One of the oldest problems in lunar geology is the source of its paleomagnetic field. Recent work by Aaron Scheinberg and colleagues suggests that the magnetic field could have developed via convection of the lunar magma ocean. Previous models have tried to simulate a magnetic field from the lunar core, but could not generate a field strong enough to explain surface measurements. This new work shows that if the magma ocean is sufficiently electrically conducting, then a field strength that matches surface observations will be produced.
A basal magma ocean dynamo to explain the early lunar magnetic field