• The Lunar regolith grains reveal a high degree of structural regularity previously underestimated in nanoscale morphology. • A three-state morphological framework captures the dynamic transitions among regolith surface morphology. • Morphological complexity evolves non-monotonically due to competing roughening and smoothing mechanisms. Nanoscale morphologies of lunar regolith record the competing processes of space weathering, yet quantitative characterization from large datasets remains rare. Using atomic force microscopy, we analyzed 18,270 nanoscale 3D datasets of Chang’e-5 particles, revealing abundant microstructural features and pronounced surface ordering. Statistical and correlation analyses show a coupling between large-scale geometric smoothness and fine-scale fractal complexity. By integrating morphological descriptors (roughness, fractal dimension, and surface entropy) with topological curvature patterns, we find a three-state evolutionary framework that captures the nonlinear behavior of regolith morphology modification. These morphological states are coexisting configurations shaped by heterogeneous exposure environments and durations. Transitions among these states are governed by spatially and temporally variable factors. These results demonstrate that nanoscale morphologies preserve a dynamic record of lunar surface regolith evolution, providing new constraints on lunar geological history and the physical mechanisms shaping airless body surfaces.
Wang et al. (Sun,) studied this question.