The First Global Catalog of Rockfall Locations on Mars

Rockfalls are ubiquitous expressions of present-day landscape evolution across the solar system. On Mars, their distribution has been proposed to indicate endo- and exogenic drivers, such as tectonic activity and solar-driven thermal fatigue. Here, we present the first global catalog of 1,383 rockfall-bearing locations on Mars, derived using MRO HiRISE images and a machine learning-driven and human-reviewed mapping approach. Rockfalls are documented between 82°N and 53°S, are heterogeneously distributed, and predominantly occur on the steep walls of craters and fossae. Globally, we do not observe a significant relation between rockfall abundance and terrain age, insolation, volatile abundance, wind speed, and impact or tectonic events, implying that rockfall drivers might act on varying spatiotemporal scales and differ across the planet—dissimilar to rockfalls on other bodies, like the Moon. Our results help characterize the current geologic processes that are shaping the surfaces of Mars and other solar system bodies today.