1. Jul 16, 2008

fluidistic

I know it's not a bright question, but I'd like to know the answer as well. I've read that the high atmosphere of Jupiter contains molecules of Hydrogen ($$H_2$$). It is well known that (under Earth atmosphere at least), this gas is highly explosive. I just wonder why the atmosphere of Jupiter doesn't explode at least partially. I'm guessing that the concentration of gas on the atmosphere is just way too low to start a fire reaction, but it's only a guess. If it appears to be true, I'd like to know the concentration required to start a fire reaction between Hydrogen molecules. (I know it produces water...in case I'm not specific enough of the gas I'm talking about).

2. Jul 16, 2008

pixel01

No, H2 explosion needs O2 as well

3. Jul 16, 2008

fluidistic

Oh you're right... that's why it produces water. Anyway, isn't it possible to find a planet with an atmosphere mixed with hydrogen and oxygen in such quantities that it can interact violently? I don't think it might occur in the Solar System since Jupiter is just heavy enough to retain the hydrogen in its atmosphere... Maybe big explosions occurs in another planets and we might see them then.

4. Jul 16, 2008

Staff: Mentor

More than 75% of the mass of the universe is hydrogen, oxygen only 1%, so big gas planets will be unlikely to have the right mix to make combustion possible.

5. Jul 16, 2008

fluidistic

Too bad... It would also be much less brighter than a little star, so there is no hope to observe it.
I believe planets don't fit the global universe statistics of component elements though.
Now I'm thinking about planets that contains liquid (or ice) $$H_2$$ and $$0_2$$. If there is a storm or a cataclysm (say, for example a big cliff falling into the liquefied gases), it would be possible to engender a terrible explosion, but yes, very unlikely to happen.
Thank you both for the clarification. I'm done with this question.

6. Jul 17, 2008

Staff: Mentor

Well, such a thing wouldn't be stable anyway. A hydrogen/oxygen mixture is explosive, so a giant ball of it would simplly explode and then be gone. There is no equilibrium to be had like in a star.