Lunar Swirls

Sam Mangham, a member of the Software Sustainability Institute here in Southampton, looks at recent work done on the Moon's magnetic fields….

The earth’s magnetic field helps protect our planet from the effects of the solar wind. Other bodies in the solar system aren’t so lucky – for example, when Mars lost its magnetic field 4 billion years ago, its atmosphere was blown away. Our Moon doesn’t have a large magnetic field either, but recent simulations have shown that mysterious bright ‘swirls’ on the moon can be explained by small magnetic fields! These fields deflect the damaging solar wind, protecting a swirl on the surface of the Moon which ends up a lighter colour than its surroundings. We don’t yet know what causes these areas to have a magnetic field, but most swirls are on the opposite side of the moon to major meteor impact craters.

You can read NASA's take on these beautiful lunar phenomena, from 2006. Alternatively, Jan Deca , from the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder , gave a talk on these lunar swirls at the EGU General Assembly 2017 and you can watch him talking on the subject at the NASA Exploration Science Forum on YouTube .