A Flat-bottomed Buried Crater and Paleo-layered Structures Revealed at the Von Kármán Crater Using Lunar Penetrating Radar

Abstract

Impact cratering is the most common geological process occurring on terrestrial planets. The morphologies of impact craters reflect not only the impact conditions but the target properties as well. They have been widely used as subsurface probes into regolith thickness and mechanical properties. A population of paleo-buried impact craters has been discovered by recent geophysical investigations of the Moon; however, their morphologies have never been constrained. The lunar penetrating radar onboard the Chang’e-4 rover has offered an unprecedented opportunity to study the morphology of those paleo-buried craters and reveal obscured depositing history. In this study, we have identified a flat-bottomed paleocrater (450 m in diameter; 11.5 m in depth) on an extraterrestrial world and reconstructed its morphology. This discovery reinforces how impacts would modify layered structures, providing additional evidence regarding subsurface interfaces between the paleoregolith layers and the final-stage lava layers, shedding light on similar processes on all planets.