In this video segment adapted from NOVA, learn about the hunt for Earthlike planets outside our solar system that may harbor life. Astronomer Geoff Marcy explains the challenges of finding infinitesimally small planets orbiting huge, very bright stars. By monitoring the light from distant stars, sensitive instruments can detect the very slight dimming that occurs when objects, such as orbiting planets, pass in front of them. The video also introduces us to NASA’s Kepler space telescope, launched in 2009 to discover Earth-sized planets and determine how many of the billions of stars in our galaxy have such planets. The video features real satellite imagery as well as simulations.

This video is available in both English and Spanish audio, along with corresponding closed captions.