Photoabsorption in Ganymede's atmosphere

► We model the impact of the solar UV flux on Ganymede's atmosphere. ► We compute both ionization and excitation rates for polar and equatorial regions. ► Comparison between our model and measurements from Galileo are in good agreement. ► EJSM should include measurement of the red line. ► Input solar EUV flux can be measured from only two passbands.