The Martian isochrons are the basis in analyzing the impact flux and surface dating, and currently, they are usually derived from those of the Moon because no samples have been collected from Mars. However, the isochrons obtained by this method have substantial uncertainty, and they urgently need to be optimized based on the samples that are about to be obtained. To support the upcoming Mars sample return missions, we utilized a high-resolution Context Camera mosaic and selected 17 regions from diverse geological units and ages across Mars’s surface to establish an observed Martian crater production function (PF). Craters were manually mapped across these regions. The crater size–frequency distributions (CSFDs) from these regions have a strong correlation at the same diameter range on a logarithmic scale, indicating that they share a similar distribution shape regardless of geological units and ages. We obtained 155 effective CSFD bins suitable for fitting the crater PF. After testing on different fitting functions, we finally obtained the crater PF for the Martian surface over the diameter range of 0.15 to 13.5 km. There were significant differences between the directly mapped Mars crater PF and those derived from lunar models. In addition, the CSFDs obtained by previous researchers when doing dating works on the Martian surface are more consistent with the newly established crater PF than with the earlier proposed PFs. With the radiometric ages of the samples returned by future Mars sample return missions, this research could become the basis for establishing a new chronology system for Mars.

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.