blots out the light of the stars and glowing gas behind it, appearing as a dark silhouette. Catalogued systematically by E. E. Barnard, dark nebulae are the cold, dusty reservoirs — often molecular clouds — from which new stars condense.
A small, dense, isolated cloud of cold gas and dust — a compact kind of dark nebula, named for Bart Bok — within which one or a few stars are collapsing into being. Bok globules are among the coldest objects in the Universe and are studied as the birthplaces of low-mass stars.
The glowing shell of gas cast off by a dying Sun-like star as it becomes a white dwarf, ionised and lit up by the hot stellar core at its centre. Despite the name — coined because their round disks resembled planets in early telescopes — planetary nebulae have nothing to do with planets; they are a brief, beautiful final phase of low- and intermediate-mass stars.
The expanding cloud of debris left behind when a star explodes as a supernova, sweeping up and shock-heating the surrounding interstellar medium. Supernova remnants seed the galaxy with heavy elements, accelerate cosmic rays, and — like the Crab — can harbour the neutron star born in the collapse.
One of the most recognisable dark nebulae in the sky — a column of cold, dusty gas in the Orion molecular cloud, about 1,500 light-years away, shaped by radiation into the silhouette of a horse's head. Catalogued as Barnard 33, it is seen against the soft red glow of the emission nebula IC 434 behind it, in the constellation Orion just south of the belt star Alnitak.
A tall pillar of cold molecular gas and dust, about seven light-years long, sculpted by the radiation and winds of hot young stars in the NGC 2264 star-forming region in Monoceros. The Cone lies at the southern end of the same complex as the Christmas Tree Cluster, roughly 2,700 light-years away, and is a textbook example of a star-forming pillar.
The imaginary sphere of arbitrarily large radius, centred on the observer, onto which all celestial bodies appear projected. It is the geometric stage on which every astronomical coordinate system is drawn — the sky treated as a two-dimensional surface whose points are fixed by pairs of angles.
The celestial equivalent of longitude — the angle measured eastward along the celestial equator from the vernal equinox, conventionally expressed in hours, minutes, and seconds (24 hours around the sky). Together with declination it fixes a star's place in the equatorial system, and it connects directly to sidereal time.
The celestial equivalent of latitude — the angle of a body north (positive) or south (negative) of the celestial equator, from +90° at the north celestial pole to −90° at the south. With right ascension it pins a star's position in the equatorial coordinate system.
The standard astronomical coordinate system, projecting the Earth's equator and poles onto the sky and fixing positions by right ascension and declination. Because it is tied to the slowly precessing equator and equinox, an equatorial position must be qualified by a reference frame and epoch, such as ICRS or J2000.
A coordinate system aligned with the Milky Way, measuring galactic longitude from the direction of the Galactic Centre along the galactic plane and galactic latitude above or below it. It is the natural frame for describing the structure of our Galaxy — spiral arms, the disk, and the distribution of stars and gas.
A coordinate system based on the ecliptic — the plane of the Earth's orbit and the Sun's apparent yearly path — measuring ecliptic longitude eastward from the vernal equinox and ecliptic latitude perpendicular to it. It is the natural frame for the Solar System, where the planets and the Moon stay close to the ecliptic.
The observer-centred system that describes where a body appears in the local sky: altitude above the horizon and azimuth around it. Simple and intuitive for pointing a telescope, horizontal coordinates change continuously as the Earth turns and depend on the observer's location and the moment of observation.
A coordinate system whose equator follows the flattened plane in which the nearby galaxies and clusters are concentrated — the supergalactic plane of the Local Supercluster. It is used to describe the large-scale distribution of galaxies in our cosmic neighbourhood.
The International Celestial Reference Frame (ICRF3)
The practical realisation of the International Celestial Reference System — a catalogue of precise positions for several thousand extragalactic radio sources, mostly quasars, measured by very-long-baseline interferometry. Its third realisation, ICRF3, was adopted in 2018; because quasars are effectively fixed, it provides the quasi-inertial grid to which optical frames such as Gaia's are aligned.
A fundamental reference frame published in 1988, giving precise positions and proper motions for 1,535 bright stars on the equinox and epoch J2000. FK5 was the optical standard of its era, but it rested on a limited number of stars; it was superseded when the ICRS, realised by Hipparcos and later Gaia, replaced star-based frames with an extragalactic one.
The predecessor of FK5, a fundamental star frame referred to the equinox and epoch B1950. Positions given in the FK4 (B1950) system must be precessed and rotated to be compared with modern J2000/ICRS coordinates — a common source of small errors when working with older catalogues and charts.
A continuous count of days (and fractions) since noon Universal Time on 1 January 4713 BC in the proleptic Julian calendar, used throughout astronomy to timestamp observations without the awkwardness of calendar months and leap years. The Modified Julian Date (MJD = JD − 2400000.5) shifts the origin to a recent midnight for convenience.
The slow conical wobble of the Earth's rotation axis, driven by the gravitational pull of the Sun and Moon on the equatorial bulge, which carries the celestial poles and the equinoxes around the sky once in about 25,772 years. Precession is why equatorial coordinates drift with time and must be referred to a stated epoch, and why Polaris is only temporarily the pole star.
The small, shorter-period nodding of the Earth's axis superimposed on the steady precessional wobble, caused mainly by the changing orientation of the Moon's orbit, with a dominant period of about 18.6 years. Nutation must be added to precession to compute a body's true position of date to arcsecond precision.
The small apparent shift of a star's position in the direction of the observer's motion, because light travels at a finite speed while the observer moves. The Earth's orbital motion makes every star describe a tiny yearly ellipse whose semi-major axis — the maximum displacement from the true position — is about 20.5 arcseconds; discovered by James Bradley in 1728, it was early direct evidence that the Earth orbits the Sun.
The bending of a light ray as it passes through the Earth's atmosphere, which lifts the apparent position of a celestial body above its true one — by about half a degree right at the horizon, so the Sun is fully refracted into view when geometrically it has already set. Refraction must be removed to turn an observed altitude into a true one.
The correction that accounts for the time light takes to travel from a moving Solar-System body to the observer: what is seen is where the body was when the light left it, not where it is now. Together with stellar aberration it makes up what is called planetary aberration, and it is essential for computing accurate apparent positions of planets, moons, and spacecraft.
The measured quantities that describe how the real, wobbling, irregularly rotating Earth is oriented in space relative to the celestial reference frame — the difference UT1−UTC, the position of the pole (polar motion), and small corrections to the precession-nutation model. Determined and published by the IERS, they are what make it possible to transform between celestial and terrestrial coordinates to full precision.
The international body, founded in 1919, that is the recognised authority for astronomical nomenclature and standards — it defines constellation boundaries, names celestial bodies and their features, and adopts the reference systems and constants used throughout astronomy, including the International Celestial Reference System.
International Earth Rotation and Reference Systems Service (IERS)
The service that maintains the international celestial and terrestrial reference frames and the parameters linking them — the Earth orientation parameters. The IERS monitors the Earth's rotation and axis, publishes UT1−UTC and polar motion, and announces the leap seconds that keep civil time aligned with the turning Earth.
Observing the sky directly with the eye, whether unaided or through binoculars or a telescope. Visual astronomy trains the observer to see faint detail through averted vision and dark adaptation, and remains the most immediate way to experience the Moon, planets, and brighter deep-sky objects — the foundation on which every imaging technique is built.
Capturing images of celestial objects with a camera, from wide starfields on a fixed tripod to long, tracked exposures through a telescope. Astrophotography trades the eye's real-time view for the camera's ability to accumulate light over minutes or hours, revealing colour and faint structure the eye can never see. It spans planetary, deep-sky, and narrowband techniques.
High-resolution imaging of the Moon and planets by recording thousands of short-exposure frames and keeping only the sharpest, to beat the blurring of atmospheric turbulence. This 'lucky imaging' approach, usually with a fast CMOS camera, lets modest telescopes resolve cloud belts on Jupiter, the rings of Saturn, and craters on the Moon.
Long-exposure imaging of faint, extended objects — galaxies, nebulae, and clusters — that requires accurate tracking of the sky's motion, often over many hours of accumulated exposure. Deep-sky imaging leans on an equatorial mount, autoguiding, and careful calibration to draw out signal from targets far too faint to see by eye.
Imaging through filters that pass only the light of specific emission lines — hydrogen-alpha, oxygen-III, sulphur-II — to isolate the glow of ionised gas and cut through light pollution and moonlight. Narrowband imaging reveals the intricate structure of emission nebulae and is the basis of the popular false-colour 'Hubble palette'.
Keeping a telescope locked precisely on target during a long exposure by continuously imaging a guide star and sending tiny correction commands to the mount to cancel tracking errors. Autoguiding is what makes hours-long deep-sky exposures possible without the stars trailing.
The reference exposures that remove a camera's own signature from an image: bias frames capture the sensor's read pedestal, dark frames the thermal signal that builds up during an exposure, and flat frames the uneven illumination and dust shadows of the optics. Subtracting and dividing by these calibration frames turns raw data into a faithful record of the sky.
The steps that turn calibrated, stacked exposures into a finished image — stretching the very high dynamic range so faint nebulosity and bright cores both show, balancing colour, reducing noise, and sharpening detail. Done honestly it reveals what the data contain; the goal is to represent real signal, not to invent it.
A technique for combining many dithered exposures that recovers resolution lost to undersampling, by mapping each input pixel onto a finer output grid. Developed for the Hubble Space Telescope's deep fields, drizzling is now widely used in both professional and amateur imaging to sharpen stacks of slightly shifted frames.
Identifying exactly where an image points by matching the pattern of stars it contains against a reference catalogue, and so assigning precise celestial coordinates to every pixel. Plate solving lets software centre a target automatically, sync a mount's pointing, and stamp images with an accurate coordinate solution.
The end-to-end chain that turns a night at the telescope into a finished picture: mount, optics, and camera acquire tracked, autoguided exposures of the target and matching calibration frames; the frames are calibrated, aligned, and stacked; and the result is stretched and processed. Understanding the whole chain — where signal is gained and where it is lost — is what separates a snapshot from a scientific-grade image.
A free, open-source planetarium that renders a photorealistic sky in real time, showing the stars, planets, constellations, and deep-sky objects as they appear from any location and time. Widely used for planning observing sessions and for teaching, Stellarium can also control telescopes and simulate the view through different eyepieces.
A free, open-source desktop planetarium and observation planner from the KDE project, showing the sky for any date and location with millions of stars and thousands of deep-sky objects. KStars integrates the Ekos astrophotography suite, making it a complete free platform for both planning and capturing images.
A free, open-source real-time 3D space simulator that lets the user fly beyond the Earth's sky to visit the planets, moons, stars, and galaxies, viewing the Solar System and beyond from any vantage point. Unlike a planetarium fixed to the ground, Celestia treats space itself as the stage.
A free, open-source sky-charting program (also known as SkyChart) that draws detailed star charts from a choice of catalogues for any time and place, with strong support for telescope control and finder charts. It is a long-standing favourite for planning deep-sky observing.
A widely used mobile and desktop planetarium app that shows the sky in the observer's hand and can point a computerised telescope at any object with a tap. SkySafari combines a large object database with real-time sky simulation and telescope control for use at the eyepiece.
A professional-grade image-processing platform built specifically for astrophotography, with a full pipeline from calibration and registration to advanced noise reduction, deconvolution, and colour work. Its scriptable, high-precision tools make it the standard choice for serious deep-sky imagers.
A free, open-source image-processing program for astrophotography that calibrates, registers, and stacks sequences of exposures and then processes the result, with plate solving and scripting built in. It is a capable free alternative for the full path from raw frames to a finished image.
A free program that automates the registration and stacking of deep-sky exposures together with their calibration frames, producing a single high-signal image ready for final processing. Its simplicity has made it a popular first step in many deep-sky imaging workflows.
A free, open-source imaging-suite application that sequences and automates a night of astrophotography — slewing, plate solving, focusing, guiding, and capturing calibrated exposures — through connected mounts, cameras, and accessories. It orchestrates the whole acquisition side of the imaging chain.
A free, open-source autoguiding application — the name stands for 'Push Here Dummy' — that images a guide star and issues corrections to the mount to hold a target steady through long exposures. PHD2 is the de-facto standard guider, used on its own or driven by imaging suites like N.I.N.A. and Ekos.
A widely adopted standard and driver platform on Windows that lets astronomy software talk to mounts, cameras, focusers, and other devices through a common interface, so any compliant application can control any compliant device. ASCOM is the interoperability glue of the Windows astrophotography ecosystem.
A free, open-source, cross-platform protocol and driver framework — the Instrument-Neutral Distributed Interface — that controls astronomical instruments over a network, independent of any single application. INDI is the device layer beneath Ekos and much of the Linux and cross-platform imaging ecosystem.
A complete astrophotography suite built into KStars and driven by INDI, handling alignment and plate solving, focusing, guiding, and fully scheduled imaging sequences. Ekos brings professional-style automated acquisition to a free, cross-platform stack.
The Image Reduction and Analysis Facility, a classic suite for the reduction and analysis of astronomical images and spectra developed at the US national optical observatory. Once ubiquitous in professional astronomy, it is no longer actively developed by the observatory but is maintained by the community, and much of its role has passed to the Python ecosystem.
The Common Astronomy Software Applications package, the primary tool for calibrating and imaging data from radio interferometers, developed for ALMA and the Very Large Array. CASA turns the raw visibilities of an interferometer into scientific images and cubes.
An interactive desktop tool for viewing, cross-matching, plotting, and manipulating large astronomical tables and catalogues, with deep support for Virtual Observatory table formats and services. TOPCAT is a workhorse for exploring catalogue data from surveys and archives.
A widely used astronomical imaging and data-visualisation application for displaying FITS images, with support for multiple frames, colour scales, region analysis, and coordinate overlays. DS9 is a standard viewer for inspecting professional image data.
An interactive sky-atlas application from the Strasbourg astronomical data centre that lets the user overlay images, surveys, and catalogues on the same patch of sky and query Virtual Observatory services directly. Aladin is a central tool for cross-identifying objects across archives.
An astronomy-focused build of the ImageJ image-analysis program, adding precise astronomical image display, calibration, and differential photometry. AstroImageJ is especially popular for measuring exoplanet transit light curves from amateur and small-professional telescopes.
A toolkit for assembling astronomical images into custom mosaics, reprojecting many overlapping FITS images onto a common grid and matching their backgrounds to make a seamless whole. Montage is used to build large image mosaics from survey data while preserving flux.
A Python library for computing precise positions of stars, planets, and satellites as seen from any point on the Earth or in space, using the same JPL ephemerides and reference frames as professional astronomy. Skyfield is a popular modern tool for accurate, easy positional astronomy.
A Python library for interactive astrodynamics and orbital mechanics — defining orbits, propagating them, and planning maneuvers — built on Astropy's units and time handling. Its active development is now archived, with the work continuing in a successor library, but it remains a well-known tool for orbit computations.
A mature, low-level space-flight-dynamics library in Java (with Python bindings) providing high-precision orbit propagation, attitude modelling, time and frame transformations, and maneuver planning. Orekit is used in professional mission analysis and operations for its accuracy and breadth.