The Birth of PICL: New Laboratory Experiments for Understanding Ocean Worlds

Citation

Denman, William Thomas Plent (2024) The Birth of PICL: New Laboratory Experiments for Understanding Ocean Worlds. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/erq7-vb46. https://resolver.caltech.edu/CaltechTHESIS:01122024-002204703

Abstract

A laboratory set up was built analogous to that of the environment of the Galilean system. Previous work has focused on vapor deposition and shied away from bulk samples which more closely resemble the surface of Europa. The focus of this research has been the relationship between laboratory data to observational spectra collected. Data from various telescopes has given an indication of the species which exist on the surface of Europa. Linear spectral modeling has not been effective in identifying these species due to a lack of viable candidates. Chapter II focuses on the instrumentation and sample preparation for the laboratory set up. In Chapter III data is presented on the irradiation of sodium chloride at Europa like conditions and the features that arise with cryogenic irradiation. This data is compared to observational data from HST and provides strong evidence for the presences of sodium chloride (NaCl) on Europa's leading hemisphere. Chapter IV presents FTIR and UV/VIS data for the irradiation of sulfate salts suspected to be present on Europa. This presents one of the first instances of cyrogenic electron irradiation of sulfates compared to new data from JWST. Mechanisms for the trapping of carbon dioxide at both Europa and Ganymede have also been investigated. These experiments are paramount for understanding the composition of Europa’s ocean and can be utilized by the Europa Clipper team. Future experiments involving laboratory spectroscopy of carbon dioxide trapping are also highlighted. The use of cyrogenic gamma irradiation experiments and their feasibility are explored.

Thesis Files