DIX Planetary Science Seminar

Asteroids hold clues to the formation of the solar system, as evidenced by meteorites and collected samples. Through the years, spacecraft missions have observed that asteroids with high-porosity rocks (low material density compared to their meteorite type) lack areas covered in sub-centimeter rock fragments, while such terrains seem common on asteroids with lower-porosity rocks. In this talk, I will present how the porosity of constituent rocks plays a central role in driving this diversity of asteroids' surfaces (Cambioni et al. 2021, https://www.nature.com/articles/s41586-021-03816-5). The geology of asteroids is a complex interplay between their low gravity and the mechanical properties of their rocks in competent and granular form. We explain the spacecraft observations by demonstrating that higher-porosity rocks comminute less efficiently through impacts and thermal fatigue than do lower-porosity rocks. The discovery of this phenomenon, which influences the geology of asteroids and our capability to sample their surfaces, was made possible by machine learning. I will also present more generally on how machine learning works and outline how machine learning is changing the way we do planetary science.