I'm wondering if, using enough neodymium magnets (dont worry where the material is coming from) in a low martian orbit, could you produce a powerful enough magnetic field to protect the atmosphere from burning away? How would this impact interplanetary travel? How much maintenance would it take per decade?

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    $\begingroup$ Giving Mars a magnetosphere is overrated. If you can introduce an Earth-like atmosphere to Mars, it will last potentially millions of years. Gradual replenishing what is lost to space is all that's really needed to maintain it, which requires much less effort than what it took to create the atmosphere in the first place. $\endgroup$
    – BMF
    Mar 3, 2021 at 17:58
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    $\begingroup$ @BMF it could also be more trouble than benefit. A magnetic field means you can experience geomagnetic storms, with that magnetic field being pushed around by disruptions in the solar wind, and that magnetic field will trap bands of charged particles in orbit, forming radiation belts that pose navigation hazards and shorten the lifetimes of satellites. $\endgroup$ Mar 3, 2021 at 19:01
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    $\begingroup$ too weak. by several hundred magnitudes. That's like draining the ocean with an eyedropper, which you empty over the side of your canoe. $\endgroup$
    – PcMan
    Mar 3, 2021 at 19:14

1 Answer 1


If you want to protect a planet from the solar wind, the scale of the magnetic field has to be comparable with the one of the planet. A magnet, no matter how strong, has its field decay with the cube of the distance.

Magnets orbiting the planet would do little to no benefit, unless you can have a magnetic bar going from pole to pole through the planet.

  • $\begingroup$ is there any specific reason it has to run through the poles? why not some other pair of points close to them? $\endgroup$
    – zackit
    Mar 3, 2021 at 18:04
  • $\begingroup$ @zackit, considering the effect of a concentrated mass on the momentum of inertia, you don't want to mess up with the rotation of the planet, I assume $\endgroup$
    – L.Dutch
    Mar 3, 2021 at 18:09
  • $\begingroup$ Magnets in orbit would also have no advantage over magnets on the surface. Really what you'd do is run a superconducting cable around the planet, but as BMF commented, it's really not necessary. $\endgroup$ Mar 3, 2021 at 18:58

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