COORDINATED CRISM AND OPPORTUNITY OBSERVATIONS TO DETERMINE THE MINERALOGY AND GEOLOGIC HISTORY OF MERIDIANI PLANUM

The Opportunity Mars Exploration Rover has traversed over 30 km across Meridiani Planum since January 2004, acquiring numerous remote sensing and in-situ measurements of rocks and soils at dozens of locations. Over the past year Mars Reconnaissance Orbiter CRISM (0.362 to 3.92 micrometer imaging spectrometer) observations have been used to directly support planning of Opportunity traverses and locations for detailed remote sensing and in-situ measurements. As part of these coordinated observations CRISM's gimbaled optics have been used to spatially oversample acquisition of image data in the along-track direction (ATO or along track oversampled observations). This new acquisition mode allows sharpening the spatial detail from the normal ~18 m/pixel observations to values as small as ~6 m/pixel, with due formal consideration of the decrease in S/N with decreasing pixel sizes for retrieval of the 544 band spectra for each pixel. CRISM ATO observations show that mono-hydrated sulfates, most likely kieserite, outcrop on the walls of Victoria crater and the southeastern rim of Santa Maria crater. In fact, Opportunity was directed to Santa Maria's southeastern rim based on CRISM spectral reflectance data, spending the last solar conjunction period acquiring long-duration in-situ measurements of outcrop that likely carries the mono-hydrated sulfate signature. Further, ATO observations of the rim of the Noachian Endeavour crater pinpoint the location of Fe/Mg smectite clays in Cape York, the rim segment that Opportunity is traversing to as of submittal of this abstract. Further, ATO observations allow detailed mapping of extensive hydrated sulfates in Botany Bay immediately to the south of Cape York. Opportunity will cross these exposures on the way to Cape York outcrops. We will report on results from Opportunity's measurements on Santa Maria crater, Botany Bay, and Cape York, focusing on the synergistic use of Opportunity and CRISM observations to understand the mineralogy and geologic history of Meridiani Planum.