F. C. Chuang

Publications (4)31.2 Total impact

• Article: A closer look at water-related geologic activity on Mars.

  A S McEwen, C J Hansen, W A Delamere, E M Eliason, K E Herkenhoff, L Keszthelyi, V C Gulick, R L Kirk, M T Mellon, J A Grant, [......], J L Griffes, S Martínez-Alonso, A Davatzes, F C Chuang, B J Thomson, K E Fishbaugh, C M Dundas, K J Kolb, M E Banks, J J Wray
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  ABSTRACT: Water has supposedly marked the surface of Mars and produced characteristic landforms. To understand the history of water on Mars, we take a close look at key locations with the High-Resolution Imaging Science Experiment on board the Mars Reconnaissance Orbiter, reaching fine spatial scales of 25 to 32 centimeters per pixel. Boulders ranging up to approximately 2 meters in diameter are ubiquitous in the middle to high latitudes, which include deposits previously interpreted as finegrained ocean sediments or dusty snow. Bright gully deposits identify six locations with very recent activity, but these lie on steep (20 degrees to 35 degrees) slopes where dry mass wasting could occur. Thus, we cannot confirm the reality of ancient oceans or water in active gullies but do see evidence of fluvial modification of geologically recent mid-latitude gullies and equatorial impact craters.
  Science 10/2007; 317(5845):1706-9. · 31.20 Impact Factor
• Conference Proceeding: Early HiRISE Observations of Slope Streaks and Avalanche Scars

  F ~C Chuang, A ~S McEwen, V ~C Gulick
  Lunar and Planetary Institute Science Conference Abstracts; 03/2007
• Source

  Available from: nasa.gov

  Article: Windy Mars: A dynamic planet as seen by the HiRISE camera

  N T Bridges, P E Geissler, A S Mcewen, B J Thomson, F C Chuang, K E Herkenhoff, L P Keszthelyi, S Martínez-Alonso
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  ABSTRACT: 1] With a dynamic atmosphere and a large supply of particulate material, the surface of Mars is heavily influenced by wind-driven, or aeolian, processes. The High Resolution Imaging Science Experiment (HiRISE) camera on the Mars Reconnaissance Orbiter (MRO) provides a new view of Martian geology, with the ability to see decimeter-size features. Current sand movement, and evidence for recent bedform development, is observed. Dunes and ripples generally exhibit complex surfaces down to the limits of resolution. Yardangs have diverse textures, with some being massive at HiRISE scale, others having horizontal and cross-cutting layers of variable character, and some exhibiting blocky and polygonal morphologies. ''Reticulate'' (fine polygonal texture) bedforms are ubiquitous in the thick mantle at the highest elevations.
• Article: Aeolian bedforms, yardangs, and indurated surfaces in the Tharsis Montes as seen by the HiRISE Camera: Evidence for dust aggregates

  N.T. Bridges, M.E. Banks, R.A. Beyer, F.C. Chuang, E.Z. Noe Dobrea, K.E. Herkenhoff, L.P. Keszthelyi, K.E. Fishbaugh, A.S. McEwen, T.I. Michaels, B.J. Thomson, J.J. Wray
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  ABSTRACT: HiRISE images of Mars with ground sampling down to 25 cm/pixel show that the dust-rich mantle covering the surfaces of the Tharsis Montes is organized into ridges whose form and distribution are consistent with formation by aeolian saltation. Other dusty areas near the volcanoes and elsewhere on the planet exhibit a similar morphology. The material composing these “reticulate” bedforms is constrained by their remote sensing properties and the threshold curve combined with the saltation/suspension boundary, both of which vary as a function of elevation (atmospheric pressure), particle size, and particle composition. Considering all of these factors, dust aggregates are the most likely material composing these bedforms. We propose that airfall dust on and near the volcanoes aggregates in situ over time, maybe due to electrostatic charging followed by cementation by salts. The aggregates eventually reach a particle size at which saltation is possible. Aggregates on the flanks are transported downslope by katabatic winds and form linear and “accordion” morphologies. Materials within the calderas and other depressions remain trapped and are subjected to multidirectional winds, forming an interlinked “honeycomb” texture. In many places on and near the volcanoes, light-toned, low thermal inertia yardangs and indurated surfaces are present. These may represent “duststone” formed when aggregates reach a particle size below the threshold curve, such that they become stabilized and subsequently undergo cementation.
  Icarus.