Lunar glasses

Glass is an important component of lunar soil produced by a series of nonequilibrium processes on the Moon, including volcanic eruptions, meteorite impacts, and solar wind and cosmic ray irradiations. Glasses can exist stably for a long geologic time in the Moon's harsh environment. They can therefore act as snapshots of their formation processes to record billions of years of historical information of the Moon, concerning the formation and evolution of the Moon, the source and distribution of lunar water/gases, the impact history of our solar system and the space weathering. Glasses can also preserve various lunar materials for an extremely long time, such as ³He implanted by solar wind, reaction-generated water and nanophase iron particles, which affect the utilization of lunar resources and remote-sensing observations. Based on detailed studies of diverse glasses in Chang'e-5 lunar samples, this paper describes the characteristics and formation mechanisms of various lunar glasses, and the unique role of each kind of glasses in recording the Moon's history. The studies of lunar glasses could also provide valuable insights into future interstellar exploration, as well as the design and preparation of novel glass materials.