HR: 0800h
AN: P21B-0154    [Abstracts]
TI: Strengths and Limitations of Spectral Parameters for Mapping Surface Composition on Mars
AU: * Pelkey, S M
EM: shannon_pelkey@brown.edu
AF: Geological Sciences, Brown University, Box 1846, Providence, RI 02912 United States
AU: Mustard, J F
EM: john_mustard@brown.edu
AF: Geological Sciences, Brown University, Box 1846, Providence, RI 02912 United States
AU: Bibring, J
EM: bibring@ias.u-psud.fr
AF: IAS, Batiment 121, Universite de Paris-Sud, Orsay, 91405 France
AU: Milliken, R
EM: Ralph_Milliken@brown.edu
AF: Geological Sciences, Brown University, Box 1846, Providence, RI 02912 United States
AU: Langevin, Y
EM: langevin@ias.u-psud.fr
AF: IAS, Batiment 121, Universite de Paris-Sud, Orsay, 91405 France
AU: Gondet, B
EM: brigitte.gondet@ias.u-psud.fr
AF: IAS, Batiment 121, Universite de Paris-Sud, Orsay, 91405 France
AU: Gendrin, A
EM: Aline_Gendrin@brown.edu
AF: Geological Sciences, Brown University, Box 1846, Providence, RI 02912 United States
AU: Poulet, F
EM: francois.poulet@ias.u-psud.fr
AF: IAS, Batiment 121, Universite de Paris-Sud, Orsay, 91405 France
AU: Murchie, S
EM: Scott.Murchie@jhuapl.edu
AF: APL, 11100 Johns Hopkins Road, Laurel, MD 20723 United States
AB: OMEGA, the visible to near-infrared (352 bands from 0.35 - 5.1 microns) imaging spectrometer on Mars Express, has achieved near-global coverage with spatial resolution varying between 300 m and 4.8 km depending on the pericenter altitude of the spacecraft's highly elliptical orbit. Data from OMEGA have dramatically increased our understanding of the types and distributions of mafic minerals, sulfates, and phyllosilicates on the martian surface resulting in a new perception of the surface composition of Mars. Employing the technique designed for CRISM multispectral operations, we use these data to calculate and globally map 46 spectral parameters formulated to highlight mineralogic and atmospheric properties. The parameters vary in utility. The most robust parameters highlight mafic mineralogy, sulfates, hydrated silicates, and surface ices, the least robust are those tailored for narrow absorptions or those that span atmospheric absorptions, which show variations with time indicating sensitivity to atmospheric corrections. However, even the most robust parameters are occasionally susceptible to false positives; therefore regions of mineralogic interest identified with this approach must always be evaluated with the full spectral resolution observations for verification. Nevertheless locations of strong mineralogic signatures previously identified by the OMEGA team are well defined in these maps and demonstrate the validity of this approach as a rapid assessment tool. Thus, this simple technique will be a useful and reasonable tool to aid in Mars exploration in the following manners: i) to identify scientifically interesting areas to target with both present and future orbiting spacecraft, ii) to support landing site selection for Mars missions already slated for launch such as Phoenix and MSL, and iii) to identify scientifically interesting areas as potential landing sites for future surface missions. Here we focus on the most robust parameters highlighting mafic mineralogy, sulfates, hydrated silicates, and surface ices for a subset of relevant and interesting regions. These parameter maps are an important resource for identifying mineralogically-diverse areas and, following CRISM, will be available at 200m/pixel global coverage.
DE: 6225 Mars
DE: 6297 Instruments and techniques
SC: Planetary Sciences [P]
MN: Fall Meeting 2005