Permanent Lunar Surface Magnetism and Its Deflection of the Solar Wind

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Science  14 May 1971:
Vol. 172, Issue 3984, pp. 716-718
DOI: 10.1126/science.172.3984.716


Magnetic compressions intermittently observed outside the lunar wake in the solar wind may be limb shocks caused by the presence of local regions of permanent magnetism on the lunar limb. Observable compression would be due to regions of length scale (radius) at least as great as several tens of kilometers and field strength ≳ 10 gammas. Thousands of such regions might exist on the lunar surface. The steady magnetic field measured at the Apollo 12 site probably has length scale ≲ 10 kilometers and probably does not produce an observable limb shock.