Revealing the internal structure of Europa with a Bayesian approach to magnetic induction studies

Abstract:

Observations of induced magnetic fields offer a powerful probe into the interiors of planetary bodies, revealing the presence and properties of subsurface oceans on icy moons. We present a new Bayesian approach for inverting magnetic induction measurements to understand the internal structures and habitability of planetary bodies. This approach has the advantages of (1) providing robust confidence intervals for retrieved parameters, aiding in mission planning and benchmarking against mission requirements; (2) incorporating a priori constraints, enabling quantitative incorporation of physical constraints and complementary datasets; and (3) quantifying degeneracies between model parameters, such that estimates for model parameters include the non-uniqueness of the solution. We have applied these techniques as part of the development of the Europa Clipper Magnetometer. Europa Clipper aims to characterize the subsurface Europan ocean by measuring the ocean thickness, ocean salinity, and ice thickness. These properties constrain the composition of the ocean and the chemical energy flux available for biology, key parameters for assessing habitability. We will demonstrate how our technique can be used to estimate the mission’s ability to constrain these astrobiological parameters (see figure). We also present re-analysis of data from the Galileo mission to the Jupiter system and a look ahead to a possible flagship mission to the ice giants and their moon systems.