Morphological Characterization of Decimeter‐ to Hectometer‐Scale Impact Craters at the Chang’E‐3/4/5 Landing Sites

Abstract

AbstractThe morphology of impact craters on the Moon is important for understanding impact cratering process and lunar surface properties. Though the morphology of lunar impact craters at hectometer scales and larger is extensively investigated and well understood, the morphology of very small craters is rarely studied due to the lack of high‐resolution data. In this study, we investigated the morphology of 1,513 craters at decimeter to hectometer scales using the 5 mm/pixel–0.5 m/pixel topographic data of the Chang’E‐3/4/5 (CE‐3/4/5) landing regions. Our results show that crater depth, rim height, and inner wall slope increase with the diameter and that the mean values of depth/diameter ratio, rim height/diameter ratio, and inner wall slope are 0.065, 0.017, and 10.5°, respectively. These morphometric parameters are smaller than those of large craters above hectometer scales, which is probably due to low‐strength surficial regolith and rapid topographic degradation. The comparison of the morphometric parameters among the three regions suggests that the CE‐4, CE‐3, and CE‐5 landing regions have the highest, intermediate, and lowest regolith strengths, respectively. In addition, we first observed widespread meter‐scale concentric and flat‐bottomed craters in optical images, which are most probably formed due to strength heterogeneity within the regolith layer. Our results can help to understand near‐surface properties of the regolith layer, lunar surface evolution, and impact cratering process in the strength regime.