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I wonder how difficult it is to create an artificial planetary magnetic field with generators? What power they would need?

The question is inspired by thinking about possible colonization of Jupiter's moons Io and Europa which are located inside the Jovian radiation belt. Is it possible to create with easy means an artificial magnetic field such that it to shield the surfaces of these moons from radiation? Or it would require astronomical amount of power?

By easy means I mean a device that would not require power greater that normal industrial power plant, best of all, solar-powered or based on once-charged superconductor coils.

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Related question physics.stackexchange.com/questions/53184/… –  Jitter Jan 13 '14 at 8:00
Well another question that opens up now, is what is the benefit of a (weak) planetary field, in comparison to stronger local fields (like just for the settlements)? And at which level would a local field have the same (shielding) effect? –  Kurtovic Aug 4 at 9:52

2 Answers 2

According to this article the energy stored in the Earth's magnetic field is about $10^{26}$ ergs or $10^{19}$J. According to Wikipedia the annual global generation of electricity is about 20,000TWh, which is between $10^{19}$ and $10^{20}$J, so actually we already produce enough power to generate the Earth's magnetic field.

Actually doing it on a moon of Jupiter would be another problem. I suppose you could use nuclear power to avoid having to build an oil pipeline between the Earth and Europa, but even if the power were available I don't know if current technology is up to generating magnetic fields with that much energy.

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Well, humans produce enough energy, to cover the energy of the magnetic field. However it's not clear, which energy conversion efficiency can we reach, and how much energy should we spend to sustain created magnetic field. If we do use a superconducting wire, do we have enough resources to produce that much of it (and the cooling system)? –  Fiktor Aug 12 '13 at 17:51
You seem to be comparing quantities with different units. By itself, the fact that there are $ \ge 10^{19}\,\mathrm{J}$ stored in the Earth's magnetic field tells you nothing about the power needed to generate it, because you also have to know how rapidly that energy is dissipated. If the dissipation time scale is about a year then fair enough, but otherwise comparing our annual energy production (Joules per year) to the total energy in the field (Joules) isn't terribly meaningful. –  Nathaniel Sep 9 '13 at 8:05

The most feasible method by which the artificial magnetic field can be generated is through placement of hundreds (if not thousands) of magnet satellites into the orbit of the target moon or planet all of which revolve at certain distance and velocity.These kind of satellites may use solar energy as their main source of energy which in fact lowers the energy costs for their global constant function. However, manufacturing and launching of this huge number of satellites will definitely remain a matter of enormous costs and resources that for sure ought to be mulled over.

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-1, there's no quantitative reasoning here. One could at least estimate a lower bound for solar panel surface area. –  NeuroFuzzy Jan 13 '14 at 3:10

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