  We have developed a statistical framework that uses collisional evolution
models, shock physics modeling and scaling laws to determine the range of
plausible collisional histories for individual meteorite parent bodies. It is
likely that those parent bodies that were not catastrophically disrupted
sustained hundreds of impacts on their surfaces - compacting, heating, and
mixing the outer layers; it is highly unlikely that many parent bodies escaped
without any impacts processing the outer few kilometers. The first 10 - 20 Myr
were the most important time for impacts, both in terms of the number of
impacts and the increase of specific internal energy due to impacts. The model
has been applied to evaluate the proposed impact histories of several meteorite
parent bodies: up to 10 parent bodies that were not disrupted in the first 100
Myr experienced a vaporizing collision of the type necessary to produce the
metal inclusions and chondrules on the CB chondrite parent; around 1 - 5% of
bodies that were catastrophically disrupted after 12 Myr sustained impacts at
times that match the heating events recorded on the IAB/winonaite parent body;
more than 75% of 100 km radius parent bodies which survived past 100 Myr
without being disrupted sustained an impact that excavates to the depth
required for mixing in the outer layers of the H chondrite parent body; and to
protect the magnetic field on the CV chondrite parent body, the crust would
have had to have been thick (~ 20 km) in order to prevent it being punctured by
impacts.
