Burning gas giants

[FungusForge]

Could a burning gas giant allow one of its moons to support life?

[Tex_NL]

Before talking about moons supporting life please answer me this: How would a gas giant burn?
Without an active mechanism (such as life on earth) to replenish either fuel or oxidizer (or both) one of them will run out very quickly.

[SargeRho]

Not really. A gas giant wouldn't burn for very long. Very high mass brown dwarfs however, might have life-supporting companions.

An ice-moon on an eccentric orbit might also allow life in its subsurface ocean, ie, Europa, Ganymede and Enceladus.

Edited March 20, 2016 by SargeRho

[Jovus]

Do you mean, "If a gas giant was burning, would its moons be able to support life?" or "If a gas giant had moons, and it started burning, would that make it so its moons could support life?"

Either way, I'm not sure that 'burning' is relevant. I'll do you the favor of assuming you meant something like a brown dwarf undergoing long-term but unsustainable fusion at the core and say "sure". But then, that's not even necessary; if all you're looking for is enough energy for a carbon-based life-form, Jupiter can give you that now. Check out Io.

[K^2]

Gas giants of Jupiters' size are of sufficient density for ignition. They just don't have enough gravity to confine the matter once it reaches sufficient temperature. Which means that even if you manage to ignite sufficient fraction of the atmosphere for a chain reaction, what you'll get is a miniature nova rather than a sustained burn.

You could make a pretty warm gas giant by messing with composition and making sure it can sustain nuclear reactions at lower temperatures. Kind of like an even cooler version of aforementioned brown dwarfs. But if you make a gas giant hot enough to have sufficient light output to qualify for a star, it will quite simply evaporate.

If neutronium is metastable, at least in chunks, it might be possible to make a tiny little star with a neutronium core. It wouldn't be a gas giant, of course, but an objects in its own class. A neutron star remnant. I shudder to think of the sort of event that could create such a thing.

[Exploro]

10 hours ago, Jovus said:

Do you mean, "If a gas giant was burning, would its moons be able to support life?" or "If a gas giant had moons, and it started burning, would that make it so its moons could support life?"

Either way, I'm not sure that 'burning' is relevant. I'll do you the favor of assuming you meant something like a brown dwarf undergoing long-term but unsustainable fusion at the core and say "sure". But then, that's not even necessary; if all you're looking for is enough energy for a carbon-based life-form, Jupiter can give you that now. Check out Io.

The internal heating within Io is not due to radiant energy emanating from Jupiter. Io's interior heating is due to the tidal kneading Jupiter and Europa subject the inner most Galilean moon to.

However I should note that at one point early in the Jovain system's history; Jupiter was much more "luminous" than it is presently. If memory serves me right this was due to the residual heat left over during Jupiter's formation. Thus close in towards Jupiter; only silicates and other high temperature condensates could exist in such an radiant environment. That is why Io formed as a rocky and parched world compared to the other three Galilean moons.

Edited March 20, 2016 by Exploro

[FungusForge]

Thank you for the answers.

Probably could have done with mentioning this in the OP, but this was something I saw in a web novel and decided to to ask people smarter than me if it was even possible.

[problemecium]

This thread confuses me. Are we talking about:
- "Burning" as in "on fire?" If so, remember that gas giants such as Jupiter contain a lot of flammable hydrogen, but only trace amounts at best of oxygen, which is just as important for combustion. If a hypothetical planet did form with large amounts of oxygen and hydrogen, it would all have combined shortly after formation into water - after all, planets are hot when they form.
- "Burning" via nuclear fusion? In this case, sure, a vaguely Jupiter-sized object could support life. Such an object is literally what a brown dwarf is, albeit more massive (at this size, gas giants don't expand significantly with increased mass but just get denser). However, Jupiter would have to be around 10 times its current mass to sustain nuclear fusion on a large scale. While a hydrogen bomb could be deployed to initiate a small amount of fusion in its atmosphere, the process would not be self-sustaining and would stop within minutes, not even covering the entire surface but just leaving a little spot in the clouds that would dissipate after a few days.

[Tex_NL]

24 minutes ago, parameciumkid said:

This thread confuses me. Are we talking about:
- "Burning" as in "on fire?" ...[snip]
- "Burning" via nuclear fusion? ...[snip]

Funny thing is, it doesn't matter. A gas giant has more than enough gravity to cause tidal friction in its moons. Heat from this tidal friction alone can be enough to sustain life.

[Exploro]

I think OP had in mind the idea of a gas giant producing radiant energy that directly shines upon nearby objects to be sufficient enough to support lifeforms much like the Sun does for life on Earth's surface.

[Sparkhead]

Why are we all arguing about this? Obviously none of you have watched Space Battleship Yamato before, or else you would know that it's totally possible to burn a gas giant. Just look what they did to Jupiter! (Yes, I'm aware that was completely off topic)

Edited March 21, 2016 by Sparkhead
I didn't wan't to use the word totally twice.

[fredinno]

15 hours ago, Jovus said:

Do you mean, "If a gas giant was burning, would its moons be able to support life?" or "If a gas giant had moons, and it started burning, would that make it so its moons could support life?"

Either way, I'm not sure that 'burning' is relevant. I'll do you the favor of assuming you meant something like a brown dwarf undergoing long-term but unsustainable fusion at the core and say "sure". But then, that's not even necessary; if all you're looking for is enough energy for a carbon-based life-form, Jupiter can give you that now. Check out Io.

6 hours ago, Tex_NL said:

Funny thing is, it doesn't matter. A gas giant has more than enough gravity to cause tidal friction in its moons. Heat from this tidal friction alone can be enough to sustain life.

Actually, most of the net energy to the Galiliean moons if via Solar heating, not Tidal Heating. Tidal Heating can allow for underground oceans and carbon based life that way (you would need a much more eccentric orbiting moon to generate enough friction for complex life in the absence of a star, and likely a larger moon overall (closer to Mars size) to generate extra internal heat via radioactive heating, but there is no equivalent for allowing for surface water life, other than fuzing stars.

6 hours ago, parameciumkid said:

This thread confuses me. Are we talking about:
- "Burning" as in "on fire?" If so, remember that gas giants such as Jupiter contain a lot of flammable hydrogen, but only trace amounts at best of oxygen, which is just as important for combustion. If a hypothetical planet did form with large amounts of oxygen and hydrogen, it would all have combined shortly after formation into water - after all, planets are hot when they form.
- "Burning" via nuclear fusion? In this case, sure, a vaguely Jupiter-sized object could support life. Such an object is literally what a brown dwarf is, albeit more massive (at this size, gas giants don't expand significantly with increased mass but just get denser). However, Jupiter would have to be around 10 times its current mass to sustain nuclear fusion on a large scale. While a hydrogen bomb could be deployed to initiate a small amount of fusion in its atmosphere, the process would not be self-sustaining and would stop within minutes, not even covering the entire surface but just leaving a little spot in the clouds that would dissipate after a few days.

An object 10x the current mass of Jupiter would burn (fuze) Deuterium only, thus quickly losing its capability to fuze anything (deuterium is rare) https://en.wikipedia.org/wiki/Deuterium_burning

 

[KAL 9000]

As @Tex_NL said, tidal forces will sustain life (--cough-- Europa --cough--). Burning? Like, on fire? I doubt that's possible for a gas giant. If you mean fusion, then by definition, it's not a gas giant, it's a star!

[fredinno]

2 hours ago, KAL 9000 said:

As @Tex_NL said, tidal forces will sustain life (--cough-- Europa --cough--). Burning? Like, on fire? I doubt that's possible for a gas giant. If you mean fusion, then by definition, it's not a gas giant, it's a star!

Or a brown dwarf, if you are referring to lithium, and/or deuterium fuzing.

[problemecium]

18 hours ago, fredinno said:

An object 10x the current mass of Jupiter would burn (fuze) Deuterium only, thus quickly losing its capability to fuze anything (deuterium is rare) https://en.wikipedia.org/wiki/Deuterium_burning

Okay yes. I meant "around 10x" as in "tossing an asteroid into it won't transmogrify it into a star." So thank you for reinforcing my general point

[DBowman]

On 3/20/2016 at 10:15 PM, K^2 said:

If neutronium is metastable, at least in chunks, it might be possible to make a tiny little star with a neutronium core. It wouldn't be a gas giant, of course, but an objects in its own class. A neutron star remnant. I shudder to think of the sort of event that could create such a thing.

an artifact? (Alien mega-structure)

Edited March 22, 2016 by DBowman

[KerikBalm]

No moon is even close to big enough to hold on to an atmosphere that would be thick and warm enough allow liquid water at its surface.

Titan can hold on to its thick atmosphere because that atmosphere is so cold... warm it up to the melting point of water at 1 atmosphere, and it would all escape into space in short order..

So then you're left with subsurface habitats... and tidal heating is enough there, and we can ignore the burning question entirely.

Back to the moon size question... a better question would be if its possibly for a mars sized moon or bigger to form around a gas giant (a sub brown dwarf)?

[peadar1987]

A lot depends on the definition of "burning". Jupiter is mostly hydrogen, with nothing to react it with, so you'd have to add a lot of oxygen.

Of course, oxygen is 16 times as massive as hydrogen, so to add enough oxygen to burn all the hydrogen, you'd increase the mass of Jupiter to a level which could possibly sustain some level of deuterium fusion in its core. Supposing the resulting detonation didn't blow the entire mass of the planet out of its own gravity well, you'd probably get a planet with all sorts of weird allotropes of hydrogen, oxygen and water.

Edited March 22, 2016 by peadar1987

[kiwi1960]

Having not read all the answers (its nearly 12:30am fro crying out loud) .... let me add this...

Life doesn't need a sun to thrive, while Earth is in the Goldilocks zone.... not too close to the sun, not too far... just RIGHT.... moons and other rocks have a chance to support life ij the following way...

Having an ice covered moon with a non frozen lake beneath it... what makes the lakes? Volcanoes... of course, that would mean the world isn't dead... it would have a molten core, hence, the volcanoes providing heat to keep the lake unfrozen... the ice cap protects the water from the harshness of space and no atmosphere (or a very cold atmosphere).

There may well be life in the lake, but simple life..... its still life.....

[fredinno]

10 hours ago, KerikBalm said:

No moon is even close to big enough to hold on to an atmosphere that would be thick and warm enough allow liquid water at its surface.

Titan can hold on to its thick atmosphere because that atmosphere is so cold... warm it up to the melting point of water at 1 atmosphere, and it would all escape into space in short order..

So then you're left with subsurface habitats... and tidal heating is enough there, and we can ignore the burning question entirely.

Back to the moon size question... a better question would be if its possibly for a mars sized moon or bigger to form around a gas giant (a sub brown dwarf)?

You can have a captured mars-sized moon. Or make the host gas giant large enough to host numerous Mars sized moons naturally.

[Tex_NL]

2 minutes ago, fredinno said:

You can have a captured mars-sized moon. Or make the host gas giant large enough to host numerous Mars sized moons naturally.

Exactly. There are plenty large gas giants that dwarf Jupiter. A larger gas giant should have more than enough gravity to create or capture an Earth/Mars sized moon/planet.

[adsii1970]

Just for giggles and grins, l'd like to submit a thought on this... for nearly two centuries, it was theorized about other planets around other stars. It wasn't until the last decade that astronomers were able to put that theory to rest. We now know of at least 2,000 exoplanets in 1,320 planetary systems, with many of those systems having binary planetary systems (I still think Pluto and Charon will eventually be classified as this). I saw another poster mentioning something about the "Goldilocks" zone, such as where earth is, that is ideal for Earth-like life.

If any planet is going to have a moon with an atmosphere, the moon will have to have enough gravity to hold its atmosphere and balance out the pull of its central planet. It would also have to have enough velocity and mass to maintain orbit and rotation. Can planets be large enough to have moons like that? Personally, in our small bit of knowledge about our own solar system, much less our home galaxy, I will be willing to bet that it is possible, and who knows, maybe in another 200 years, we'll discover that very thing.

Until then...

  'Super-Jupiter' Discovery Dwarfs Solar System's Largest Planet

  Largest Known Exoplanet Discovered

 

[fredinno]

2 hours ago, adsii1970 said:

Just for giggles and grins, l'd like to submit a thought on this... for nearly two centuries, it was theorized about other planets around other stars. It wasn't until the last decade that astronomers were able to put that theory to rest. We now know of at least 2,000 exoplanets in 1,320 planetary systems, with many of those systems having binary planetary systems (I still think Pluto and Charon will eventually be classified as this). I saw another poster mentioning something about the "Goldilocks" zone, such as where earth is, that is ideal for Earth-like life.

If any planet is going to have a moon with an atmosphere, the moon will have to have enough gravity to hold its atmosphere and balance out the pull of its central planet. It would also have to have enough velocity and mass to maintain orbit and rotation. Can planets be large enough to have moons like that? Personally, in our small bit of knowledge about our own solar system, much less our home galaxy, I will be willing to bet that it is possible, and who knows, maybe in another 200 years, we'll discover that very thing.

Until then...

  'Super-Jupiter' Discovery Dwarfs Solar System's Largest Planet

  Largest Known Exoplanet Discovered

 

Yes. Only problem is that finding exomoons is very difficult, and even harder to confirm.

[KerikBalm]

12 hours ago, fredinno said:

You can have a captured mars-sized moon. Or make the host gas giant large enough to host numerous Mars sized moons naturally.

A bar assertion with no facts or simulation to back it up. Mars is 4x more massive than ganymede, and its much farther out...

If you want a planet to be in the habitable zone, it needs to be much closer to the sun, where its harder for volatiles to coalesce due to the temperatures.

For some reason, there's a similar size of the massive moons of jupiter and saturn.

Titan's mass is within 10% of ganymede's, Callisto is fiarly similar (1.1 vs 1.4 x 10^23 kg) Europa is about half the mass... Io is about half.

It would be quite a jump to get to a mars sized moon. I would want to see the outcome of a simulation before declaring it possible or not.

Many of these things in space do not just scale linearly.

[fredinno]

10 hours ago, KerikBalm said:

A bar assertion with no facts or simulation to back it up. Mars is 4x more massive than ganymede, and its much farther out...

If you want a planet to be in the habitable zone, it needs to be much closer to the sun, where its harder for volatiles to coalesce due to the temperatures.

For some reason, there's a similar size of the massive moons of jupiter and saturn.

Titan's mass is within 10% of ganymede's, Callisto is fiarly similar (1.1 vs 1.4 x 10^23 kg) Europa is about half the mass... Io is about half.

It would be quite a jump to get to a mars sized moon. I would want to see the outcome of a simulation before declaring it possible or not.

Many of these things in space do not just scale linearly.

Yeah? Earth could have a Mars-sized moon too, technically. Nothing is barring from that, it'd just make Earth a binary.

No reason Jupiter could not host a Mars sized moon under the right conditions.