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by ortusdux 1656 days ago
If we are going down that rabbit hole, I love the plan to create an artificial Martian magnetosphere by placing a magnetic field generating satellite between mars and the solar winds. Generating an atmosphere on mars is all well and good, but it will just blow away again without some protection. The generator would only require roughly 583.9 exajoules, or roughly the world's total energy consumption in 2020.

https://arxiv.org/pdf/2111.06887.pdf
3 comments
db65edfc7996 1656 days ago
>Generating an atmosphere on mars is all well and good, but it will just blow away again without some protection.

NASA estimates the Martian atmosphere is ~2.5e16 kgs[0]. Current estimate[1] is that the Martian atmosphere loses 2-3 kg/s. Presently losing something on the order of 1e-9 percentage per day. I think if humans ever have the ability to thicken the Martian atmosphere, we can cover the loss.

[0] https://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.htm... [1] https://doi.org/10.1016/j.icarus.2018.05.030

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m4rtink 1655 days ago
A man made denser atmosphere after terraforming would presumably loose more due to higher pressure.
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ncmncm 1656 days ago
A superconducting tape girdling the planet's equator would suffice, and require after startup only the power needed to keep it chilled at all times below 70K.
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upwardbound 1656 days ago
That sounds actually quite practical and like an amazing option! Are there papers about this you could please share the links to?
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ncmncm 1656 days ago
Just a youtube video.

21340 km of superconducting tape could take rather some time to fabricate. Then, of course you need to get it there, and lay it out, and construct 20k refrigeration plants. Then, extract enough nitrogen from the atmosphere (1.89% concentration) for refrigerant; you'll need about 4M tons of it. You also need 21340 km of cryo-safe piping bonded to the tape, which probably weighs another 4M tons. Plus heat insulation.

Leakage from 21340 km of tubing, even if just migration of single molecules through the walls of the tube, would require continuous injection of fresh nitrogen.

And, I guess, you had better protect it from meteorite strikes. A planet-sized magnetic field suddenly imploding would seem to release enough energy to vaporize your whole tape. Maybe you should have two of them, parallel, 100km apart so they are unlikely to both be taken out by the same meteorite.

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ryanmercer 1656 days ago
>but it will just blow away again without some protection.

Not in any appreciable amount over human timescales.

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