Now showing items 1-20 of 31

    • Acid weathering of basalt and basaltic glass: 2. Effects of microscopic alteration textures on spectral properties 

      Smith, Rebecca J.; Horgan, Briony H. N.; Mann, Paul; Cloutis, Edward A.; Christensen, Philip R. (Journal of Geophysical Research: Planets, 2017-01-24)
      Acid alteration has long been proposed for the Martian surface, and so it is important to understand how the resulting alteration textures affect surface spectra. Two basaltic materials of varying crystallinity were altered ...
    • Acidic weathering of basalt and basaltic glass: 1. Near-infrared spectra, thermal infrared spectra, and implications for Mars 

      Horgan, Briony H. N.; Smith, Rebecca J.; Cloutis, Edward A.; Mann, Paul; Christensen, Philip R. (Journal of Geophysical Research: Planets, 2017-01-24)
      Acid-leached rinds and coatings occur in volcanic environments on Earth and have been identified using orbital spectroscopy on Mars, but their development is poorly understood. We simulated long-term open-system acidic ...
    • Calibrations of phase abundance, composition, and particle size distribution for olivine-orthopyroxene mixtures from reflectance spectra 

      Cloutis, Edward A.; Gaffey, Michael J.; Jackowski, Timothy L.; Reed, Kevin L. (American Geophysical Union, 1986-10-10)
      Spectral reflectance measurements of characterized (phase abundance, particle size) mixtures of olivine and orthopyroxene were utilized to define the correlations between spectral and albedo parameters of such assemblages ...
    • Composition of Jupiter irregular satellites sheds light on their origin 

      Bhatt, M.; Reddy, V.; Schindler, K.; Cloutis, E.; Bhardwaj, A.; Corre, L. L.; Mann, P. (EDP Sciences, 2017)
      Context. Irregular satellites of Jupiter with their highly eccentric, inclined and distant orbits suggest that their capture took place after the giant planet migration. Aims. We aim to improve our understanding of the ...
    • Compositional homogeneity of CM parent bodies. 

      Vernazza, P.; Marsset, M.; Beck, P.; Binzel, R. P.; Birlan, M.; Cloutis, E. A.; DeMeo, F. E.; Dumas, C.; Hiroi, T. (The Astronomical Journal, 2016-08-10)
      CM chondrites are the most common type of hydrated meteorites, making up ∼1.5% of all falls. Whereas most CM chondrites experienced only low-temperature (∼0°C–120°C) aqueous alteration, the existence of a small fraction ...
    • Detection of rotational spectral variation on the M-type asteroid (16) Psyche 

      Sanchez, Juan A.; Reddy, Vishnu; Shepard, Michael K.; Thomas, Cristina; Cloutis, Edward A.; Takir, Driss; Conrad, Albert; Kiddell, Cain; Applin, Daniel (The Astronomical Journal, 2016-12-28)
      The asteroid (16) Psyche is of scientific interest because it contains ∼1% of the total mass of the asteroid belt and is thought to be the remnant metallic core of a protoplanet. Radar observations have indicated the ...
    • Diaspores and related hydroxides' Spectral-compositional properties and implications for Mars 

      Cloutis, Edward A; Bell, James F. III (Journal of Geophysical Research, 2000-03-25)
      Differences in spectral reflectance properties (0.3-26 μm) of a suite of metal hydroxides (gibbsite, böhmite, diaspore, goethite, and manganite) have been found to be a function of both structural and compositional differences ...
    • Distribution of hydrated minerals in the north polar region of Mars 

      Horgan, B. H.; Bell, J. F. III; Noe Dobrea, E. Z.; Cloutis, E. A.; Bailey, D. T.; Craig, M. A.; Roach, L. H.; Mustard, J. F. (Journal of Geophysical Research, 2009-01-28)
      The previous discovery of extensive deposits of hydrated minerals in Olympia Planum in the north polar region of Mars by the Mars Express OMEGA instrument raises important questions about the origin and subsequent ...
    • Evolution of Occator Crater on (1) Ceres 

      Nathues, A.; Platz, T.; Thangjam, G.; Hoffmann, M.; Mengel, K.; Cloutis, E. A.; Le Corre, L.; Reddy, V.; Kallisch, J.; D. A. Crown, D. A. (The Astronomical Journal, 2017-02-17)
      The dwarf planet Ceres (diameter 939 km) is the largest object in the main asteroid belt. Recent investigations suggest that Ceres is a thermally evolved, volatile-rich body with potential geological activity, a body which ...
    • Imaging spectroscopy of geological samples and outcrops: Novel insights from microns to meters 

      Greenberger, Rebecca N.; Mustard, John F.; Ehlmann, Bethany L.; Blaney, Diana L.; Cloutis, Edward A.; Wilson, Janette H.; Green, Robert O.; Fraeman, Abigail A. (GSA Today, 2015-12-01)
      Imaging spectroscopy is a powerful, non-destructive mineralogic tool that provides insights into a variety of geological processes. This remote measurement technique has been used for decades from orbital or aerial platforms ...
    • Light-toned salty soils and coexisting Si-rich species discovered by the Mars Exploration Rover Spirit in Columbia Hills 

      Wang, Alian; Bell, J. F. III; Li, Ron; Johnson, J. R.; Farrand, W. H.; Cloutis, E. A.; Arvidson, R. E.; Crumpler, L.; Squyres, S. W.; McLennan, S. M.; Herkenhoff, K. E.; Ruff, S. W.; Knudson, A. T.; Chen, Wei; Greenberger, R. (Journal of Geophysical Research, 2008-12-19)
      Light-toned soils were exposed, through serendipitous excavations by Spirit Rover wheels, at eight locations in the Columbia Hills. Their occurrences were grouped into four types on the basis of geomorphic settings. At ...
    • Manganese-rich olivines: Identification from spectral reflectance properties 

      Cloutis, Edward A. (Journal of Geophysical Research, 1997-11-25)
      Reflectance spectra of manganese-rich olivines were examined to determine which spectral features allow these minerals to be distinguished from forsteritic-fayalitic olivines. The results indicate that manganese-rich ...
    • Metal-silicate mixtures: Spectral properties and applications to asteroid taxonomy. 

      Cloutis, Edward A.; Gaffey, Michael J.; Smith, Dorian G. W.; St. J. Lambert, Richard (Journal of Geophysical Research, 1990-06-10)
      The reflectance spectra of combinations of olivine, orthopyroxene, and iron meteorite metal show systematic variations in spectral properties which can be used to constrain many of the physical and chemical properties of ...
    • Mineralogic constraints on sulfur-rich soils from Pancam spectra at Gusev crater, Mars 

      Johnson, J. R.; Bell, J. F. III; Cloutis, E.; Staid, M.; Farrand, W. H.; McCoy, T.; Rice, M.; Wang, A.; Yen, A. (Geophysical Research Letters, 2007-07-06)
      The Mars Exploration Rover (MER) Spirit excavated sulfur-rich soils exhibiting high albedo and relatively white to yellow colors at three main locations on and south of Husband Hill in Gusev crater, Mars. The multispectral ...
    • Optical and radiometric models of the NOMAD instrument part I: the UVIS channel 

      Vandaele, Ann C.; Willame, Yannick; Depiesse, Cédric; Thomas, Ian R.; Robert, Séverine; Bolsée, David; Patel, Manish R.; Mason, Jon P.; Leese, Mark; Lesschaeve, Stefan; Antoine, Philippe; Daerden, Frank; Delanoye, Sofie; Drummond, Rachel; Neefs, Eddy; Ristic, Bojan; Lopez-Moreno, José-Juan; Bellucci, Giancarlo; NOMAD Team, NOMAD Team (Optics Express, 2015-11-09)
      The NOMAD instrument has been designed to best fulfil the science objectives of the ExoMars Trace Gas Orbiter mission that will be launched in 2016. The instrument is a combination of three channels that cover the UV, ...
    • Optical and radiometric models of the NOMAD instrument part II: the infrared channels - SO and LNO 

      Thomas, I. R.; Vandaele, A.C.; Robert, S.; Neefs, E.; Drummond, R.; Daerden, F.; Delanoye, S.; Ristic, B.; Berkenbosch, S.; Clairquin, R.; Maes, J.; Bonnewijn, S.; Depiesse, C.; Mahieux, A.; Trompet, L.; Neary, L.; Willame, Y.; Wilquet, V.; Nevejans, D.; Aballea, L.; Moelans, W.; De Vos, L.; Lesschaeve, S.; Van Vooren, N.; Lopez-Moreno, J.-J.; Patel, M. R.; Bellucci, G.; NOMAD Team, NOMAD Team (Optics Express, 2016-02-16)
      NOMAD is a suite of three spectrometers that will be launched in 2016 as part of the joint ESA-Roscosmos ExoMars Trace Gas Orbiter mission. The instrument contains three channels that cover the IR and UV spectral ranges ...
    • Oxo Crater on (1) Ceres: Geological History and the Role of Water-ice 

      Nathues, A.; Platz, T.; Hoffmann, M.; Thangjam, G.; Cloutis, E. A.; Applin, D. M.; Le Corre, L.; Reddy, V.; Mengel, K.; Protopapa, S.; Takir, D.; Preusker, F.; Schmidt, B. E.; Russell, C. T. (The Astronomical Journal, 2017-08-04)
      Dwarf planet Ceres (∅ ∼ 940 km) is the largest object in the main asteroid belt. Investigations suggest that Ceres is a thermally evolved, volatile-rich body with potential geological activity, a body that was never ...
    • Physical characterization of ~2 m diameter near-Earth asteroid 2015 TC25: A possible boulder from E-type asteroid (44) Nysa 

      Reddy, Vishnu; Sanchez, Juan A.; Bottke, William F.; Thirouin, Audrey; Rivera-Valentin, Edgard G.; Kelley, Michael S.; Ryan, William; Cloutis, Edward A.; Tegler, Stephen C.; Ryan, Eileen V.; Taylor, Patrick A.; Richardson, James E.; Moskovitz, Nicholas; Le Corre, Lucille (The Astronomical Journal, 2016-11-11)
      Small near-Earth asteroids (NEAs) (<20 m) are interesting, because they are progenitors for meteorites in our terrestrial collection. The physical characteristics of these small NEAs are crucial to our understanding of the ...
    • Pyroxene reflectance spectra: Minor absorption bands and effects of elemental substitutions 

      Cloutis, Edward A. (Journal of Geophysical Research, 2002-06-13)
      Reflectance spectra of a suite of compositionally diverse pyroxenes exhibit variable spectral properties which are associated with various elemental substitutions. Those associated with transition series elements, such as ...
    • Pyroxene spectroscopy revisited: Spectral-compositional correlations and relationship to geothermometry. 

      Cloutis, Edward A.; Gaffey, Michael J. (Journal of Geophysical Research, 1991-12-25)
      Pyroxene reflectance and transmittance spectra have been examined in a search for systematic relationships between spectral features and compositional variations and to assess the applicability of reflectance spectroscopy ...