Publications
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The nucleus of Comet Borrelly: A study of morphology and surface brightness The nucleus of Comet Borrelly: A study of morphology and surface brightness
Stereo images obtained during the DS1 flyby were analyzed to derive a topographic model for the nucleus of Comet 19P/Borrelly for morphologic and photometric studies. The elongated nucleus has an overall concave shape, resembling a peanut, with the lower end tilted towards the camera. The bimodal character of surface-slopes and curvatures support the idea that the nucleus is a...
Authors
J. Oberst, Elpitha Howington-Kraus, Randolph Kirk, Laurence Soderblom, B. Buratti, M. Hicks, R. Nelson, D. Britt
Observations and temperatures of Io's Pele Patera from Cassini and Galileo spacecraft images Observations and temperatures of Io's Pele Patera from Cassini and Galileo spacecraft images
Pele has been the most intense high-temperature hotspot on Io to be continuously active during the Galileo monitoring from 1996–2001. A suite of characteristics suggests that Pele is an active lava lake inside a volcanic depression. In 2000–2001, Pele was observed by two spacecraft, Cassini and Galileo. The Cassini observations revealed that Pele is variable in activity over timescales...
Authors
Jani Radebaugh, Alfred McEwen, Moses Milazzo, Laszlo P. Keszthelyi, Ashley G. Davies, Elizabeth Turtle, Douglas Dawson
A post-Galileo view of Io's interior A post-Galileo view of Io's interior
We present a self-consistent model for the interior of Io, taking the recent Galileo data into account. In this model, Io has a completely molten core, substantially molten mantle, and a very cold lithosphere. Heat from magmatic activity can mobilize volatile compounds such as SO2 in the lithosphere, and the movement of such cryogenic fluids may be important in the formation of surface...
Authors
Laszlo P. Keszthelyi, Windy Jaeger, Elizabeth Turtle, Moses Milazzo, Jani Radebaugh
Morphometric properties of Martian volcanoes Morphometric properties of Martian volcanoes
Mars Orbiter Laser Altimeter (MOLA) data have been used to construct Digital Elevation Models (DEM) of the Martian volcanoes in order to determine height, flank slope, caldera depth, and volumes. Summit elevations range from 21.1 km to −0.5 km, and relief varies from 1.0 km to almost 22 km. Average flank slopes are in the range of
Authors
J. Plescia
Reconciling different observations of the CO2 ice mass loading of the Martian north polar cap Reconciling different observations of the CO2 ice mass loading of the Martian north polar cap
The GRS measurements of the peak mass loading of the north polar CO2 ice cap on Mars are about 60% lower than those calculated from MGS TES radiation data and those inferred from the MOLA cap thicknesses. However, the GRS data provide the most accurate measurement of the mass loading. We show that the TES and MOLA data can be reconciled with the GRS data if (1) subsurface heat conduction...
Authors
Robert Haberle, Bridget Mattingly, Timothy Titus
Wind-related processes detected by the Spirit rover at Gusev crater, Mars Wind-related processes detected by the Spirit rover at Gusev crater, Mars
Wind-abraded rocks, ripples, drifts, and other deposits of windblown sediments are seen at the Columbia Memorial Station where the Spirit rover landed. Orientations of these features suggest formative winds from the north-northwest, consistent with predictions from atmospheric models of afternoon winds in Gusev Crater. Cuttings from the rover Rock Abrasion Tool are asymmetrically...
Authors
R. Greeley, S. Squyres, R. E. Arvidson, P. Bartlett, J.F. Bell, D. Blaney, N.A. Cabrol, J. Farmer, B. Farrand, M.P. Golombek, S.P. Gorevan, J. Grant, A. Haldemann, Kenneth Herkenhoff, J. Johnson, G. Landis, M.B. Madsen, S.H. McLennan, J. Moersch, J. Rice, L. Richter, S. Ruff, R.J. Sullivan, S.D. Thompson, A. Wang, C.M. Weitz, P. Whelley
Surficial deposits at Gusev crater along Spirit Rover traverses Surficial deposits at Gusev crater along Spirit Rover traverses
The Mars Exploration Rover Spirit has traversed a fairly flat, rock-strewn terrain whose surface is shaped primarily by impact events, although some of the landscape has been altered by eolian processes. Impacts ejected basaltic rocks that probably were part of locally formed lava flows from at least 10 meters depth. Some rocks have been textured and/or partially buried by windblown...
Authors
J. Grant, R. Arvidson, J.F. Bell, N.A. Cabrol, M. Carr, P. Christensen, L. Crumpler, D.J. Des Marais, B.L. Ehlmann, J. Farmer, M. Golombek, F.D. Grant, R. Greeley, Kenneth Herkenhoff, R. Li, H.Y. McSween, D. Ming, J. Moersch, J. Rice, S. Ruff, L. Richter, S. Squyres, R. Sullivan, C. Weitz
Ridges and tidal stress on Io Ridges and tidal stress on Io
Sets of ridges of uncertain origin are seen in twenty-nine high-resolution Galileo images, which sample seven locales on Io. These ridges are on the order of a few kilometers in length with a spacing of about a kilometer. Within each locale, the ridges have a consistent orientation, but the orientations vary from place to place. We investigate whether these ridges could be a result of...
Authors
Gwendolyn Bart, Elizabeth Turtle, Windy Jaeger, Laszlo P. Keszthelyi, Richard Greenberg
Localization and physical property experiments conducted by opportunity at Meridiani Planum Localization and physical property experiments conducted by opportunity at Meridiani Planum
The location of the Opportunity landing site was determined to better than 10-m absolute accuracy from analyses of radio tracking data. We determined Rover locations during traverses with an error as small as several centimeters using engineering telemetry and overlapping images. Topographic profiles generated from rover data show that the plains are very smooth from meter- to centimeter...
Authors
R. E. Arvidson, R. Anderson, P. Bartlett, J.F. Bell, P. Christensen, P. Chu, K. Davis, B.L. Ehlmann, M.P. Golombek, S. Gorevan, E.A. Guinness, A. Haldemann, Kenneth Herkenhoff, G. Landis, R. Li, R. Lindemann, D. Ming, T. Myrick, T. Parker, L. Richter, F.P. Seelos, Laurence Soderblom, S. Squyres, R.J. Sullivan, Jim Wilson
The Rock Elm meteorite impact structure, Wisconsin: Geology and shock-metamorphic effects in quartz The Rock Elm meteorite impact structure, Wisconsin: Geology and shock-metamorphic effects in quartz
The Rock Elm structure in southwest Wisconsin is an anomalous circular area of highly deformed rocks, ∼6.5 km in diameter, located in a region of virtually horizontal undeformed sedimentary rocks. Shock-produced planar microstructures (PMs) have been identified in quartz grains in several lithologies associated with the structure: sandstones, quartzite pebbles, and breccia. Two distinct...
Authors
B.M. French, W.S. Cordua, J. Plescia
Mapping of the Culann-Tohil region of Io from Galileo imaging data Mapping of the Culann-Tohil region of Io from Galileo imaging data
We have used Galileo spacecraft data to produce a geomorphologic map of the Culann–Tohil region of Io's antijovian hemisphere. This region includes a newly discovered shield volcano, Tsũi Goab Tholus and a neighboring bright flow field, Tsũi Goab Fluctus, the active Culann Patera and the enigmatic Tohil Mons-Radegast Patera–Tohil Patera complex. Analysis of Voyager global color and...
Authors
D.A. Williams, Paul M. Schenk, Jeffrey M. Moore, Laszlo P. Keszthelyi, Elizabeth Turtle, Windy Jaeger, Jani Radebaugh, Moses Milazzo, Rosaly Lopes, Ronald Greeley
The Spirit Rover's Athena science investigation at Gusev crater, Mars The Spirit Rover's Athena science investigation at Gusev crater, Mars
The Mars Exploration Rover Spirit and its Athena science payload have been used to investigate a landing site in Gusev crater. Gusev is hypothesized to be the site of a former take, but no clear evidence for lacustrine sedimentation has been found to date. Instead, the dominant lithology is basalt, and the dominant geologic processes are impact events and eolian transport. Many rocks...
Authors
S. Squyres, R. E. Arvidson, J.F. Bell, J. Bruckner, N.A. Cabrol, W. Calvin, M. Carr, P. Christensen, B.C. Clark, L. Crumpler, D.J. Des Marais, C. D'Uston, T. Economou, J. Farmer, W. Farrand, W. Folkner, M. Golombek, S. Gorevan, J. Grant, R. Greeley, J. Grotzinger, L. Haskin, Kenneth Herkenhoff, S. Hviid, J. Johnson, G. Klingelhofer, A. Knoll, G. Landis, M. Lemmon, R. Li, M.B. Madsen, M. Malin, S. McLennan, H.Y. McSween, D. Ming, J. Moersch, R.V. Morris, T. Parker, J. Rice, L. Richter, R. Rieder, M. Sims, M. Smith, P. Smith, Laurence Soderblom, R. Sullivan, H. Wanke, T. Wdowiak, M. Wolff, A. Yen