A new study shows that the Moon has a large amount of rust, which can be caused by the Earth
The Moon is taking on a subtle reddish color, and it is probably a reaction caused by the Earth, it is rust, a red compound that forms when iron is exposed to water and oxygen.
Rust is the result of a common chemical reaction on our planet, but not all celestial bodies have the characteristics necessary for oxidation, particularly our dry, atmosphereless Moon.
Shuai Li, is the assistant researcher at the Hawaii Institute of Geophysics and Planetology at the University of Hawaii at Mānoa, who has been key to the discovery of lunar oxidation.
Li was studying data from the JPL Moon Mineralogy Mapper, which was aboard the Indian Space Research Organization’s Chandrayaan-1 orbiter while surveying the Moon in 2008, at which time he realized that the Moon’s poles had compositions very different from the rest of the surface.
During his research, Moon Mineralogy Mapper detected spectra, or wavelengths of light reflected from various surfaces of the Moon, with the intention of analyzing their surface composition, but when Li focused on the poles, he discovered that the Moon’s polar surfaces they had iron-rich rocks with spectral signatures that matched those of hematite.
Rust on the Moon How did it happen?
The mineral hematite, commonly found on the surface of the Earth, is a specific type of iron oxide with the formula Fe2O3. The fact that the Moon featured rust was puzzling, as it shouldn’t exist due to the conditions on the lunar surface.
The Moon does not have an atmosphere of its own to provide sufficient amounts of oxygen, but has traces donated by the Earth’s atmosphere, this terrestrial oxygen travels to the Moon along an elongated extension of the planet’s magnetic field called “magnetic tail”.
The magnetic tail of the Earth can reach the near side of the Moon, where more hematite was found, in addition, in each full Moon, the magnetic tail blocks 99% of the solar wind so that it does not hit the Moon, drawing a temporary curtain on the lunar surface, allowing periods of time for rust to form. But there is still an additional ingredient that is needed for rust to form: water.
The Moon is mostly devoid of water, except for the frozen water found in lunar craters on the opposite side of the Moon, far from where most of the hematite was found. But the researchers propose that fast-moving dust particles that bombard the Moon could release water molecules trapped in the Moon’s surface layer, allowing water to mix with iron.
These dust particles could even be carrying water molecules, and their impact could generate heat that could increase the rate of oxidation, the researchers said.