The collisional and dynamical evolution of the main-belt and NEA size distributions

摘要: Abstract The size distribution of main belt asteroids is determined primarily by collisional processes. Large break up and form smaller in a cascade, with the outcome controlled strength–size relationship for asteroids. In addition to processes, non-collisional removal from (and their insertion into near-Earth asteroid (NEA) population) critical, involves several effects: strong resonances increase orbital eccentricity cause them enter inner planet region; chaotic diffusion numerous weak causes slow leak Mars- Earth-crossing populations; Yarkovsky effect, radiation force on asteroids, primary process that drives these resonant escape routes. drift size-dependent can modify main-belt distribution. NEA its source, population, processes deliver bodies belt. All effects are simulated numerical evolution model incorporates We test our against wide range observational constraints, such as observed distributions, number families, preserved basaltic crust Vesta large south-pole impact basin, cosmic ray exposure ages meteorites, cratering records find rates fits constraints best possible within parameter space we explore. Our results consistent other independent estimates strength rates.