- 18 Oct 2020
Recently, around 12 years after its launch, the orbiter data from Chandrayan 1, ISRO’s introductory mission to the Moon has shed light on another phenomenon taking place on the Moon, which can be another indication towards existence of water around the lunar poles.
Newly discovered information from ISRO’s first lunar probe has indicated rusting on the Moon, around its poles. Rusting which is a phenomenon which is only possible when some reactive interaction takes place between, iron, oxygen and water. While, the Moon’s surface has been known for some abundancy in the iron, but there has been no solid indication or proof of existence of water and oxygen on its surface. The rusting on the Moon was discovered when the data orbiter’s data showed presence of hematite, a kind of rust, near the poles of the Moon. On this discovery, Shuai Li, the lead author of the paper published in Science Advances was quoted saying that the Moon is a terrible surface for the formation of hematite.
To provide a probable reason for this discovery, scientists from National Aeronautics and Space Administration (NASA), explained how Earth may have a role to play in the occurring of this phenomenon on the Moon. The Moon, which receives continuous bombardments of solar particles which is abundant in hydrogen. So, with the lack of any atmosphere, the hydrogen from the solar particles, should oppose the formation of rust on the moon as it acts a reducer by providing an electron to the iron. Contrary of that during the process of rusting, the iron undergoes an oxidizing reaction in the presence of oxygen which absorbs/reduces electron from the iron.
According to the data from the Kaguya orbiter of Japan, it was confirmed in 2007 that the Earth’s magnetotail which is a part of the planet’s magnetic atmosphere and extends in a direction opposite to the Sun’s shields the Moon during the full Moon phase, during which it shields the Moon and blocks 99% of solar particles reaching to the Moon. In addition to that during this period, the magnetotail plays some role in transfer some amount of oxygen from the planet to the Earth’s natural satellite. So, even without the absence of oxygen on its surface, the Moon gets its share of oxygen from the Earth during this period.
While the Moon is already suspected of holding water on its surface near its pole, but that too in farther shadowed craters in spots away from the spot of discovery of rust. So, the possible source of water that can be contributing towards the rusting process, as explained by the researchers can be from the fast-moving dust particles which release water molecule upon hitting the lunar surface. The heat generated from this impact can be acting as catalysts to induce faster rusting process. Hence, as per the explanation from the NASA’s researcher’s the entire scenario of rusting on the Moon’s surface can be represented using following diagram:
Also, the formation of rust on the Moon was represented by the researchers using the Moon Minerology Mapper which was aboard the ISRO’s Chandrayan-1 orbiter. The blue portion in this image represent the concentrated water present near the poles of the Moon. The hematite which indicated rust was found in the spectra of rocks that are present near the blue area.
Although the theories that has been explained till now for the formation of rust on Moon, is for now limited to paper only, there is still scope for furthermore discovery and research to exactly explain and understand the phenomenon of rusting in the lunar rocks.