Global Color Variations on Io

Galileo multispectral imaging of Io augments existing Voyager color data by extending the sensitivity to near-infrared wavelengths. Global 4-color coverage was obtained during Galileo’s first two orbits, at resolutions ranging from 10 to 23 km/pixel and phase angles from 4 to 55 degrees [1]. In this poster we present preliminary spectral maps of the global distribution of low albedo materials (usually associated with volcanic centers), bright red deposits, yellow materials, and SO2 frost. Further Galileo imaging will improve the definition of these spectral units by mapping the surface at a consistent phase angle and sampling diverse terrains at 889 and 968 nm.