They Came from Outer Space: Comets, Unseen Planets, and 'Oumuamua'

Wed 4 Dec 2019

Space Telescope Science Institute (STScI)
3700 San Martin Drive
Baltimore, MD 21218


2:45 PM - 4:00 PM

Contact Information:

Have questions? Please contact Kailash Sahu.


Comets have inspired awe since prehistoric times, but the modern study of comets only began with Halley's successful prediction of the return of what is now called Halley's comet.  Even today there are only a few thousand comets with well-determined orbits. Nevertheless, the analysis of these orbits yields a compelling model for the formation, evolution and present distribution of comets. This model implies that there are two distinct sources of comets: the Oort cloud, containing over 100 billion comets at 5,000 to 50,000 times the Earth-Sun distance; and the Kuiper belt outside Neptune's orbit. I will review our current understanding of the formation of the Oort cloud and Kuiper belt, and what they can tell us about possible undiscovered planets beyond Neptune. I'll also describe some of the puzzles arising from the recent discovery of the interstellar asteroid/comet 'Oumuamua.'

Speaker: Scott Tremaine (IAS, Princeton University)


All 2019 Fall Colloquia talks are held on Wednesdays in the STScI John N. Bahcall Auditorium at 3:00 p.m. preceded by tea at 2:45 p.m.

Please direct questions or comments to the contact above. The 2019-20 committee members are Paule Sonnentrucker (STScI Chair), Annalisa Calamida (STScI), Will Fischer (STScI), Ethan Vishniac (JHU Co-chair), Kevin Schlaufman (JHU), and Graeme Addison (JHU).