Solar storms are sandblasting the Moon

National Geographic : The ions that make up the solar wind can collide with the Moon’s surface, essentially sandblasting it in a process called sputtering. During coronal mass ejections (CMEs), the Sun throws off intense bursts of plasma at up to a million miles per hour in a cloud that’s several times the size of Earth. Normal solar wind consists mostly of lightweight protons from hydrogen atoms that have been stripped of their electrons, but CMEs contain a much higher percentage of heavier ions such as helium, oxygen, and iron. The heavier atoms collide with the Moon with much greater momentum than protons do, and they can dislodge more material from its surface. William Farrell, leader of the Dynamic Response of the Environment At the Moon (DREAM) team at NASA’s Goddard Space Flight Center in Maryland, and colleagues created a model of the process that predicts that between 100 and 200 tons of lunar material could be blasted off the lunar surface by a large CME.