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.