Mars. Titan. Kepler-22b. All of these and millions more have made the list of potential life hot-spots.
But what about Saturn's moon Enceladus?
While not quite the feature item in most extraterrestrial news, planetary scientist (and occasional sci-fi movie advisor) Carolyn Porco has kept a close eye on the moon through NASA's Cassini-Huygens space probe, which has taken extensive photographs of the moon's south pole region.
Though the surface of Enceladus would be pretty unbearable for humans, not all life might find it so. Also, heated underground water (the geysers are coming from somewhere) could also be an environment to inspect. This also brings up the popular questions of: what if there is intelligent life that evolved to be entirely aquatic? How would they operate? How could we communicate with them? Could they travel in space?
Enceladus probably won't have answers to those questions; no one does. But the moon is interesting, and certainly worth keeping an eye on.
And Porco finishes her quick video in the spirit of the new and privately owned company Planetary Resources by holding out hope for some space tourism. Which is always a good note to end on.
Rachel is the co-founder of How To Survive Alien Invasion Novels, and spends her time writing, studying, and reading what would probably considered far too many books. Connect with her and Rusty on Twitter and Facebook, and click here to read more of her articles about alien theories and how to survive alien invasion novels.