  Vesta has a complex cratering history, with ancient terrains as well as
recent large impacts that have led to regional resurfacing. Crater counts can
help constrain the relative ages of different units on Vesta's surface, but
converting those crater counts to absolute ages requires a chronology function.
We present a cratering chronology based on the best current models for the
dynamical evolution of asteroid belt, and calibrate it to Vesta using the
record of large craters on its surface. While uncertainties remain, our
chronology function is broadly consistent with an ancient surface of Vesta as
well as other constraints such as the bombardment history of the rest of the
inner Solar System and the Ar-Ar age distribution of howardite, eucrite and
diogenite (HED) meteorites from Vesta.
