Interior Models that Explain the Gravity Fields of Saturn and Jupiter
Abstract
This talk will discuss the recent gravity measurements of Saturn and Jupiter by the Cassini and Juno spacecrafts. During 13 years in orbit around Saturn, the Cassini spacecraft made many surprising discoveries about the planet and its moons. However, only during its Grand Finale phase when it traveled inside Saturn's rings, it came close enough to measure the planet's gravitational field with high precision. Such measurements tell us about the planet's interior mass distribution and thus provide us with information about its current interior structure and, to some degree, about its evolution and the processes that triggered its formation. The measurements of Saturn's even gravity harmonics led to highly unusual results. The magnitude of J6, J8, and J10 were so large that they could not be explained with any existing model. In this talk, we introduce differential rotation into our interior models that we construct with the concentric McLaurin spheroid (CMS) method. We show that the even gravity harmonics J2 through J10 can then be matched. We will compare our findings for Saturn with recent measurements of Jupiter's gravity field that have been made by the Juno spacecraft. We conclude by discussing common features and differences between the interior models of the two planets.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.P23A..05M
- Keywords:
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- 1221 Lunar and planetary geodesy and gravity;
- GEODESY AND GRAVITYDE: 1510 Dynamo: theories and simulations;
- GEOMAGNETISM AND PALEOMAGNETISMDE: 5724 Interiors;
- PLANETARY SCIENCES: FLUID PLANETSDE: 5749 Origin and evolution;
- PLANETARY SCIENCES: FLUID PLANETS