Publications
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Spectrophotometric properties of materials observed by Pancam on the Mars Exploration Rovers: 1. Spirit
Multispectral observations of rocks and soils were acquired under varying illumination and viewing geometries in visible/near‐infrared wavelengths by the Panoramic Camera (Pancam) on the Spirit Mars Exploration Rover to provide constraints on the physical and mineralogical nature of geologic materials in Gusev Crater. Data sets were acquired at six sites located near the landing site, in the surro
Authors
J. R. Johnson, W.M. Grundy, M.T. Lemmon, J.F. Bell, M. J. Johnson, R.G. Deen, R. E. Arvidson, W. H. Farrand, E.A. Guinness, A. G. Hayes, Kenneth E. Herkenhoff, F. Seelos, J. Soderblom, S. Squyres
Aqueous processes at Gusev crater inferred from physical properties of rocks and soils along the Spirit traverse
Gusev crater was selected as the landing site for Spirit on the basis of morphological evidence of long-lasting water activity, including possibly fluvial and lacustrine episodes. From the Columbia Memorial Station to the Columbia Hills, Spirit's traverse provides a journey back in time, from relatively recent volcanic plains showing little evidence for aqueous processes up to the older hills, whe
Authors
N.A. Cabrol, J.D. Farmer, E.A. Grin, L. Ritcher, L. Soderblom, R. Li, Kenneth E. Herkenhoff, G. A. Landis, R. E. Arvidson
The sand seas of titan: Cassini RADAR observations of longitudinal dunes
The most recent Cassini RADAR images of Titan show widespread regions (up to 1500 kilometers by 200 kilometers) of near-parallel radar-dark linear features that appear to be seas of longitudinal dunes similar to those seen in the Namib desert on Earth. The Ku-band (2.17-centimeter wavelength) images show ∼100-meter ridges consistent with duneforms and reveal flow interactions with underlying hills
Authors
R. D. Lorenz, S. Wall, J. Radebaugh, G. Boubin, E. Reffet, M. Janssen, E. Stofan, R. Lopes, Randolph L. Kirk, C. Elachi, J. Lunine, Ken Mitchell, F. Paganelli, Laurence A. Soderblom, C. Wood, L. Wye, H. Zebker, Y. Anderson, S. Ostro, M. Allison, R. Boehmer, P. Callahan, P. Encrenaz, G.G. Ori, G. Francescetti, Y. Gim, G. Hamilton, S. Hensley, W. Johnson, K. Kelleher, D. Muhleman, G. Picardi, F. Posa, L. Roth, R. Seu, S. Shaffer, B. Stiles, S. Vetrella, E. Flamini, R. West
Two years at Meridiani Planum: Results from the Opportunity Rover
The Mars Exploration Rover Opportunity has spent more than 2 years exploring Meridiani Planum, traveling ∼8 kilometers and detecting features that reveal ancient environmental conditions. These include well-developed festoon (trough) cross-lamination formed in flowing liquid water, strata with smaller and more abundant hematite-rich concretions than those seen previously, possible relict “hopper c
Authors
S. W. Squyres, A.H. Knoll, R. E. Arvidson, B. C. Clark, J.P. Grotzinger, B.L. Jolliff, S. M. McLennan, N. Tosca, J.F. Bell, W. M. Calvin, W. H. Farrand, T.D. Glotch, M.P. Golombek, Kenneth E. Herkenhoff, J. R. Johnson, G. Klingelhofer, H.Y. McSween, A. S. Yen
The heartbeat of the volcano: The discovery of episodic activity at Prometheus on Io
The temporal signature of thermal emission from a volcano is a valuable clue to the processes taking place both at and beneath the surface. The Galileo Near Infrared Mapping Spectrometer (NIMS) observed the volcano Prometheus, on the jovian moon Io, on multiple occasions between 1996 and 2002. The 5 micron (μm) brightness of this volcano shows considerable variation from orbit to orbit. Prometheus
Authors
Ashley G. Davies, Lionel Wilson, Dennis Matson, Giovanni Leone, Laszlo P. Keszthelyi, Windy L. Jaeger
Remote sensing studies of the Dionysius region of the Moon
The Dionysius region is located near the western edge of Mare Tranquillitatis and is centered on Dionysius crater, which exhibits a well-developed dark ray system. Proposed origins for these dark rays included impact melt deposits and dark primary ejecta. The region also contains extensive deposits of Cayley-type light plains. Clementine multispectral images and a variety of spacecraft photography
Authors
Thomas A. Giguere, B. Ray Hawke, Lisa R. Gaddis, David T. Blewett, J. J. Gillis-Davis, Paul G. Lucey, G.A. Smith, P. D. Spudis, G.J. Taylor
Rocks of the Columbia Hills
The Mars Exploration Rover Spirit has identified five distinct rock types in the Columbia Hills of Gusev crater. Clovis Class rock is a poorly sorted clastic rock that has undergone substantial aqueous alteration. We interpret it to be aqueously altered ejecta deposits formed by impacts into basaltic materials. Wishstone Class rock is also a poorly sorted clastic rock that has a distinctive chemic
Authors
S. W. Squyres, R. E. Arvidson, D.L. Blaney, B. C. Clark, L. Crumpler, W. H. Farrand, S. Gorevan, Kenneth E. Herkenhoff, J. Hurowitz, A. Kusack, H.Y. McSween, D. W. Ming, R.V. Morris, S. W. Ruff, A. Wang, A. Yen
Evidence of phyllosilicates in Wooly Patch, an altered rock encountered at West Spur, Columbia Hills, by the Spirit rover in Gusev crater, Mars
On its traverse to Columbia Hills, the Mars Exploration Rover Spirit investigated an outcrop designated “Wooly Patch” that exhibited morphological, mineralogical, and geochemical characteristics at the extreme ends of ranges observed among rocks studied at West Spur, a westward projecting salient near the foot of the Columbia Hills, Gusev crater. The major‐element composition and Fe‐mineralogy, as
Authors
A. Wang, R.L. Korotev, B.L. Jolliff, L.A. Haskin, L. Crumpler, W. H. Farrand, Kenneth E. Herkenhoff, Jr. de Souza, A.G. Kusack, J.A. Hurowitz, N.J. Tosca
Flood lavas on Earth, Io and Mars
Flood lavas are major geological features on all the major rocky planetary bodies. They provide important insight into the dynamics and chemistry of the interior of these bodies. On the Earth, they appear to be associated with major and mass extinction events. It is therefore not surprising that there has been significant research on flood lavas in recent years. Initial models suggested eruption d
Authors
Laszlo P. Keszthelyi, Stephen Self, Thorvaldur Thordarson
Spirit rover localization and topographic mapping at the landing site of Gusev crater, Mars
By sol 440, the Spirit rover has traversed a distance of 3.76 km (actual distance traveled instead of odometry). Localization of the lander and the rover along the traverse has been successfully performed at the Gusev crater landing site. We localized the lander in the Gusev crater using two-way Doppler radio positioning and cartographic triangulations through landmarks visible in both orbital and
Authors
Rongxing Li, Brent A. Archinal, Raymond E. Arvidson, Jim Bell, Phillip R. Christensen, Larry S. Crumpler, David J. Des Marais, Kaichang Di, Tom Duxbury, Matthew P. Golombek, John Grant, Ronald Greeley, Joe Guinn, Aaron H. Johnson, Randolph L. Kirk, Mark Maimone, Larry H. Matthies, Michael Malin, Timothy Parker, Michael H. Sims, Shane D. Thompson, Steven W. Squyres, Laurence A. Soderblom
Petrogenesis of the Apollo 14 high-alumina basalts: Implications from ion microprobe analyses
In this study, ion microprobe analyses of individual minerals are used to investigate the petrogenesis of the Apollo 14 high-Al basalts. We use trace element concentrations from individual minerals in the Apollo 14 high-Al basalts to evaluate both endogenic and exogenic models. The data show that if the Apollo 14 high-Al basalts were produced by melting within the lunar mantle, these basalts canno
Authors
Justin Hagerty, Charles K. Shearer, James J. Papike
Stratigraphy and sedimentology of a dry to wet eolian depositional system, Burns formation, Meridiani Planum, Mars
Outcrop exposures of sedimentary rocks at the Opportunity landing site (Meridiani Planum) form a set of genetically related strata defined here informally as the Burns formation. This formation can be subdivided into lower, middle, and upper units which, respectively, represent eolian dune, eolian sand sheet, and mixed eolian sand sheet and interdune facies associations. Collectively, these three
Authors
J. P. Grotzinger, R. E. Arvidson, J. F. III Bell, W. Calvin, B. C. Clark, D.A. Fike, M. Golombek, R. Greeley, A. Haldemann, Kenneth E. Herkenhoff, B. L. Jolliff, A. H. Knoll, M. Malin, S. M. McLennan, T. Parker, Laurence A. Soderblom, J. N. Sohl-Dickstein, S. W. Squyres, N.J. Tosca, W.A. Watters