On the 28th, information from the Institute of Geochemistry, Chinese Academy of Sciences, revealed that studies conducted on lunar soil particles collected by the Chang'e 5 mission led to the discovery of titanium-bearing evaporitic deposition particles within microcrater impacts on the surface of lunar glass beads. These findings highlight previously unidentified space weathering products.
The research enhances our understanding of the space weathering processes on the lunar surface and offers insights into the space weathering experienced by other airless bodies within the solar system.
Schematic diagram of titanium nanominerals in lunar soil micro-meteorite impact craters (left image is a false-color image, blue areas represent impact ejecta). (Image provided by the Institute of Geochemistry, Chinese Academy of Sciences) The provided material explains that space weathering is one of the transformative processes on the surfaces of the Moon and other atmosphere-less celestial bodies in the solar system. This includes micro-meteorite bombardment, solar wind ion implantation, and the effects of high-energy cosmic rays, among which the lunar surface is characterized by micro-meteorite bombardment with small particle sizes, high velocities, and large fluxes.
High-velocity micro-meteorite bombardment can alter the material composition, constituents, spectral, and physical properties of lunar soil through mechanisms such as high-temperature melting, fragmentation, vaporization, deposition, and cementation. Due to the diverse composition of lunar surface materials, the complexity of micro-meteorite bombardment processes, and the instability of the products of bombardment, the understanding of the transformative mechanisms and their effects on the lunar surface is incomplete and even controversial due to the coupling effects of multiple factors.
Schematic diagram illustrating the formation process of titanium nanominerals in lunar regolith due to micro-meteorite impacts. (Image provided by the Institute of Geochemistry, Chinese Academy of Sciences)
The Institute of Geochemistry, Chinese Academy of Sciences, in collaboration with the University of Macau and Guangdong University of Technology, conducted research on lunar soil particles from the Chang'e-5 mission. They discovered a series of titanium-containing evaporative deposition particles in micro-meteorite impact pits on lunar soil glass beads. TEM analysis revealed that these titanium-containing particles consist of three titanium nanominerals: ilmenite, Ti2O with a trigonal structure, and Ti2O with a monoclinic structure. Among them, the monoclinic and trigonal phases of Ti2O had not been previously identified in natural geological samples. However, in the field of materials science, Ti2O is a photocatalytic thin film material that can be synthesized in the laboratory.
Since ilmenite and Ti2O are effective natural photocatalytic mineral materials, this study proposes a new perspective that lunar surface space weathering processes can alter the photocatalytic properties of lunar regolith.
The research findings have been published in the prestigious international journal Nature Astronomy.
