Where in the Solar System Are We Most Likely to Find Life?

Last week, NASA announced one of its most exciting missions in recent memory: a plan to visit Europa, one of Jupiter's largest moons. Previous research has shown that the moon is covered with water ice, and may contain a liquid ocean underneath its surface—raising the tantalizing possibility that Europa could harbor life.

 In recent years, the remarkable number of planets we've discovered orbiting distant stars (1780, at latest count) has shifted the focus of the search for extraterrestrial life to other solar systems. But these planets are far, far away, so it would likely take thousands of years to reach even the closest ones.

With the Europa announcement, it's worth remembering that there are a number of destinations here in our own solar system that we could visit (with unmanned probes) during our lifetimes and perhaps find life. Here's our rundown of the best bets: