Our Earth and Venus each keep a thick atmosphere because of a magnetosphere. Most terraforming scenarios of Mars involve transferring water and other gases from the ground to the atmosphere.

We now know Mars won’t be able to keep them. We also now know the process is happening naturally.
So, if Mars got a magnetic shield (even an extra thin one like Venus) to protect against solar radiation, it would be able to held water oceans again.

So, how can we create such a field ?

  • $\begingroup$ Pretty sure I answered a question like this before... $\endgroup$ Nov 21, 2015 at 19:49
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    $\begingroup$ I think the solution involves melting the planet's core and getting the molten material spinning. I hesitate to offer that as an answer as my scientific knowledge isn't up to the challenge of defending that solution. It might also be possible to build a mesh out of satellites to generate magnetic armor, but again, I'm not scientifically adept enough to design it, even on paper. $\endgroup$ Nov 21, 2015 at 19:50
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    $\begingroup$ @VilleNiemi, like worldbuilding.stackexchange.com/questions/8832/… ? $\endgroup$
    – Ghanima
    Nov 21, 2015 at 19:54
  • $\begingroup$ @Ghanima Yes, seems to be what I was thinking about. $\endgroup$ Nov 21, 2015 at 19:59
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    $\begingroup$ Not sure why the close votes are still increasing - this is obviously not a duplicate after the edit, since it requires modern technology. On the other hand, I don't think it can be accomplished with modern technology, but that's an entirely different problem... $\endgroup$ Nov 22, 2015 at 3:04

3 Answers 3


You can't.

Since you've narrowed the scope of your question to current technology, you've eliminated any possible solutions. We currently have no technology for generating artificial planetary magnetic fields. It's just not something we're keeping in a closet somewhere.

If we were to develop new technology, this existing question and its answers cover that altered scope rather well.

  • $\begingroup$ To elaborate a little, it's theoretically possible that we could spin up a planet like Mars with asteroid bombardment (given enough thousands of years). However, we don't think Mars has a liquid metal core, so the spin up wouldn't induce a magnetic field like that possessed by Earth. $\endgroup$
    – Jim2B
    Nov 22, 2015 at 3:44

To be honest, with current technology, you are out of luck. HOWEVER, with NEAR-TERM technology (and some large scale engineering) it could be doable to create an artificial magnetic field using at least 6 to 8 planet-sized, superconducting rings tops. In this report here, it was concluded that for an Earth-sized magnetic field, you need 12 of those rings. I am extrapolating to take into account the less massive Mars, and NASA did propose the creation of a magnetic dipole field at Mars Lagrange Point 1. So, those two techniques could be useful. Good luck!


It's actually relatively easy. The proposed solution is to park a giant expandable net or balloon dotted with magnets in the sun-Mars L1 orbit (a stable orbit that would keep the magnet between the sun and Mars at all times). The magnets would need to be quite powerful*, but aren't out of reach of current science.

What it would do is deflect the solar wind to the sides of the planet, to keep the atmosphere from getting ripped off.

This is all possible now, just very expensive, and would take at least two years to put in place.

*1-2 Tesla. For reference, the most powerful commercially available permanent magnets, neodymium rare earth magnets, are typically around 1.3 Tesla at their surface, though much stronger examples exist.

  • $\begingroup$ Something giant can not be done with actual technology. Also in reality you need to have fuels in order to stabilize to the L1. $\endgroup$ May 9, 2017 at 15:12
  • $\begingroup$ @user2284570 What? The balloon/network doesn't have to be planet sized. It's totally doable. And, sure, it would likely require stationkeeping of some sort, but that's also not a terribly difficult challenge, considering we have tens of thousands of satellites that have stationkeeping engines on them. $\endgroup$
    – Emmett R.
    May 9, 2017 at 17:22
  • $\begingroup$ But isn’t it supposed to be building or 100 times ɪꜱꜱ sized ? $\endgroup$ May 9, 2017 at 22:03

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