Characteristics and Possible Genetic Link between Dust Aggregate Bedforms and Yardangs as Seen by the Hirise Camera

AGGREGATE BEDFORMS AND YARDANGS AS SEEN BY THE HIRISE CAMERA N.T. Bridges, L.P. Keszthelyi, B.J. Thomson, J.J. Wray, M.E. Banks, R.A. Beyer, F.C. Chuang, K.E. Herkenhoff, K.E. Fishbaugh, A.S. McEwen, and T.I. Michaels; Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 ([email protected]); U.S. Geological Survey, Flagstaff, AZ 86001;Applied Physics Laboratory, Laurel, MD 20723;Astronomy Dept., Cornell Univ., Ithaca, NY 14853;Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721; SETI Institute, Mountain View, CA 94043; Planetary Science Institute, Tucson, AZ 85719;Center for Earth and Planetary Studies, Smithsonian Air and Space Museum, Washington, D.C. 20013-7012; Southwest Research Institute, Boulder, CO 80302 Introduction: The High Resolution Imaging Science Experiment (HiRISE) on the Mars Reconnaissance Orbiter (MRO) has documented “reticulate” ridges in low thermal inertia areas that are interpreted as saltation bedforms [1,2]. Previous reports were overviews of a limited number of images. Now, at the conclusion of MRO’s Primary Science Phase, we have completed an analysis of all images on and near the Tharsis Montes and integrated other data and saltation theory into the analysis. We propose that the bedforms are dust aggregates. These may eventually lithify into abradable yardangs and indurated surfaces, a “duststone” that appears to be a common Martian rock with no known terrestrial analog.