Earth's magnetic tail creates rust on the Moon: How?
Scientists just found rust (hematite) on the Moon—pretty wild, since rust usually needs both oxygen and water, and while the Moon has some water at its poles, it has very little oxygen.
Turns out, some oxygen sneaks over from Earth, hitching a ride on what's called "Earth wind."
The process
Each month, for about five days, the Moon passes through Earth's magnetic tail. During this time, charged oxygen ions from our atmosphere drift over and react with iron in lunar soil to make hematite.
Scientists even recreated this in labs using real lunar-like materials and confirmed it works.
More connected
This discovery shows Earth and the Moon are more connected than we thought—Earth's atmosphere literally leaves its mark on the lunar surface.
The research used data from India's Chandrayaan-1 mission and was published in Geophysical Research Letters in 2020.