The evolution of the Kuiper Belt during the accretion of the outer planets

MELITA M.D. AND BRUNINI A.

Evolution and source regions of asteroids and comets

IAU

Año: 1999; p. 37 - 44

A set of numerical simulations of the formation of Uranus and Neptune are performed to study the evolution of the native KBO´s in the process. Our main goal is to have a deeper understanding of the impact of the formation of the outer planets on the present orbital structure of the trans-Neptunian region. We aim to understand if resonance capture driven by the outer migration of Neptune can actually occur and its interplay with the invasion of massive planetesimals expelled from the Uranus-Neptune region as a byproduct of their formation. From the simulations with end-states which reassemble our Planetary System, we can conclude that most of the dynamical sculpting of the inner Kuiper belt is due to the perturbations of Neptune. Resonance capture does not appear to be a very conspicuous phenomenon, although temporary captures are present in our experiments. Also, our results suggest that the notorious absence of objects in the region with a < 39 AU of the present Kuiper belt could be attributed to a strong invasion of planetoids scattered out from the Uranus-Neptune zone. This invasion introduces a gravitational warming of the inner region of the Kuiper belt, which would stop very early the runaway growth of large planetesimals. Finally, it should be pointed out that, according to our estimations, a significant portion of the Oort cloud of comets could have been originated in the primordial Kuiper belt.