[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.

[w4WBthjv]

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.

Well if we look at that situation in reverse, that is we found a planet with Oxygen, we could be confident of it supporting life of some sort.
What type of conditions could exist on Mars, to release enough Oxygen from either water/Ice or its CO2 atmosphere to support life?....Internal heating???
I'm not sure of the answer, but I would think that there maybe some circumstances to align with the requirements of your question.....
We need a chemist.

[sbgctsa]

Unlikely, as the majority of Earth's oxygen was made by Stromatolites (have a read of that page, it's very interesting) that took a couple of billion years to change the atmosphere to something like where it is now.
I don't claim to know a lot about how an otherwise dead planet could get an oxygen atmosphere but the only thing I could think of is if it was hit by quite a lot of comets.
AFAIK comets are more popular towards the middle of the galaxy so you'd stand a better chance of finding such a planet there.

But, after watching several documentaries on the universe & so on, the latest view is that it's infinite and so there is a small but non-zero chance of such a planet existing.

[quorceopporce]

I was wondering if active volcanoes with the right mix of gases could temporarily give the atmosphere a boost to support humans for a short time?

[MortgFinsJohnQ]

I was wondering if active volcanoes with the right mix of gases could temporarily give the atmosphere a boost to support humans for a short time?

I doubt it, the volcanoes we're used to don't make any gasses we can breath.
Exoplanet volcanoes might but I doubt it.

[OlgaBorovikovva]

Our volcanoes tend to make gases that are pretty nasty for most organisms.

There are always a few odd species that will live in hostile places.

[RafaelYV]

Our volcanoes tend to make gases that are pretty nasty for most organisms.

There are always a few odd species that will live in hostile places.

Ah yes I forgot about those - Such as the odd creatures that live around Black Smokers. I very much doubt any oxygen-eaters would be able to benefit though.

[tobaccoman]

Yep, it was the black smokers I was thinking of. Although there are some weird and wonderful things in the hot lakes at Yellowstone National Park too (on my list of places to go one day).

I agree about the oxygen-eaters. I don't remember reading about oxygen rich gases associated with volcanoes.

[illilmicy]

I need a lifeless planet that you and I can walk around on.

I don't think anyone will come up with anything (because I didn't)


What about a water-rich world at the triple-point, with ice and water
sloshing about between states all the time?

[Htb48JBf]

I agree about the oxygen-eaters. I don't remember reading about oxygen rich gases associated with volcanoes.

More of a Michael V / geologist question there.

[YmolafBp]

This paper might have answers, but I'm none the wiser after reading the abstract.

http://www.agu.org/pubs/crossref/196...02p00545.shtml

[nannysuetle]

You're a chemist. I'm here to *save* time.

[Shark&Nike]

http://www.agu.org/journals/jz/v068/...i002p00545.pdf

There were measurable concentrations of oxygen gas tabulated in the paper. However the text says that they expect it is all atmospheric contamination of their samples as the presence of reduced gases such as H2 and H2S indicate that the partial pressure of oxygen within the volcano must have been very low.

[Narkeere]

http://www.agu.org/pubs/crossref/199...GL008383.shtml

Wow, there is some nasty stuff coming out of this one!

[gorbasevhuynani]

Well if we look at that situation in reverse, that is we found a planet with Oxygen, we could be confident of it supporting life of some sort.
------------------
If you mean that a planet with 20% O2 would definitly have life already, then I think you are drawing a very low bow.

[Feelundseenna]

"That reference was not found." (AGU)

[tearidrusydet]

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.

If it doesn't contain life prior to humans walk around for a bit, then it certainly would after. It would have been panspermia-ed.

[Cersdog]

Weird. The one that the link does not work is the full text of the first abstract I linked to. I got there by clicking on full text html, and then from that site on full text pdf.

[Zwnkkvle]

>>...If you mean that a planet with 20% O2 would definitly have life already, then I think you are drawing a very low bow.

I know that oxygen is highly reactive, second only to fluorine in electronegativity.

And no, 'not life already' - no life at all, ever.

[electmobile]

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).

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