Laboratory measurements and simulations supporting the search for liquid water in the solar system using radar sounders

This thesis presents a support study for radar missions aimed at detecting water and habitability conditions in the Solar System, with a focus on two distinct environments addressing key questions related to the use of Radio Echo Sounding (RES) techniques. The first topic concerns the characterization of the subglacial lake on Mars detected in 2018 by the MARSIS radar onboard the Mars Express spacecraft. In order to constrain the physical and chemical nature of this potential water body, the electromagnetic properties of magnesium and calcium perchlorate solutions were investigated. These salts have been identified on the Martian surface and represent plausible solutes in a subglacial brine environment. The second topic addresses the propagation of radar signals through the icy shells of the Jovian Icy Moons, in the context of the upcoming ESA JUICE and NASA Europa Clipper missions, which carry onboard the radar instruments RIME and REASON respectively. To simulate realistic signal propagation scenarios, electromagnetic property data of salty ices and dirty ices — the latter produced using both meteoritic material and planetary simulants — were employed. These measurements were used to model radar wave attenuation and reflection across a range of possible subsurface configurations, allowing the assessment of the detectability of potential subsurface liquid water reservoirs under different compositional and structural assumptions. The results provide a framework for interpreting future radar data and for evaluating the performance of the instruments under various plausible geophysical scenarios that the missions may encounter. Taken together, the two components of this work contribute to a broader effort to characterize icy and briny environments in the Solar System through the integration of laboratory electromagnetic measurements and radar data analysis, supporting the scientific objectives of both current and future planetary exploration missions in the search for liquid water beyond Earth.