China News Service, Guiyang, March 28 (Reporter Pu Wensi) The reporter learned from the Institute of Geochemistry of the Chinese Academy of Sciences on the 28th that through research on Chang'e-5 lunar soil particles, a micrometeorite impact crater was discovered on the surface of the lunar soil glass beads. A series of titanium-containing evaporative deposition particles, a previously unrecognized product of space weathering.
The research results improve the understanding of the space weathering process on the lunar surface and provide clues for understanding the space weathering process on the surfaces of other atmospheric bodies in the solar system.
Schematic diagram of titanium nanominerals in lunar soil micrometeorite impact craters (the picture on the left is a false color image, and the blue area is the impact sputter). (Photo courtesy of the Institute of Geochemistry, Chinese Academy of Sciences)
According to relevant information, space weathering is one of the modification processes on the surface of the moon and other atmospheric bodies in the solar system, including micrometeorite bombardment, solar wind ion injection, high-energy cosmic rays, etc. Among them, the micrometeorite bombardment environment on the lunar surface has small particle size and high speed. Features such as fast speed and large throughput.
High-speed micrometeorites bombarding the lunar soil can modify the material composition, composition, spectrum, physical properties, etc. of the lunar soil through mechanisms such as high-temperature melting, fragmentation, vaporization, deposition, and cementation. Due to the coupling influence of multiple factors such as the diverse composition of the lunar surface materials, the complex micrometeorite bombardment process, and the instability of the bombardment products, the understanding of the modification mechanism and effects of micrometeorite bombardment on the lunar surface is incomplete and even controversial.
Schematic diagram of the formation process of micrometeorite bombardment of titanium nanominerals in lunar soil. (Photo courtesy of the Institute of Geochemistry, Chinese Academy of Sciences)
In this regard, the Institute of Geochemistry of the Chinese Academy of Sciences, together with Macau University of Science and Technology and Guangdong University of Technology, conducted research on Chang'e-5 lunar soil particles and found a series of titanium-containing evaporative deposition particles in micrometeorite impact craters on the surface of lunar soil glass beads. TEM analysis results show that these titanium-containing particles are three titanium nanominerals: rutile, trigonal Ti2O and triclinic Ti2O. Among them, the two physical phases of trigonal Ti2O and triclinic Ti2O have not been found in natural geological samples before. In the field of materials science, Ti2O is a photocatalytic thin film material that can be prepared in the laboratory. Since rutile and Ti2O are effective natural photocatalytic mineral materials, this study puts forward a new perspective that the space weathering process on the lunar surface can change the photocatalytic properties of the lunar soil.
The research results have been published in the internationally authoritative journal "Nature Astronomy". (over)