New Horizons Mapping of Europa and Ganymede

Abstract

The New Horizons spacecraft observed Jupiter's icy satellites Europa and Ganymede during its flyby in February and March 2007 at visible and infrared wavelengths. Infrared spectral images map H 2 O ice absorption and hydrated contaminants, bolstering the case for an exogenous source of Europa's “non-ice” surface material and filling large gaps in compositional maps of Ganymede's Jupiter-facing hemisphere. Visual wavelength images of Europa extend knowledge of its global pattern of arcuate troughs and show that its surface scatters light more isotropically than other icy satellites.