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Kebsis
2003-Jul-06, 07:22 AM
Would it be possible for a Planet to be completely consumed in flames constantly? I'm thinking something like the planet having a very pourus crust with ignitable gas constantly leaking out, a spark of some sort going off somewhere and fwooom! the entire planet goes up.

A silly question, I know, but I just got this image in my head and was wondering if it was possible.

Karthesios
2003-Jul-06, 07:33 AM
I'd think that the planet would run out of oxygen before too long though.

DStahl
2003-Jul-06, 07:50 AM
Oooo! You'd have to have a planet made up of a combustible or explosive compound or mixture of some kind, and an environment which never produced the energy necessary to ignite the stuff. No lightning, no meteorite impacts! Too hot!

Or, if somehow the mixture were constantly being produced, then it could periodically ignite--the planet's combustible deposits would burn whenever a meteorite hit the surface, for instance. You might be able to figure out a compound or mixture with a high enough ignition temperature so that it wouldn't ignite very easily...maybe something like thermite?

Incidentally, some neutron stars do something like this, except that the surface explosions are powered by nuclear fusion. We discussed this in another thread. Basically, a neutron star orbiting close to a giant star can capture hydrogen and/or helium gas from the other star. The gas builds up in a layer on the surface of the neutron star until the lower layers are pressurized and hot enough to ignite in a thermonuclear explosion. It's thought that some of these periodic flares engulf pretty much the whole surface of the neutron star.

eburacum45
2003-Jul-06, 08:30 AM
Well, the combustible material would tend to reach an equilibrium with the oxygen in the atmosphere; the carbon on Earth is mostly underground, in rocks, but once long ago much of it was in the atmosphere as CO2.
If you could somehow extract all the carbon from the rocks you could burn it,
until the oxygen in the atmosphere was all combined to make CO2 again- but there isn't any realistic method of doing that.

One fairly realistic burning planet I have read about had a planet wide forest which gradually sequestered the carbon out of the air in the form of biomass, thereby enriching the O2 level in the atmosphere- eventually the forests became so inflammable that they burst into flame, a forest fire sweeping round the world every twelve years.
(Echronedal, Iain Banks).

Of course brown dwarfs fuse deuterium - they are a bit like big planets- but they aren't very hospitable places.

aurorae
2003-Jul-06, 02:06 PM
Would it be possible for a Planet to be completely consumed in flames constantly? I'm thinking something like the planet having a very pourus crust with ignitable gas constantly leaking out, a spark of some sort going off somewhere and fwooom! the entire planet goes up.

A silly question, I know, but I just got this image in my head and was wondering if it was possible.

All the forests on Earth probably burned during large impacts.

That isn't exactly what you were thinking of, though.

Kebsis
2003-Jul-07, 06:20 AM
I'd think that the planet would run out of oxygen before too long though.

Hmm...well, wouldn't the oxygen, after it gets used for fuel in the fire, break up into sperate elements and then just float around in the atmosphere for awhile before reforming as oxygen again?

Perhaps if the planet was still in a liquid stage with no solid crust, and the liquid was flamable... and maybe it would be in a newly formed solar system so plenty of meteors are hitting it and keeping it fueled?

Also, is there any other compound that fire can use as fuel other than oxygen?

eburacum45
2003-Jul-07, 11:45 AM
Hmm...well, wouldn't the oxygen, after it gets used for fuel in the fire, break up into separate elements and then just float around in the atmosphere for awhile before reforming as oxygen again? --------------------------------------------
Well, no- fire is the combination of oxygen with other flammable materials to make more stable compounds. typically water and carbon dioxide. Both these compounds are very stable, and as you know both are found in fire extinguishers, so will build up and tend to put the fire out.
...
To get rid of them, and produce more fuel, you need an active process, usually life, to convert the carbon dioxide and water back into fuel and oxygen. This process uses sunlight as an energy input; this is what is happening on Iain Bank's Echroneda... the fire cycle is part of the ecology, just as it is in the Australian eucalyptus forests.

Perhaps you could have a thick layer of biological material over your planet, producing methane as a waste byproduct; the methane could burn permanently like a will'o the wisp above the biological layer converting methane into carbon dioxide and water, which is immediately used in photosynthesis to produce more oxygen and eventually more methane.
You see fire is a process- you can't just add more and more fuel, because without more oxygen being produced in a balancing process, it won't burn.
-----------------------
Also, is there any other compound that fire can use as fuel other than oxygen?
----------------------
Well, It might be possible to produce a similar phenomenon in other reactive atmospheres- a pure chlorine atmosphere might produce a flame if you burn hydrogen in it- but this process would produce hydrocloric acid, which would build up until you couldn't burn any more.
You must have a way of breaking down the waste products or the fire, whatever it is, will choke itself and go out.

Glom
2003-Jul-07, 01:53 PM
Hmm...well, wouldn't the oxygen, after it gets used for fuel in the fire, break up into sperate elements and then just float around in the atmosphere for awhile before reforming as oxygen again?

Careful! You're coming dangerously close to suggesting a perpetual motion machine.

Kebsis
2003-Jul-07, 06:25 PM
To get rid of them, and produce more fuel, you need an active process, usually life, to convert the carbon dioxide and water back into fuel and oxygen. This process uses sunlight as an energy input; this is what is happening on Iain Bank's Echroneda... the fire cycle is part of the ecology, just as it is in the Australian eucalyptus forests.

Maybe a planet that's surface is ablaze, and has high concentration of microscopic lifeforms in the upper atmosphere to convert the carbon Dioxide?

eburacum45
2003-Jul-07, 07:09 PM
Maybe a planet that's surface is ablaze, and has high concentration of microscopic lifeforms in the upper atmosphere to convert the carbon Dioxide?
That's good; now all you need is a cyclable fuel source and you have a burning planet!
Perhaps the microscopic lifeforms fall onto the surface when they die, and form oil, resin or some other inflammable material.

The Supreme Canuck
2003-Jul-07, 08:18 PM
Or it could just be their waste products. Cows produce methane. :o

Defender
2003-Jul-09, 10:44 PM
Incidentally, some neutron stars do something like this, except that the surface explosions are powered by nuclear fusion. We discussed this in another thread. Basically, a neutron star orbiting close to a giant star can capture hydrogen and/or helium gas from the other star. The gas builds up in a layer on the surface of the neutron star until the lower layers are pressurized and hot enough to ignite in a thermonuclear explosion. It's thought that some of these periodic flares engulf pretty much the whole surface of the neutron star.

That's a mindblowing idea; it fits in quite well with the conclusion for a story I was thinking about. Tell me- this gas building up. Would it be possible to trigger the detonation of the gas ahead of time? And if so, what sort of event would you need to trigger it?

And how big would these explosions be? I'm guessing they wouldn't reach out very far from the surface of the neutron star, but that they'd put out a lot of energy. Is that right?

DStahl
2003-Jul-10, 02:12 AM
Good questions! I don't know all the answers, but there's a lot of info on the topic available online. X-ray bursters is another term used for pulsars that accrete hydrogen and helium and fuse it. From one website I read that hydrogen fusion on the surface of some of these pulsars gives a sort of steady rumble of fusion, while the helium that builds up both from accretion and as the product of hydrogen fusion tends to go up all at once in a massive flare.

RafaelAustin
2003-Jul-10, 02:45 AM
Everybody sing! :lol:


I Fell Into A Burning Sphere Of Fire
I Went Down, Down, Down
And The Flames Went Higher

And It Burns, Burns, Burns
The Sphere Of Fire
The Sphere Of Fire

The Supreme Canuck
2003-Jul-10, 02:47 AM
Burn baby burn! - Disco inferno!
Burn baby burn! - Burn that mother down
Burn baby burn! - Disco inferno!
Burn baby burn! - Burn that mother down
Burnin'!

russ_watters
2003-Jul-10, 03:42 AM
There is a planet that "burns". Its a gas giant made mostly of hydrogen, so it has no surface, but it is constantly aflame through nuclear fusion...

Kebsis
2003-Jul-10, 07:50 AM
Doesn't that make is a star?

nebularain
2003-Jul-10, 02:01 PM
Well, considering the term "planet" has not actually been defined . . . . :-k

Kebsis
2003-Jul-11, 03:05 AM
Well it must have been somewhat defined, if there is a difference between a brown dwarf and a planet, correct?