Alessandro Morbidelli
CNRS
Observatory of Nice

New Clues to the Primordial Evolution of the Solar System
 
The existence of the asteroid belt and of the Edgeworth-Kuiper belt,
both dynamically excited and with a total
mass that is only a small fraction of the original one, is very
intriguing and may provide several clues for understanding the
formation phase and the primordial evolution of our Solar System.
The existence and the main properties of the belts of small bodies
should be considered as observational constraints to discriminate
among scenarios of Solar System's primordial evolution.
The large numbers of bodies in the belts make them statistically
significant sets of evidence.

In this talk I will show that the best reconstruction of the
presently observed characteristics of the belts of small bodies
can be achieved in the framework of a primordial Solar System
that was crowded of massive planetary embryos.
Our improved model for the sculpting of the asteroid belt
allows to explain the delivery to the Earth of a large amount of
water with a low Deuterium to Hydrogen ratio.