Diversity of New Martian Crater Clusters Informs Meteoroid Atmospheric Interactions

• Published in: Journal of geophysical research. Planets Vol. 128; no. 4
• Main Authors: Neidhart, T., Sansom, E. K., Miljković, K., Collins, G. S., Eschenfelder, J., Daubar, I. J.
• Format: Journal Article
• Language: English
• Published: 01.04.2023
• Subjects: cluster; crater; fragmentation; Mars; meteoroid
• ISSN: 2169-9097; 2169-9100
• DOI: 10.1029/2022JE007611

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. Plain Language Summary Between 2007 and 2021, over a thousand newly formed impact craters have been detected on the surface of Mars. Over half are from bodies that have broken up in the atmosphere, forming clusters of craters. We have mapped all the individual craters in each of these clustered impact sites. By investigating the properties of these sites, such as how many individual craters are there, their dispersion and their size, we can improve our understanding of the impacting bodies and how they break up. We find a wide diversity of cluster patterns, with some elevation dependence. This suggests that, although the atmosphere plays a role in meteoroid break up, there is great variety in the impactor bodies themselves. Key Points Crater cluster properties inform our understanding of meteoroid fragmentation Atmospheric influence reflected in crater cluster properties varies with elevation Size‐frequency crater distribution in clusters suggests larger impactors are weaker in bulk strength