Astronomy
How Astronomers Measure Distances Using Parallax
Quick fact
The nearest star, Proxima Centauri, has a parallax of about 0.77 arcseconds, corresponding to a distance of about 4.24 light-years. This is among the largest parallax angles measurable.
Why this is interesting
Hold your finger in front of your nose and close one eye, then switch eyes. Your finger appears to jump against the background. Astronomers use this same principle to measure the distances to stars.