[Baps] MIT Physics Colloquium

[Prof. Richard P. Binzel]

MIT Physics Colloquium
Thursday, October 19, 2006 
Time: 4:15 pm
Place: Room 10-250 / MIT
Refreshments @ 3:45 pm in 8-329 (Physics Common Room)

                   EUGENE CHIANG
        University of California - Berkeley

    "Celestial Engineering: Resonance and the 
   Dynamical Architecture of Planetary Systems"

The music of the spheres can be heard in resonant astrophysical 
systems. The fixed gaze of the Moon, the commensurate orbital 
periods of the Galilean satellites, and the arms of grand-design 
spiral galaxies testify to how dynamical resonances organize 
the universe. We discuss how resonances have ordered our view 
of one of the newest frontiers of planetary science: 
the Kuiper Belt, that great expanse extending beyond the 
orbit of the last known planet in our solar system. This 
space is strewn with icy, rocky bodies---Kuiper belt 
objects (KBOs)---of which Pluto is merely one (and not 
the largest) member. These objects occupy orbits of a 
formerly unimagined variety and inform our understanding 
of how planetary systems form and evolve. Their size 
spectrum preserves a record, unweathered by erosive 
collisions, of the process by which large bodies assemble 
from small bodies. Moreover, KBOs serve as test particles 
whose trajectories testify to how the giant planets---
and perhaps even planets that once resided within our 
system but have since been evicted---had their orbits 
sculpted. We recount the formation history of our 
planetary system as told through KBOs recently discovered 
to be locked in orbital resonance with Neptune, 
highlighting unsolved problems. Connections are drawn 
between the Kuiper belt and extra-solar examples of
nascent planetary systems. Time permitting, we illustrate 
the power of resonance in shaping systems on Galactic scales.