Chinese Scientists Find Molecular Water in Lunar Soil

Chinese scientists have discovered molecular water and ammonium in lunar soil samples from the Chang’e-5 mission, marking the first identification of molecular water on the Moon. The hydrated mineral, with the formula (NH4)MgCl3·6H2O, was found in samples returned in December 2020. This mineral resembles novograblenovite, which was first identified on Earth in 2012. Its formation is linked to reactions between hot basalt and water-rich volcanic gases. The discovery is significant for understanding the Moon's water sources and the Earth-Moon relationship. Researchers from various institutions conducted a detailed analysis to confirm that the mineral was not contaminated by terrestrial sources or rocket exhaust. The presence of water in the form of hydrated salts suggests potential resources for lunar exploration, as this hydrate is stable in the Moon's harsh environment. This finding contrasts with earlier Apollo missions, which indicated a lack of water-bearing minerals in lunar soil. Previous studies had only detected minute traces of water-related compounds. In comparison, the Chang’e-5 samples contain water molecules that make up to 41% of the sample's mass. Observations of the lunar poles and remote sensing data have previously suggested the existence of water ice and molecules in sunlit regions. China's Chang’e-6 mission recently returned samples from the far side of the Moon, while the upcoming Chang’e-7 mission aims to explore the lunar South Pole for ice, crucial for sustaining a long-term lunar presence.