Formation of Asteroid Satellites

Southwest Research Institute, San Antonio TX

Investigators

Abstract

AST 0407045 Durda Collisions are a fundamental process in the origin and evolution of planetary systems. For this reason, investigating impacts and impact outcomes is a prerequisite for accurately modeling the formation and evolution of planetary bodies. The inventory of satellites orbiting small Solar System bodies provides critical constraints that can be used to understand small body collisions. Dr. Durda will make the numerical models of asteroid satellite formation increasingly more realistic, in order to address several fundamental issues about binary asteroid formation that are still not fully understood and to enhance the ability to compare modeled binary properties with the ever-increasing variety of observed asteroid satellite systems. Using the same numerical methods employed in ongoing studies, Dr. Durda will investigate asteroid satellite formation via impacts onto pre-shattered targets and rubble-pile targets (collisional evolution models suggest that most asteroids have been substantially fractured or shattered and reassembled by impacts since their formation). Using a new version of the N-body code that preserves strength-controlled irregular primary shapes, the orbital evolution of ejecta around non-spherical target body remnants will be tracked to compare and check previous results (for computational expediency, simulations to date have treated the resulting collision fragments as spheres, but several system primaries are observed to have elongate and irregular shapes). In addition, more realistic friction and particle interlocking effects in the resulting target remnants will be explored by replacing the previously spherical N-body particles with dumbbell-shaped constituents. Finally, the formation and survival of satellite systems during the late stages of planet formation will be investigated to determine the steady-state fraction of asteroid binaries capable of surviving from the planet formation epoch to today. Broader Impacts. This project will provide a strong synergistic link to ongoing observational programs that are detecting minor planet satellite systems at an ever-increasing rate. The many results of the ongoing research project have been presented to scientific colleagues at major, international astronomical meetings, and in journal papers and book articles in the peer-reviewed press. The research results are shared with students as research activities and results are incorporated into lecture and discussion material in college level astronomy courses and in presentations in primary school classrooms where visually exciting results are shared with eager young students. Research results are also shared with the general public through extensive public outreach efforts that include television documentaries, radio interviews, and popular articles in magazines. ***