Chinese Moon probe finds water in lunar soil samples

Water molecules make up more than 40 per cent of mineral samples brought from the Moon, scientists say

Chinese scientists have found a mineral “enriched” with water in lunar soil samples returned from the Moon by the Chang’e 5 mission.

This discovery “revealed the presence of trace water” from a “much higher latitude” than any previous missions and could power future missions to the Moon amid an ongoing “space race” between the US and China.

Researchers from the Chinese Academy of Sciences found that “water molecules can persist in sunlit areas of the Moon in the form of hydrated salts”.

The findings, published recently in the journal Nature Astronomy, offer fresh clues about the chemical and physical form of Moon water, an advance that could shape how minerals are extracted for rocket fuel on the lunar surface.

While samples brought back by Apollo astronauts decades earlier suggested the Moon was likely completely dry, recent discoveries suggest the Earth’s closest neighbour indeed has reservoirs of water.

For instance, in 2009, India’s Chandrayaan-1 mission detected signs of hydrated minerals on the Moon in the form of oxygen and hydrogen molecules.

More recently, Nasa announced the discovery of water on the Moon’s sunlit surface in 2020, followed by China’s Chang’e-5 lunar lander sending back the first on-site evidence of lunar water.

Samples collected by the Chang’e 5 probe continue to shed light on the presence of water on the lunar surface.

The latest study of samples collected during this mission found an unidentified mineral crystal dubbed “unknown lunar mineral (ULM-1)” to be rich in water and ammonia molecules.

“Our findings also suggest that water molecules can persist in sunlit areas of the Moon as hydrated salts,” scientists wrote.

They found that water molecules make up over 40 per cent of the mineral sample by mass, while also ruling out the possibility that it was contaminated by rocket exhaust.

“We rule out terrestrial contamination or rocket exhaust as the origin of this hydrate on the basis of its chemical and isotopic compositions and formation conditions,” scientists wrote.

More evidence of the presence of water on the Moon may follow with last month’s return of China’s Chang’e 6 probe, which brought back the first samples from the lunar far side.

China has amped up its space program over the last decade, closely competing with the US in what Nasa administrator Bill Nelson calls a new “space race.”

The country plans to send a crewed mission to the moon by 2030 and also aims to build a lunar base.

Finding water on the Moon is not just about fuel extraction and building bases, as it can also reveal fresh insights into lunar history and evolution.