# Combustion on Titan (or somewhere similar)
**URL:** https://boards.straightdope.com/t/combustion-on-titan-or-somewhere-similar/707592
**Category:** Factual Questions
**Created:** [December 18, 2014, 6:10pm UTC](https://boards.straightdope.com/t/combustion-on-titan-or-somewhere-similar/707592 "2014-12-18T18:10:01Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@eburacum45](https://boards.straightdope.com/u/eburacum45)
#### Post date: [December 18, 2014, 6:10pm UTC](https://boards.straightdope.com/t/combustion-on-titan-or-somewhere-similar/707592/1 "2014-12-18T18:10:01Z")
Here’s a question that has come up on the OA worldbuilding group, the answer to which I cannot guess.
If you have a moon or planet like Titan with an atmosphere of nitrogen/carbon dioxide then it might support combustion if there is a substantial amount of methane in the atmosphere. On such a world you could set fire to an oxygen jet (for instance) like a Bunsen burner.
But what is the critical level of methane that would allow a flame? 2%, 5%, 10%, more? Is this affected by the total pressure of the atmosphere and/or the partial pressure of methane? How about the ambient temperature?
Perhaps you could get a flame by playing an oxygen jet onto the ethane seas, if they are not too impure.
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### Author:  [@Habeed](https://boards.straightdope.com/u/Habeed)
#### Post date: [December 18, 2014, 8:06pm UTC](https://boards.straightdope.com/t/combustion-on-titan-or-somewhere-similar/707592/2 "2014-12-18T20:06:56Z")
On a planet that’s all fuel, the “flammable” substance is the oxidizer. Amusingly, this makes me wonder what an “oxygen flame” looks like in a purely combustible environment.
At first principles, just invert the equations. You know fuel and a 21% oxygen environment supports fire. So 100% oxygen + 20% fuel should also work just fine. The CO2 shouldn’t matter at all, the equilibria is so in favor of combustion that the reverse reaction will be rare.
02 has a heavier molecular weight than methane, so the flame is going to be closer to what it looks like when you burn a heavier substance than methane on earth. Probably more like a propane fire.
Partial pressures are the only pressures that matter, of course. I meant at 1 atmosphere, but in actuality, it matters much more what the partial pressure of the fuel is on Titan.
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### Author:  [@eburacum45](https://boards.straightdope.com/u/eburacum45)
#### Post date: [December 18, 2014, 9:18pm UTC](https://boards.straightdope.com/t/combustion-on-titan-or-somewhere-similar/707592/3 "2014-12-18T21:18:03Z")
That is more or less what I thought. The methane gas should burn, even though it is very cold there.