Numerical Simulations of Collisional Disruption of Rotating Gravitational Aggregates: Dependence on Material Properties

Abstract

Our knowledge of the strengths of small bodies in the Solar System is limited by our poor understanding of their internal structures, and this, in turn, clouds our understanding of the formation and evolution of these bodies. Observations of the rotational states of asteroids whose diameters are larger than a few hundreds of meters have revealed that they are dominated by gravity and that most are unlikely to be monoliths; however, there is a wide range of plausible internal structures. Numerical and analytical studies of shape and spin limits of gravitational aggregates and their collisional evolution show a strong dependence on shear strength. In order to study this effect, we carry out a systematic exploration of the dependence of collision outcomes on dissipation and friction parameters of the material components making up the bodies. We simulate the catastrophic disruption (leading to the largest remnant retaining 50% of the original mass) of km-size asteroids modeled as gravitational aggregates using pkdgrav, a cosmology N-body code adapted to collisional problems and recently enhanced with a new soft-sphere collision algorithm that includes more realistic contact forces. We find that for a range of three different materials, higher friction and dissipation values increase the catastrophic disruption threshold by about half a magnitude. Furthermore, we find that pre-impact rotation systematically increases mass loss on average, regardless of the target's internal configuration. Our results have important implications for the efficiency of planet formation via planetesimal growth, and also more generally to estimate the impact energy threshold for catastrophic disruption, as this generally has only been evaluated for non-spinning bodies without detailed consideration of material properties.

arXiv comment27 pages, 6 figures, Accepted for publication in Planetary and Space Science. arXiv admin note: text overlap with arXiv:1406.5228

References in corpus (12)

• Catastrophic disruptions revisited
• Collisions between Gravity-Dominated Bodies: 2. The Diversity of Impact Outcomes during the End Stage of Planet Formation
• Collisions Between Gravity-Dominated Bodies: 1. Outcome Regimes and Scaling Laws
• Modeling the Formation of Giant Planet Cores I: Evaluating Key Processes
• Full Numerical Simulations of Catastrophic Small Body Collisions
• Tidal Evolution of Rubble Piles
• Fragment properties at the catastrophic disruption threshold: The effect of the parent body's internal structure
• Numerical simulations of impacts involving porous bodies: I. Implementing sub-resolution porosity in a 3D SPH Hydrocode
• Direct N-body Simulations of Rubble Pile Collisions
• Numerical predictions of surface effects during the 2029 close approach of asteroid 99942 Apophis
• Numerical simulations of granular dynamics. I. Hard-sphere discrete element method and tests
• Low-speed Impact Simulations into Regolith in Support of Asteroid Sampling Mechanism Design I.: Comparison with 1-g Experiments

Cited by in corpus (13)

• Creep stability of the proposed AIDA mission target 65803 Didymos: I. Discrete cohesionless granular physics model
• Small Solar System Bodies as granular media
• Asteroid Family Associations of Active Asteroids
• The spherical Brazil Nut Effect and its significance to asteroids
• Collisional Formation and Modeling of Asteroid Families
• Modeling asteroid collisions and impact processes
• Realistic On-The-Fly Outcomes of Planetary Collisions: Machine Learning Applied to Simulations of Giant Impacts
• The role of fragment shapes in the simulations of asteroids as gravitational aggregates
• A recent origin for Saturn's rings from the collisional disruption of an icy moon
• Impacts into rotating targets: angular momentum draining and efficient formation of synthetic families
• Asteroid Evolution: Role of Geotechnical Properties
• The Influence of Central Body Tides on Catastrophic Disruptions of Close-in Planetary Satellites
• Considering contact forces during the formation of planetesimals by gravitational collapse: mutual orbits, spin states, and shapes