Electromagnetic Characterization of Dirty Ice and NaCl Doped Ice for Radar Investigations of Jupiter Icy Moons

Jupiter’s icy satellites Europa, Ganymede, and Callisto, primary targets of the upcoming Juice (ESA) and Europa Clipper (NASA) missions, exhibit unique characteristics within our Solar System. Classified as “ocean worlds,” they host subsurface oceans beneath icy crusts. These satellites are of exceptional scientific interest for two main reasons: (a) their potential in the search for extraterrestrial life, especially Europa, whose subsurface ocean interacts with the seafloor, providing liquid water, energy sources, and access to nutrients and organic compounds—key ingredients for life; (b) their relevance to understanding formation patterns of planets and satellites within protoplanetary disks, with the Jovian system serving as an archetype of gas giant systems. The Juice and Europa Clipper missions will pioneer the exploration of the outer Solar System by studying the internal structure of the first kilometers of these bodies. This objective will be achieved using the Radio Echo Sounding (RES) technique, previously applied on Earth, Mars, and the Moon. This technique detects subsurface water layers and discontinuities by analyzing radio wave attenuation and reflection based on the electromagnetic properties—electrical permittivity and magnetic permeability—of penetrated media. For accurate interpretation of RES data, this dissertation experimentally characterizes electrical permittivity and magnetic permeability of two ice types identified on the satellites’ surfaces: “dirty ice” (ice with mineral grains) and NaCl-doped ice (from sodium chloride solutions). These parameters were analyzed at 9 and 60 MHz—operational frequencies of RIME (aboard Juice) and REASON (aboard Europa Clipper)—and at expected surface temperatures. Performance estimations of radar attenuation provide essential indications for subsurface imaging, advancing the understanding of Jupiter’s icy moons and contributing to broader planetary science.