Chinese Scientists Discover Water Molecules On Moon, Lunar Soil Sample Was Brought To Earth In Chang'e-5 Mission

Chinese scientists studying soil samples from the moon, brought back by the Chang'e-5 mission, have discovered water molecules in lunar soil, according to a report from The Economic Times.

This research, a collaboration between the Beijing National Laboratory for Condensed Matter Physics, the Institute of Physics of CAS, and other domestic institutions, was published in the peer-reviewed journal Nature Astronomy on 16 July.

Based on lunar soil samples returned by the Chang'e-5 mission in 2020, Chinese scientists identified a hydrated mineral enriched with molecular water.

In 2009, India's Chandrayaan-1 spacecraft detected signs of hydrated minerals, in the form of oxygen and hydrogen molecules, in sunlit areas of the moon.

In 2020, NASA announced the discovery of water on the sunlit surface of the moon, based on data from the Stratospheric Observatory for Infrared Astronomy, which detected water molecules in the Clavius crater, located in the moon's southern hemisphere.

However, the absence of lunar samples from high latitude and polar regions means that "neither the origin nor the actual chemical form of lunar hydrogen has been determined," as stated in the Nature article.

The Chinese researchers isolated more than 1,000 mineral clasts from the lunar soil. Among these was a platelike transparent crystal, named "unknown lunar mineral" (ULM-1), which contained water molecules, as per the same report.

The researchers ruled out the possibility of contamination from terrestrial sources or rocket exhaust. However, a geochemist not associated with the study suggested that further evidence is needed.

The Chang'e-5 mission, China's first lunar sample-return mission, provided the first on-site evidence of water on the moon's surface in 2020. More discoveries are anticipated following the return of the Chang'e-6 mission, which brought back up to 2kg of material from the moon's oldest basin on its far side last month.