Scientists suggested Earth's magnetotail has a mediating effect on the hydrogen, which prevents rust from occurring, being delivered by the solar wind on the Moon. It also remains unclear how exactly the water on the moon interacts with rocks. Earth's magnetic field trails behind the planet like a windsock.
"At first, I totally didn't believe it".
"It's very puzzling", NASA quoted planetary scientist Shuai Li of the University of Hawaii, as saying. But the Moon isn't supposed to have oxygen or liquid water, so how can it be rusting?
Map of hematite on the moon-redder color means more hematite.
Mired in disbelief at his finding, Li took the matter up with NASA's Jet Propulsion Laboratory JPL scientists Abigail Fraeman and Vivian Sun in a bid to get his discovery confirmed. The current theory is that dust particles that often hit the moon are helping release water molecules, mixing those water molecules with iron on the surface.
Ahead of a slew of new missions to Earth's natural satellite, researchers have detected a freaky and unexpected anomaly on the lunar surface: the airless, liquid water-free Moon is rusting. The Earth's atmosphere could be protecting the Moon as well. In 2007, Japan's Kaguya orbiter discovered that oxygen from Earth's upper atmosphere can actually travel through this magnetotail, allowing it to traverse the 239,000 miles (385,00 kilometers) of space from Earth to the Moon.
The researchers found the locations where hematite is present are strongly correlated with water content at high latitudes and are more concentrated on the nearside, which always faces the Earth. "This suggested that Earth's oxygen could be driving the formation of hematite", Li says.
It is also possible that more oxygen was transferred to the Moon when it was closer to the Earth, as the two bodies have been moving further away from each other for billions of years.
"Earth may have played an important role on the evolution of the Moon's surface". The presence of hematite can also be tied with traces of liquid water and meteor impacts, which were spotted in the past. Dust particles on the moon's surface might float off the ground, and moon dust might fly into a dust storm, according to NASA.
This theory could also explain why rust has been found in other air-free bodies such as asteroids.
Another reason why the rust could be present is because of the ice that is present on the Moon, found under lunar craters on the Moon's far side. Micro-water particles were born there.
Understanding the myriad complexities on the lunar surface is critical to the future of research and potential human colonization, set to begin in some form in 2024 with NASA's Artemis missions.
"I think these results indicate that there are more complex chemical processes happening in our solar system than have been previously recognized", Sun said. The probe also carried an instrument built by NASA that could analyze the moon's mineral composition.