Gravity Science at Jupiter: Initial Results from Juno (Plus a Teaser from Cassini)
When
Where
Dr. William Hubbard
Professor Emeritus
Lunar and Planetary Laboratory
The solar-powered geophysical orbiter Juno was successfully injected into a low-periapse Jupiter orbit on 4 July 2016. Since then Juno has completed seven perijoves within ~5000 km of the cloudtops. The radio-science/gravity experiment of primary interest to interior studies has provided unprecedentedly precise measurements of the gravity field, enough to reveal departures from hydrostatic equilibrium and provide insight about interior dynamics. We've measured Jupiter's second-degree love number revealed by the Io tide, which agrees (maybe a little too well) with static theory. My talk will touch on some of the theoretical work on Jupiter's interior that we are testing with Juno, and I'll describe relevant data. Meantime, radio-science data from Cassini's perikrones this year have gravitationally detected a dynamical uplift near Saturn's equator whose profile was noticeable in data from the 1989 stellar occultation observed from Tucson.
Host: Dr. Jeffrey Andrews-Hanna