New Model Predicts Asteroid Strength from Particle Size and Shape
An international team of researchers has introduced a scalable framework in Nature Communications that estimates the tensile strength of granular asteroids solely from the characteristics of their constituent grains. The study focused on particle size and shape, which the authors say directly control the macroscopic strength of the material.
To validate the approach, the scientists applied it to the near‑Earth asteroid Bennu, whose surface regolith has been extensively mapped by the OSIRIS‑REx mission. The calculations show that the effective tensile strength of Bennu’s loose regolith is only about one‑fiftieth that of ground coffee, illustrating how fragile and loosely packed the material really is.
The researchers emphasize that the scaling law is not limited to Bennu but can be used for any asteroid surface composed of loosely packed grains. This allows better assessment of impact resistance, which is relevant for spacecraft landings and atmospheric entry scenarios.
Furthermore, the work highlights that microscopic shape variations – whether particles are more rounded or angular – significantly affect bulk strength. Such insight could aid the design of landing gear and improve hazard evaluations for small asteroids.
By linking granular physics with planetary science, the study demonstrates how interdisciplinary methods can uncover fundamental properties of celestial bodies.