Physics Colloquium: Astro Visco-elastodynamics: Cracking moons and spin and obliquity evolution in tidal evolving and migrating satellite and planetary systems
Prof. Alice Quillen, Department of Physics and Astronomy, University of Rochester
Abstract: Mass spring models, originally developed for graphics and gaming applications, can accurately measure small deformations and can model the dynamics of vibrating viscoelastic objects. I will describe some recent applications in planetary science. We can simulate tidal spin down of moons and planets, directly tying simulated rheology to orbital drift and internal heat generation. Inspired by the rapidly spinning Kuiper belt object Haumea, we go past analytical methods to measure how the tidal spin down rate depends on body shape and internal composition. We find tidal encounters can induce sufficient stress on the surface to cause large scale brittle failure of an icy crust. Strong tidal encounters may be responsible for the formation of chasmata in ancient terrain of icy moons such as Dione, Tethys, Ariel and Charon. The new Horizons mission discovered that Pluto and Charon’s minor satellites Styx, Nix, Kerberos, and Hydra, are rapidly spinning, but surprisingly they have spin axis tilted into the orbital plane (they have high obliquities). Long simulations of the minor satellites in a drifting Pluto-Charon binary system exhibit rich resonant spin dynamics, including spin-orbit resonance capture, tumbling resonance and spin-binary resonances leading to the discovery of a new type of spin resonance that can lift satellite obliquities in the Pluto/Charon system.
Tuesday, October 24, 2017 at 3:15pm
Regents Hall, 109
3700 O St. NW