Astronomy
How Stellar Parallax Calibrates the Cosmic Distance Ladder
Quick fact
The nearest star system, Alpha Centauri, has a parallax angle of only 0.76 arcseconds—about the width of a human hair seen from 100 meters away.
Why this is interesting
Have you ever noticed how nearby objects seem to shift against the background when you move your head? Astronomers use that same effect—on a cosmic scale—to measure the stars.