Publications
Filter Total Items: 990
A closer look at water-related geologic activity on Mars A closer look at water-related geologic activity on Mars
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 ∼2 meters in diameter are ubiquitous in...
Authors
Alfred S. McEwen, C.J. Hansen, W.A. Delamere, E. M. Eliason, Kenneth E. Herkenhoff, Laszlo P. Keszthelyi, V. C. Gulick, Randolph L. Kirk, M. T. Mellon, J. A. Grant, N. Thomas, C.M. Weitz, S. W. Squyres, N.T. Bridges, S.L. Murchie, F. Seelos, K. Seelos, C.H. Okubo, M.P. Milazzo, L.L. Tornabene, W.L. Jaeger, S. Byrne, P.S. Russell, J.L. Griffes, S. Martinez-Alonso, A. Davatzes, F. C. Chuang, B.J. Thomson, K.E. Fishbaugh, C. M. Dundas, K.J. Kolb, M. E. Banks, J.J. Wray
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
The lakes of Titan The lakes of Titan
The surface of Saturn’s haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface1,2. Initial visible3 and radar4,5 imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface5,6. Here we provide definitive evidence for the presence of...
Authors
Ellen R. Stofan, Charles Elachi, Jonathan I. Lunine, Ralf D. Lorenz, B. Stiles, K. L. Mitchell, S. Ostro, Laurence A. Soderblom, C. Wood, H. Zebker, S. Wall, Michael A. Janssen, Randolph L. Kirk, Rosaly Lopes, F. Paganelli, Jani Radebaugh, L. Wye, Y. Anderson, M. Allison, R. Boehmer, P. Callahan, P. Encrenaz, E. Flamini, G. Francescetti, Y. Gim, G. Hamilton, S. Hensley, W.T.K. Johnson, K. Kelleher, D. Muhleman, Philipe Paillou, G. Picardi, F. Posa, L. Roth, R. Seu, S. Shaffer, S. Vetrella, R. West
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
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
Correlations between Cassini VIMS spectra and RADAR SAR images: Implications for Titan's surface composition and the character of the Huygens Probe Landing Site Correlations between Cassini VIMS spectra and RADAR SAR images: Implications for Titan's surface composition and the character of the Huygens Probe Landing Site
Titan's vast equatorial fields of RADAR-dark longitudinal dunes seen in Cassini RADAR synthetic aperture images correlate with one of two dark surface units discriminated as “brown” and “blue” in Visible and Infrared Mapping Spectrometer (VIMS) color composites of short-wavelength infrared spectral cubes (RGB as 2.0, 1.6, 1.3 μm). In such composites bluer materials exhibit higher...
Authors
Laurence A. Soderblom, Randolph L. Kirk, Jonathan I. Lunine, Jeffrey A. Anderson, Kevin H. Baines, Jason W. Barnes, Janet M. Barrett, Robert H. Brown, Bonnie J. Buratti, Roger N. Clark, Dale P. Cruikshank, Charles Elachi, Michael A. Janssen, Ralf Jaumann, Erich Karkoschka, Stéphane Le Mouélic, Rosaly Lopes, Ralph D. Lorenz, Thomas B. McCord, Philip D. Nicholson, Jani Radebaugh, Bashar Rizk, Christophe Sotin, Ellen R. Stofan, Tracie L. Sucharski, Martin G. Tomasko, Stephen D. Wall
THEMIS observes possible cave skylights on Mars THEMIS observes possible cave skylights on Mars
Seven possible skylight entrances into Martian caves were observed on and around the flanks of Arsia Mons by the Mars Odyssey Thermal Emission Imaging System (THEMIS). Distinct from impact craters, collapse pits or any other surface feature on Mars, these candidates appear to be deep dark holes at visible wavelengths while infrared observations show their thermal behaviors to be...
Authors
Glen Cushing, Timothy N. Titus, J. Judson Wynne, P. R. Christensen
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
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
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
Initial insights from 2.5D hydraulic modeling of floods in Athabasca Valles, Mars Initial insights from 2.5D hydraulic modeling of floods in Athabasca Valles, Mars
We present the first application of a 2.5D hydraulic model to catastrophic floods on Mars. This model simulates flow over complex topography and incorporates flood dynamics that could not be modeled in the earlier 1D models. We apply this model to Athabasca Valles, the youngest outflow channel on Mars, investigating previous bank-full discharge estimates and utilizing the interpolated...
Authors
Laszlo P. Keszthelyi, Roger P. Denlinger, D. R. H. O’Connell, Devon M. Burr
The Unified Lunar Control Network 2005 The Unified Lunar Control Network 2005
This report documents a new general unified lunar control network and lunar topographic model based on a combination of Clementine images and a previous network derived from Earth-based & Apollo photographs, and Mariner 10, & Galileo images. This photogrammetric network solution is the largest planetary control network ever completed. It includes the determination of the 3-D positions of...
Authors
Brent A. Archinal, Mark R. Rosiek, Randolph L. Kirk, Bonnie L. Redding