Assessing the Feasibility of an Artificial Martian Magnetopause

The primary objective of the “MarsB” project is to model and assess planetary-scale artificial magnetic field configurations that induce a magnetopause shield to deflect the solar wind and enable build-up and protection of a future modest Martian atmosphere. Such an artificial magnetopause is one important part of a larger project for terraforming Mars, which is of great public interest. The MarsB extensible computer model and trade-study environment was developed and successfully benchmarked against other models for magnetic fields and magnetopauses reported in the literature, against spacecraft-measured empirical data for dipole magnetic fields and magnetopauses of Earth and the other solar system dipole-bearing planets, against measured data for solar-flare buffeting of Earth's magnetopause, and against estimates for Earth's magnetopause compression during the 780-KyBP Brunhes-Matuyama magnetic field reversal. Using the MarsB systems model, we assessed surface and subsurface superconducting coil configurations. MarsB shows that a modest coil current can protect a future Martian atmosphere from the solar wind, requiring far less amperage (~1 MA for a 2-Mars-radii-distant magnetopause) than that commonly discussed in the informal literature. Because a dipole magnetic field falls as the distance-cubed, and because Earth's magnetopause resides at a relatively distant 10-Earth-radii, a protective surface current-ring around Earth's surface, equal in effect to Earth's internal natural dynamo current-ring, would require a whopping 619 MA. We cover the development of `true' dipole B-field topology related to current rings, and demonstrate why one should NOT use the simple dipole math equations when the measurement is less than 17 ringRii distant from the current ring. For distances closer than 17-ringRii, one should use more sophisticated mathematical methods to determine the magnetic field density, magnetopause standoff distance, ring current, and many other system properties. For a surface ring encircling Earth, we show that the simple dipole math leads to an erroneous value of 7.04 MA to hold a magnetopause shield at 2 EarthRii distant, but that for our elliptic-integral implementation, the actual current needed is only 3.65 MA. Mars requires only about 1 MA to hold an artificial magnetopause shield at 2-MarsRii distant. Notionally, a thin superconducting cable could be `printed' around Mars by automated machines, and many of the construction materials could be obtained and processed in-situ. For the subsurface superconducting-cable case, we consider a notional tunnel-boring strategy that includes a large-volume reserve for oxygen, a high-speed equatorial transport system, and research for subsurface discovery.