Publications
Filter Total Items: 915
Thorium abundances of basalt ponds in South Pole-Aitken basin: Insights into the composition and evolution of the far side lunar mantle
Imbrian-aged basalt ponds, located on the floor of South Pole-Aitken (SPA) basin, are used to provide constraints on the composition and evolution of the far side lunar mantle. We use forward modeling of the Lunar Prospector Gamma Ray Spectrometer thorium data, to suggest that at least five different and distinct portions of the far side lunar mantle contain little or no thorium as of the Imbrian
Authors
Justin Hagerty, D. J. Lawrence, B. R. Hawke
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 Titan basi
Authors
R. Cartwright, J.A. Clayton, Randolph L. Kirk
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 demonstrate the imp
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
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 history. Hydrat
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
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 hyperspectral data pro
Authors
R. Greg Vaughan, Timothy N. Titus, Jeffery R Johnson, Justin Hagerty, Lisa R. Gaddis, Laurence A. Soderblom, Paul E. Geissler
Meteorites at Meridiani Planum provide evidence for significant amounts of surface and near-surface water on early Mars
Six large iron meteorites have been discovered in the Meridiani Planum region of Mars by the Mars Exploration Rover Opportunity in a nearly 25 km-long traverse. Herein, we review and synthesize the available data to propose that the discovery and characteristics of the six meteorites could be explained as the result of their impact into a soft and wet surface, sometime during the Noachian or the H
Authors
Alberto G. Fairen, James M. Dohm, Victor R. Baker, Shane D. Thompson, William C. Mahaney, Kenneth E. Herkenhoff, J. Alexis P. Rodriguez, Alfonso F. Davila, Dirk Schulze-Makuch, M. Ramy El Maarry, Esther R. Uceda, Ricardo Amils, Hirdy Miyamoto, Kyeong J. Kim, Robert C. Anderson, Christopher P. McKay
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 seasons and fad
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
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 overloaded the rive
Authors
Ivo Lucchitta, Richard F. Holm, Baerbel K. Lucchitta
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 stratigraphy of the
Authors
Kenneth L. Tanaka, Corey M. Fortezzo, Rosalyn K. Hayward, J. Alexis P. Rodriguez, James A. Skinner
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 processed, by
Authors
N. Thomas, R. Stelter, A. Ivanov, N.T. Bridges, Kenneth E. Herkenhoff, A. S. McEwen
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 highland–low
Authors
S.C. Werner, K. L. Tanaka, J.A. Skinner
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 in the fi
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