Astrogeology Science Center

To present more information-rich views of Io, the global color derived from the Galileo color images was superimposed on the more detailed, higher resolution monochrome mosaics. The procedure adopted was to calculate color ratio images from the Galileo data and apply them to the monochrome mosaics, requiring that the color ratios of the composite images match the color ratios of the Galileo data. The Galileo SSI camera's silicon CCD was sensitive to longer wavelengths than the vidicon cameras of Voyager, so that dist inctions between red and yellow hues can be more easily discerned. However, this approach suffers from an obvious disadvantage in areas where the surface appearance changed dramatically during the 20+ year interval between the Voyager and Galileo eras, for example near Kaneh ekili.