Publications
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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
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
Volcanism on Io: New insights from global geologic mapping Volcanism on Io: New insights from global geologic mapping
We produced the first complete, 1:15 M-scale global geologic map of Jupiter’s moon Io, based on a set of monochrome and color Galileo–Voyager image mosaics produced at a spatial resolution of 1 km/pixel. The surface of Io was mapped into 19 units based on albedo, color and surface morphology, and is subdivided as follows: plains (65.8% of surface), lava flow fields (28.5%), mountains (3...
Authors
David A. Williams, Laszlo P. Keszthelyi, David A. Crown, Jessica A. Yff, Windy L. Jaeger, Paul M. Schenk, Paul E. Geissler, Tammy L. Becker
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
Evidence of volcanic and glacial activity in Chryse and Acidalia Planitiae, Mars Evidence of volcanic and glacial activity in Chryse and Acidalia Planitiae, Mars
Chryse and Acidalia Planitiae show numerous examples of enigmatic landforms previously interpreted to have been influenced by a water/ice-rich geologic history. These landforms include giant polygons bounded by kilometer-scale arcuate troughs, bright pitted mounds, and mesa-like features. To investigate the significance of the last we have analyzed in detail the region between 60°N, 290...
Authors
Sara Martinez-Alonso, Michael T. Mellon, Maria E. Banks, Laszlo P. Keszthelyi, Alfred S. McEwen
Measurements of Martian dust devil winds with HiRISE Measurements of Martian dust devil winds with HiRISE
We report wind measurements within Martian dust devils observed in plan view from the High Resolution Imaging Science Experiment (HiRISE) orbiting Mars. The central color swath of the HiRISE instrument has three separate charge‐coupled devices (CCDs) and color filters that observe the surface in rapid cadence. Active features, such as dust devils, appear in motion when observed by this...
Authors
D.S. Choi, Colin M. Dundas
Mars: the evolutionary history of the northern lowlands based on crater counting and geologic mapping Mars: the evolutionary history of the northern lowlands based on crater counting and geologic mapping
The geologic history of planetary surfaces is most effectively determined by joining geologic mapping and crater counting which provides an iterative, qualitative and quantitative method for defining relative ages and absolute model ages. Based on this approach, we present spatial and temporal details regarding the evolution of the Martian northern plains and surrounding regions. The...
Authors
S.C. Werner, K. L. Tanaka, J.A. Skinner
Seasonal flows on warm Martian slopes Seasonal flows on warm Martian slopes
Water probably flowed across ancient Mars, but whether it ever exists as a liquid on the surface today remains debatable. Recurring slope lineae (RSL) are narrow (0.5 to 5 meters), relatively dark markings on steep (25° to 40°) slopes; repeat images from the Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment show them to appear and incrementally grow during warm...
Authors
Alfred S. McEwen, Lujendra Ojha, Colin M. Dundas, Sarah S. Mattson, Shane Byrne, James J. Wray, Selby C. Cull, Scott L. Murchie, Nicolas Thomas, Virginia C. Gulick
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
Active aeolian processes on Mars: A regional study in Arabia and Meridiani Terrae Active aeolian processes on Mars: A regional study in Arabia and Meridiani Terrae
We present evidence of widespread aeolian activity in the Arabia Terra/Meridiani region (Mars), where different kinds of aeolian modifications have been detected and classified. Passing from the regional to the local scale, we describe one particular dune field in Meridiani Planum, where two ripple populations are distinguished by means of different migration rates. Moreover, a...
Authors
S. Silvestro, D.A. Vaz, L.K. Fenton, Paul E. Geissler
Spectral heterogeneity on Phobos and Deimos: HiRISE observations and comparisons to Mars Pathfinder results Spectral heterogeneity on Phobos and Deimos: HiRISE observations and comparisons to Mars Pathfinder results
The High-Resolution Imaging Science Experiment (HiRISE) onboard Mars Reconnaissance Orbiter (MRO) has been used to observe Phobos and Deimos at spatial scales of around 6 and 20 m/px, respectively. HiRISE (McEwen et al.; JGR, 112, CiteID E05S02, DOI: 10.1029/2005JE002605, 2007) has provided, for the first time, high-resolution colour images of the surfaces of the Martian moons. When...
Authors
N. Thomas, R. Stelter, A. Ivanov, N.T. Bridges, Kenneth E. Herkenhoff, A. S. McEwen
History of plains resurfacing in the Scandia region of Mars History of plains resurfacing in the Scandia region of Mars
We present a preliminary photogeologic map of the Scandia region of Mars with the objective of reconstructing its resurfacing history. The Scandia region includes the lower section of the regional lowland slope of Vastitas Borealis extending about 500–1800 km away from Alba Mons into the Scandia sub-basin below −4800 m elevation. Twenty mapped geologic units express the diverse...
Authors
Kenneth L. Tanaka, Corey M. Fortezzo, Rosalyn K. Hayward, J. Alexis P. Rodriguez, James A. Skinner