Jupiter Fusion Reactor?

[chriswight]

Hi. I posted this question in the Intro forum yesterday, when it probably should've been here. I'd really appreciate any imaginative input (as any answer to this question will require a stretch of the imagination).

 

Question: is the planet Jupiter a natural fusion reactor like the Sun? And if so, how might it be used to power an orbital space colony. Any ideas how far in the future this might be, if ever?

 

Thanks,

 

Chris

[CraigD]

To our best understanding of physics, Jupiter isn’t generating any energy by fusing light elements into heavier - or, at most, a tiny amount due to weird phenomena.

 

It’s big, and it’s thermally hot, however, so it has a lot of energy. How one could put this energy to a useful application, however, is a difficult question.

 

IMHO, the best power source for an space colony orbiting Jupiter is to draw from the tremendous kinetic energy stored in its many smaller moons, using its strong magnetic field. I described this at some length in a couple of previous posts, ”Sheer human fecundity” and ”Relevance of space elevators in a 1,000,000 times more energy rich civilization”. I suspect you’d enjoy reading the entire 5550 thread.

 

PS: Welcome to hypography, chriswight! Happy reading and posting!

[C1ay]

If Jupiter were fusing it would be a star, a binary companion to our sun, instead of a planet. With the strongest magnetic field of any planet in the solar system and has a huge radiation output. I see m to remember reading that Jupiter radiates about twice as much energy as it receives. I would look there for methods to extract energy.

[alxian]

based on your post C1ay i'd wonder how much energy that really is.

 

earth radiates energy also, and being so far from the sun Jupiter doesn't recieve quite as much energy as earth does.

 

it might be something like earth outputs 2% versus the amount of energy it receives. with Jupiter putting out 200% versus what it receives its gotta be higher than what earth puts out but still nothing close to what hits the earth that we can convert directly albeit inefficiently to electricity.

 

i.e. circling Jupiter in close orbit with a solar panel pointed down at the planet would be pointless.

 

you'd probably get more power if you could harness the incredible force of the winds of the highly turbulent atmosphere... more than enough to power earth thousands of millions of times over.. no?

[CraigD]

you'd probably get more power if you could harness the incredible force of the winds of the highly turbulent atmosphere... more than enough to power earth thousands of millions of times over.. no?

Though possible, I don’t think such a scheme is the easiest or best.

 

By almost any estimate, giant planets and their moons have many kinds of energy reserves many times greater than all of the Earth’s. Almost anywhere you look, there’s energy waiting to be taken. The question of how to do this is more a matter of finding the easiest – from an engineering perspective – than finding the biggest.

 

One way I find it useful to organize lists of possible energy sources and engineering approaches is according to the depth of the gravity well they require to be navigated. For a gas giant planet system like Jupiter, this groups them into 3 main classes:

• Almost no gravity well
  Just flying by or orbiting a gas giant – as most of our current probes have done – is the easiest to engineer. Rendezvousing with small orbiting objects – “moonlets” – requires spacecraft with more impulse (fuel) than present day probes, but no technology beyond present capabilities.
  • Solar power is available, but only 4% as much as in Earth orbit
    
  • As I suggested in my previous post, electrodynamic tether, while presently still an experimental technology, can potentially extract huge amounts of the planet’s rotational kinetic energy via interaction with its. Because Jupiter’s magnetic field is 10 times stronger than Earths, a 3,500 V potential could be generated with 2,000 m, rather than the 20,000 m of tether necessary in Earth orbit.
    

  [*]Moon-sized gravity well

  Landing and operating on a major moon – which several probes have done to a limited extent – is doable, but more difficult.

  • The large moons of Jupiter are internally very hot from gravitational kneading. A lot of energy could be had by geothermal generators constructed on these moons. In the case of an intensely volcanic moon such as Io, such generators could be as simple as caps placed over suitable volcanic vents.
    

  [*]Really big gravity well

  A controlled descending into the atmosphere – which has only been managed for slightly more than 1 hour, by Galileo's atmospheric entry probe – and constructing and operating a power station there, requires some very challenging engineering.

  • There’s also a major, basic engineering problem with attempting to get any of the huge amount of wind energy of a gas giant. Practically any sort of wind generator must be attached to something fixed – the ground. Running any sort of cable to the surface of a gas giant is a daunting, possible impossible challenge, as is attaching one to a moon or spacecraft. Any gas giant wind generator would have to free-float, “anchoring” itself to a region of atmosphere moving at a different velocity – possible, in principle, but challenging. And, generated power would have to be transmitted from generators traveling at 100s of m/s, to where it is needed – the “space stations” – a separate, difficult engineering challenge.
    

[chriswight]

Hi. Sorry for the late reply. I just returned from a week in Hawaii, where I was checking out the Mauna Kea Observatories (among other things). :)

 

Regarding CraigD's post about the electrodynamic tethers, this is a facinating idea. But what would such a device look like around Jupiter? Especially considering the probable far-future implementation? Current concepts for tethers that convert kinetic energy to electrical energy seem a bit ... clunky.

 

I'm going to do some more research, and maybe somebody on this forum will have additional insights.

 

Chris

[Moontanman]

If Jupiter were fusing it would be a star, a binary companion to our sun, instead of a planet. With the strongest magnetic field of any planet in the solar system and has a huge radiation output. I see m to remember reading that Jupiter radiates about twice as much energy as it receives. I would look there for methods to extract energy.

 

Most of the planets radiate more energy than they recieve from the sun. the earth does and some scientists believe there is a nuclear reactor in the form a ball of uranium abouit five miles in diameter at the center of the earth. jupiter could have the same or even some fusion reactions using heavy hydrogen. of course no one has been in either place to make sure.

 

Michael

[Eclogite]

earth radiates energy also, and being so far from the sun Jupiter doesn't recieve quite as much energy as earth does.

 

it might be something like earth outputs 2% versus the amount of energy it receives. with Jupiter putting out 200% versus what it receives its gotta be higher than what earth puts out but still nothing close to what hits the earth that we can convert directly albeit inefficiently to electricity.

Here is a back of the envelope calculation.

Jupiter is approximately 5.5 times as far away from the Sun as the Earth, so it receives around 1/30th of the solar radiation that the Earth does.

However it is over 11 times larger in diameter, and so has a 'catchment area' around 120 times greater.

Put the two together and you find it recives four times as much radiation as the Earth does, and radiates eight times what the Earth receives.