The lunar swirls: distribution and possible origins

Many of the strongest lunar magnetic anomalies correlate in location with swirl-like high- and low-albedo markings of the Reiner Gamma class. Models involving both meteoroid and cometary impact processes have previously been proposed to explain their origins. It has also been proposed that the high-albedo markings represent areas of the surface that have been magnetically shielded from the solar wind ion bombardment and have therefore not reached optical maturity. These models are investigated further here, using both correlative data analysis and theoretical modeling methods. It is concluded that the solar wind deflection model provides a possible explanation for the unusual morphologies of these albedo markings and their preferred occurrence in basin antipode zones. Meteoroid impacts occurring in zones of strong preexisting crustal fields may also have contributed to the formation of the lunar swirls. -Authors