A5043857211- Planetary Science and Exploration
- Astro and Planetary Science
- Space Exploration and Technology
- Space Science and Extraterrestrial Life
- Geology and Paleoclimatology Research
- Laser-induced spectroscopy and plasma
- Geochemistry and Geologic Mapping
- Marine and environmental studies
- Nuclear Physics and Applications
- Solar and Space Plasma Dynamics
- Geological and Geochemical Analysis
- Spaceflight effects on biology
- Isotope Analysis in Ecology
- Space Satellite Systems and Control
- Space exploration and regulation
- Scientific Research and Discoveries
- Mercury impact and mitigation studies
- Methane Hydrates and Related Phenomena
- Atmospheric aerosols and clouds
- Calibration and Measurement Techniques
- Maritime and Coastal Archaeology
- Stellar, planetary, and galactic studies
- Geomagnetism and Paleomagnetism Studies
- High-Velocity Impact and Material Behavior
- Archaeological Research and Protection
Washington University in St. Louis
2020-2025
California State University, San Marcos
2021
University of Hawaiʻi at Mānoa
2008-2019
University of Hawaii System
2008-2019
Oceanography Society
2017
University of Hawaii–West Oahu
2014
Arizona State University
2008
Carnegie Institution for Science
2008
Johns Hopkins University Applied Physics Laboratory
2008
Johns Hopkins University
2008
MESSENGER observations of Mercury’s high northern latitudes reveal a contiguous area volcanic smooth plains covering more than ~6% the surface that were emplaced in flood lava mode, consistent with average crustal compositions broadly similar to terrestrial komatiites.
The origin of plains on Mercury, whether by volcanic flooding or impact ejecta ponding, has been controversial since the Mariner 10 flybys (1974–75). High-resolution images (down to 150 meters per pixel) obtained during first MESSENGER flyby show evidence for vents around Caloris basin inner margin and demonstrate that were emplaced sequentially inside adjacent numerous large craters, thicknesses in excess several kilometers. Radial graben a floor-fractured crater may indicate intrusive...
We present new polarimetric radar data for the surface of north pole Moon acquired with Mini‐SAR experiment onboard India's Chandrayaan‐1 spacecraft. Between mid‐February and mid‐April, 2009, mapped more than 95% areas polewards 80° latitude at a resolution 150 meters. The polar region displays backscatter properties typical Moon, circular polarization ratio (CPR) values in range 0.1–0.3, increasing to over 1.0 young primary impact craters. These higher CPR likely reflect roughness...
Mercury's regolith, derived from the crustal bedrock, has been altered by a set of space weathering processes. Before we can interpret composition, it is necessary to understand nature these surface alterations. The processes that weather are same as those form exosphere (micrometeoroid flux and solar wind interactions) moderated local environment presence global magnetic field. To comprehend how acts on an understanding needed contributing act interactive system. As no direct information...
As a first step in preparing for the return of samples from Moon by Artemis Program, NASA initiated Apollo Next Generation Sample Analysis Program (ANGSA). ANGSA was designed to function as low-cost sample mission and involved curation analysis previously returned 17 that remained unopened or stored under unique conditions 50 years. These include lower portion double drive tube sealed on lunar surface, upper had unopened, variety at −27 °C approximately constitutes preliminary examination...
[1] We have used multispectral images from Clementine and data Lunar Prospector's magnetometer to conduct a survey of lunar crustal magnetic anomalies, prominent swirls, lesser known swirl markings provide new information on the nature swirls their association with anomalies. find that all swirl-like albedo patterns are associated areas magnetized crust, but not crust colocated All observed exhibit spectral characteristics similar immature material generally slightly lower FeO values...
Abstract We present new observations of pyroclastic deposits on the surface Mercury from data acquired during orbital phase MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. The global analysis brings total number such identified features 40 to 51. Some 90% are found within impact craters. locations most appear be unrelated regional smooth plains deposits, except some cluster around margins plains, similar relation between many lunar maria. A survey...
The source of water (H2O) and hydroxyl radicals (OH), identified on the lunar surface, represents a fundamental, unsolved puzzle. interaction solar-wind protons with silicates oxides has been proposed as key mechanism, but laboratory experiments yield conflicting results that suggest proton implantation alone is insufficient to generate liberate water. Here, we demonstrate in simulation combined imaging studies can be efficiently generated released through rapid energetic heating like...
Research Article| December 01, 2023 Space Weathering At The Moon Brett W. Denevi; Denevi Johns Hopkins University Applied Physics Laboratory, 11100 Road, Laurel, Maryland, 20723, U.S.A. brett.denevi@jhuapl.edu Search for other works by this author on: GSW Google Scholar Sarah K. Noble; Noble NASA Headquarters, 300 Hidden Figures Way, SW, Washington, D.C., 20546, sarah.noble-1@nasa.gov Roy Christoffersen; Christoffersen Jacobs, Mail Code XI3, Johnson Center, Houston, Texas, 77058,...
Significance Whether water is produced by solar wind (SW) radiolysis has been debated for more than four decades. In this paper, we exploit the high spatial resolution of electron microscopy and sensitivity valence energy-loss spectroscopy to detect (liquid or vapor) in vesicles within (SW-produced) space-weathered rims on interplanetary dust particle (IDP) surfaces. Water implications origin airless bodies like Moon asteroids, delivery surfaces terrestrial planets, production other...
Abstract High‐resolution images from MESSENGER provide morphological information on the nature and origin of Mercury's hollows, small depressions that likely formed when a volatile constituent was lost surface. Because graphite may be component low‐reflectance material hosts we suggest loss carbon by ion sputtering or conversion to methane proton irradiation could contribute hollows formation. Measurements widespread in 565 with pixel scales <20 m indicate average depth is 24 ± 16 m. We...
Simulated space weathering experiments on volatile-rich carbonaceous chondrites (CCs) have resulted in contrasting spectral behaviors (e.g. reddening vs bluing). The aim of this work is to investigate the origin these trends by simulating a subset minerals found meteorites. We use pulsed laser irradiation simulate micrometeorite impacts aqueously altered and observe their physical evolution as function time. Irradiation mineral lizardite, Mg-phyllosilicate, produces small degree darkening,...
Radiative transfer theory will assist in determining olivine and pyroxene proportions compositions from the surface of a planetary body composed intimately mixed minerals. In order to use radiative techniques, model requires optical constants pyroxene. Optical are parameters that describe degree light absorbed ( k ) refracted n medium. Here we only parameterize near infrared 0.6 2.5 µm natural as function forsterite number synthetic with respect wollastonite ferrosilite number. contrast...
Abstract The “light mantle” deposit at the base of South Massif in Moon's Taurus‐Littrow Valley was a primary science target for Apollo 17 exploration. possibility that it landslide triggered by ejecta from Tycho Crater is critical establishing age and constraining recent lunar impact chronology; however, mechanism emplacement has recently been questioned. newly opened 73001/73002 double drive tube Station 3 sampled 70.6 cm deep into regolith represents first stratigraphic section an...