CO₂ν₃ band gas spectra from Ganymede’s exosphere. Left (A–C): North polar cap of the leading side of Ganymede (averaged spectra for latitudes > 45° N); Right (D–F): Southern hemisphere of the trailing side (latitudes 30–60° S). A, D) Observed spectra showing both the CO₂ν₃ absorption band from CO₂ in solid state, and ro-vibrational emission lines of gaseous CO₂; B, E) CO₂ gaseous emission spectra obtained after removing the continuum emission shown in red in panels A and D (Appendix B). C, F) Residual CO₂-gas DIFF spectra obtained by removing the continuum obtained from low-pass filtering (Appendix B). Best fit synthetic spectra are shown in blue, with a fitted rotational temperature of 108±8 K for the leading side, and a fixed rotational temperature of 105 K for the trailing side. In all plots, vertical-axis unit is μJy per pixel (1 pixel = 0.1”× 0.1”).