Monday, September 26, 2022 at 4:00pm to 5:00pm
Rockefeller Hall, Schwartz Auditorium
General Physics Colloquium and Gold Lecture, Prof. Alessandro Morbidelli, Observatoire de la Cote D'Azur
Title: Planet formation and evolution: key processes to understand the diversity of planetary systems
Host: Dong Lai
Abstract: The discovery of a large number of extrasolar planets has demonstrated that our own system is not "typical". Exo-planetary systems can be very different from our own, and diverse from each other. Understanding this diversity is a major goal of modern planetary science. The formation of planetary systems is not fully understood, but major advances have been obtained in the last 10 years. New concepts have been proposed, such as the streaming instability for the formation of planetesimals and pebble accretion for the formation of protoplanets. It is also now clear that planets forming in the proto-planetary disks have to migrate during their accretion, if their mass exceeds a few times the mass of Mars. Accretion and dynamical evolution are therefore very coupled processes. This leads to complex evolutions, very sensitive to initial conditions and fortuitous events, that are the key to understand the observed diversity of planetary systems. The early formation of Jupiter and its limited migration due to the formation of Saturn are two fundamental ingredients that determined the basic structure of the Solar System. There is also evidence that the vast majority of planetary systems become unstable after the removal of the protoplanetary disk. The effects of this instability are very different depending on the masses of the planets involved. Our Solar System also experienced a global instability, but fortuitously our giant planets did not develop large orbital eccentricities.
This talk will also be available via Zoom, and the link will be emailed to the Physics listserv the week of the talk. If you are not on the listserv, please contact Sue Sullivan at email@example.com by Monday at 3:00 pm to request the link.