Vesta Cratering: is it a Record of Primordial Bombardment?

The next-to-be-launched mission Dawn will provide the first, detailed images of Vesta surface and supply crucial informations to constrain its mineralogical and elemental composition through VIR, its imaging spectrometer. Thank to these data, we will be able to study in depth the crater record on the surface of Vesta and get an insight on its place in the context of Solar System history. Vesta is believed, basing on the Hubble observations and the relationship with HED meteorites whose dating is very old, to have underwent early to a substantial differentiation. If this should be the case, we would expect Vesta's surface to have been affected by the early bombardment following the displacement of bodies due to the final phases of Jupiter accretion. In the framework of our studies on the origin of Jupiter, we evaluated the accretion rate during the final phases of Jupiter formation and, through an N-Body code developed on purpose, we evaluated the flux of impactors on Vesta keeping track of their formation zones, which can bear information on their composition. We also evaluated the flux of impactors in the case Jupiter formed earlier than Vesta and underwent to a mild displacement, as hypothesized by the Nice model, and in the case the planet formed later but still radially migrated, to estimate the relative importance of the different processes. We will describe the different scenarios and their implications for the evolution of Solar System to provide a reference frame for future studies of Vesta's cratering history.