Extended Data Fig. 8: The time required to thermally break rocks is shorter for low-porosity rocks than for high-porosity rocks.
From: Fine-regolith production on asteroids controlled by rock porosity
We consider the asteroid to be in near-Earth space and explore a range of rotation periods corresponding to the shaded areas. The latter is to take into account changes in the current rotation periods (4.296 h and 12.1 h for Bennu and Itokawa, respectively) that these asteroids may have experienced in the past49 due to the Yarkovsky–O’Keefe–Radzievskii–Paddack (YORP) effect. We estimate that in their main belt source region, at about 2.3 au from the Sun, the time to break is ~60 times longer.
