As far as we know, only one planet has life on it—Earth. But is it really possible that our planet is the only life-bearing planet in the entire universe? Some scientists believe that extraterrestrial life does exist, and some even believe that there may be advanced alien life. In this video segment adapted from NOVA, learn about the search for extraterrestrial intelligence.
Visit the program page here.
© 2015 PBS & WGBH Educational Foundation. All rights reserved.