Extended Data Fig. 6: Comparison between observed and modeled crater populations for the large craters and an MBA flux.

a, residuals for all combinations of bin sets and modeled ages. The residuals are in the same form as the differential SFD, as described in Extended Data Fig. 5. b, the specific residuals for bin set 2, which consists of diameter bins a0, a1, A and B (Extended Data Fig. 4). Colors are as in Extended Data Fig. 5. c, d, and e are the same as b for bin sets 3, 4, and 5, respectively. We use the 1-99% minimum residuals across the modeled ages to bound the possible ranges for the small-crater retention age. The broad minimum in bin set 2 establishes the maximum age at 65 Myr; the two smallest residuals at 45 Myr and 60 Myr correspond to two cases, one for each of those ages, when there were no modeled craters larger than the observed craters, and the number of modeled craters in bin A match the observations. Bin set 5 establishes the minimum age at 10 Myr. f and g are the differential versions of the observed crater SFD and TS2018 model fits (see also Fig.1 and Fig. 4) for the 10 Myr and 65 Myr (minimum and maximum ages, respectively) with the 99% minimum residuals between observations and model results. The black data are the measured differential crater SFD of Bennu, the purple data are the median results of 100 runs, and the gray band is the 99% range of the 100 runs. Across this age span the range of the 100 modeled outcomes encompasses the variability in density seen in the three largest diameter bins.