Moon

The Moon

Type: Moon
Diameter: 3,475 km

NASA/Caltech-JPL/MIT/SRS · NASA media (public domain)

Overview

Scientific overview

The Moon is a moon orbiting Earth.

Physical characteristics

Mass: 0.073 ×10²⁴ kg
Diameter: 3,475 km
Radius: 1,737.5 km
Density: 3.344 g/cm³
Surface gravity: 1.62 m/s² · derived
Escape velocity: 2.4 km/s · derived
Albedo: 0.12
Magnitude: -12.74

Derived values

Computed from source-backed inputs via standard formulae — not observations. Every input and constant is traced below.

Escape velocity2.4 km/sderived
Formula & inputs
Formula: v = √(2GM / r) (v1.0.0, impl v1.0.0)
Inputs:
- mass1e24Kg = 0.07346 ×10²⁴ kg · NASA
- radiusKm = 1737.5 km · NASA
Assumptions: G = 6.674e-11 m³ kg⁻¹ s⁻² (CODATA 2018)
Limitations: Assumes a spherical, non-rotating body.; Inputs carry no catalogued uncertainty, so none is propagated.
Uncertainty: not propagated (inputs carry no catalogued uncertainty)
Computed as of 2026-06-29.
Surface gravity1.62 m/s²derived
Formula & inputs
Formula: g = GM / r² (v1.0.0, impl v1.0.0)
Inputs:
- mass1e24Kg = 0.07346 ×10²⁴ kg · NASA
- radiusKm = 1737.5 km · NASA
Assumptions: G = 6.674e-11 m³ kg⁻¹ s⁻² (CODATA 2018)
Limitations: Assumes a spherical, non-rotating body.; Inputs carry no catalogued uncertainty, so none is propagated.
Uncertainty: not propagated (inputs carry no catalogued uncertainty)
Computed as of 2026-06-29.

Scale

Compared to Earth

Earth

The Moon

The Moon is 3.7× smaller than Earth

3,475 km across · Earth is 12,742 km

Gallery

Graben on the Moon
These graben - a kind of trench that is formed as a surface expands - were imaged near a region of the Moon called Mare Frigoris by NASA's Lunar Reconnaissance Orbiter (LRO).
2019
NASA · NASA media (public domain)
Source archive ↗

Observation

How this was captured

Source: NASA
Observation date: 2012-03-22

Notable surface features

Exploration

Sources

The primary and reference sources this topic draws on.

NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.
NASA JPLJet Propulsion Laboratory / Solar System Dynamics
Orbital data, ephemerides, and small-body parameters for planets, asteroids, and comets.

Quick facts

Type: Moon
Orbits: Earth

Provenance & sources

review 2026.1

Asteria Scientific Review Process · verification: sourced · accurate

High evidenceconfirmed
The Moon is Earth's only natural satellite and the fifth-largest moon in the Solar System; it is tidally locked, always presenting the same face to Earth.
Source: NASA (NSSDCA) — NASA Planetary Fact Sheet · Public domain (US Government work)
- NASA Planetary Fact Sheet, Planetary Fact Sheet

Reviewed by the internal Asteria Scientific Review Process — not an external institutional review. See the evidence framework and authority dashboard.

Scientific citations

Real, source-backed references — primary papers first, then datasets and institutional sources. Formatted through the citation engine; nothing is fabricated.

DatasetMoon Fact Sheet

NASA Goddard — NSSDCA

Cite (APA / BibTeX)

NASA Goddard — NSSDCA (n.d.). Moon Fact Sheet. NASA Goddard — NSSDCA. https://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html

@misc{cite:factsheet-moon-the-moon,
  title        = {Moon Fact Sheet},
  organization = {NASA Goddard — NSSDCA},
  year         = {n.d.},
  url          = {https://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html},
  note         = {Physical and orbital parameters for Moon.}
}

Archive pageJPL Horizons System

NASA Jet Propulsion Laboratory (Caltech)

Cite (APA / BibTeX)

NASA Jet Propulsion Laboratory (Caltech) (n.d.). JPL Horizons System. NASA Jet Propulsion Laboratory (Caltech). https://ssd.jpl.nasa.gov/horizons/

@misc{cite:jpl-horizons,
  title        = {JPL Horizons System},
  organization = {NASA Jet Propulsion Laboratory (Caltech)},
  year         = {n.d.},
  url          = {https://ssd.jpl.nasa.gov/horizons/},
  note         = {Authoritative Solar System ephemerides — the reference standard for high-precision Moon position (not fetched in v1).}
}

Institutional pageEarth's Moon — NASA Science

NASA

Cite (APA / BibTeX)

NASA (n.d.). Earth's Moon — NASA Science. NASA. https://science.nasa.gov/moon/

@misc{cite:nasa-moon,
  title        = {Earth's Moon — NASA Science},
  organization = {NASA},
  year         = {n.d.},
  url          = {https://science.nasa.gov/moon/},
  note         = {NASA overview of the Moon: phases, the synodic month, and lunar facts.}
}

Institutional pageMoon — NASA Solar System Exploration

NASA

Cite (APA / BibTeX)

NASA (n.d.). Moon — NASA Solar System Exploration. NASA. https://science.nasa.gov/

@misc{cite:nasa-moon-the-moon,
  title        = {Moon — NASA Solar System Exploration},
  organization = {NASA},
  year         = {n.d.},
  url          = {https://science.nasa.gov/},
  note         = {NASA overview of Moon.}
}

Institutional pageUSNO Astronomical Applications Department

United States Naval Observatory

Cite (APA / BibTeX)

United States Naval Observatory (n.d.). USNO Astronomical Applications Department. United States Naval Observatory. https://aa.usno.navy.mil/

@misc{cite:usno-astronomical-applications,
  title        = {USNO Astronomical Applications Department},
  organization = {United States Naval Observatory},
  year         = {n.d.},
  url          = {https://aa.usno.navy.mil/},
  note         = {Solar and lunar coordinates, phase, and rise/set/twilight/transit methodology (the Astronomical Almanac); the public-domain formulae behind the computed Moon phase, the computed Sun & twilight times, and the computed moonrise/moonset and lunar position.}
}

Quality & authority

Substantial

Reviewed

Description: Complete
Source coverage: Partial
Relationship coverage: Complete
Review coverage: Complete
Citation coverage: Complete
Image coverage: Complete

Data from the NASA Planetary Fact Sheet & JPL (public domain). See source quality.

The Moon

Scientific overview

Physical characteristics

Derived values

Compared to Earth

Gallery

How this was captured

Notable surface features

Exploration

Apollo 11

Luna 2

Sources