Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 915

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 reflectance at 1.
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 M.C. 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

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 consistent with su
Authors
Glen Cushing, Timothy N. Titus, J. Judson Wynne, P. R. Christensen

The lakes and seas of Titan

No abstract available.
Authors
Rosaly M.C. Lopes, Karl L. Mitchell, Stephen D. Wall, Giuseppe Mitri, Michael Janssen, Steven J. Ostro, Randolph L. Kirk, Alexander G. Hayes, Ellen R. Stofan, Jonathan I. Lunine, Ralph D. Lorenz, Charles Wood, Jani Radebaugh, Philipe Paillou, H. Zebker, Flora Paganelli

Near-infrared spectral mapping of Titan's mountains and channels

We investigate the spectral reflectance properties of channels and mountain ranges on Titan using data from Cassini's Visual and Infrared Mapping Spectrometer (VIMS) obtained during the T9 encounter (26 December 2005). We identify the location of channels and mountains using synthetic aperture radar maps obtained from Cassini's RADAR instrument during the T13 (30 April 2006) flyby. Channels are ev
Authors
Jason W. Barnes, Jani Radebaugh, Robert H. Brown, Steve Wall, Laurence A. Soderblom, Jonathan I. Lunine, Devon M. Burr, Christophe Sotin, Stephane Le Mouelic, Sebastien Rodriguez, Bonnie J. Buratti, Roger N. Clark, Kevin H. Baines, Ralf Jaumann, Philip D. Nicholson, Randolph L. Kirk, Rosaly Lopes, Ralph D. Lorenz, Ken Mitchell, Charles A. Wood

Mars global digital dune database and initial science results

A new Mars Global Digital Dune Database (MGD3) constructed using Thermal Emission Imaging System (THEMIS) infrared (IR) images provides a comprehensive and quantitative view of the geographic distribution of moderate‐ to large‐size dune fields (area >1 km2) that will help researchers to understand global climatic and sedimentary processes that have shaped the surface of Mars. MGD3 extends from 65°
Authors
Rosalyn K. Hayward, Kevin F. Mullins, Lori K. Fenton, Trent M. Hare, Timothy N. Titus, Mary C. Bourke, Anthony Colaprete, Phillip R. Christensen

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 applied. Much
Authors
Laszlo P. Keszthelyi, Windy L. Jaeger, Moses P. Milazzo, Jani Radebaugh, Ashley G. Davies, Karl L. Mitchell

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 lakes on th
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

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 possible origi
Authors
Rosaly M.C. 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

Evidence for and implications of sedimentary diapirism and mud volcanism in the southern Utopia highland-lowland boundary plain, Mars

Several types of spatially associated landforms in the southern Utopia Planitia highland–lowland boundary (HLB) plain appear to have resulted from localized geologic activity, including (1) fractured rises, (2) elliptical mounds, (3) pitted cones with emanating lobate materials, and (4) isolated and coalesced cavi (depressions). Stratigraphic analysis indicates these features are Hesperian or youn
Authors
James A. Skinner, Kenneth L. Tanaka

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 interpretations regardi
Authors
David A. Williams, Laszlo P. Keszthelyi, David A. Crown, Windy L. Jaeger, Paul M. Schenk

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) from the mult
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

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 d
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