Direct N-body simulations of rubble pile collisions

We present N-body simulations of planetesimal collisions and accretion in a strong tidal field modeled after the environment of Saturn’s F ring. These simulations examined the outcome of collisions between gravitational aggregates, or rubble piles, with the collision speed, mass ratio and coefficient of restitution being the variable parameters. The outcomes proved to be very dependent on collision speed and the coefficient of restitution, and less dependent on mass ratio. These results demonstrate a complicated collisional environment for icy bodies in planetary rings, and shed light on important assumptions made in previous models, most importantly those of complete accretion. FIGURE 1: Equal mass bodies with a bulk density of 1.0 g cm3 colliding at 5 m s1 with a coefficient of restitution 0.5 in orbit around a Saturn–mass central object at the distance of Saturn’s F ring. Rubble Pile Collisions Evidence for rubble piles found in: – spin period analysis – crater chains – tidal breakups – density/porosity measurements Rubble pile collisions previously modeled by Lein-hardt & Richardson 2002 to explore effects of mass ratio, impact speed, impact parameter and coefficient of restitution on collision outcome. Analytical estimates for colliding rubble piles consider rubble pile’s mutual Hill Sphere, impact speed and co-efficient of restitution to determine results in a tidal fiel