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Comment by protomyth | Hacker News Reader

What is the actual story of Mars's magnetic field and would we ever have the tech to create one?

As things stand now, we don't have a perfect understanding of how the Earth's core works. Even if we did, though, the amount of energy that would be required to start up a magnetic field on another planet would be, well, astronomical. Keep in mind, the planet weighs 6x10^23 kilograms. A full mole of kilograms is going to take a lot to get spinning.

Will we ever have that much energy at our disposal? That depends on how likely you think humans are to a) annihilate ourselves and b) continue our roughly exponential growth of technology indefinitely.

Should we ever have that much energy at our disposal, I think we're pretty likely to annihilate ourselves with it

If we have that much energy at our disposal, we'll presumably be so spread out we'll be incapable of annihilating ourselves all in one go. Some will remain to learn from the mistakes of others, and the anti-tech-crazies will get to say "we told you so".

China is building 400 nuclear reactors over the next 30 years, that would do it.

Not even close.

Re-spinning the core is unlikely to be the best approach. Winding a giant cable around the equator and pushing a giant current through it is probably within our capacity, though orders of magnitude more expensive than any project ever attempted.

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