Alessandro Morbidelli

Collège de France and Observatoire de la Côte d'Azur

Research field

Planet formation and the dynamical history of the solar system

Alessandro Morbidelli's simulations show that the giant planets did not stay on the orbits where they formed. He is one of the four authors of the Nice model, in which an instability among the giant planets scattered the outer disk of planetesimals and shaped the Kuiper belt. The Grand Tack paper featured here proposes that Jupiter first moved inward to 1.5 au and then back out, which removed most of the building material beyond 1 au and left Mars small. The unit uses both models to explain the present structure of the solar system.

In the masterclass

Section 6 on planetary migration presents the Nice model and, in the spotlight box, the Grand Tack simulations.

The research is presented in Unit 5: The Solar System, in a research spotlight box that explains the result at the level of the unit and links it to the physics you have just learned.

The paper

A low mass for Mars from Jupiter's early gas-driven migration