So let’s say that I’m travelling the solar system and I decide to stop at Jupiter. Since I can’t actually land on Jupiter (even if there’s a “solid” core down there formed by the pressure) I just descend to a depth where the pressure is roughly one atmosphere. And since I happen to be a niccotine addict I decide that this is the perfect place to light up a cigarette. Forgetting I’m in a spacesuit a flip open my butane lighter and there’s a spark.
My question is what happens then. Is there an explosion? How large of one? I don’t think the reaction would spread to consume the entire planet but if it did what would Jupiter be like afterward? If there is a major reaction, does this occur any time there’s enough heat or does there need to be some other factor? Should gas giants be considdered entirely non-smoking sections?
Have no real clue as to the answer but an excellent first question! Welcome to the SDMB! You’ll fit right in. Astro-Physics geeks will be along shortly.
The answer is that nothing will happen. The lighter won’t even light normally. No flame. Nada.
Why? Because there’s no oxygen. Fire only burns on Earth because of all the free oxygen in the atmosphere. There’s no free oxygen on Jupiter. Its atmosphere is mainly composed of hydrogen, helium, ammonia and methane. None of these are oxydizing compounds so they won’t support a fire.
Okay, but I thought that hydrogen alone was reactive to start that process. Obviously I’ll conceed to those more knowledgeable about the chemestry (I did need to ask the question, after all), but it’s safe to play with sparks in a pure hydrogen atmosphere then? That doesn’t seem right to me.
And the natural follow up question, what about trace elements in Jupiter’s atmosphere. Is there enough oxygen that something would happen? If not at one atmosphere’s pressure what if I went deeper?
I just want to point out that I am not planning on blowing up Jupiter, but no one would notice if Neptune was missing, right?
Hydrogen is a fairly reactive element, but it has to have something to react with. The butane in your lighter is a hydrocarbon. That means it’s a chain of carbon atoms with a bunch of hydrogen atoms stuck to it on all sides. So it has as much hydrogen as it can handle. Hydrogen won’t react with it because there’s no more places for the hydrogen to be added.
Ditto with the ammonia and methane. And helium doesn’t react with anything.
Only because you’re used to working within a high oxygen environment. It’s safe unless a lot of oxygen gets mixed up with the hydrogen. That’s a danger on Earth, which has a lot of oxygen on the loose. There’s no free oxygen on Jupiter except what you bring with you. Any oxygen that’s there is already combined with hydrogen (i.e. water vapor).
Earth once had a reducing atmosphere, as they say. Before chlorophyll we had no free oxygen here. (Finding another planet with free oxygen in it’s atmosphere would be very interesting.)
At one point in history, oxygen was building up in our methane atmosphere and a lightning strike would have set it off.
Well, I doubt it. Possibly the zillion lightning strikes that occur daily on a planet would have done something locally. But the idea is interesting.
First step: ignore the Helium, it’ll do nothing. The density is also irrelevant.
Hydrogen = 89% of Jupiter (assuming this figure is by mass rather than volume) = 1.68922E+27
Oxygen has a mass 16 * Hydrogen’s = 2.70275E+28
But combustion requires only 1 oxygen to 2 hydrogen.
So, assuming complete and perfect combustion, you’d need 1.35138E+28 kilograms of oxygen, i.e. roughly 7 times as massive as Jupiter itself.
It’s probably just me, but I’d just like to say that I find this utterly bizarre and fascinating. The very idea of water ‘burning’ tantalises me. What would THAT look like?
This is the kind of thing we infest the Boards for. Well done AWB! Got any more gems to share?