Impact-driven Deposition of Metallic Titanium on the Moon

Abstract Impact-induced high temperatures are a key driver of titanium (Ti) redistribution in Ti-bearing phases, which is crucial for understanding element cycling on the Moon. However, direct mineralogical evidence for the redistribution pathways of Ti during extreme impact processes is still lacking. In this study, we report the first discovery of metallic Ti grains preserved in Chang’e-6 lunar regolith. These grains are characterized by their microscale size, droplet morphology, native Ti composition, and polycrystalline structure. The presence of Np–Fe 0 -bearing silicate glass inclusions within the metallic Ti indicates a lunar surface origin rather than terrestrial contamination. Our results reveal that the coexistence of metallic Ti and Np–Fe 0 grains formed via the impact-induced vaporization of ilmenite (FeTiO 3 ), followed by Ti and Fe vapor deposition on the Moon. The discovery of lunar metallic Ti documents a novel impact-driven vapor-deposition process on the Moon. This finding also suggests that impact heating on the Moon and other airless planetary bodies is a viable mechanism for generating high-purity metallic Ti resources.