Lunar Evolution Analysis Based on Numerical Simulations of Typical Lunar Impact Craters

Abstract

Impact craters are one of the most important landforms on the lunar surface, playing a crucial role in the formation and later evolution of the Moon. For example, as a primary source of remote sensing observations and lunar samples, lunar regolith is predominantly composed of impact ejecta. Based on their morphologies, lunar impact craters with increasing sizes can be classified into simple craters, complex craters, and multiring basins, and they play different roles in lunar evolution. In our study, we conducted numerical simulations of the South Pole-Aitken basin and the Orientale basin on the lunar surface, as well as the Aristarchus complex crater and the Zhinyu simple crater. The resultant effects of them are further analyzed. Because Zhinyu crater is relatively close to the Chang’e-4 landing site, while Aristarchus crater is relatively close to the Chang’e-5 landing site, their simulation results have direct significance for interpreting the corresponding exploration data from both missions. The numerical simulation results demonstrate that the formation of large basins not only affects the subsurface structure within the basin but also significantly disturbs the surrounding geological layers. Complex and simple craters mainly disturb the subsurface layers within the crater, but complex craters can cause uplift of the underlying strata. These impact processes dominate the primary geological framework of the lunar surface, depositing ejecta materials of varying thicknesses from different depths, which has important implications for future sample collection missions. In conclusion, impact processes are one of the primary driving forces in the lunar evolution.