Publications
Filter Total Items: 988
Channel morphometry, sediment transport, and implications for tectonic activity and surficial ages of Titan basins Channel morphometry, sediment transport, and implications for tectonic activity and surficial ages of Titan basins
Fluvial features on Titan and drainage basins on Earth are remarkably similar despite differences in gravity and surface composition. We determined network bifurcation (Rb) ratios for five Titan and three terrestrial analog basins. Tectonically-modified Earth basins have Rb values greater than the expected range (3.0–5.0) for dendritic networks; comparisons with Rb values determined for...
Authors
R. Cartwright, J.A. Clayton, Randolph L. Kirk
A Miocene river in northern Arizona and its implications for the Colorado River and Grand Canyon A Miocene river in northern Arizona and its implications for the Colorado River and Grand Canyon
The southwesterly course of the pre–late Miocene Crooked Ridge River can be traced continuously for 48 km and discontinuously for 91 km in northern Arizona. It is visible today in inverted relief. Pebbles in the river gravel came from at least as far northeast as the San Juan Mountains. The river valley was carved out of easily eroded Jurassic and Cretaceous rocks, whose debris...
Authors
Ivo Lucchitta, Richard F. Holm, Baerbel K. Lucchitta
Hyperspectral analysis of rocky surfaces on the Earth and other planetary systems: Chapter 27 Hyperspectral analysis of rocky surfaces on the Earth and other planetary systems: Chapter 27
This book is focused on studies of vegetation on Earth using hyperspectral remote sensing methods. However, it is appropriate to extend the application of these methods out to other rocky bodies in our Solar System for a variety of reasons. First, minerals, soils, and rocks form the substrate on which vegetation grows on Earth. Compositional analyses of these components with...
Authors
R. Greg Vaughan, Timothy N. Titus, Jeffery R Johnson, Justin Hagerty, Lisa R. Gaddis, Laurence A. Soderblom, Paul E. Geissler
Evidence for mechanical and chemical alteration of iron-nickel meteorites on Mars: Process insights for Meridiani Planum Evidence for mechanical and chemical alteration of iron-nickel meteorites on Mars: Process insights for Meridiani Planum
The weathering of meteorites found on Mars involves chemical and physical processes that can provide clues to climate conditions at the location of their discovery. Beginning on sol 1961, the Opportunity rover encountered three large iron meteorites within a few hundred meters of each other. In order of discovery, these rocks have been assigned the unofficial names Block Island, Shelter...
Authors
James W. Ashley, M.P. Golombek, P. R. Christensen, S. W. Squyres, T.J. McCoy, C. Schroder, I. Fleischer, J. R. Johnson, Kenneth E. Herkenhoff, T. J. Parker
Seasonal erosion and restoration of Mars' northern polar dunes Seasonal erosion and restoration of Mars' northern polar dunes
Despite radically different environmental conditions, terrestrial and martian dunes bear a strong resemblance, indicating that the basic processes of saltation and grainfall (sand avalanching down the dune slipface) operate on both worlds. Here, we show that martian dunes are subject to an additional modification process not found on Earth: springtime sublimation of Mars' CO 2 seasonal...
Authors
C.J. Hansen, M. Bourke, Nathan T. Bridges, Shane Byrne, C. Colon, S. Diniega, Colin M. Dundas, Kenneth E. Herkenhoff, A. McEwen, M. Mellon, Ganna Portyankina, N. Thomas
The indication of Martian gully formation processes by slope-area analysis The indication of Martian gully formation processes by slope-area analysis
The formation process of recent gullies on Mars is currently under debate. This study aims to discriminate between the proposed formation processes - pure water flow, debris flow and dry mass wasting - through the application of geomorphological indices commonly used in terrestrial geomorphology. High-resolution digital elevation models (DEMs) of Earth and Mars were used to evaluate the...
Authors
Susan J. Conway, Matthew R. Balme, John B. Murray, Martin C. Towner, Chris Okubo, Peter M. Grindrod
Extreme volcanism on Io: Latest insights at the end of Galileo era Extreme volcanism on Io: Latest insights at the end of Galileo era
Galileo has now completed 7 years exploring Jupiter. The spacecraft obtained breathtaking views of the four major satellites, and studied Jupiter's clouds and atmospheric composition, rings, small satellites, and magnetic field. It had five successful close flybys and many distant observations of Io. Scientists already knew from Voyager and Earth‐based astronomy that Io is by far the...
Authors
Jeffrey S. Kargel, Robert R. Carlson, Ashley G. Davies, Bruce Fegley, Alan R. Gillespie, Ronald Greeley, Robert G. Howells, Kandis Lea Jessup, Lucas Kamp, Laszlo P. Keszthelyi, Rosaly Lopes, Timothy MacIntyre, Franck Marchis, Alfred McEwen, Moses P. Milazzo, Jason Perry, Jani Radebaugh, Laura Schaefer, Nicholas Schmerr, William Smythe, John M. Spencer, David A. Williams, Ju Zhang, Mikhail Zolotov
Opportunity Mars Rover mission: Overview and selected results from Purgatory ripple to traverses to Endeavour crater Opportunity Mars Rover mission: Overview and selected results from Purgatory ripple to traverses to Endeavour crater
Opportunity has been traversing the Meridiani plains since 25 January 2004 (sol 1), acquiring numerous observations of the atmosphere, soils, and rocks. This paper provides an overview of key discoveries between sols 511 and 2300, complementing earlier papers covering results from the initial phases of the mission. Key new results include (1) atmospheric argon measurements that...
Authors
R. E. Arvidson, James W. Ashley, J.F. Bell, M. Chojnacki, J. Cohen, T.E. Economou, W. H. Farrand, Robin L. Fergason, I. Fleischer, Paul E. Geissler, Ralf Gellert, M.P. Golombek, J.P. Grotzinger, E.A. Guinness, R.M. Haberle, Kenneth E. Herkenhoff, J.A. Herman, K.D. Iagnemma, B.L. Jolliff, J. R. Johnson, G. Klingelhofer, A.H. Knoll, A.T. Knudson, R. Li, S. M. McLennan, D. W. Mittlefehldt, R.V. Morris, T. J. Parker, M.S. Rice, C. Schroder, Laurence A. Soderblom, S. W. Squyres, R.J. Sullivan, M.J. Wolff
Organic sedimentary deposits in Titan's dry lakebeds: Probable evaporite Organic sedimentary deposits in Titan's dry lakebeds: Probable evaporite
We report the discovery of organic sedimentary deposits at the bottom of dry lakebeds near Titan’s north pole in observations from the Cassini Visual and Infrared Mapping Spectrometer (VIMS). We show evidence that the deposits are evaporitic, making Titan just the third known planetary body with evaporitic processes after Earth and Mars, and is the first that uses a solvent other than...
Authors
J. W. Barnes, J. Bow, J. Schwartz, R. H. Brown, J.M. Soderblom, A. G. Hayes, G. Vixie, Stéphane Le Mouélic, S. Rodriguez, Christophe Sotin, R. Jaumann, K. Stephan, L.A. Soderblom, Roger N. Clark, B. J. Buratti, K. H. Baines, P. D. Nicholson
Characteristics, distribution, origin, and significance of opaline silica observed by the Spirit rover in Gusev crater, Mars Characteristics, distribution, origin, and significance of opaline silica observed by the Spirit rover in Gusev crater, Mars
The presence of outcrops and soil (regolith) rich in opaline silica (∼65–92 wt % SiO2) in association with volcanic materials adjacent to the “Home Plate” feature in Gusev crater is evidence for hydrothermal conditions. The Spirit rover has supplied a diverse set of observations that are used here to better understand the formation of silica and the activity, abundance, and fate of water...
Authors
S. W. Ruff, J.D. Farmer, W. M. Calvin, Kenneth E. Herkenhoff, J. R. Johnson, R.V. Morris, M.S. Rice, R. E. Arvidson, J.F. Bell, P. R. Christensen, S. W. Squyres
Columbus crater and other possible groundwater-fed paleolakes of Terra Sirenum, Mars Columbus crater and other possible groundwater-fed paleolakes of Terra Sirenum, Mars
Columbus crater in the Terra Sirenum region of the Martian southern highlands contains light‐toned layered deposits with interbedded sulfate and phyllosilicate minerals, a rare occurrence on Mars. Here we investigate in detail the morphology, thermophysical properties, mineralogy, and stratigraphy of these deposits; explore their regional context; and interpret the crater's aqueous...
Authors
J.J. Wray, R.E. Milliken, Colin M. Dundas, Gregg A. Swayze, J. C. Andrews-Hanna, A.M. Baldridge, M. Chojnacki, J.L. Bishop, B.L. Ehlmann, S.L. Murchie, Roger N. Clark, F.P. Seelos, L.L. Tornabene, S. W. Squyres
The Mairan domes: silicic volcanic constructs on the Moon The Mairan domes: silicic volcanic constructs on the Moon
The Mairan domes are four features located in northern Oceanus Procellarum at ∼312.3E, 41.4N on the Moon. High resolution visible imagery, visible-to-mid-IR spectra, and Lunar Prospector Th abundance data all indicate that these four domes have a composition that is consistent with derivation from a Si-rich, highly evolved magma.
Authors
Timothy D. Glotch, Justin Hagerty, Paul G. Lucey, B. Ray Hawke, Thomas A. Giguere, Jessica A. Arnold, Jean-Pierre Williams, Bradley L. Jolliff, David A. Paige