Publications
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Global spatial deconvolution of Lunar Prospector Th abundances Global spatial deconvolution of Lunar Prospector Th abundances
We have completed the first global spatial deconvolution analysis of planetary gamma‐ray data for lunar Th abundances as measured by the Lunar Prospector Gamma‐ray Spectrometer. We tested two different spatial deconvolution techniques – Jansson's method and the Pixon method – and determined that the Pixon method provides superior performance. The final deconvolved map results in a...
Authors
D. J. Lawrence, R.C. Puetter, R.C. Elphic, W. C. Feldman, Justin Hagerty, Thomas H. Prettyman, P. D. Spudis
Comparison of flood lavas on Earth and Mars Comparison of flood lavas on Earth and Mars
Flood lavas, by definition, cover vast areas in great sheets of lava, without the construction of major edifices (e.g., Geikie, 1880; Washington, 1922; Tyrrell, 1937; Self et al., 1997). The flat terrain that flood lavas produce has led to the term “plateau volcanism” to be used as a synonym for flood volcanism. In addition, the classic erosion pattern of flood lavas leaves a series of...
Authors
Laszlo P. Keszthelyi, Alfred S. McEwen
Evidence for montmorillonite or its compositional equivalent in Columbia Hills, Mars Evidence for montmorillonite or its compositional equivalent in Columbia Hills, Mars
During its exploration of the Columbia Hills, the Mars Exploration Rover "Spirit" encountered several similar samples that are distinctly different from Martian meteorites and known Gusev crater soils, rocks, and sediments. Occurring in a variety of contexts and locations, these "Independence class" samples are rough-textured, iron-poor (equivalent FeO ??? 4 wt%), have high Al/Si ratios...
Authors
B. C. Clark, R. E. Arvidson, Ralf Gellert, R.V. Morris, D. W. Ming, L. Richter, S. W. Ruff, J.R. Michalski, W. H. Farrand, A. S. Yen, Kenneth E. Herkenhoff, R. Li, S. W. Squyres, C. Schroder, G. Klingelhofer, J.F. Bell
Athabasca Valles, Mars: A lava-draped channel system Athabasca Valles, Mars: A lava-draped channel system
Athabasca Valles is a young outflow channel system on Mars that may have been carved by catastrophic water floods. However, images acquired by the High-Resolution Imaging Science Experiment camera onboard the Mars Reconnaissance Orbiter spacecraft reveal that Athabasca Valles is now entirely draped by a thin layer of solidified lava - the remnant of a once-swollen river of molten rock...
Authors
Windy L. Jaeger, Laszlo P. Keszthelyi, Alfred S. McEwen, Colin M. Dundas, Paul C. Russell
Evaluating planetary digital terrain models-The HRSC DTM test Evaluating planetary digital terrain models-The HRSC DTM test
The High Resolution Stereo Camera (HRSC) has been orbiting the planet Mars since January 2004 onboard the European Space Agency (ESA) Mars Express mission and delivers imagery which is being used for topographic mapping of the planet. The HRSC team has conducted a systematic inter-comparison of different alternatives for the production of high resolution digital terrain models (DTMs)...
Authors
C. Heipke, J. Oberst, J. Albertz, M. Attwenger, P. Dorninger, E. Dorrer, M. Ewe, S. Gehrke, K. Gwinner, H. Hirschmuller, J.R. Kim, Randolph L. Kirk, H. Mayer, Jan-Peter Muller, R. Rengarajan, M. Rentsch, R. Schmidt, F. Scholten, J. Shan, M. Spiegel, M. Wahlisch, G. Neukum
Windy Mars: A dynamic planet as seen by the HiRISE camera Windy Mars: A dynamic planet as seen by the HiRISE camera
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...
Authors
Nathan T. Bridges, Paul E. Geissler, Alfred S. McEwen, B.J. Thomson, Frank C. Chuang, Kenneth E. Herkenhoff, Laszlo P. Keszthelyi, Sara Martinez-Alonso
Meter-scale morphology of the north polar region of mars Meter-scale morphology of the north polar region of mars
Mars' north pole is covered by a dome of layered ice deposits. Detailed (∼30 centimeters per pixel) images of this region were obtained with the High-Resolution Imaging Science Experiment on board the Mars Reconnaissance Orbiter (MRO). Planum Boreum basal unit scarps reveal cross-bedding and show evidence for recent mass wasting, flow, and debris accumulation. The north polar layers...
Authors
Kenneth E. Herkenhoff, S. Byrne, P.S. Russell, K.E. Fishbaugh, A. S. McEwen
Mars reconnaissance orbiter's high resolution imaging science experiment (HiRISE) Mars reconnaissance orbiter's high resolution imaging science experiment (HiRISE)
The HiRISE camera features a 0.5 m diameter primary mirror, 12 m effective focal length, and a focal plane system that can acquire images containing up to 28 Gb (gigabits) of data in as little as 6 seconds. HiRISE will provide detailed images (0.25 to 1.3 m/pixel) covering ∼1% of the Martian surface during the 2‐year Primary Science Phase (PSP) beginning November 2006. Most images will...
Authors
Alfred S. McEwen, Eric M. Eliason, James W. Bergstrom, Nathan T. Bridges, Candice J. Hansen, W. Alan Delamere, John A. Grant, Virginia C. Gulick, Kenneth E. Herkenhoff, Laszlo P. Keszthelyi, Randolph L. Kirk, Michael T. Mellon, Steven W. Squyres, Nicolas Thomas, Catherine M. Weitz
Titan's surface from Cassini RADAR SAR and high resolution radiometry data of the first five flybys Titan's surface from Cassini RADAR SAR and high resolution radiometry data of the first five flybys
The first five Titan flybys with Cassini's Synthetic Aperture RADAR (SAR) and radiometer are examined with emphasis on the calibration and interpretation of the high-resolution radiometry data acquired during the SAR mode (SAR-radiometry). Maps of the 2-cm wavelength brightness temperature are obtained coincident with the SAR swath imaging, with spatial resolution approaching 6 km. A...
Authors
F. Paganelli, Michael A. Janssen, B. Stiles, R. West, Ralf D. Lorenz, Jonathan I. Lunine, Stephen D. Wall, Philip S. Callahan, Rosaly Lopes, Ellen R. Stofan, Randolph L. Kirk, W.T.K. Johnson, L. Roth, Charles Elachi
New estimates for Io eruption temperatures: Implications for the interior New estimates for Io eruption temperatures: Implications for the interior
The initial interpretation of Galileo data from Jupiter's moon, Io, suggested eruption temperatures ≥1600°C. Tidal heating models have difficulties explaining Io's prodigious heat flow if the mantle is >1300°C, although we suggest that temperatures up to ~1450°C may be possible. In general, Io eruption temperatures have been overestimated because the incorrect thermal model has been...
Authors
Laszlo P. Keszthelyi, Windy L. Jaeger, Moses P. Milazzo, Jani Radebaugh, Ashley G. Davies, Karl L. Mitchell
Cryovolcanic features on Titan's surface as revealed by the Cassini Titan Radar Mapper Cryovolcanic features on Titan's surface as revealed by the Cassini Titan Radar Mapper
The Cassini Titan Radar Mapper obtained Synthetic Aperture Radar images of Titan's surface during four fly-bys during the mission's first year. These images show that Titan's surface is very complex geologically, showing evidence of major planetary geologic processes, including cryovolcanism. This paper discusses the variety of cryovolcanic features identified from SAR images, their...
Authors
Rosaly Lopes, K. L. Mitchell, Ellen R. Stofan, Jonathan I. Lunine, Ralf D. Lorenz, F. Paganelli, Randolph L. Kirk, C. A. Wood, Stephen D. Wall, L.E. Robshaw, A.D. Fortes, Catherine D. Neish, Jani Radebaugh, E. Reffet, S.J. Ostro, Charles Elachi, M.D. Allison, Y. Anderson, R. Boehmer, G. Boubin, Philip S. Callahan, P. Encrenaz, E. Flamini, G. Francescetti, Y. Gim, G. Hamilton, S. Hensley, Michael A. Janssen, W.T.K. Johnson, K. Kelleher, D.O. Muhleman, G. Ori, R. Orosei, G. Picardi, F. Posa, L.E. Roth, R. Seu, S. Shaffer, Laurence A. Soderblom, B. Stiles, S. Vetrella, R.D. West, L. Wye, H. A. Zebker
Geologic mapping of the Amirani-Gish Bar region of Io: Implications for the global geologic mapping of Io Geologic mapping of the Amirani-Gish Bar region of Io: Implications for the global geologic mapping of Io
We produced the first geologic map of the Amirani-Gish Bar region of Io, the last of four regional maps generated from Galileo mission data. The Amirani-Gish Bar region has five primary types of geologic materials: plains, mountains, patera floors, flows, and diffuse deposits. The flows and patera floors are thought to be compositionally similar, but are subdivided based on...
Authors
David A. Williams, Laszlo P. Keszthelyi, David A. Crown, Windy L. Jaeger, Paul M. Schenk