EEPS Colloquium: Katherine de Kleer

Assistant Professor Katherine de Kleer, Caltech Planetary Science and Astronomy

Jupiter’s moon Io is heated internally by tides arising from its LaPlace orbital resonance with neighboring moons Europa and Ganymede. The resultant volcanic activity provides remotely-observable signatures by which we can study the influence of tides on the interior of a planetary-scale body. This talk will present telescopic observations of Io’s volcanic gasses and lava flows, which we use to derive constraints on Io’s interior and on the interactions between its outgassed atmosphere and the jovian magnetosphere. Such observations provide important clues into the processes governing Io’s current state. However, Io’s activity rapidly erases any indicators of its history prior to the most recent ~million years. As a consequence, the history of Io’s volcanism, and of the resonance between the galilean moons, has remained largely unknown. We are currently using isotopic measurements of the volatile-forming elements at Io to constrain the processes acting on its volatile reservoirs over long timescales. This talk will present results from millimeter-wavelength telescopic measurements of Io’s sulfur and chlorine isotopes and plans for future measurements. The isotopic ratios hold a record of Io’s volcanic activity, volatile recycling, and mass loss over the age of the Solar System, shedding light on past tidal heating at Io and hence the age of the LaPlace resonance between the moons.

Host: Bill McKinnon

EEPS colloquia are made possible by the William C. Ferguson Fund

_{Header Image: Juno Captures North Polar Region of Io. Image data: NASA/JPL-Caltech/SwRI/MSSS. Image processing by Gerald Eichstädt}