A5008108308- Astro and Planetary Science
- Planetary Science and Exploration
- Isotope Analysis in Ecology
- High-pressure geophysics and materials
- Geological and Geochemical Analysis
- Stellar, planetary, and galactic studies
- Spacecraft and Cryogenic Technologies
- Nuclear Physics and Applications
- Astrophysics and Star Formation Studies
- Space Satellite Systems and Control
- Hydrocarbon exploration and reservoir analysis
- Gamma-ray bursts and supernovae
- X-ray Diffraction in Crystallography
- Mass Spectrometry Techniques and Applications
- Geochemistry and Geologic Mapping
- Laser-induced spectroscopy and plasma
- Chemical and Environmental Engineering Research
- Analytical Chemistry and Chromatography
- Solidification and crystal growth phenomena
- Solar and Space Plasma Dynamics
- Astronomical and nuclear sciences
- Conducting polymers and applications
- Seismic Imaging and Inversion Techniques
- Space Exploration and Technology
- Marine Biology and Environmental Chemistry
University of Tennessee at Knoxville
2012-2024
Planetary Science Institute
2024
University of Oxford
2015-2018
East Tennessee State University
2017
Science Oxford
2015
New Mexico State University
2011-2014
Abstract The exposure to irradiation from high‐energy particles alters the reflectance properties of asteroid surfaces and is referred as space weathering . This process leads an increase in spectral slope visible near‐infrared wavelengths. However, changes regolith particle size, which can vary dramatically among population, are known influence meteorites asteroids. In this context, we investigate absorption band depths fresh irradiated ordinary chondrite quantitatively compare effects...
Abstract We present evidence, via a large survey of 191 new spectra along with previously published spectra, divide in the 3 μ m spectral properties low-albedo asteroid population. One group (“sharp types,” or STs, band centers <3 m) has shape consistent carbonaceous chondrite meteorites, while other (“not sharp NSTs, bands centered >3 is not represented meteorite literature but as abundant STs among objects. Both groups are most taxonomic classes, and, except limited cases,...
Abstract The surface composition of S-type asteroids can be determined using band parameters extracted from their near-infrared (NIR) spectra (0.7–2.50 μ m) along with spectral calibrations derived laboratory samples. In the past, these empirical equations have been obtained by combining NIR meteorite samples information about and mineral abundance. For to give accurate results, characteristics they are should similar those asteroid data (i.e., signal-to-noise ratio (S/N) wavelength range)....
We compute the absorption efficiency (Qabs) of forsterite using discrete dipole approximation (DDA) in order to identify and describe what characteristics crystal grain shape size are important shape, peak location, relative strength spectral features 8-40 {\mu}m wavelength range. Using DDSCAT code, we Qabs for non-spherical polyhedral shapes with a_eff = 0.1 {\mu}m. The identified are: 1) elongation/reduction along one three crystallographic axes; 2) asymmetry, such that all axes different...
Potentially hazardous asteroids (PHAs) represent a unique opportunity for physical characterization during their close approaches to Earth. The proximity of these makes them accessible sample-return and manned missions, but could also risk life on Earth in the event collision. Therefore, detailed mineralogical analysis is key component planning future exploration missions developing appropriate mitigation strategies. In this study we present near-infrared spectra (0.7-2.55 microns) PHA...
Abstract Spacecraft missions to asteroids have revealed surfaces that variations in albedo and spectral properties. Such are also detected across the asteroid population with ground‐based observations, controlled by physical characteristics of regolith processes such as space weathering. Here, we investigate how weathering grain size influence spectra ordinary chondrite‐like observed from spectroscopy. The estimation diagnostic band parameters visible near‐infrared reflectance allow us...
Abstract Near‐infrared reflectance spectra of S‐type asteroids contain two absorptions at 1 and 2 μm (band I II ) that are diagnostic mineralogy. A parameterization these bands is frequently employed to determine the mineralogy S( IV through use ordinary chondrite calibration equations link band parameters. The most widely used study uses a Band terminal wavelength point (red edge) 2.50 μm. However, due limitations NIR detectors on prominent telescopes in asteroid research, spectral data for...
Twinkle is an upcoming 0.45-m space-based telescope equipped with a visible and two near-infrared spectrometers covering the spectral range 0.4 to 4.5 μm resolving power <italic>R</italic> ∼ 250 (λ < 2.42 μm) 60 > μm). We explore Twinkle’s capabilities for small bodies science find that, given sensitivity, pointing stability, range, mission can observe large number of bodies. The sensitivity calculated compared flux from object magnitude. number, brightness, asteroids comets that enter...
Remote-sensing observations of Solar System objects with a space telescope offer key method understanding celestial bodies and contributing to planetary formation evolution theories. The capabilities Twinkle, in low Earth orbit 0.45m mirror, acquire spectroscopic data targets the visible infrared are assessed. Twinkle is general observatory that provides on demand wide variety within wavelength ranges currently not accessible using other telescopes or only oversubscribed observatories...
Abstract Trojan asteroids (911) Agamemnon, (1172) Aneas, and (624) Hektor primitive asteroid (944) Hidalgo share a common thermal infrared spectral feature: prominent 10 μ m plateau that is also present in cometary comae spectra. To fit these spectra, we modeled individual minerals using the light-scattering multiple sphere T-matrix (MSTM) Hapke reflectance models. Modeled mineral spectra were then combined weighted least-squares (WLS) model included library of varied particle sizes...