Comparison of bright and moderately bright terrains in Ganymede’s leading and trailing hemispheres, through spectral ratios. Moderately bright and bright terrains are defined by a Bond albedo A_B = 0.35 − 0.4, A_B = 0.4 − 0.6, respectively. For the leading hemisphere, only the northern regions at latitudes >35°N are considered, whereas for the trailing hemisphere, we consider both northern and southern high-latitude regions (>35°N/S). The spectrum shown in green dashed line is a spectrum of amorphous water ice obtained using Fresnel’s formulae (applicable for flat surfaces; Born & Wolf 1999) and the optical constants at 120 K of Mastrapa et al. (2009). The vertical dashed lines are at the wavelengths of the two main H₂O Fresnel peaks (3.09 and 3.20 µm), H₂O₂ (3.505 µm) and CO₂ (4.26 µm) absorption bands. The vertical dashed-dotted line at 3.6 µm is roughly at the H₂O inter-band position.