Light seconds, light years, light centuries: How to measure extreme distances - Yuan-Sen Ting

View full lesson: When we look at the sky, we have a flat, two-dimensional view. So how do astronomers figure the distances of stars and galaxies from Earth? Yuan-Sen Ting shows us how trigonometric parallaxes, standard candles and more help us determine the distance of objects several billion light years away from Earth. Lesson by Yuan-Sen Ting, animation by TED-Ed.