A5083828484- Planetary Science and Exploration
- Astro and Planetary Science
- Space Exploration and Technology
- Space Science and Extraterrestrial Life
- Isotope Analysis in Ecology
- Space exploration and regulation
- Paleontology and Stratigraphy of Fossils
- Geology and Paleoclimatology Research
- Geochemistry and Geologic Mapping
- Analytical Chemistry and Chromatography
- Space Satellite Systems and Control
- Maritime and Coastal Archaeology
- Impact of Light on Environment and Health
- Aeolian processes and effects
- Spacecraft Design and Technology
- Spacecraft Dynamics and Control
- Historical and Architectural Studies
- Spaceflight effects on biology
- Geomagnetism and Paleomagnetism Studies
- Groundwater and Isotope Geochemistry
- Arctic and Antarctic ice dynamics
- Water Quality and Resources Studies
- Methane Hydrates and Related Phenomena
- Nuclear Physics and Applications
- Granular flow and fluidized beds
Jet Propulsion Laboratory
2015-2024
California Institute of Technology
2021-2022
Marshall Space Flight Center
2021
Johns Hopkins University Applied Physics Laboratory
2021
Astrogeology Science Center
2021
United States Geological Survey
2021
University of New Mexico
2021
Arizona State University
2007-2015
British Oceanographic Data Centre
2002
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGas Chromatographic Response as a Function of Sample Input Profile.C. N. Reilley, G. P. Hildebrand, and J. W. Ashley, Jr.Cite this: Anal. Chem. 1962, 34, 10, 1198–1213Publication Date (Print):September 1, 1962Publication History Published online1 May 2002Published inissue 1 September 1962https://pubs.acs.org/doi/10.1021/ac60190a008https://doi.org/10.1021/ac60190a008research-articleACS PublicationsRequest reuse permissionsArticle...
The Mars rover Opportunity has explored Victoria crater, an approximately 750-meter eroded impact crater formed in sulfate-rich sedimentary rocks. Impact-related stratigraphy is preserved the walls, and meteoritic debris present near rim. size of hematite-rich concretions decreases up-section, documenting variation intensity groundwater processes. Layering walls preserves evidence ancient wind-blown dunes. Compositional variations with depth mimic those 6 kilometers to north demonstrate that...
[1] Opportunity has been traversing the Meridiani plains since 25 January 2004 (sol 1), acquiring numerous observations of atmosphere, soils, and rocks. This paper provides an overview key discoveries between sols 511 2300, complementing earlier papers covering results from initial phases mission. Key new include (1) atmospheric argon measurements that demonstrate importance transport to winter carbon dioxide polar ice caps; (2) showing aeolian ripples were generated by easterly winds during...
Reduced weathering rates due to the lack of liquid water and significantly greater typical surface ages should result in a higher density meteorites on Mars compared Earth. Several were identified among rocks investigated during Opportunity's traverse across sandy Meridiani plains. Heat Shield Rock is IAB iron meteorite has been officially recognized as “Meridiani Planum.” Barberton olivine‐rich contains metallic Fe form kamacite, suggesting meteoritic origin. It chemically most consistent...
New geologic sketch maps and digital elevation models for King crater the surrounding lunar farside highlands were created from Lunar Reconnaissance Orbiter Camera (LROC) Wide‐angle (WAC) Narrow Angle (NAC) images. NAC images reveal that high volume impact melt accumulations exhibit evidence of dynamic processes during following emplacement resulted in downwarped zones, other morphologic anomalies visible at 50 cm pixel scale. Among most significant these forms are negative relief features,...
Abstract Wind‐abraded rocks and aeolian bedforms have been observed at the Mars 2020 Perseverance landing site, providing evidence for recent older wind directions. This study reports orientations of features measured in images to infer formative It compares these measurements with orbital observations, climate model predictions, data acquired by Environmental Dynamics Analyzer. Three‐dimensional flute textures on rocks, regolith tails extending from behind obstacles, other were using...
Abstract McLaughlin crater is a 92‐km diameter complex that formed on Mars ~4 billion years ago. The resulting basin was the site of large (~3,000 km 2 ), deep (~500 m), voluminous (~1,500 3 ) Martian lake circa 3.8 Ga. While there strong evidence hundreds lakes have existed at some point during same time period, geology extraordinary for number reasons. Detailed spectral analyses show deep‐water sediments include detrital inputs olivine and pyroxene, but lake‐floor lithologies with abundant...
[1] The weathering of meteorites found on Mars involves chemical and physical processes that can provide clues to climate conditions at the location their discovery. Beginning sol 1961, Opportunity rover encountered three large iron within a few hundred meters each other. In order discovery, these rocks have been assigned unofficial names Block Island, Shelter Mackinac Island. Each rock presents unique but complimentary set features increase our understanding Meridiani Planum. Significant...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDe-Tailing and Sharpening of Response Peaks in Gas ChromatographyJ. W. Ashley Charles N. ReilleyCite this: Anal. Chem. 1965, 37, 6, 626–630Publication Date (Print):May 1, 1965Publication History Published online1 May 2002Published inissue 1 1965https://pubs.acs.org/doi/10.1021/ac60225a001https://doi.org/10.1021/ac60225a001research-articleACS PublicationsRequest reuse permissionsArticle Views140Altmetric-Citations18LEARN ABOUT THESE METRICSArticle...
The Mars Exploration Rover Opportunity investigated four rocks, informally dubbed Barberton, Santa Catarina, Santorini, and Kasos, that are possible stony meteorites. Their chemical mineralogical composition is similar to the howardite, eucrite, diogenite group but with additional metal, mesosiderite silicate clasts. Because of their virtually identical because they appear represent a relatively rare meteorites, probably paired. rocks were serendipitously several kilometers apart, suggesting...
Abstract– Meridiani Planum is the first officially recognized meteorite find on surface of Mars. It was discovered at and named after landing site Mars Exploration Rover Opportunity. Based its composition, it classified as a IAB complex iron meteorite. Mössbauer spectra obtained by Opportunity are dominated kamacite (α‐Fe‐Ni) exhibit small contribution ferric oxide. Several features in have been neglected to date. To shed more light these features, five specimens were investigated analogs...
Spacecraft exploring Mars such as the Exploration Rovers Spirit and Opportunity, well Science Laboratory or Curiosity rover, have accumulated evidence for wet habitable conditions on early more than 3 billion years ago. Current conditions, by contrast, are cold, extremely arid seemingly inhospitable. To evaluate exactly how dry today's environment is, it is important to understand ongoing current weathering processes. Here we present chemical rates determined Mars. We use oxidation of iron...
Numerous loose rocks with dimensions of a few centimeters to tens and no obvious physical relationship outcrop have been observed along the traverse Mars Exploration Rover Opportunity. To date, about dozen these analyzed Opportunity's contact instruments, providing information elemental chemistry (Alpha Particle X‐ray Spectrometer), iron mineralogy oxidation states (Mössbauer Spectrometer) texture (Microscopic Imager). These “cobbles” appear be impact related, three distinct groups can...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGas Chromatographic Response to Plug-Shaped Sample Inputs. Calculation of Plate Height from Curve.J. W. Ashley, G. P. Hildebrand, and C. N. ReilleyCite this: Anal. Chem. 1964, 36, 7, 1369–1371Publication Date (Print):June 1, 1964Publication History Published online1 May 2002Published inissue 1 June 1964https://pubs.acs.org/doi/10.1021/ac60213a003https://doi.org/10.1021/ac60213a003research-articleACS PublicationsRequest reuse permissionsArticle...
We have used visible and near‐infrared Panoramic Camera (Pancam) spectral data acquired by the Opportunity rover to analyze 15 rock fragments at Meridiani Planum landing site. These results were then compared geochemistry measurements made in situ instruments Mössbauer (MB) Alpha Particle X‐ray Spectrometer (APXS) determine feasibility of mineralogic characterization from Pancam data. Our suggest that dust alteration rinds coat many fragments, which limits our ability adequately measure...
Abstract We have used Mars Exploration Rover Opportunity data to investigate the origin and alteration of lithic types along western rim Noachian‐aged Endeavour crater on Meridiani Planum. Two geologic units are identified rim: Shoemaker Matijevic formations. The formation consists two polymict impact breccia: clast‐rich with coarser clasts in upper units; clast‐poor smaller lower units. Comparisons terrestrial craters show that represent more distal ejecta from at least earlier impacts,...