Astronomers use an effect called parallax to measure distances to nearby stars. Parallax is the apparent displacement of an object because of a change in the observer's point of view.
Astronomers measure the parallax of stars to measure the distance of the earth from other stars.
Explanation:
Parallax is the displacement or difference of an object's position when measured from two different places or positions.
As we know stars and our own earth are in continues motion.
So it is difficult to measure the difference between stars and earth.
Parallax is measured through an angle which is measured from a nearby star and is the angle between earth position at one time and at after six months.
