Mystery of swirls on Moon may finally have an answer — they're formed by solar wind

Swirls on the moon seem to be a kind of sunburn from how solar wind & the crust magnetic field interact. In the case of Earth, its magnetic field shields all things on the planet’s surface from solar wind and harsh radiation in space. New data collected by the ARTEMIS mission suggest that a combination of solar wind and the Moon’s magnetic field leave behind distinctive patterns of darker and lighter swirls, some of which are visible to us on the Moon’s surface. Reiner Gamma and the dozens of other swirls on the Moon could simply be a form of “sunburn” created by how solar wind and the magnetic field of the Moon’s crust interact.