What i meant about the oxygen was that the microbes could produce it. But you might be right that microbes can't survive under these circumstances for long. This might be far out, but could the microbes live beneath the surface from a meteor impact and now producing the oxygen we see today - the oxygen is lighter than the solid stuff on the moon and therefore it reaches the surface of the moon. Don't worry, i believe in your theory that the oxygen comes from meteors, i just want to pursuit a theory about life on some of the moons
