Magnification of pre-existing magnetic fields in impact-produced plasmas, with reference to impact craters
Magnetic fields generated by the electrical currents associated with thermal forces in an impact-produced plasma cloud are proposed as a possible explanation of the magnetic perturbation observed during hypervelocity impact events. Order of magnitude estimates for this effect show that this is compatible with experimental findings. We suggest that this effect may contribute to the magnetisation observed in the neighbourhood of lunar craters (see, e.g. Anderson and Wilhelms, Earth Planet. Sci. Letts.46, 107).