Artificial Magnetosphere to Terra-form Mars?

Question

I was reading a 2017 article on a potential that Mars could be terraformed using a magneto-tail; A Future Mars Environment for Science and Exploration. This would basically entail sticking a giant magnet that carried a charge between 10,000 and 20,000 Gauss at the Mars' L1 point.

Models hosted at the Coordinated Community Modeling Center (CCMC) are used to simulate a magnetic shield, and an artificial magnetosphere, for Mars by generating a magnetic dipole field at the Mars L1 Lagrange point within an average solar wind environment. The magnetic field will be increased until the resulting magnetotail of the artificial magnetosphere encompasses the entire planet as shown in Figure 1. The magnetic field direction could also maintain an orientation that keeps it parallel with the impinging solar wind interplanetary field thereby significantly reducing mass, momentum, and energy flow into the magnetosphere and thus also damping internal magnetospheric dynamics. This situation then eliminates many of the solar wind erosion processes that occur with the planet’s ionosphere and upper atmosphere allowing the Martian atmosphere to grow in pressure and temperature over time.

Figure 1: https://i.stack.imgur.com/UQJNW.jpg

Three questions I have about this article:

• How big would the magnet have to actually be to have a significant effect on Mars?
• What material could be used to construct something so large w/ such a high magnetic charge?
• Would a magnet this large, with this high of a charge, even be transportable using conventional rocketry? Or would it drastically interfere with the functioning of a modern rocket? Organic Marble pointed out it would likely be an electromagnet with a negligible charge when inactive.

Answer 1

Hmmm this is an interesting theory, though I am confused how they would maintain that position between Mars and the Sun. Moreover I want to point out this is theoretical and is not actually building or making a magnetosphere around Mars. It's more like making a shield between the Sun and Mars. This sort of raises the question of whether the value of a magnetosphere is really just in deflecting solar winds or if it plays other roles in retaining atmosphere.

Anyways, to answer the question:

10-20K Guass isnt that much:

3000–70,000 gauss – a medical magnetic resonance imaging machine

So for the question of size we have hospital MRI machines currently the size of a few refrigerators that can generate that field or greater.

As for material composition: - lots of copper wire - maybe some iron or other metal - maybe some rare earth magnets like neodymium - maybe superconductors

At 10-20K Gauss and the size of current satellite capabilities, the material compositions are relatively insignificant factors. I think the logistics of maintaining the solution both in power and orbit are far more troublesome.

But it's an interesting theory.

Answer 2

Anon answered with Rare Earth Magnets---visa vis neodymium. Don't forget that the (apparent) abundance of Rare Earth Elements---visa vis KREEP, will inevitably (if extended from the Apollo landing sites) generate a super-conductive metals/coils/wires capability that will make the production of various electro-magnets natural to lunar mining economy.