A5050371740- Planetary Science and Exploration
- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Space Exploration and Technology
- Astrophysics and Star Formation Studies
- Space Satellite Systems and Control
- Geological and Geochemical Analysis
- Isotope Analysis in Ecology
- Atmospheric Ozone and Climate
- Geology and Paleoclimatology Research
- Calibration and Measurement Techniques
- Scientific Research and Discoveries
- Atmospheric and Environmental Gas Dynamics
- Mineralogy and Gemology Studies
- High-pressure geophysics and materials
- Geochemistry and Geologic Mapping
- Spacecraft and Cryogenic Technologies
- Astronomy and Astrophysical Research
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Laser-induced spectroscopy and plasma
- Atmospheric aerosols and clouds
- Space Science and Extraterrestrial Life
- Nuclear Physics and Applications
Space Science Institute
2005-2023
American Astronomical Society
2023
Planetary Science Institute
2009-2015
Jet Propulsion Laboratory
2008-2009
Washington University in St. Louis
2006-2008
California Institute of Technology
2008
Louisiana State University
2000-2005
Louisiana State University Agricultural Center
2005
Aims. The SiC optical constants are fundamental inputs for radiative transfer (RT) models of astrophysical dust environments. However, previously published values contain errors and do not adequately represent the bulk physical properties cubic (β) polytype usually found around carbon stars. We provide new, uncompromised β- α-SiC derived from single-crystal reflectance spectra investigate quantitatively (i) whether there is any difference between α- β-SiC that can be seen in infrared (IR)...
Laboratory measurements of unpolarized and polarized absorption spectra various samples crystal structures silicon carbide (SiC) are presented from 1200–35000 cm−1 (λ ∼ 8–0.28 μm) used to improve the accuracy optical functions (n k) infrared (IR) ultraviolet (UV). Comparison with previous λ 6–20 μm thin-film constrains thickness films verifies that recent IR reflectivity data provide correct values for k in region. We extract n needed radiative transfer models using a new "difference...
We derive optical constants ( n λ ) and k )) from laboratory reflectance spectra acquired at visible to near‐infrared wavelengths for epsomite (MgSO 4 ⋅7H 2 O), bloedite (Na Mg(SO ⋅4H hexahydrite ⋅6H O) both room temperature 120 K. These hydrated sulfates are candidate surface compounds outer solar system icy satellites such as Europa, Ganymede, Callisto, well Mars. Our results permit quantitative abundance modeling of Galileo , Cassini‐Huygens New Horizons Mars Reconnaissance Orbiter...
The 2175 Å absorption bump, a feature often ascribed to graphite grains and ubiquitous in the spectra of sight lines through Galactic diffuse interstellar medium, is generally weak or nonexistent for objects outside our Galaxy. Many active galaxies seem have Small Magellanic Cloud–type dust extinction, suggesting that presence bump Galaxy may be exceptional. Recently, it was suggested spectrum high‐ionization broad line QSO UM 425 shows feature. This apparent seen rest frame other QSOs...
Planetary remote sensing of regolith surfaces requires use theoretical models for interpretation constituent grain physical properties. In this work, we review and critically evaluate past efforts to strengthen numerical radiative transfer (RT) with comparison a trusted set nadir incidence laboratory quartz emissivity spectra. By first establishing baseline statistical metric rate successful model‐laboratory spectral fits, assess the efficacy hybrid computational solutions (Mie theory +...
Laboratory measurements quantifying the effect of Fe substituting for Mg in olivine are needed to distinguish compositional from temperature, grain size and shape effects observational data. To address this need, we study room temperature absorption spectra a large suite olivines evenly spaced across compositions. We apply principle that classical dispersion theory may be used determine peak positions as well widths, strengths possibly optical function (n(λ) k(λ)) estimates thin film samples...
Visible and near-infrared wavelength (VNIR, λ = 0.35-5 mm) laboratory diffuse reflectance spectra corresponding optical functions (real imaginary refractive indices) for several iron sulfates (natural K- Na-jarosite, szomolnokite, rhomboclase) are presented. On Mars, jarosite has been identified in Meridiani Planum, Mawrth Vallis, Melas Chasma, Eridania Basin; szomolnokite found as distinct layers at Columbus Crater outcrops Juventae rhomboclase Gusev Crater. Constraining the mineralogy...
Abstract We spectrally characterize ( λ = 0.35–10 µm) the low‐humidity polymorph of kieserite (MgSO 4 ·H 2 O), which is abundant on Mars and likely present Europa, at various grain sizes temperatures (100–300 K) relevant to surfaces Europa. Compositional analysis these often relies remote sensing using imaging spectrometers such as Reconnaissance Orbiter Compact Imaging Spectrometer for (CRISM), Express Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité, Galileo Near‐Infrared...
In the domain of space science, numerous ground-based and space-borne data various phenomena have been accumulating rapidly, making analysis scientific interpretation challenging. However, recent trends in application artificial intelligence (AI) shown to be promising extraction information or knowledge discovery from these extensive sets. Coincidentally, preparing for use as inputs AI algorithms, referred AI-readiness, is one outstanding challenges leveraging science. Preparation AI-ready...
Optical functions (n and k) of cosmic dust species like forsterite (Mg2SiO4) are required at all wavelengths to quantify the temperature amount dust. Astronomers combine optical olivine in different ways, which will affect radiative transfer models. We investigated what recent updates ultraviolet-visible-near-infrared (UV-VIS-NIR) laboratory spectra choice n, k dataset have on measured UV-VIS-NIR transmission synthetic forsterite, MgO, SiO2, (Fo90), meteoritic (pallasite). derived for these...
Nitride dust is predicted to form in small amounts around carbon stars, but the most likely candidate species such as aluminium nitride (AlN) have not yet been detected. Recently, α-Si3N4 was inferred be main carrier of 8.5–12.5 μm absorption band(s) an extreme star (AFGL 5625), based on comparison with laboratory KBr dispersion spectra. However, this band has also attributed silicon carbide (SiC) and C3. To investigate whether or truly detected if it present other we (i) gathered new...
Using radiances acquired with Cassini's Visual and Infrared Mapping Spectrometer (VIMS), we construct high solar phase angle curves for Saturn's second largest moon, Rhea. Ground-based studies of Rhea Saturnian icy satellites are focussing on low angles; to our knowledge, these the first curve data angles >70°. We compare similar Enceladus at near-infrared wavelengths estimate amount water vapor that could possibly be generated thus set an upper limit geologic activity may occurring find...