LASP Science Seminars
Exploring Europa’s surface with Earth-based observatories: salts, radiolytic products, and thermal emission
Samantha Trumbo (Caltech)
Jupiter’s moon Europa is a prime target for exploring habitability in the Solar System. Beneath a comparatively thin ice shell, Europa harbors a global, salty, liquid water ocean that is likely in contact with a rocky seafloor. Its geologically young, salty, and fractured surface suggests that there may be exchange between the ocean and surface environments, such that the surface composition may reflect that of the internal ocean to some degree. However, the interpretation of surface constituents as oceanic signatures is complicated by the fact that Europa’s surface is continuously radiolytically processed by electron and ion bombardment due to its location within Jupiter’s magnetosphere. I will present a diverse suite of astronomical observations of Europa with the goal of furthering our understanding of the balance and interplay of endogenous and exogenous processes in shaping its surface. Spatially resolved spectroscopy from the Hubble and Keck telescopes allow us to identify, map, and study both endogenous species likely sourced from the interior and substances produced by the bombardment of Europa’s surface with magnetospheric particles. In contrast, spatially resolved observations of Europa’s thermal emission from the Atacama Large Millimeter/submillimeter Array (ALMA) allow us to search for potential thermal signatures of geologic activity, while also providing insight into the surface thermophysical properties.