Fig. 1.  Cumulative plot of the time spectrum of martian meteorite delivery. Dashed line and heavy squares:  CRE data from the martian meteorites. Dotted line:  Collisionless N-body model, nuinfinity = 1 km/s launches from Mars. Solid line:  Inclusion of a 2-Myr collisonal half-life for meteoroids while in the asteroid belt (Q > 2.1 AU). The model provides a good fit to the data. Errors on the CRE ages are about 10-30%.