Widespread hematite at high latitudes of the Moon
Hematite is a type of rust, and a lunar orbiter just found some on the Moon. That shouldn't be possible, so Science thought, because the moon lacks the oxygen/water combo required. But now they're thinking it is because of Earth's atmosphere:
The study suggests the oxygen needed for the chemical reaction to create rust is actually spilling over from Earth's atmosphere driven by the planet's magnetic field to the surface of the Moon. From there, fast-moving dust slamming into the Moon might stir up small amounts of water that interact with oxygen and iron, producing the hematite found by the orbiter.