The Moon is known for its arid environment and complete lack of oxygen. So what causes the rust phenomenon on its surface?
When thinking of “rust”, many people envision the flaky red substance that can be found on the underside of a 1983 Buick. It is still a type of iron oxide, meaning it is formed from iron and oxygen atoms. However, the rust on the Moon is actually a mineral called hematite. The discovery of hematite on the Moon in 2020 caused quite a stir. The thing is, hematite typically forms when a metallic iron is exposed to water and oxygen.
The Moon is slightly turning reddish due to rust.
Yet, the Moon is known for its desolate and completely oxygen-free environment. So what explains the rust phenomenon on the Moon’s surface?
The Moon is slightly turning reddish due to rust, and this may be the fault of Earth. Earth is reaching out into outer space while simultaneously providing a source of oxygen for the Moon. The protective magnetic field of our planet is not a perfect sphere. When solar wind blows, it gets distorted. And that long tail extends all the way to the Moon. Therefore, for about five days each month, when shielding the Moon from solar wind, the tail also sends charged particles from Earth’s upper atmosphere toward the Moon’s surface.
Back in 2017, a study published in the journal Nature Astronomy estimated that tens of thousands of oxygen ions originating from Earth are “planted” on the Moon every second. That’s the source of oxygen, but what about water?
According to a study published in 2023, some authors discovered that the formation of water does not decrease when the Moon is shielded from solar wind.
Thus, the research team hypothesized that Earth is not just emitting oxygen ions that help the Moon rust.
A series of electrons are also swept along on this journey. Scientists believe that fast-moving dust particles collide with the Moon, releasing water molecules and mixing them with the Moon’s surface iron. These dust particles may even carry a significant amount of water molecules, and their impact could generate heat, accelerating oxidation.
