Hydrogen peroxide on Enceladus

Scientists have recently discovered a dynamic, geologically active world in Saturn's icy moon, Enceladus. This small satellite has a south polar hot spot at least 70 K hotter than surrounding regions and a plume of water vapor and ice particles surging from the tiger stripe cracks that flank the pole. Spectral data of the surface of Enceladus can help us understand the processes occurring on and beneath the surface and in the regional south polar atmosphere. Using observations from Cassini's Visual and Infrared Mapping Spectrometer (VIMS), we have tentatively detected hydrogen peroxide on the surface of Enceladus, by identification of the 3.5 mu m hydrogen peroxide band. Hydrogen peroxide is produced in the solar system by bombardment of water ice with energetic particles, such as protons, electrons, and magnetospheric ions. Its detection indicates an intense radiative environment at Enceladus and can help us understand plume and surface chemistry, as well as constrain the timescale of plume activity.