Prospects of Using Tidal Tomography to Constrain Ganymede's Interior

Journal Article (2025)
Author(s)

M. Rovira Navarro (TU Delft - Planetary Exploration)

I. Matsuyama (TU Delft - Planetary Exploration, University of Arizona)

D. Dirkx (TU Delft - Astrodynamics & Space Missions)

Alexander Berne (California Institute of Technology)

D. Calliess (Student TU Delft)

Sam Fayolle (TU Delft - ESA X, TU Delft - Astrodynamics & Space Missions)

Research Group
Planetary Exploration
DOI related publication
https://doi.org/10.1029/2025GL114708
More Info
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Publication Year
2025
Language
English
Research Group
Planetary Exploration
Issue number
11
Volume number
52
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Abstract

Juice (JUpiter ICy moons Explorer) 3GM Radio Science Experiment will map the gravitational field of Ganymede with unprecedented accuracy and measure tidally-induced variations. These measurements will allow the characterization of its putative ocean and may resolve lateral variations in internal structure. Lateral variations cause an additional tidal signal that depends on their wavelength and amplitude. We show that shell thickness variations of (Formula presented.) the mean thickness produce an additional tidal signal (Formula presented.) times smaller than the main tidal signal, detectable given the accuracy of Juice. Using a Bayesian framework, we show that measuring differences between (Formula presented.) and (Formula presented.) constrain equator to pole shell thickness differences. Also measuring the degree-3 spherical harmonic signal due to degree 2 forcing constrain degree-1 and degree-3 structure. This demonstrates tidal tomography's potential to map three dimensional structure and supports its consideration for future missions.