Hydrogen peroxide on the surface of Europa

Spatially resolved infrared and ultraviolet wavelength spectra of Europa's Leading, anti-jovian quadrant observed from the Galileo spacecraft show abs orption features resulting from hydrogen peroxide. Comparisons with laborat ory measurements indicate surface hydrogen peroxide concentrations of about 0.13 percent, by number, relative to water ice. The inferred abundance is consistent with radiolytic production of hydrogen peroxide by intense energ etic particle bombardment and demonstrates that Europa's surface chemistry is dominated by radiolysis.