Graphitization of nitrogen-bearing organic-like carbonaceous material in a dust particle from Chang’e-6 lunar samples

Abstract

Abstract The delivery and evolution of carbonaceous materials to airless planetary bodies remain poorly constrained. This study characterized a porous, aggregated, carbon-rich dust particle (CE6-CDP) from Chang’e-6 lunar samples. CE6-CDP yielded a mean δ13CVPDB value of − 25.92 ± 3.62‰ and exhibited significant nitrogen enrichment. Nano-infrared spectroscopy further detected N–H, C = N, and C–H bonds, indicating that the carbonaceous material within CE6-CDP shows organic-like signatures. Graphitic carbon with tangled and concentric textures within CE6-CDP exhibited a comparable δ13CVPDB value (−27.31‰) but contained low nitrogen, suggesting possible graphitization of some organic precursors. The coexistence of organic-like carbonaceous material and graphitic carbon is consistent with dust ejection during an impact involving a larger carbon-rich projectile. This study indicates that extraterrestrial carbon may constitute an important lunar carbon reservoir and contribute to the dark surfaces of Mercury and Vesta. These findings provide new insights into carbon transport and evolution across airless planetary bodies.