Main Belt evolution in the context of adaptive-optics observations of large asteroids
Résumé
According to the size-frequency distribution (SFD) of the Main Belt, there are approximately 4 times 105 small (D = 2-3 km) projectiles which determine the surface topography of large (D > 100 km) targets. Nowadays, the topography is accessible to adaptive-optics observations by the VLT/SPHERE/ZIMPOL instrument, which typically have a pixel scale 3 km and capability to resolve Dc = 30-40 km craters in suitably illuminated areas. We used statistical collisional models (Monte-Carlo) to compute intrinsic collisional probabilities, impact velocities, expected number of catastrophic collisions, numbers of cratering events, taking into account not only mean numbers but also their dispersion. Even within the Main Belt, collisional environment can be very different from target to target.