James Tuttle Keane
Fri, April 13, 2018, 10:30am - 11:30am

Video Broadcast

Host: Duncan Young

Abstract:
The spins of planets and moons are not constant with time; they change in response to both external and internal forces on a variety of spatial and temporal scales. These changes can have important consequences for the geology of a planet, including stirring up the core dynamo, generating tectonic stresses in the crust, and altering the stability of water and other volatile ices across the planet's surface. Beyond the Earth, the Moon is the only other solar system body where we have been able to constrain multiple aspects of its rotational history. In this seminar, I will present a variety of new results detailing our investigations into the Moon's rotational dynamics over time: from long-term true polar wander due to mantle convection, to chaotic tumbling due to giant impacts. While I will focus on the Moon, these dynamical processes are incredibly general, and I will touch on some prospects for future analogous studies of Mercury, Venus, Mars, and the icy worlds.