Recently however, the Cassini craft found that on the Saturnian moon Enceladus, there exists a form of hydrogen, which in addition to liquid sub-surface water and methane which we already knew were there, forms when water comes into contact with hot rocks, such as around geothermal vents on Earth. This shows that there is likely a heat source inside Enceladus that keeps the subterranian water in the liquid state.
We need to go ahead and design investigational craft to land on and explore both moons. This is pretty exciting stuff.
I've included helpful pictures of the Jovian moon Europa and the ice-covered Enceladus......both of which may harbor rudimentary life and may provide a sanctuary for humans for when hostile aliens decide to harvest Earth for all its resources.