Article by: Andacs Robert Eugen, on 24 June 2022, at 10:44 am Los Angeles time

In 2020, China's Chang'E-5 landfill module conducted the first research on water from the lunar soil, but many questions remained unanswered about the origin of the water.

In a new article published in the journal Nature Communications, researchers who analyzed evidence from Earth provided an answer about the origin of water: the Moon itself.

Water and hydroxyl - the latter consisting of a single hydrogen atom associated with an oxygen atom, instead of two hydrogens to one oxygen atom, as in the case of water - had been found in samples of regolith from the Moon taken in the Apollo program. Chang'E-5 also detected hydroxyl in its lunar rock and soil samples.

Hydroxyl often results from the chemical interaction of water with other materials, but can also be formed by chemical reactions, and some theories claim that hydroxyl resulted from hydrogen atoms carried by the solar wind that interacted with the lunar soil. Chang'E-5 took samples during times of low solar wind activity to help minimize the impact of this source on its measurements.

The recently published analysis shows that although one-third of the hydroxyl in the Chang'E-5 samples came from the solar wind, most of the hydroxyl was found in a common mineral on Earth and the Moon, known as apatite. This means that water probably played a role in the crystallization of the lunar magma that formed the basaltic rock at the landing site of Chang'E 5 - in the Oceanus Procellarum region, in free translation "sea of ​​storms".

China's future Moon missions, Chang'E-6 and 7, will continue to search for water on the lunar surface. It is a research project with both academic and practical implications, as China, like the United States, hopes to send people to the moon again in the near future.