Moon is rusting and Earth might be to blame: Scientists stunned by Haematite discovery at lunar poles

Something unusual appears to be happening on the Moon, and Earth may be playing a part. Researchers have reportedly detected haematite, a form of iron oxide commonly known as rust, on the Moon’s surface, particularly near its poles. Scientists have expressed surprise at the discovery, as rust typically forms in the presence of both oxygen and water, which are considered scarce on the Moon.

According to a report in Nature, Ziliang Jin, a planetary scientist at Macau University of Science and Technology, suggested that these findings could provide insights into the Moon’s connection with Earth. Jin and his colleagues detailed their observations earlier this month in Geophysical Research Letters.

The study indicates that oxygen from Earth’s atmosphere might reach the Moon. Charged particles from the Sun are known to bombard both Earth and the Moon most of the time.

However, during periods when Earth passes between the Sun and the Moon, roughly five days each month, most solar particles are blocked. During this time, the Moon is reportedly exposed mainly to particles originating from Earth’s atmosphere, a phenomenon sometimes referred to as the “Earth wind.”

Sky at Night Magazine reported that Earth’s magnetotail could play a role in this process. By blocking much of the solar wind, the magnetotail might reduce hydrogen bombardment, allowing oxidation to occur on the lunar surface during certain phases of the Moon.

Laboratory experiments have reportedly tested this idea using an Earth wind simulation. Scientists accelerated hydrogen and oxygen ions to high energies and directed them onto single crystals of iron-rich minerals similar to those found on the Moon. Some of the crystals reportedly transformed into haematite after exposure to high-energy oxygen, while exposure to hydrogen appeared to reverse some of the oxidation.

Shuai Li, a planetary scientist at the University of Hawaii at Manoa who led the 2020 study, described the experiment as “a great experiment,” noting that it helped shed light on previous observations.

Earlier, in 2020, India’s Chandrayaan-1 mission reportedly detected haematite near the lunar poles. The study suggests that understanding rust formation on the Moon could have practical implications for future lunar missions, including equipment design and resource utilisation.

The researchers, in their study titled ‘Earth wind-driven formation of haematite on the lunar surface’, reportedly concluded that their findings offer a possible explanation for the formation and distribution of lunar haematite. They also noted that these results might indicate long-term material exchange between Earth and the Moon.

Inputs from agencies