Joel Levine: Why we need to go back to Mars

At TEDxNASA, planetary scientist Joel Levine shows some intriguing — and puzzling — new discoveries about Mars: craters full of ice, traces of ancient oceans, and some compelling hints at the presence, at some time in the past, of life. He makes the case for going back to Mars to find out more. TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world’s leading thinkers and doers give the talk of their lives in 18 minutes. Featured speakers have included Al Gore on climate change, Philippe Starck on design, Jill Bolte Taylor on observing her own stroke, Nicholas Negroponte on One Laptop per Child, Jane Goodall on chimpanzees, Bill Gates on malaria and mosquitoes, Pattie Maes on the “Sixth Sense“ wearable tech, and “Lost“ producer JJ Abrams on the allure of mystery. TED stands for Technology, Entertainment, Design, and TEDTalks cover these topics as well as science, business, development and the arts. Closed captions and translated subtitles in a variety of languages are now available on , at Watch a highlight reel of the Top 10 TEDTalks at