Numerical Simulation of N-Body Asteroid Aggregation with GPU-Parallel Hierarchical Treecode Algorithm

Over the past years significant evidence has shown that asteroids with dimensions exceeding few hundreds of meters are gravitational aggregates of smaller bodies bound together only by gravitational forces.1 The study of such complex bodies is motivated by the recent efforts by space agencies, trying to intercept or redirect near-Earth asteroids (DART, ARM missions), as well as the ever-expanding possibilities of reaching further objects such as Jupiter trojans. The development of models for orbital dynamics about gravitational aggregates, complex gravity fields around irregular objects and collisions between orbiters and asteroids is therefore required. This work presents a new modeling and implementation of a N-body numerical solver using a GPU-parallel Barnes-Hut implementation to evaluate the effects of gravitational interactions and the Chrono::Engine multi-physics simulation engine to simulate collisions between bodies and integrate the dynamics of the problem.2 The code is successfully validated for different cases of study based on previous works by P. Michel and P. Tanga concerning collisional disruption and gravitational re-accumulation leading to formation of asteroid families in different energetic regimes and by comparing relevant results obtained for well-known dynamical scenarios.3–5 Results of numerical simulations show good agreement with established theories and observations and confirm the ability of the developed code to predict natural aggregation phenomena.