  The large scale structure of the Solar System has been shaped by a transient
dynamical instability that may have been triggered by the interaction of the
giants planets with a massive primordial disk of icy debris. In this work, we
investigate the conditions under which this primordial disk could have
coalesced into planets using analytic and numerical calculations. In
particular, we perform numerical simulations of the Solar System's early
dynamical evolution that account for the viscous stirring and collisional
damping within the disk. We demonstrate that if collisional damping would have
been sufficient to maintain a temperate velocity dispersion, Earth mass
trans-Neptunian planets could have emerged within a timescale of 10 Myr.
Therefore, our results favor a scenario wherein the dynamical instability of
the outer Solar System began immediately upon the dissipation of the gaseous
nebula to avoid the overproduction of Earth mass planets in the outer Solar
System.

Earth and Planetary Astrophysics