WE PROPOSE TO OBSERVE THE CLASSICAL URANIAN SATELLITES MIRANDA ARIEL UMBRIEL TITANIA AND OBERON TO CONSTRAIN THE COMPOSITION AND DISTRIBUTION OF CONSTITUENTS ON THEIR SURFACES. BY MAPPING THE COMPOSITION OF THE URANIAN SATELLITES AND CHARACTERIZING THE SPECTRAL PROPERTIES OF DETECTED CONSTITUENTS WE WILL INVESTIGATE THE PROCESSES MODIFYING THE SURFACES OF THESE MOONS. THE URANIAN MOONS ARE PRIMARILY COMPOSED OF WATER ICE MIXED WITH DARK POTENTIALLY CARBONACEOUS MATERIAL. CARBON DIOXIDE ICE HAS ALSO BEEN DETECTED PRIMARILY ON THE TRAILING HEMISPHERES OF THESE TIDALLY-LOCKED MOONS AND PRIMARILY ON THE MOONS CLOSEST TO URANUS. WATER ICE BANDS ARE STRONGER ON THE LEADING HEMISPHERES OF THESE MOONS WITH THE LEADING/TRAILING ASYMMETRY IN BAND STRENGTH DECREASING WITH DISTANCE FROM URANUS. SIMILARLY THE LEADING HEMISPHERES OF THESE MOONS ARE SPECTRALLY REDDER THAN THEIR TRAILING HEMISPHERES WITH THE DEGREE OF REDDENING INCREASING WITH DISTANCE FROM URANUS. OUR PREFERRED HYPOTHESES TO EXPLAIN THE OBSERVED CONSTITUENT DISTRIBUTIONS ARE THAT MAGNETOSPHERICALLY-EMBEDDED CHARGED PARTICLE BOMBARDMENT AND MICROMETEORITE IMPACTS ARE PRIMARILY MODIFYING THE TRAILING AND LEADING HEMISPHERES OF THESE MOONS RESPECTIVELY. PREVIOUS OBSERVATIONS OF THESE MOONS ARE GENERALLY CONSISTENT WITH THESE COMPLEMENTARY HYPOTHESES BUT NOTABLE MYSTERIES REGARDING THE DISTRIBUTION OF CONSTITUENTS ON THESE MOONS STILL REMAIN. OVER THE LAST DECADE NEAR-INFRARED OBSERVATIONS HAVE DETECTED THE CARBON DIOXIDE COMBINATION AND OVERTONE BANDS BETWEEN 1.9 AND 2.1 MICRONS; HOWEVER THE SIGNIFICANTLY STRONGER CARBON DIOXIDE ASYMMETRIC STRETCH FUNDAMENTAL BAND (CENTERED NEAR 4.27 MICRONS) HAS NOT BEEN DETECTED. ALTHOUGH CARBON DIOXIDE ABUNDANCE IS GREATER ON THE MOONS CLOSE TO URANUS (ARIEL AND UMBRIEL) COMPARED TO THE OUTER SATELLITES (TITANIA AND OBERON) THERE HAS BEEN NO DETECTION OF CARBON DIOXIDE ON THE INNERMOST CLASSICAL MOON MIRANDA. FURTHERMORE WATER ICE BAND STRENGTHS APPEAR TO BE INVERTED ON MIRANDA WITH STRONGER WATER ICE BANDS ON ITS TRAILING HEMISPHERE. RECENT OBSERVATIONS BY OUR TEAM CONFIRM THAT THE OUTER MOONS TITANIA AND OBERON ARE SPECTRALLY REDDER THAN THE INNER MOONS BUT OUR DATA SUGGEST THAT TITANIA IS SPECTRALLY REDDER THAN THE FURTHEST CLASSICAL MOON OBERON UNLIKE PREVIOUS ANALYSES MADE USING DATA COLLECTED BY VOYAGER 2. WE ALSO DETECT CLEAR LATITUDINAL TRENDS IN WATER ICE BAND STRENGTHS ON THESE MOONS WITH STRONGER WATER ICE BANDS ON THEIR CURRENTLY OBSERVABLE NORTHERN HEMISPHERES COMPARED TO OBSERVATIONS MADE PREVIOUSLY OVER THEIR SOUTHERN HEMISPHERES. NEAR-INFRARED SPECTRA OF BOTH MIRANDA AND ARIEL INCLUDE POTENTIAL HINTS OF AMMONIA-HYDRATE FEATURES BETWEEN 2.2 AND 2.3 MICRONS BUT THE POOR QUALITY OF THESE DATA LIMIT ANALYSES REQUIRING HIGHER SIGNAL-TO-NOISE FOLLOW UP OBSERVATIONS. THUS THE DISTRIBUTION OF CONSTITUENTS ON THE CLASSICAL URANIAN SATELLITES IS STILL POORLY UNDERSTOOD WITH MANY MYSTERIES LEFT TO EXPLORE. IN ORDER TO INVESTIGATE THE COMPOSITIONS AND DISTRIBUTION OF MATERIALS ON THESE MOONS WE PROPOSE TO: * GATHER VISIBLE AND NEAR-INFRARED SPECTRA. * MEASURE CONSTITUENT BAND DEPTHS AND AREAS. * MEASURE SPECTRAL SLOPES. * CHARACTERIZE HEMISPHERICAL TRENDS IN THE DISTRIBUTION OF CONSTITUENTS * USE SPECTRAL MODELING CODES TO CONSTRAIN THE GRAIN SIZE AND MIXING REGIMES OF DETECTED CONSTITUENTS. * WITH MINOR ADDITIONAL EFFORT WE WILL USE THESE OBSERVATIONS MEASUREMENTS AND MODELING CODES TO CONSTRAIN THE COMPOSITION OF THE DARK AND POTENTIALLY C-RICH MATERIAL. THE GOALS OF THIS PROJECT ARE WELL ALIGNED WITH NASA S PLANETARY SCIENCE OBJECTIVES IN THE OUTER SOLAR SYSTEM WHICH INCLUDES INVESTIGATION OF THE PROCESS MODIFYING THE SURFACES OF THE CLASSICAL URANIAN MOONS CONSTRAINING POTENTIAL SOURCES OF ORGANIC MATERIAL AND EXPLORING BODIES THAT COULD BE OCEAN WORLDS WITH SUBSURFACE LIQUID LAYERS.