Giving Mars A New Magnetic Field | Vol. 4 / No 19.2

Terraformed Mars | Image: Kevin Gill, CC BY-SA 2.0

Last week, at a NASA Planetary Science Division (PSD) workshop, Jim Green, the PSD’s director, gave a brief lecture that raised more than a few eyebrows. Mostly because what it suggested was (a) very science fictiony-sounding and (b) not totally impossible.

The workshop, styled as the “Planetary Science Vision 2050 Workshop,” was about possibilities: what we could be doing (or at least starting) by 2050. Green’s lecture was about building up Mars’s atmosphere to reduce radiation, increase pressure, and rebuild it’s oceans, all with one action.

Green wants to give Mars a new magnetic field.

The field wouldn’t be quite like Earth’s, of course. Ours is generated by the planet itself, and processes taking place well beneath the surface. Mars had one like this once, too, but it disappeared over four billion years ago, leading to the stripping of its atmosphere and the evaporation of its oceans. Mars’s new field would be at it’s L1 point, a stable gravitational eddy always between Mars and the Sun. (For reference, every planet has several such L points — if successful, the James Webb Space Telescope will find its home at Earth’s L2 point, with the Earth always between it and the Sun.)

Once there, a satellite would generate a 1-2 Tesla magnetic field, or about 10,000 to 20,000 Gauss. This is beyond our technology right now, but thanks to work that’s being done on spacecraft shielding that’s pushing the technology forward, Green says that we could already put a satellite there that could generate a 0.2 Tesla field, or about 2,000 Gauss, so it’s not as unreasonable as it seems.

Green then explained that his team has done a great deal of modeling of what the fallout of this would be.

Mars would find itself in the wake of this new magnetic field, shielding the planet from the solar winds. Right now the winds and the offgassing of the frozen CO2 poles keeps the Martian atmosphere at an equilibrium of about 1% of the Earth’s. Eliminating the interaction with the solar wind would allow the planet’s atmosphere to rebuild, causing the temperature to go up by 4 or 5 degrees, and likely melting the water ice stored at the poles. The figure he gave was that the melting could produce as much as 1/7 of the red planet’s original oceans, and of course the water vapour in the atmosphere would cause an even greater greenhouse effect.

From his presentation, it wasn’t clear where exactly this would lead, and perhaps that’s because (as he admits) they still have plenty of modeling to do. But it is certain that a thicker atmosphere and greater radiation shielding would go a long way toward facilitating human exploration of Mars, at least in the next century.

You can watch his talk here, starting at the 1:36:00 mark. It’s about 15 minutes long.


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Richard Ford Burley is a human, writer, and doctoral candidate at Boston College, as well as Deputy Managing Editor at Ledger, the first academic journal devoted to Bitcoin and other cryptocurrencies. In his spare time he writes about science, skepticism, feminism, and futurism here at This Week In Tomorrow.