Institute for Advanced Study Astrophysics Seminar

The formation and evolution of the giant planets of our Solar System presents several problems: the cores of the planets should have been driven into the Sun by Type I migration, faster than they could accrete their massive gaseous atmosphere; once formed, Jupiter and Saturn should have suffered Type-II migration towards the Sun, becoming hot or warm giants, like most of the extra-solar planets known so far; the planets most likely underwent a late reorganization of their orbital architecture, as indicated by the Late Heavy Bombardment (LHB) of the Moon, which suggests that a massive reservoir of small bodies suddenly became unstable. Without pretension of providing any definitive answer, I will present a scenario of the formation and evolution of the giant planets that addresses these problems. More specifically I will present simulations of the dynamics of planetary cores in the vicinity of a `planet trap', which can exist at the transition between the active and the dead zones of the disk. I will illustrate how the dynamics of the fully formed planets in the gas disk leads to one of 6 possible mutual configurations, that are stable and avoid significant migration towards the Sun. Finally I will describe our model for the origin of the LHB and how it connects with some of these mutual stable configurations.