title: Exposed water ice discovered near the south pole of Mars.
abstract: The Mars Odyssey Thermal Emission Imaging System (THEMIS) has discovered water ice exposed near the edge of Mars' southern perennial polar cap. The surface H2O ice was first observed by THEMIS as a region that was cooler than expected for dry soil at that latitude during the summer season. Diurnal and seasonal temperature trends derived from Mars Global Surveyor Thermal Emission Spectrometer observations indicate that there is H2O ice at the surface. Viking observations, and the few other relevant THEMIS observations, indicate that surface H2O ice may be widespread around and under the perennial CO2 cap.
authors.affiliation: Branch of Astrogeology, U.S. Geological Survey, 2255 North Gemini Drive, Flagstaff, AZ 86001, USA. ttitus@usgs.gov
authors.forename: Timothy N
authors.initials: TN
authors.lastname: Titus
authors.forename: Hugh H
authors.initials: HH
authors.lastname: Kieffer
authors.forename: Phillip R
authors.initials: PR
authors.lastname: Christensen
mesh_terms: D001272:Atmosphere; D004367:Dry Ice; D005118:Extraterrestrial Environment; D007053:Ice; D018535:Mars; D012621:Seasons; D013696:Temperature; D014867:Water
chemical_list: D004367:Dry Ice; D007053:Ice; D014867:Water