When considering the likeliest hosts for extraterrestrial life in our very own system, Europa surely is near the top of possible candidates. One of Jupiter’s 79 (!) moons, it possesses the smoothest surface of any celestial body in the solar system. Because of this and imaging from probes, scientists have hypothesized that Europa has a vast subsurface saltwater ocean about 100km thick covering the entire planet. This has led to discussion about the strong possibility of life evolving here; life could exist in a manner similar to deep sea hydrothermal vents on Earth. Additionally, clay-like minerals have been found on Europa which are strongly connected to the proliferation of organic life. The multiple contributing factors to the possibility of life on Europa have led to countless different theories on the nature of life on Europa. Could it be hydrothermal vent dwelling organisms? Or perhaps plankton-like creatures closer to the surface? Or maybe an entirely new form of life that has arisen from processes extremely different to those on Earth? The exciting possibilities of Europa’s ocean has ensured funding for many missions in the near future, which hopefully will provide us with more answers.
Danny's Solar System Blog 