Abstract
The lunar mare regolith preserves tripartite records of volcanism, impacting, and space weathering. However, previous studies based on limited soil particle numbers were hindered by issues of sample representativeness. Here we conduct micro-CT scans of bulk soil samples from Chang’e-5 (nearside) and Chang’e-6 (farside), and develop machine learning-based image segmentation and classification methods to identify a vast number of basalt, agglutinate, breccia, and monomineralic particles. The Chang’e-5 basalt exhibits higher plagioclase content than Chang’e-6, while agglutinates from Chang’e-6 have lower void ratios, respectively indicating different lava origins and more intense micrometeorite bombardment for farside Chang’e-6. Despite their contrasting volcanic and impacting histories, the soil particles for these youngest nearside/farside samples exhibit similar morphometric distributions, suggesting that space weathering reached saturation in shaping surficial soil particle morphology in ~ 2.2 million years or less. These findings may extend to other mare regions and help establish space weathering models for other airless bodies.
Data availability
All data supporting this study are presented in the paper and its Supplementary Information. Source data are also provided with this paper. Source data are provided with this paper.
Code availability
All code used in this study is cited and no proprietary code was developed for this work.
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Acknowledgements
This work was funded by the National Natural Science Foundation of China 42241109 (Y.F.C.) and 42577187 (J.Y.N.) and Tsinghua University Initiative Scientific Research Program 20253080040 (Y.F.C.). The financial support from the Young Elite Scientists Sponsorship Program by CAST 2023QNRC001 (J.Y.N.) is gratefully acknowledged. We would also like to appreciate the China National Space Administration for providing the invaluable lunar samples from both the Chang’e-5 and Chang’e-6 missions.
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A.L., Y.F.C., G.D.W., J.Y.N., and Y.L. conceived and designed the experiments. A.L., G.D.W., J.Y.N., and C.S.X. performed the experiments. A.L., Y.F.C., G.D.W., J.Y.N., Z.H.Z., Q.Z., and H.Y.H analyzed the data. A.L., Y.F.C., G.D.W., and J.Z. contributed materials tools. A.L. and Y.F.C. wrote the paper.
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Luo, A., Cui, Y., Wang, G. et al. Saturation of space weathering in shaping lunar regolith particle morphology. Nat Commun (2026). https://doi.org/10.1038/s41467-026-68824-3
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DOI: https://doi.org/10.1038/s41467-026-68824-3
