The moon is getting rusty. And it actually takes rocket science to understand the phenomenon.

There are plenty of iron-rich rocks on the moon — but rust is only produced when iron is exposed to oxygen and water.

The dichotomy has been solved by researchers, who have enough evidence to prove their findings.

India’s lunar probe, Chandrayaan-1, orbited the moon in 2008, and gathered data that said there are water molecules on its surface.

When researchers at NASA and the Hawai’i Institute of Geophysics and Planetology analysed the data recently, they were stunned to find hints of hematite, a form of iron oxide known as rust. 

Not only is there no air on the moon, but it is flooded with hydrogen that flows from the sun, carried by solar wind. Rust is produced when oxygen removes electrons from iron; hydrogen does the opposite by adding electrons, which means it’s all the harder for rust to form on the hydrogen-rich moon.

This rust was more concentrated on the side of the moon that faces Earth — which gave impetus to their research.

Earth is encompassed in a magnetic field, and solar wind stretches this bubble to create a long magnetic tail in the downwind direction. The moon enters this tail three days before it’s full, and it takes six days to cross the tail and exit on the other side.

During these six days, Earth’s magnetic tail covers the moon’s surface with electrons. Dust particles on the moon’s surface can then float off the ground, and moon dust might fly into a dust storm, according to NASA.

And oxygen from the Earth travels on this magnetic tail to land on the moon, where it interacts with lunar water molecules to create rust.

The magnetic tail also blocks nearly all solar wind during the full moon — meaning the moon is temporarily shielded from the blast of hydrogen, opening a window for rust to form.

This theory could also explain why rust has been found on other airless bodies like asteroids. 

It, however, remains unclear how exactly water on the moon is interacting with rock.