Asteroid Fragmentation and Evolution of Asteroids

To understand the complex collisional history of asteroids and explain their observed characteristics, it is necessary to be able to describe the fundamental physics of large-scale impact events. Because data collected on collisional outcomes is derived from small-scale laboratory experiments, success at describing asteroid evolution hinges sensitively on methods devised to “scale” this data to the appropriate size ranges. The recent use of numerical modeling to study collisional fragmentation is a valuable asset for calculating important impact parameters: energies required for catastrophic fragmentation, and resulting fragment size and velocity distributions. The current size distribution of main belt asteroids provides an important constraint of model predictions, as do comparisons of numerical impact calculations to asteroid families. Agreement between theory and observations is reasonable, but improvements in collision simulations are required for the modeling of more realistic asteroid shapes and structures.