Modeling 3-D Electromagnetic Induction Effects in Enceladus

Enceladus possesses all key requirements for habitability (liquid water, essential chemical elements, and source of energy) and is currently the top target for the next Large-class mission in the ESA’s Voyage 2050 plan. Measurements of the magnetic field around and/or at the surface of Enceladus will enable electromagnetic sounding of Enceladus to provide quantitative constraints on key thermo-chemical properties and structure in the moon’s interior. The case of Enceladus is rather peculiar as Cassini observations provided strong evidence for a very heterogeneous non-axisymmetric structure of its ice shell, suggesting ice is much thinner at the poles than at the equator.

This poses a challenge for conventional electromagnetic induction techniques that are mostly limited to 1-D geometries. Here, we present a first comprehensive study of 3-D electromagnetic induction effects in the non-axisymmetric Enceladus’s interior based on the observationally constrained heterogeneous ice shell thickness and ocean depth models. We analyse the variability of the induced fields over the surface at a range of periods, but focusing on recently quantified mechanisms of the external inducing field [1]. We discuss both challenges of detecting induced magnetic signals and new opportunities offered by the complexity of Enceladus’s interior.

 

[1] Saur, J., Duling, S., Grayver, A., & Szalay, J. R. (2024). Analysis of Enceladus’s Time-variable Space Environment to Magnetically Sound its Interior. The Planetary Science Journal, 5(11), 245.