And Enceladus, too! I've been reading about it lately, and I would be quite surprised (not to say I'm anywhere close to an expert) if there wasn't life there. I

And Enceladus, too! I've been reading about it lately, and I would be quite surprised (not to say I'm anywhere close to an expert) if there wasn't life there. It's got a rocky core surrounded by a deep ocean surrounded by a layer of ice. It's core gets a geological workout from tidal forces from Saturn (i.e., heat), and there's clear evidence of volcanic activity from the plumes that are ejected. I'm a little surprised we don't more readily explore Europa and Enceladus. They are far more interesting than Mars.