Titan, Saturn's largest satellite, is the only moon with a thick atmosphere. In many ways, Titan is a cold twin of the Earth, with liquid methane playing the same role there as water plays on our planet. Life on Earth is based on liquid water; could there be life on Titan based on liquid methane? Dr. Chris McKay from the NASA Ames Research Center (co-investigator on the Huygens probe that landed on Titan) discuss the new picture we have of this alien world, with its lakes, its rivers, and its rocks made of water ice. Recorded March 9, 2011.