weathering of methane clathrate and/or hydrocarbon ice material originating from nearby moonlets. Additional components We report the first multifilter set of absolutely calibrated consistent with the ring spectrum include silicates such as pynear-infrared images of Uranus, its rings, and three major roxene, but not olivine. Analytical modeling of the ring structure satellites-Titania, Ariel, and Miranda. Along with imagery indicates -ring near-infrared opacities of 0.37 ุ 0.05 and utilizing the canonical K filter bandpass (effective wavelength 1.8 ุ 0.3 at apoapsis and periapsis, respectively. Ariel is more 2.20 m), absolutely calibrated images of the uranian system than 25% brighter than Miranda and 15% brighter than Titania are presented for the first time for three additional filter bandat all near-infrared wavelengths. Comparisons with UV-visible passes: J (1.27 m), H (1.62 m), and in a narrow bandpass (0.1 m full-width-at-half-maximum) centered at 1.73 m spectra by Karkoschka (1997, Icarus 125, 348-363) show con- (hereafter designated H) particularly diagnostic of C-H stretch sistency with the hypothesis that the water-ice surfaces of Titavibrational absorptions common in hydrocarbons. Multifilternia and Ariel are contaminated with low-reflectance, near-IRderived spectra of the southern ring ansa including the bright reddened substances similar to the weathered high C : H mateapoapse of the dominant ring show no absorptions due to rial postulated for the uranian ring system. The relatively blue, condensable volatiles, including water, ammonia, and light near-infrared dark surface of Miranda (full-disk near-infrared (high H : C) hydrocarbons. Plausible near-infrared spherical albedo of ศ0.22 at 2.4ุ phase angle) exhibits the greatest water geometric and single-scattering particle albedos consistent with ice absorption band-depth and the largest H-and K-filter Voyager-derived phase functions range from 0.069 to 0.102 and brightness surge measured among the uranian satellites, consisfrom 0.030 to 0.037, respectively. These are approximately 50% tent with (1) a markedly heterogeneous surface punctuated greater than visible values, consistent with the optical properties with localized outcroppings of relatively pure water ice and (2), as with Titania and Ariel, a surface composition dominated of charcoal, carbonaceous chondrite material, and the darkside of Iapetus, and consistent with the hypothesis that a primary in the near infrared by weathered high C : H material. The uranian disk shows marked latitudinal variability in tropo-component of the ring particles is high stoichiometric ratio C : H organics produced by charged-particle and/or photochemical spheric cloud structure, with a ''polar cap'' of aerosols lying 266