Publications
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Rocks of the Columbia Hills 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...
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 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...
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
Characterization and petrologic interpretation of olivine-rich basalts at Gusev Crater, Mars Characterization and petrologic interpretation of olivine-rich basalts at Gusev Crater, Mars
Rocks on the floor of Gusev crater are basalts of uniform composition and mineralogy. Olivine, the only mineral to have been identified or inferred from data by all instruments on the Spirit rover, is especially abundant in these rocks. These picritic basalts are similar in many respects to certain Martian meteorites (olivine-phyric shergottites). The olivine megacrysts in both have...
Authors
H.Y. McSween, M.B. Wyatt, Ralf Gellert, J.F. Bell, R.V. Morris, Kenneth E. Herkenhoff, L.S. Crumpler, K.A. Milam, K.R. Stockstill, L.L. Tornabene, R. E. Arvidson, P. Bartlett, D. Blaney, N.A. Cabrol, P. R. Christensen, B. C. Clark, J.A. Crisp, D.J. Des Marais, T. Economou, J.D. Farmer, W. Farrand, A. Ghosh, M. Golombek, S. Gorevan, R. Greeley, V.E. Hamilton, J. R. Johnson, B.L. Joliff, G. Klingelhofer, A.T. Knudson, S. McLennan, D. Ming, J.E. Moersch, R. Rieder, S. W. Ruff, C. Schroder, P.A. de Souza, S. W. Squyres, H. Wanke, A. Wang, A. Yen, J. Zipfel
Spectrophotometric properties of materials observed by Pancam on the Mars Exploration Rovers: 2. Opportunity Spectrophotometric properties of materials observed by Pancam on the Mars Exploration Rovers: 2. Opportunity
The Panoramic Camera (Pancam) on the Mars Exploration Rover Opportunity acquired visible/near‐infrared multispectral observations of soils and rocks under varying viewing and illumination geometries that were modeled using radiative transfer theory to improve interpretations of the microphysical and surface scattering nature of materials in Meridiani Planum. Nearly 25,000 individual...
Authors
J. R. Johnson, W.M. Grundy, M.T. Lemmon, J.F. Bell, M. J. Johnson, R. Deen, R. E. Arvidson, W. H. Farrand, E. Guinness, A. G. Hayes, Kenneth E. Herkenhoff, F. Seelos, J. Soderblom, S. Squyres
The sand seas of titan: Cassini RADAR observations of longitudinal dunes 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...
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
Cartography for lunar exploration: 2006 status and planned missions Cartography for lunar exploration: 2006 status and planned missions
The initial spacecraft exploration of the Moon in the 1960s–70s yielded extensive data, primarily in the form of film and television images, that were used to produce a large number of hardcopy maps by conventional techniques. A second era of exploration, beginning in the early 1990s, has produced digital data including global multispectral imagery and altimetry, from which a new...
Authors
Randolph L. Kirk, Brent A. Archinal, Lisa R. Gaddis, Mark R. Rosiek
Sulfate deposition in subsurface regolith in Gusev crater, Mars Sulfate deposition in subsurface regolith in Gusev crater, Mars
Excavating into the shallow Martian subsurface has the potential to expose stratigraphic layers and mature regolith, which may hold a record of more ancient aqueous interactions than those expected under current Martian surface conditions. During the Spirit rover's exploration of Gusev crater, rover wheels were used to dig three trenches into the subsurface regolith down to 6-11 cm depth...
Authors
A. Wang, L.A. Haskin, S. W. Squyres, B.L. Jolliff, L. Crumpler, Ralf Gellert, C. Schroder, Kenneth E. Herkenhoff, J. Hurowitz, N.J. Tosca, W. H. Farrand, R. Anderson, A.T. Knudson
Flood lavas on Earth, Io and Mars 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...
Authors
Laszlo P. Keszthelyi, Stephen Self, Thorvaldur Thordarson
Soil grain analyses at Meridiani Planum, Mars Soil grain analyses at Meridiani Planum, Mars
Grain‐size analyses of the soils at Meridiani Planum have been used to identify rock sources for the grains and provide information about depositional processes under past and current conditions. Basaltic sand, dust, millimeter‐size hematite‐rich spherules interpreted as concretions, spherule fragments, coated partially buried spherules, basalt fragments, sedimentary outcrop fragments...
Authors
C.M. Weitz, R. C. Anderson, J.F. Bell, W. H. Farrand, Kenneth E. Herkenhoff, J. R. Johnson, B.L. Jolliff, R.V. Morris, S. W. Squyres, R.J. Sullivan
Sedimentary textures formed by aqueous processes, Erebus crater Meridiani Planum, Mars Sedimentary textures formed by aqueous processes, Erebus crater Meridiani Planum, Mars
New observations at Erebus crater (Olympia outcrop) by the Mars Exploration Rover Opportunity between sols 671 and 735 (a sol is a martian day) indicate that a diverse suite of primary and penecontemporaneous sedimentary structures is preserved in sulfate-rich bedrock. Centimeter-scale trough (festoon) cross-lamination is abundant, and is better expressed and thicker than previously...
Authors
J. Grotzinger, J. Bell, Kenneth E. Herkenhoff, J. Johnson, A. Knoll, E. McCartney, S. McLennan, J. Metz, Jeff Moore, S. Squyres, R. Sullivan, O. Ahronson, R. Arvidson, B. Joliff, M. Golombek, K. Lewis, T. Parker, J. Soderblom
Titan Radar Mapper observations from Cassini's T3 fly-by Titan Radar Mapper observations from Cassini's T3 fly-by
Cassini's Titan Radar Mapper imaged the surface of Saturn's moon Titan on its February 2005 fly-by (denoted T3), collecting high-resolution synthetic-aperture radar and larger-scale radiometry and scatterometry data. These data provide the first definitive identification of impact craters on the surface of Titan, networks of fluvial channels and surficial dark streaks that may be...
Authors
C. Elachi, S. Wall, M. Janssen, E. Stofan, R. Lopes, Randolph L. Kirk, R. Lorenz, J. Lunine, F. Paganelli, Laurence A. Soderblom, C. Wood, L. Wye, H. Zebker, Y. Anderson, S. Ostro, M. Allison, R. Boehmer, P. Callahan, P. Encrenaz, E. Flamini, 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, R. West
CO2 jets formed by sublimation beneath translucent slab ice in Mars' seasonal south polar ice cap CO2 jets formed by sublimation beneath translucent slab ice in Mars' seasonal south polar ice cap
The martian polar caps are among the most dynamic regions on Mars, growing substantially in winter as a significant fraction of the atmosphere freezes out in the form of CO2 ice. Unusual dark spots, fans and blotches form as the south-polar seasonal CO2 ice cap retreats during spring and summer. Small radial channel networks are often associated with the location of spots once the ice...
Authors
Hugh H. Kieffer, Phillip R. Christensen, Timothy N. Titus