# A localized artificial magnetosphere for Mars

Mars has a couple of problems with regards to colonization such as lack of atmosphere, lack of magnetosphere, weak sunlight, and a few others. Of concern in this question is how to shield human colonists from all the nasty radiation?

Shielding by building habitats underground is feasible but boring. Let us assume for this question that passive dirt shielding is infeasible for whatever reason and we require some kind of active shielding.

How powerful would a magnetosphere generator need to be provide sufficient shielding for humans in above ground habitats?

Tech levels are near future (2100) and this shielding is just for the habitat, not the entire planet.

## Between 500W and 5kW.

To steal from a similar answer to a question about spacecraft shielding:

In order to provide an effective shield, the strength of the shield magnetic field at the source is preferably at least 1×10$^{−4}$ Tesla. To obtain a boundary between the shield magnetic field and a typical solar wind background magnetic field of around 1×10$^{−7}$ Tesla (perhaps 5×10$^{−8}$ to 5×10$^{−6}$ Tesla depending on the conditions of the solar wind) at a distance of up to a few hundred metres from the spacecraft a field strength of less than 0.1 Tesla at the magnetic field source will generally be sufficient. Allowing for effects of field persistence in the plasma environment, average electrical power from about 100 W to 10 kW, and more preferably from about 500 W to 5 kW may be provided by the power supply to drive the magnetic field source to generate the shield magnetic field.

As quoted from this patent.

Of course, if you have superconductors you can generate a magnetic field and only need to replenish it when it actually deflects a particle.

To anticipate the next question, the protection area of the field will depend on the distance from the field generator to the protected area (assuming a collinear arrangement with the radiation source) and the applied power. Protected areas with a radius of hundreds of meters is quite feasible with the above power values.

There is a plethora of information on this page about spacecraft shielding, which directly relates to shielding a small area for humans to live.

• OK good because I can't borrow magnets from the LHC but I think we can fit a thousand people in a tight circle from it... Dec 22 '16 at 5:54