Juno in-situ Observations of Io's Interaction with Jupiter and Comparisons with Enceladus
Abstract
During each perijove pass, the Juno spacecraft crosses magnetic flux tubes connected to Io's orbit at least once in each hemisphere. The Waves instrument onboard detects a variety of plasma wave emissions characteristic of the coupling between Io and Jupiter's ionosphere. These emissions have a clear upper frequency cutoff, understood to be the electron plasma frequency, thus making the electron number density calculable. Cutoffs related to other fundamental plasma frequencies are also visible. More interestingly, the ultra-high magnetic field of Jupiter makes lower frequencies in the ion and Aflvénic range measurable, and provides a new view of the structure of moon-ionosphere plasma waves. For this reason, we are able to examine the physics of wave-mode propagation and the relative contributions of particles (electrons, protons, possibly heavies) in generating plasma wave instabilities within their corresponding frequency ranges. We further explore particle, magnetic field, and E/B ratios to quantify the power of this interaction. We compare these in-situ measurements to those made available by Cassini in its similar orbits during the Grand Finale and construct a broader picture of how moon-magnetosphere coupling operates in parameter space.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSM43B..07S
- Keywords:
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- 2704 Auroral phenomena;
- MAGNETOSPHERIC PHYSICS;
- 2756 Planetary magnetospheres;
- MAGNETOSPHERIC PHYSICS;
- 5719 Interactions with particles and fields;
- PLANETARY SCIENCES: FLUID PLANETS;
- 6220 Jupiter;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS