The things that happen in space far from us and within our own solar system never cease to amaze me. We don't have the luxury of sending probes to other galaxies and solar systems to search directly for signs of life or the building blocks of life. However, within our own solar system, we can and do, send out probes to satisfy curiosity and scientific interest. A couple years ago, the Cassini spacecraft flew by one of Saturn's icy moons called Dione.
During the flyby, the Cassini spacecraft detected a thin layer of oxygen surrounding the moon. Since Dione has no liquid water, despite the presence of oxygen the conditions to support life don't exist. However, the discovery of the thin layer of oxygen surrounding the Dione suggests that some of Saturn's other moons, believed to have liquid oceans beneath their icy surfaces, could have oxygen as well.
The layer of oxygen around the moon is so thin that scientists call it an exosphere rather than an atmosphere. The scientists believe there is some process at work between Jupiter and its moons that causes oxygen to be released. One theory is that highly charged particles emanating from Saturn's radiation belts could be splitting water in Dione's ice into hydrogen and oxygen. The search for oxygen on Saturn's moons believed to have liquid oceans under icy surfaces is one of the things scientists hope to accomplish with future missions.