Diversity of New Martian Crater Clusters Informs Meteoroid Atmospheric Interactions

We investigated 634 crater clusters on Mars detected between 2007 and 2021, which represent more than half of all impacts discovered in this period. Crater clusters form when meteoroids in the 10 kg-10 ton mass range break up in Mars' atmosphere to produce a few to a few hundred fragments that hit the ground. The properties of the clusters can inform our understanding of meteoroid properties and the processes that govern their fragmentation. We mapped individual craters >1 m within each cluster and defined a range of cluster properties based on the spatial and size distributions of the craters. The large data set, with over eight times more cluster observations than previous work, provides a more robust statistical investigation of crater cluster parameters and their correlations. Trends in size, dispersion, and large crater fraction with elevation support weak atmospheric filtering of material. The diversity in the number of individual craters within a cluster, and their size-frequency distributions, may reflect either a diversity in fragmentation style, fragility, or internal particle sizes.

Automated summary

We studied 634 clusters of craters on Mars detected from 2007 to 2021, which account for more than half of all impacts found during this period. These clusters are formed when meteoroids in the 10 kg-10 ton mass range break apart in Mars' atmosphere, producing a few to a few hundred fragments that impact the ground. The characteristics of these clusters can provide insights into meteoroid properties and the processes governing their fragmentation. By mapping individual craters within each cluster and analyzing their spatial and size distributions, we defined a range of cluster properties. This large dataset, with over eight times more cluster observations than previous studies, allows for a more comprehensive statistical examination of crater cluster parameters and their correlations. The trends in size, dispersion, and large crater fraction with elevation support the idea of weak atmospheric filtering of materials. The variations in the number of individual craters and their size-frequency distributions within a cluster may reflect differences in fragmentation style, fragility, or internal particle sizes.