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Astronomy

How Astronomers Measure Distances Using Parallax

Quick fact

The nearest star, Proxima Centauri, has a parallax angle of only about 0.77 arcseconds — roughly the size of a coin seen from several kilometers away.

Why this is interesting

Have you ever noticed how objects seem to jump when you look through one eye, then the other? Now imagine doing that with a baseline as wide as Earth's orbit — that's how astronomers measure the stars.