A sketch of the primordial disk cumulative mass distribution (in units of Earth’s masses), based on dynamical constraints and current observational constraints from Kuiper belt objects and Trojan asteroids. We plot, as a function of diameter, the total disk mass contained in all larger objects. Two Earth masses have been allocated to objects larger than 1000. The total mass of objects larger than 1 km has been set to 20 Earth masses, at the low end of published primordial disk masses. The two solid curves correspond to slopes of −2.0 and −2.5 for the cumulative size-frequency distribution at D< 100 km.