The Moon is Rusting

The Moon shouldn’t have rust—there’s no liquid water, and no atmosphere to sustain oxidation. But in 2020, scientists reported hematite, an iron oxide, at the Moon’s high latitudes near the poles. How? Earth may be to blame. Oxygen from our planet’s upper atmosphere can ride along the long magnetic tail trailing behind Earth and reach the Moon, especially when the Moon passes through that tail around full moon. Over billions of years, tiny amounts of rust may have built up. It’s slow, subtle, and weird—because the Moon, by all logic, shouldn’t be rusting at all.