New research suggests that there is plenty of oxygen available in the subsurface ocean of Europa to support oxygen-based metabolic processes for life similar to that on Earth. In fact, there may be enough oxygen to support complex, animal-like organisms with greater oxygen demands than microorganisms.
We need to send probes to Europa. If we find life there, it will be strong indication that 1) life can form outside of the Godilock's Zone, or the Habitable Zone and 2) life can form on icy moons orbiting gas giants. Since icy moons orbiting gas giants may be more common than small terrestrial planets orbiting in the HZ of its parent star, it means that we should not ignore gas giants when looking for extrasolar life.
"Jupiter's Moon Europa Has Enough Oxygen for Life." PhysOrg.com. PhysOrg.com. 16 October 2009. Web. 16 October 2009. <http://www.physorg.com/news174918239.html>
Image Credit: NASA/JPL