Radiolytic processes in surface ice grains over time.

Figure 3 for Oza. et al "Plasma and Thermal Processing Leading to Latitudinal and Temporal Variability of the Trapped O2 at Europa and Ganymede." Radiolytic processes in surface ice grains in time. Diurnal temperature variations on Europa (85-130K) and Ganymede (70 – 150 K) and variable energetic particles (~keV MeV) lead to observed O2 bubble formation (radiation damage vs annealing ) observed via the 5773 Å O2 dimer absorption bands. Watercolor painting: Emily Costello (Hawaii Institute of Geophysics and Planetology). N.B. bubbles painted in the figure are natural nitrogen/oxygen bubbles in watercolor paint.