HR: 0800h
AN: P31A-0196    [Abstracts]
TI: Geomorphology of the 2007 Phoenix Mission Landing Sites in the Northern Plains of Mars
AU: * Seelos, K D
EM: deal@levee.wustl.edu
AF: Washington University, Campus Box 1169 One Brookings Drive, St. Louis, MO 63130
AU: Arvidson, R E
EM: arvidson@wunder.wustl.edu
AF: Washington University, Campus Box 1169 One Brookings Drive, St. Louis, MO 63130
AU: Golombek, M
EM: mgolombek@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109
AU: Parker, T
EM: timothy.j.parker@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109
AU: Tamppari, L
EM: leslie.tamppari@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109
AU: Smith, P
EM: psmith@hindmost.lpl.arizona.edu
AF: Lunar and Planetary Lab, University of Arizona, Tucson, AZ 85721
AB: In 2008, the Phoenix lander will touch down in the northern plains of Mars to sample and characterize near surface and underlying ice-rich soils, gather meteorological data, and provide insight into the evolution of the surrounding landscape. Three regions from 65 to 72 N and (A) 250-270E, (B) 120-140E, and (C) 65-85E that meet both engineering and scientific constraints were chosen for concentrated acquisition of remote data to support landing site selection. Smaller areas (150x75 km) within these regions devoid of large craters or other hazards were selected as potential landing sites; center coordinates for these targeted areas are (A) 68N, 260E, (B) 67.5N, 130E, and (C) 70N, 80E. MOLA topographic data along with MOC imagery and THEMIS 36m/pixel visible, 18m/pixel visible, and ~100m/pixel infrared data are utilized to produce geomorphologic maps at 36m/pixel for the larger regions and 18m/pixel for the targeted sites. All regions are dominated by intercrater plains units, with the plains in regions B and C comprised of slightly elevated, multiple kilometer-scale polygonal blocks surrounded or infilled by finer-grained material. The plains unit of region A lacks large polygons, instead exhibiting a smooth to mottled appearance. Patterned ground is ubiquitous throughout all regions. The characteristic dimpled texture of "basketball" terrain is most common, being superposed on the large polygons in regions B and C, and often organized into stripes with orientations partially controlled by local slopes. Small-scale polygonal ground is also observed usually in association with crater ejecta. Craters throughout all regions appear highly degraded, with most small craters (< 1km) remarkably worn with little or no rim definition and ejecta present only as a faint dark halo. Larger craters frequently exhibit pedestal-style ejecta. The style and state of landform degradation and the consistent presence of patterned ground throughout all regions suggests the long-term influence of periglacial processes. The inferred depth to ice values based on Odyssey GRS data is correlated to observed crater degradation states.
DE: 5462 Polar regions
DE: 5464 Remote sensing
DE: 5470 Surface materials and properties
SC: Planetary Sciences [P]
MN: Fall Meeting 2005