A protoplanet with orange and black surface

Title: The Birth of Minor Planets and their Planetary Systems

Speaker: Andrew Youdin, Associate Professor of Astronomy, University of Arizona

When: Friday, April 22nd, 2022 at 3 pm

Where: Zoom https://ucsd.zoom.us/j/98072001104?pwd=NUdaYUIwN2V5ai9LQU5FaVpzeXJnUT09

Abstract: The current era of astronomical observations, Solar System exploration and powerful supercomputers is bringing new insights to the origin of planetary systems. I will focus on the origin of planetesimals, primordial minor planets with sizes ~10 km. These are the least massive gravitationally bound objects in the universe, and their origin is crucial to understanding our Solar System and extrasolar planets. I will describe current ideas for how particle growth crosses the daunting “meter size barrier” where collisions tend to be destructive and solids can drift rapidly into the host star. I will describe the Streaming Instability, a mechanism that can concentrate pebbles (large dust) to high densities in the disk midplane, triggering planetesimal formation by the gravitational collapse of these pebbles. I will describe how these theories relate to recents observations of protoplanetary disks by ALMA and to the study of the Kuiper belt by telescopes and by the New Horizons mission.