Reshaping and ejection processes on rubble-pile asteroids by impacts

Abstract

Context. Most small asteroids (<50 km in diameter) are the result of the breakup of a larger parent body and are often considered to be rubble-pile objects. Similar structures are expected for the secondaries of small asteroid binaries, including Dimorphos, the smaller component of the 65803 Didymos binary system and the target of NASA's Double Asteroid Redirection Test (DART) and ESA's Hera mission. The DART impact occurs on September 26th, 2022 and it will alter the orbital period of Dimorphos around Didymos. Aims. In this work we assume Dimorphos-like bodies with a rubble-pile structure, and quantify the effects of boulder packing in its interior on the post-impact morphology, degree of shape change and material ejection processes. Methods. We used the Bern SPH shock physics code to numerically model hypervelocity impacts into small, 160 m in diameter rubble-pile asteroids, with a variety of boulder distributions. Results. We find that the post-impact target morphology is most sensitive to the mass-fraction of boulders in the target, while the asteroid deflection efficiency depends on both the mass-fraction of boulders in the target and on the boulder size-distribution close to the impact point. Our results may also have important implications for the structure of small asteroids.

References in corpus (6)

• Catastrophic disruptions revisited
• Density of asteroids
• Scaling forces to asteroid surfaces: The role of cohesion
• Numerical simulations of impacts involving porous bodies: I. Implementing sub-resolution porosity in a 3D SPH Hydrocode
• SPH calculations of asteroid disruptions: The role of pressure dependent failure models
• Creep stability of the proposed AIDA mission target 65803 Didymos: I. Discrete cohesionless granular physics model

Cited by in corpus (7)

• Successful Kinetic Impact into an Asteroid for Planetary Defense
• Physical properties of asteroid Dimorphos as derived from the DART impact
• The Dimorphos Boulder Swarm
• The Dynamical State of the Didymos System Before and After the DART Impact
• Lessons learned from NASA's DART impact about disrupting rubble-pile asteroids
• Rapid formation of binary asteroid systems post rotational failure: a recipe for making atypically shaped satellites
• Physical Analysis of Bennu Samples Reveals Regolith Production by Collisional Disruption on Near-Earth Asteroids