The importance of impacts in Mars crater degradation: Predictions for atmospheric filtering of small impactors

Abstract

The characterization of crater degradation on Mars has been closely tied to the development of landform evolution models whose goals have been to better understand the influence of climate-driven erosive processes. Three types of landform evolution are generally identified: aggradation, advection, and diffusion. Many different processes have been invoked to explain the diffusive degradation of impact craters on Mars, some of which are climate-dependent. The prevalence of topographic diffusion from subsequent small impacts on the Moon suggests that similar processes may have been operating on the surface of Mars throughout its history. We find that the effectiveness of impact-induced diffusive degradation on Mars is highly dependent upon both atmospheric pressure and the size scaling of impact craters. Thus, it is critical that further quantitative observations be made of diffusively degraded craters on Mars in order to determine whether impact-induced diffusion has had a measurable effect on the evolution of the martian landscape.