Mission Europa - Jupiter Or Bust

Jupiter's ocean-filled moon might hold the life we've long searched for in space. And scientists have one shot to reach it.

- Corey S. Powell

The search for alien life has recently taken a surprise twist away from Mars and toward Europa, an ice ball of a moon in orbit around Jupiter.  To understand why, you just need to look at these three numbers: ZERO, 1.33 BILLION, 3 BILLION

The first is the volume of known water on Mars (sorry,permafrost and billion-year-old riverbeds don’t count).The second is the volume of water on Earth, measured in cubic kilometers. The third is the inferred volume of water sloshing around just beneath Europa’s frozen surface. Sure, Mars may have had oceans billions of years ago, but Europa has them right now—and they are more than twice as large as all of Earth’s oceans combined.