Numerical simulation of the final stages of terrestrial planet formation
Abstract
Three representative numerical simulations of the growth of the terrestrial planets by accretion of large protoplanets are presented. The mass and relativevelocity distributions of the bodies in these simulations are free to evolve simultaneously in response to close gravitational encounters and occasional collisions between bodies. The collisions between bodies, therefore, arise in a natural way and the assumption of expressions for the relative velocity distribution and the gravitational collision cross section is unnecessary. These simulations indicate that the growth of bodies with final masses approaching those of Venus and the Earth is possible, at least for the case of a twodimensional system. Simulations assuming an initial uniform distribution of orbital eccentricities on the interval from 0 to e_{max} are found to produce final states containing too many bodies with masses which are too small when e_{max} < 0.10, while simulations with e_{max} > 0.20 result in too many catastrophic collisions between bodies thus preventing rapid accretion of planetarysize bodies. The e_{max} = 0.15 simulation ends with a state surprisingly similar to that of the present terrestrial planets and, therefore, provides a rough estimate of the range of radial sampling to be expected for the terrestrial planets.
 Publication:

Icarus
 Pub Date:
 December 1980
 DOI:
 10.1016/00191035(80)901384
 Bibcode:
 1980Icar...44..706C
 Keywords:

 Astronomical Models;
 Gravitational Effects;
 Planetary Evolution;
 Protoplanets;
 Terrestrial Planets;
 Deposition;
 Mass Distribution;
 Meteorite Collisions;
 Orbital Elements;
 Velocity Distribution;
 Lunar and Planetary Exploration