The James Webb Space Telescope (JWST) has observed the leading and trailing hemisphere of Jupiter's largest moon Ganymede in August 2022. The resulting spectra from the Near InfraRed Spectrograph (NIRSpec) are dominated by water ice and CO2 features. At 3.1 micron the spectra sho
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The James Webb Space Telescope (JWST) has observed the leading and trailing hemisphere of Jupiter's largest moon Ganymede in August 2022. The resulting spectra from the Near InfraRed Spectrograph (NIRSpec) are dominated by water ice and CO2 features. At 3.1 micron the spectra show the Fresnel reflection peak of water ice. Analysing this feature gives insight into the crystallinity of water ice on Ganymede's surface. Crystallinity is influenced by temperature, particle bombard-
ment, water vapor deposition and cryovolcanic activity. Therefore, analysing the distribution of the crystallinity of water ice on Ganymede gives inside into energetic processes occurring on the surface of the icy moon as well as the longitudinal and latitudinal variations of these processes.
