BROADER IMPACT: THE SPATIAL DISTRIBUTION OF MARTIAN IMPACT CRATERS

The spatial distribution of impact craters, while offering the possibility to constrain planetary surface processes, remains understudied, particularly given arguments that impacting should lead to random distributions of craters and therefore distributions do not reveal geologic phenomena. While a random spatial distribution does indicate an ideal pattern and is common, numerous instances of non-random impact crater spatial distributions have been presented in literature, indicating more complex processes are at play. Here we will review the different non-random patterns impact craters can display and the various surface processes that lead to them. Additionally, we will present data on a series of crater populations from the Martian surface that were analyzed using spatial point pattern analysis. Results from this method reveal numerous surfaces throughout the Martian surface with either aggregated (closer than random) or segregated (further apart than random) impact crater distributions. While some of these regions can be tied to obvious process (e.g., Amazonian and Hesperian impact unit having aggregated distributions with abundant impacting increasing the chances that patterns would be aggregated) other regions have more nebulous reasons for deviating from randomness, possibly related to post impact resurfacing (e.g., segregated distributions in Amazonian and Hesperian transition units). We argue that the spatial distributions of impact craters both on Mars, and other rocky bodies in the solar system, can be utilized to enhance remote sensing of surfaces and our understanding of planetary surface evolution.