Saturn's Moon Dione has Oxygen
Dione is a 700 miles diameter moon discovered astronomer Giovanni Cassini in 1684. It obits Saturn at about a quarter of a million miles every 2.7 days, This small moon is seems to be mainly thick water ice around an
even smaller smaller rocky core. Recently the Cassini spacecraft (named for the discoverer of Dione) found molecular oxygen ions (O2+) during a 2010 pass of Dione. The oxygen ions are a result of charged particles from Saturn's magnetosphere that strip an electron from the oygen molecules. The same magnetosphere then strips away these oxygen ions fron the Moons atmosphere.