In Fall 2017 the Pan-STARRS telescope detected the first object of clearly interstellar origin passing fleetingly through the inner Solar System. Named 'Oumuamua, after the Hawaiian word for "scout", our first interstellar visitor was a small body that may have originated as an asteroid or comet within an extrasolar planetary system. The existence of interstellar asteroids and comets was no surprise - our Solar System probably ejected many Earth masses of such bodies as it formed - but 'Oumuamua showed unexpected and mysterious properties that remain to be fully explained. In this talk I will discuss what we know about 'Oumuamua, and what we hope to learn about planet formation from future observations of similar visitors.
Prof. Phil Armitage is a theoretical astrophysicist in the Stony Brook Physics & Astronomy Department. He is interested in the formation of planetary systems and the astrophysics of black holes. He joined Stony Brook last year after many years at the University of Colorado in Boulder.