IndexThe Origin of the UniverseA survey of the evidence
Introduction |
Parallax Distances
The positions of nearby stars change as the Earth orbits the Sun. The movement is called parallax. If a star's parallax is known, the distance to it can be calculated. Astronomers have used the technique to measure the distance to more than a million stars out to about 3,000 light years, beyond which parallax shifts become too small to yield accurate measurements. |