[Taunteefrurge]

Bit of a science-fiction question: are there any circumstances in which a completely lifeless planet/moon could sustain enough atmospheric oxygen to support some humans for some time? (I can't think of any).

Give it water or ice, or whatever elemental weirdness you can think of, as long as humans could conceivably walk around there without vac-suits. But no native life, not even bacteria.