A5020708868- Planetary Science and Exploration
- Astro and Planetary Science
- Space Exploration and Technology
- Isotope Analysis in Ecology
- Geological and Geochemical Analysis
- Geology and Paleoclimatology Research
- Spacecraft and Cryogenic Technologies
- Geochemistry and Geologic Mapping
- Methane Hydrates and Related Phenomena
- High-pressure geophysics and materials
- Spectroscopy and Chemometric Analyses
- Mineralogy and Gemology Studies
- Radioactive element chemistry and processing
- Nuclear Physics and Applications
- Stellar, planetary, and galactic studies
- Marine and environmental studies
- Spectroscopy Techniques in Biomedical and Chemical Research
- Hydrocarbon exploration and reservoir analysis
- Paleontology and Stratigraphy of Fossils
- RNA regulation and disease
- Iron oxide chemistry and applications
- RNA modifications and cancer
- Glass properties and applications
- RNA Research and Splicing
- Advanced Chemical Sensor Technologies
Wesleyan University
2011-2024
University of Colorado Boulder
2024
Yale University
2003-2006
University of California, Los Angeles
1999-2004
Whitney Museum of American Art
2004
Planetary Science Institute
2000-2003
University of Tennessee at Knoxville
1997-2001
Cornell University
2000
Brown University
1995
Wetted Apatite The long-running story of the dry Moon was rewritten a few years ago when hydrogen-bearing glass spherules were discovered. highest water contents are found in lunar apatite, at levels suspiciously comparable to content Earth apatites. Boyce et al. (p. 400 , published online 20 March; see Perspective by Anand ) now show that apatite is not reliable indicator abundance mare basalts. existence with high an almost inevitable consequence loss tiny amounts fluorine-rich from melt...
Mars Pathfinder obtained multispectral, elemental, magnetic, and physical measurements of soil dust at the Sagan Memorial Station during course its 83 sol mission. We describe initial results from these measurements, concentrating on multispectral elemental data, use along with previous Viking, SNC meteorite, telescopic results, to help constrain origin evolution Martian dust. find that soils can be divided into least eight distinct spectral units, based parameterization Imager for (IMP) 400...
Rocks at the Mars Pathfinder site are probably locally derived. Textures on rock surfaces may indicate volcanic, sedimentary, or impact‐generated rocks, but aeolian abration and dust coatings prevent unambiguous interpretation. Multispectral imaging has resolved four spectral classes of rocks: gray red, which occur different same rocks; pink, is soil crusts; maroon, occurs as large boulders, mostly in far field. assigned to two trends based position peak reflectance: primary trend contains...
The high D/H of the Martian atmosphere (∼5–6 × terrestrial) is considered strong evidence for loss water to space. timing and magnitude from Mars can be constrained by measurements in meteorites. Previous studies meteorites have shown a large range D/H, terrestrial values as current atmosphere. Here we show that ancient (∼4 Ga) meteorite ALH84001 has 4 young (∼0.17 Shergotty 5.6 terrestrial. We also find Los Angeles shergottite zoning correlated igneous growth zoning, strongly suggesting...
The Moon contains chlorine that is isotopically unlike of any other body yet studied in the Solar System, an observation has been interpreted to support traditional models formation a nominally hydrogen-free ("dry") Moon. We have analyzed abundances and isotopic compositions Cl H lunar mare basalts, find little evidence anhydrous lava outgassing was important generating isotope anomalies, because (37)Cl/(35)Cl ratios are not related abundance, or D/H manner consistent with lava-outgassing...
Research Article| November 01, 2000 Los Angeles: The most differentiated basaltic martian meteorite Alan E. Rubin; Rubin 1Institute of Geophysics and Planetary Physics, University California, Angeles, California 90095-1567, USA Search for other works by this author on: GSW Google Scholar Paul H. Warren; Warren James P. Greenwood; Greenwood Robert S. Verish; Verish 2P.O. Box 237, Sunland, 91040, Laurie A. Leshin; Leshin 3Department Geology Center Meteorite Studies, Arizona State University,...
Abstract— We compare and contrast the mineralogy petrology of 2 stones extremely ferroan Cr‐poor martian meteorite, Los Angeles. The are similar in many characteristics, strongly suggesting that they originated from a single flow or shallow intrusion. However, stone is more enriched late‐stage materials than its larger, widely studied, sibling. Stone has far higher abundance (˜25 vol%) 1 (10 combined “opaques,” meaning not only conventional opaque minerals but also, abundantly, fine‐grained...
Abstract We report two experiments using 13 mineral and rock samples exposed to a complex synthetic Venus atmosphere composed of nine gases for durations 30 11 days conducted the NASA Glenn Extreme Environments Rig (GEER). Examination our run products scanning electron microscope equipped with an energy dispersive spectrometer reveals secondary minerals predominantly formed from reactions Fe Ca in solid sulfur atmospheric gas, results largely predicted literature, indicating that such...
Apatite grains in lunar mare basalts contain hydrogen that ranges D/H ratio by more than a factor of two. For most these basalts, the ratios their apatite decrease with measures host basalts' time spent at elevated temperature, specifically Fe-Mg homogenization pyroxenes. Most homogeneous pyroxenes (i.e., constant Fe/Mg ratio) have low (δD ≈ –100‰), whereas heterogeneous varying or zoned Fe/Mg) high up to ~ +1100‰). This relationship suggests values were acquired during thermal processing,...
Abstract— Compositional and textural relationships of shock‐melted glasses in the Allan Hills (ALH) 84001 meteorite have been examined by optical microscopy, electron microprobe analysis, compositional mapping. The feldspathic silica exhibit features which constrain relative timing shock events carbonate deposition ALH 84001. are stoichiometric compositions plausibly described as forming from igneous plagioclase (An 27–39 Ab 58–68 Or 3–7 ) or sanidine (Or 51 46 An 3 ), a mixture these phases...
Research Article| November 01, 2006 Evidence for an acidic ocean on Mars from phosphorus geochemistry of Martian soils and rocks James P. Greenwood; Greenwood 1Department Earth Environmental Sciences, Wesleyan University, Middletown, Connecticut 06459, USA, Department Geology Geophysics, Kline Laboratory, Yale New Haven, 06520, USA Search other works by this author on: GSW Google Scholar Ruth E. Blake 2Department Author Article Information Publisher: Geological Society America Received: 21...
The volcanic Sulphur Springs, St. Lucia, present an extreme environment due to high temperatures, low pH values, and concentrations of sulfate boron. Lucia offers some unique geochemical characteristics that may shape the microbial communities within Springs area. We chose six pools representing a range for detailed community analyses. Chemical varied greatly between sites. Microbial diversity was analyzed using 16S rRNA gene clone library With exception one pool with relatively dissolved...
While it is now recognized that the Moon has indigenous water and volatiles, their total abundances are unclear, with current literature estimates ranging from nearly absent to Earth-like levels. Similarly unconstrained source of Moon's water, which could be cometary, chondritic, or primordial nebula. Here we measure H2O D/H in olivine-hosted melt inclusions lunar mare basalts 12018, 12035, 12040, part consanguineous suite Apollo 12 olivine differ primarily because cooling rate (Walker et...
Abstract We use the known surface boulder-size distribution of C-type rubble pile asteroid Ryugu (NEA 162173) to determine its macroporosity, assuming it is a homogeneous granular aggregate. show that volume-frequency boulders, cobbles, and pebbles, well-represented by lognormal function with σ = 2.4 ± 0.1 μ 0.2 0.05. Application linear-mixture packing theory yields value for macroporosity ϕ 0.14 0.04. Given low bulk density 1.19 gm cm −3 , this implies an average Ryugu’s rocks 1.38 0.07...
Research Article| August 01, 2004 Age and temperature of shock metamorphism Martian meteorite Los Angeles from (U-Th)/He thermochronometry Kyoungwon Min; Min 1Department Geology Geophysics, Yale University, 210 Whitney Avenue, New Haven, Connecticut 06511, USA Search for other works by this author on: GSW Google Scholar Peter W. Reiners; Reiners Stefan Nicolescu; Nicolescu James P. Greenwood (2004) 32 (8): 677–680. https://doi.org/10.1130/G20510.1 Article history received: 24 Jan rev-recd:...