N-body gravitational and contact dynamics for asteroid aggregation

Abstract

The development of dedicated numerical codes has recently pushed forward the study of N-body gravitational dynamics, leading to a better and wider understanding of processes involving the formation of natural bodies in the Solar System. A major branch includes the study of asteroid formation: evidence from recent studies and observations support the idea that small and medium size asteroids between 100 m and 100 km may be gravitational aggregates with no cohesive force other than gravity. This evidence implies that asteroid formation depends on gravitational interactions between different boulders and that asteroid aggregation processes can be naturally modeled with N-body numerical codes implementing gravitational interactions. This work presents a new implementation of an N-body numerical solver. The code is based on Chrono::Engine (2006). It handles the contact and collision of large numbers of complex-shaped objects, while simultaneously evaluating the effect of N to N gravitational interactions. A special case of study is considered, investigating the relative dynamics between the N bodies and highlighting favorable conditions for the formation of a stable gravitationally bound aggregate from a cloud of N boulders. The code is successfully validated for the case of study by comparing relevant results obtained for typical known dynamical scenarios. The outcome of the numerical simulations shows good agreement with theory and observation, and suggests the ability of the developed code to predict natural aggregation phenomena

Libration-induced Orbit Period Variations Following the DART Impact

“…In this case, the characteristic time of the shape change will be comparable to the orbital and spin period of Dimorphos. This is confirmed by preliminary results of rubble-pile simulations run using DEM codes PKDGRAV (Richardson et al 2000) and GRAINS (Ferrari et al 2017), which show that even small shape change can lead to strong oscillations in Dimorphos's libration motion. Compared to the rigid-body case, the slow but steady deformation of the body facilitates the motion between stable and unstable regions identified by Agrusa et al (2021).…”

Libration-induced Orbit Period Variations Following the DART Impact

“…In this case, the characteristic time of the shape change will be comparable to the orbital and spin period of Dimorphos. This is confirmed by preliminary results of rubble-pile simulations run using DEM codes pkdgrav (Richardson et al 2000) and grains (Ferrari et al 2017), which show that even small shape change can lead to strong oscillations in Dimorphos's libration motion. Compared to the rigid body case, the slow but steady deformation of the body facilitates the motion between stable and unstable regions identified by Agrusa et al (2021).…”

Validating N-body code chrono for granular DEM simulations in reduced-gravity environments

“…CHRONO is used to model either rigid-body or soft-body interactions and can be executed in parallel by using the OpenMP, MPI, or CUDA algorithms for shared, distributed, or GPU computing (Mazhar et al 2013;Tasora et al 2016). Past CHRONO studies have spanned a wide range of applications, including structural stability (Coïsson et al 2016;Beatini, Royer-Carfagni & Tasora 2017), 3D printing (Mazhar, Osswald & Negrut 2016), terrain-vehicle interactions (Serban et al 2019), and asteroid aggregation (Ferrari et al 2017). Given its versatility, users must install the software and construct physical systems based on their individual needs.…”