Geological Evolution Studies of Chang’e Landing Sites: Multi-Scale Degraded Crater Analyses

Impact craters are the most ubiquitous geomorphic features on the lunar surface, playing a crucial role in helping us understand lunar formation, evolution, and surface modification processes. High-resolution data from lunar orbiters, landers, and rovers have enabled detailed studies of degraded craters across multiple size ranges. However, existing research has often overlooked the combined analysis of small- and large-sized degraded craters to evaluate localized resurfacing events and refine geological unit dating.
This study focuses on the mare basalt regions at the Chang’e 3, 4, and 5 landing sites. We analyzed small degraded craters using cumulative size-frequency distribution (SFD) curves to assess impact saturation and degradation levels. For larger degraded craters, depth-to-diameter ratios were employed to derive a novel crater-based dating equation for mare basalt units.
Key findings reveal that in older regions, such as the Chang’e-4 landing area, the proportion of degraded craters decreases more significantly with increasing crater diameter compared to younger regions like the Chang’e-5 site. Geological unit ages estimated from depth-to-diameter ratios closely align with isotopic dating, with discrepancies within 0.2 Ga. Additionally, our method effectively estimates the model ages for the Chang’e-6 landing site, confirming its broader applicability. This study demonstrates the potential of integrating multi-scale degraded crater analyses to investigate localized resurfacing phenomena. The approach can be extended to future lunar and planetary landing sites, providing a robust framework for geological evolution studies.