View full lesson: http://ed.ted.com/lessons/how-do-we-measure-distances-in-space-yuan-sen-ting

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.