Reprocessed Galileo image of Europa’s frozen surface. NASA/JPL/Ted Stryk The big question that astrobiologists are asking is: Is there life on Europa?

Europa is a tiny moon that orbits the largest planet in our solar system, Jupiter.

Despite being about a quarter of the size of our planet, Europa has approximately two times as much liquid salt water than Earth, scientists estimate.

The vast and deep oceans that lie beneath Europa's outer icy shell are why scientists think that if there is life in our solar system that is not on Earth, then it's probably swimming in Europaian waters.

Thanks to additional funding this year, NASA is one step closer to launching a probe that would take detailed measurements of Europa's surface.

Check out this infographic of Earth and Europa — just about the only thing Earth has that Europa doesn't is (that we know of) is life.