Analysis of the observations of several Pluto-Charon occultation and transit events in 1985 and 1986 has provided a more detailed knowledge of the system. The sum of the radii of Pluto and Charon is 1786 +/- 19 kilometers, but the individual radii are somewhat more poorly determined; Pluto is 1145 +/- 46 kilometers in radius, and Charon is 642 +/- 34 kilometers in radius. The mean density of the system is 1.84 +/- 0.19 grams/cm^3, implying that more than half of the mass is due to rock. Charon appears to have hemispheres of two different colors, the Pluto-facing side being neutral in color and the opposite hemisphere being a reddish color similar to Pluto.
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