Technique · Astrometry & Motion
Parallax
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.
Astrometry & MotionMeasures: Distance to nearby stars
Highlights
- ›The one direct, geometric distance measurement
Builds on
Knowledge connections
- Member of groupAstrometry & Motion
- Associated withGaia
- Associated withRR Lyrae Stars
- Associated withThe International Celestial Reference System
- Associated withDistance Modulus
- Associated withParallax Distance
- Associated withThe Equatorial Coordinate System
- Associated withThe Aberration of Light
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.
- ESAEuropean Space Agency
European missions, observatories, and space science imagery.