Vortrag 16.04.2018

Sprecher: Jack Connerney
Jet Propulsion Laboratory, NASA, Pasedena, USA

Titel: The Juno Magnetometer Investigation and Jupiter's magnetic field: A new dynamo

Characterizing the planetary magnetic field of Jupiter is one of the primary science objectives of the Juno Mission. Juno’s 53.5-day capture orbit trajectory carries her science instruments from pole to pole in approximately 2 hours, with a closest approach to within 1.06 Rjupiter of the center of the planet (one Rj = 71,492 km), just a few thousand km above the clouds. Observations acquired during 8 of Juno’s first 9 orbits provide the first truly global coverage of Jupiter’s magnetic field with a coarse longitudinal separation of ~45 degrees between perijoves. The magnetic field is represented with a degree 20 spherical harmonic model for the planetary field, combined with an explicit model of the magnetodisc. Partial solution of the underdetermined inverse problem using generalized inverse techniques yields a model (“JRM09”) of the planetary magnetic field with spherical harmonic coefficients determined through degree and order 10, providing the first detailed view of a planetary dynamo beyond Earth’s. The Jovian magnetic field is unlike anything previously imagined, evidencing a complexity that portends great insight into the dynamo process in general and the dynamics of Jupiter’s interior in particular.