HR: 10:20h
AN: P32A-01 INVITED     [Abstracts]
TI: Overview of Initial Results from CRISM
AU: * Seelos, F
EM: Frank.Seelos@jhuapl.edu
AF: JHU Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, United States
AU: Murchie, S
AF: JHU Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, United States
AU: Mustard, J
AF: Brown University, Box 1846, Providence, RI 02912, United States
AU: Pelkey, S
AF: Brown University, Box 1846, Providence, RI 02912, United States
AU: Roach, L
AF: Brown University, Box 1846, Providence, RI 02912, United States
AU: Elhmann, B
AF: Brown University, Box 1846, Providence, RI 02912, United States
AU: Arvidson, R
AF: Washington University, 1 Brookings Drive Box 1169, St. Louis, MO 63130, United States
AU: Wiseman, S
AF: Washington University, 1 Brookings Drive Box 1169, St. Louis, MO 63130, United States
AU: Milliken, R
AF: NASA/JPL, 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AU: CRISM Team, T
AB: The Mars Reconnaissance Orbiter (MRO) reached 100 days of primary science phase operations on February 15th, 2007. Over this time period, the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) has acquired high spatial resolution hyperspectral observations and contextual multispectral survey data of type localities that record water-rock interaction through much of the geologic history of Mars. CRISM's primary science objectives are to characterize the mineralogical record of past aqueous environments and to monitor the contemporary spatial and seasonal distributions of volatiles in the surface-atmosphere system. These objectives are accomplished through an observation strategy that includes targeted data acquisition, atmospheric and seasonal monitoring, and global mapping. Targeted observations are acquired by gimbaling the instrument along-track to reduce apparent ground motion, resulting in a spatial resolution of 15-20 m/pixel in 544 wavelengths from 362 to 3920 nm. As a part of each targeted observation 10 additional spatially binned images are acquired at different atmospheric path lengths, creating an emission phase function (EPF) that allows surface-atmosphere separation in the analysis of the observed radiance. The atmospheric and seasonal monitoring campaigns consist of global grids of EPF measurements at regular Ls intervals. In CRISM's global mapping campaign, data are acquired in a push broom observing mode at a reduced spatial and spectral resolution of 200m/pxl and 72 selected spectral channels. Initial data analysis reveals evidence for environmental variability throughout Martian history. Noachian deposits exhibit diverse phyllosilicate mineralogy in a greater number of geologic units than previously recognized. Distinct mineralogic signatures are sometimes separated only by hundreds of meters, indicating variability in alteration environment or parent rock composition. Hesperian layered deposits exhibit strong vertical heterogeneity with different abundances and types of sulfate minerals, suggesting local environmental changes on short geologic timescales. The Amazonian north polar layered deposits exhibit complex vertical layering in the abundance and/or grain size of water ice. The underlying basal unit shows little evidence for ice except in restricted locations where the morphology is consistent with subsequent modification of the deposits by fluid flow. Multispectral mapping is nearly complete at the high northern latitudes and shows evidence for significant hydrated mineral content in portions of the basal unit.
DE: 5410 Composition (1060, 3672)
DE: 5464 Remote sensing
DE: 5470 Surface materials and properties
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2007 Joint Assembly