If there is a planet whose atmosphere consists of :

  • 30% methane
  • 70% oxygen

Then, can we land on it? If yes, then how, and why would it not explode? Also, can such a planet exist for a long time?

  • $\begingroup$ Just checking, by oxygen, do you mean air? which is something like 78% nitrogen and only 20% oxygen and a few other smaller % of other elements $\endgroup$
    – Mr.Burns
    Commented Jun 24, 2016 at 12:37
  • $\begingroup$ @Mr.Burns No. I mean Oxygen. Pure Oxygen. $\endgroup$
    – dryairship
    Commented Jun 24, 2016 at 12:44
  • $\begingroup$ I don't have the science to answer the question, but my instincts suggest that, yes, we can land on it. We would have to leave orbit very slowly and our ship would have to have a massive surface to weight ratio so that it settles slowly into the atmosphere without a lot of re-entry friction. Landing would be comparatively. Leaving... not so much! Welcome to Planet Hotel California! $\endgroup$ Commented Jun 24, 2016 at 12:57
  • $\begingroup$ As I am still looking at stuff for this question, if there is a planet and we try to land with our current technology, either entry will blow us out the sky or if we do land we cant leave, easily at least. If the atmosshere is dense enough we wouldnt be able to breath for very long either $\endgroup$
    – Mr.Burns
    Commented Jun 24, 2016 at 12:59
  • 4
    $\begingroup$ A better question might be why don't the highly reactive atmospheric gasses react by themselves. See also this question: worldbuilding.stackexchange.com/questions/35704/… This doesn't have to be an explosion, but your gasses would naturally react with each other over time, until most of them are gone. Unless there is something weird going on or something is constantly resupplying the gases. $\endgroup$
    – Peter S.
    Commented Jun 24, 2016 at 13:13

1 Answer 1


Only if you have a serious death wish

Take a look at this...

enter image description here

At 30% Methane, 70% oxygen and 0% of everything else, you have a near perfect mixture to go BOOM.

It is a pure miracle this place has not gone up in literal flames by now... the first meteor that comes along will make the entire atmosphere burn up. Do you need any more motivation to stay far, far away?

  • 1
    $\begingroup$ You got it wrong. I said 30% methane and 70% oxygen. $\endgroup$
    – dryairship
    Commented Jun 24, 2016 at 13:11
  • $\begingroup$ @Hackerdarshi Eh.. very well... edit coming up. $\endgroup$
    – MichaelK
    Commented Jun 24, 2016 at 13:12
  • 4
    $\begingroup$ Michael is right and I have upvoted this answer. I think, though, that this mix of gases wouldn't last a fraction of second even without meteors. That mix would quickly react so that CH3 + O2 ⇋ COH2 + H2O (I know it still needs balancing). Not all the methane and oxygen would be consumed in this, but you'd get a new atmosphere where all the four substances above, and some others like CO, CO2 and O3 reach an equilibrium. While I don't know right now which would be the percentage of each, this would be a whole different, less combustible atmosphere than the one proposed in the question. $\endgroup$ Commented Jun 24, 2016 at 13:28
  • 3
    $\begingroup$ If the planet has a sun, the UV radiation will make methane and oxygen to react... So some process generating both methane and oxygen FAST would be required. And even then there would have to be significant (as in much more than half combined) amounts of carbon dioxide and water in the atmosphere, so unless the planet is cryogenic and distant from stars this is not possible. $\endgroup$ Commented Jun 24, 2016 at 14:38
  • 1
    $\begingroup$ @CircleSquared I doubt there would be any gases left in that planet after the explosion. The whole place would get so hot that individual gas molecules could all reach escape velocity. The atmosphere would literally disperse into space. $\endgroup$ Commented Jun 24, 2016 at 17:31

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