HR: 08:15h
AN: P21A-02 INVITED     [PDF]
TI: Mars as seen from the 2001 Mars Odyssey Thermal Emission Imaging System Experiment
AU: * christensen, P R
EM: phil.christensen@asu.edu
AF: Arizona State University, Department of Geological Sciences, tempe, az 85287-6305 United States
AB: Data from the Thermal Infrared Imaging System (THEMIS) instrument have been used to investigate the surface mineralogy, physical properties, polar regions, and atmosphere of Mars using multi-spectral thermal-infrared and visible images in 14 spectral bands from 0.45 to 15.5 æm. These multi-spectral images have provided new information on the physical and compositional properties of the martian surface. Layered basaltic rocks rich in olivine have been detected in the walls of Valles Marineris. The presence of olivine indicates that this region has experienced very little liquid water, either surface or sub-surface, throughout its history. Carbonate outcrops at 100-m scales have not been detected, despite the discovery by the MGS TES instrument of several percent carbonate in the martian dust. Local variations in volcanic bedrock composition have been detected, suggesting compositional variations in a local source region. Variations in the physical properties of layered rock units occur in numerous regions indicating either different lithification/cementation processes or different initial depositional conditions or environments. Regional 100-m resolution mapping has revealed the presence of channel, fan, and delta systems not detected by Viking and not mapped by the high-resolution camera on MGS. To date no nighttime or daytime temperature anomalies have been identified that cannot be attributed to thermophysical properties, such as bedrock or dust exposures, alone. Crater ejecta show differing degrees of rock preservation, providing an additional tool for determining surface modification rates and assessing crater ages. The combination of IR and visible imagery has demonstrated that the dark spots and splotches that form in regions of the south polar cap are CO2 ice, suggesting a complex surface of transparent glaze ice and subtle variations on the absorption/transmission properties of this ice. Numerous aeolian surfaces, including dunes, wind streaks, inter-dune surfaces, lags, and mega-ripples, have been observed in day and night IR, allowing assessment of their grain size and the processes that formed these features.
DE: 5410 Composition
DE: 5462 Polar regions
DE: 5464 Remote sensing
DE: 5470 Surface materials and properties
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting