Fig. 10. Spectrum Slope as a Function of Time of Day and Latitude on Ganymede and Callisto.

Each circle shows a spectrum location, the diameter of the circle increasing linearly with spectrum slope from a minimum of 1.5\oK, represented by a dot, with the same scale on each plot. Voyager1 and 2 data are both shown, but are not distinguished. The morning and evening terminators and the equator are shown. Note the fairly uniform slopes on Ganymede (apart from high values near the south pole), the increasing slope away from the subsolar point on Callisto, and the greater slope of the nightside spectra on Callisto than on Ganymede.
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