"Saturn's moon Enceladus is a mystery. From Earth it looks tiny and cold, and yet it's not a dead hunk of rock. Passing spacecraft see trenches and ridges, similar to Earth, and in 2005 NASA's Cassini mission spotted ice geysers streaming from its south pole."

"'The moon is actually alive in a sense,' says Sean Hsu with the Laboratory for Atmospheric and Space Physics at the University of Colorado at Boulder."

"Beneath the surface, most researchers believe it even has a liquid ocean. Now Hsu and his colleagues have found new evidence that it's a downright balmy ocean."