Europa has become a focal point of interest in our solar system. Subject to the same tidal forces that tear Io apart, Europa is less severely effected by this and here the stress takes the form of internal heating which keeps the moon from being frozen throughout. It has more-or-less been confirmed that below its icy crust lies an almost global ocean of 100% water. Considering that the center of the moon is quite warm and the icy shell is of course frozen rock-solid, somewhere in between must lie a zone with temperatures similar to that of earth deep within this watery underground ocean. As any marine biologist will tell you, the Earth's oceans are riddled with life. Even in places of extreme heat and cold, life still somehow has survived the ages and has adapted to such extreme environments. Leading to conjecture that no-matter the obstacles to life ever developing on the surface of such a place… the mere presence of earth-like conditions deep within Europa's dark underground water ocean may have been just enough for some if not many forms of life to evolve and survive to this day. There are many missions on the drawing board right now to find out more answers including a Europa orbiter, various landers and one truly aggressive mission that would involve melting through the crust and “injecting” a submersible probe into the watery core. For a new and improved portrait image of Europa see here.