One of the most promising places to date, in the search for extra-terrestrial life, seems to be one of Saturn’s moons: Enceladus. This happens to be Saturn’s sixth largest moon and it was recently discovered to have a warm ocean, with hydro-thermal activity, at it’s southern pole.
The ocean, discovered by the Cassini spacecraft, appears to be approximately six miles deep and is thought to be home to many other chemicals associated with signs of life.
In 2005 a massive icy geyser, approximately 125 miles high, was discovered shooting material into the atmosphere. Recently, this material was analyzed and found to be mostly silica dust particles; the remnants of evaporated salt-water. One investor suggested that this was the first clue to the fact that Enceladus harbored a warm ocean. Not just warm either, there is thought to be hot springs at the bottom of this ocean that may reach 200 degrees Fahrenheit.
It’s difficult to tell, for the moment, how long there has been hydro-thermal activity here. Some researchers believe that this may be how life began on Earth. The exception being that here on Earth we have a hot core, while there on Saturn’s moon, warmth is created by gravitational friction between the planet and it’s many moons.
Perhaps soon we will know, thanks to NASA and the Cassini spacecraft, that we are not alone in the solar system.