HR: 17:15h
AN: P24A-06    [Abstracts]
TI: Coordinated Mars Exploration Rover and Mars Express OMEGA Observations over Meridiani Planum
AU: * Arvidson, R E
EM: arvidson@wunder.wustl.edu
AF: Washington University, Box 1169, St. Louis, MO 63130 United States
AU: Bibring, J
AF: University of Paris-Sud University of Paris-Sud, IAS, Orsay, 91405 France
AU: Poulet, F
AF: University of Paris-Sud University of Paris-Sud, IAS, Orsay, 91405 France
AU: Squyres, S W
AF: Cornell University, Department of Astronomy, Ithaca, NY 14853 United States
AU: Wolff, M
AF: Space Science Institute, 18970 Cavendish Rd, Brookfield, WI 53045 United States
AU: Morris, R
AF: Johnson Space Center, Code SR, Houston, TX 77058 United States
AB: The OMEGA hyperspectral imager (0.35 to 5.1 micrometers) covered the hematite-bearing plains and underlying etched terrains of Meridiani Planum during orbits 171, 314, 430, 485, 518, and 529, with spatial resolutions ranging from several hundred meters to approximately a kilometer. In addition, the Opportunity rover acquired Pancam and Mini-TES observations of the surface and atmosphere during the times when OMEGA acquired its data. Using a radiative transfer modeling approach (DISORT) that combines surface and orbital observations we extracted surface reflectance spectra from OMEGA for the approximately 864,000 square kilometers surrounding the Opportunity site. OMEGA spectra show significant variation within the hematite-bearing plains from the northwest to the southeast, in part associated with an increasingly deeper and asymmetrical band centered at 1 micrometer, assigned to ferrous silicates. The etched terrains that underlie the hematite bearing plains show significant spectral variability that is associated with stratigraphic position within the 300 m thick stack of layered materials. Significant features include a prominent 1.92 micrometer absorption in some deposits (associated with hydrated phases and/or molecular water) and absorptions in the 2.2 to 2.5 micrometer region associated with cation-hydroxl vibrations. Finally, the 3 micrometer water band also shows high absorption values for the etched terrain materials (as compared to the underlying cratered terrain), consistent with an abundance of hydrated phases and/or molecular in the layered deposits. OMEGA data, calibrated using ground truth observations from Opportunity, will allow us to extend to rover-based observations to regional scales and thus provide the overall geologic context and environments of deposition for the sedimentary sections explored by the rover since January 2004.
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting