An improved global catalog of lunar impact craters (≥1 km) with 3D morphometric information and updates on global crater analysis

Abstract

Impact craters are common surface features on planetary surfaces. Their distribution offers important clues regarding geological and temporal processes on the Moon. Numerous endeavors have generated global catalogs of lunar craters; however, most of the existing catalogs only contain large craters (larger than several kilometers in diameter), and none of them offer three-dimensional (3D) morphometric information. In this study, we first present a machine-learning approach for automatic crater detection from digital elevation models (DEMs). Our crater detection approach can achieve a detection rate of about 85%. We also present an approach for extracting 3D morphometric information of craters based on the topography. These approaches were applied to producing a global crater data set covering the entire lunar surface that includes approximately 1.32 million craters (≥1 km). Verification was performed against previously published catalogs (Head et al., 2010, https://doi.org/10.1126/science.1195050; Robbins, 2019, https://doi.org/10.1029/2018je005592), with about 23% of our craters transferred from the previous catalogs after a rim-fitting process. The crater catalog includes 3D morphometric data on the craters such as depths. Global analyses of craters based on this improved catalog indicate that the lunar mare and highlands have distinctive crater density differences of small craters (1–5 km). Craters of 2.5–5 km have reached saturation in several local regions in the highlands. Small craters (1–5 km) on the lunar mare are deeper than those on the highlands. The data in our comprehensive crater catalog can support various other lunar scientific studies.