¹Ziyan Han (>10)
Earth and Planetary Science Letters, 693, 120294 Link to Article [DOI: 10.1016/j.epsl.2026.120294]
¹State Key Laboratory of Critical Earth Material Cycling and Mineral Deposits & Lunar and Planetary Science Institute, School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu, 210023, China
Copyright Elsevier

The Moon is currently airless, but intense impact bombardments in its history may have resulted in transient atmospheres on the early Moon. However, the existence and scale of the impact-induced atmosphere have remained speculative. Here, we identified pervasive Na and K in-gassing profiles in Chang’e 6 impact glass beads that were produced from formation of craters with diameters larger than 10 m. These profiles were generated in the impact plumes where both Na and K partial pressures were larger than 10^–6 to 10^–4 bar. Using mass balance calculations, the total vapor pressures in the impact plumes containing H, N, S, C, Cl, and F could have been larger than 10^–5 to 10^–3 bar. Combined with lunar impact-flux models, our results imply that impact bombardments could have provided an important mechanism capable of generating a global transient atmosphere on the Moon with high impact flux at ≥4.4 Ga, and younger impacts alone likely only sustained local transient atmospheres as impact flux decreased after 4.4 Ga.