Comparison with laboratory data. CO₂ band in Ganymede spectra at the pole (60–75°N; dotted light gray lines) and the equator (0–15°N; dot-dashed gray lines) of the leading hemisphere compared with transmission spectra from Berlanga et al. (2016; carboneous chondrites), Bekhti et al. (2021; zeolites), Ehrenfreund et al. (1999; CO₂ ice and CO₂-H₂O ice mixture) and Fleyfel & Devlin (1991; CO₂ clathrates). Some spectra are vertically shifted for the sake of clarity.