Browsing by Author "Cloutis, Edward A."

Now showing items 1-15 of 15

    • 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 ...

    • 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 ...

    • 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 ...

    • 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 ...

    • 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 ...

    • Reflectance spectra of "featureless" materials and the surface mineralogies of M- and E-class asteroids 

      Cloutis, Edward A.; Gaffey, Michael J.; Smith, Dorian G.W.; St. J. Lambert, Richard (Journal of Geophysical Research, 1990-01-10)
      The 0.3- to 2.6-μm reflectance spectra of meteoritic enstatite (nearly pure MgSiO3), iron meteorite metal, magnetite and amorphous carbon, and various mixtures of these materials with mafic silicates have been measured in ...

    • Spectral reflectance properties of zeolites and remote sensing implications 

      Cloutis, Edward A.; Asher, Pranoti M.; Mertzman, Stanley A. (Journal of Geophysical Research, 2002-09-25)
      The 0.3- to 26-μm reflectance spectra of a suite of 28 zeolites were measured and analyzed to derive spectral-compositional-structural relationships. Below ~7 μm, the spectra are largely dominated by absorption features ...

    • Stability of hydrated minerals on Mars 

      Cloutis, Edward A.; Craig, Michael A.; Mustard, John F.; Kruzelecky, Roman V.; Jamroz, Wes R.; Scott, Alan; Bish, David L.; Poulet, François; Bibring, Jean-Pierre; King, Penelope L. (Geophysical Research Letters, 2007-10-20)
      The validity of recent identification of various hydrated minerals (kieserite, gypsum, hexahydrite, nontronite, chamosite, and montmorillonite) on Mars was assessed by exposing these minerals to simulated Martian surface ...

    • Submicroscopic metallic iron in lunar soils estimated from the in situ spectra of the Chang’E-3 mission 

      Wang, Zhenchao; Wu, Yunzhao; Blewett, David T.; Cloutis, Edward A.; Zheng, Yongchun; Chen, Jun (Geophysical Research Letters, 2017-04-22)
      Submicroscopic metallic iron (SMFe) created by space weathering has strong effects on the optical properties of the lunar surface. Spectra measured in situ by the visible-near-infrared spectrometer (VNIS) on board the ...

    • Surface albedo and spectral variability of Ceres 

      Li (李荐扬), Jian-Yang; Reddy, Vishnu; Nathues, Andreas; Le Corre, Lucille; Izawa, Matthew R. M.; Cloutis, Edward A.; Sykes, Mark V.; Carsenty, Uri; Castillo-Rogez, Julie C.; Hoffmann, Martin; Jaumann, Ralf; Krohn, Katrin; Mottola, Stefano; Prettyman, Thomas H.; Schaefer, Michael; Schenk, Paul; Schröder, Stefan E.; Williams, David A.; Smith, David E.; Zuber, Maria T.; Konopliv, Alexander S.; Park, Ryan S.; Raymond, Carol A.; Russell, Christopher T. (The Astrophysical Journal Letters, 2016-01-29)
      Previous observations suggested that Ceres has active, but possibly sporadic, water outgassing as well as possibly varying spectral characteristics over a timescale of months. We used all available data of Ceres collected ...