A5034666199- Planetary Science and Exploration
- Astro and Planetary Science
- Geology and Paleoclimatology Research
- Space Exploration and Technology
- Space Science and Extraterrestrial Life
- Marine and environmental studies
- Geophysics and Gravity Measurements
- Methane Hydrates and Related Phenomena
- Paleontology and Stratigraphy of Fossils
- Advancements in Solid Oxide Fuel Cells
- Hydrocarbon exploration and reservoir analysis
- Geomagnetism and Paleomagnetism Studies
- Electrocatalysts for Energy Conversion
- Geological and Geochemical Analysis
- Fuel Cells and Related Materials
- Scientific Research and Discoveries
- Spaceflight effects on biology
- Electronic and Structural Properties of Oxides
- Spacecraft and Cryogenic Technologies
- earthquake and tectonic studies
- Isotope Analysis in Ecology
- Gamma-ray bursts and supernovae
- Maritime and Coastal Archaeology
- Hydraulic Fracturing and Reservoir Analysis
- High-pressure geophysics and materials
University of Arizona
2015-2025
Planetary Science Institute
2017-2024
Southwest Research Institute
2010-2022
Lunar and Planetary Institute
2021-2022
Target (United States)
2017
Solar System Exploration Research Virtual Institute
2017
Massachusetts Institute of Technology
2006-2016
Colorado School of Mines
2008-2016
Geological Society of America
2010
California Institute of Technology
2008
High-resolution gravity data obtained from the dual Gravity Recovery and Interior Laboratory (GRAIL) spacecraft show that bulk density of Moon's highlands crust is 2550 kilograms per cubic meter, substantially lower than generally assumed. When combined with remote sensing sample data, this implies an average crustal porosity 12% to depths at least a few kilometers. Lateral variations in correlate largest impact basins, whereas lateral composition. The low-bulk allows construction global...
The Gravity Recovery and Interior Laboratory (GRAIL) mission has sampled lunar gravity with unprecedented accuracy resolution.The GM, the product of gravitational constant G mass M, is very well determined.However, uncertainties in mean density, 3345.56 ± 0.40 kg/m 3 , are limited by G. Values spherical harmonic degree-2 coefficients J 2 C 22 as Love number k describing elastic response to tidal forces, come from two independent analyses month GRAIL Primary Mission data at Jet Propulsion...
Observations from the Gravity Recovery and Interior Laboratory (GRAIL) mission indicate a marked change in gravitational signature of lunar impact structures at morphological transition, with increasing diameter, complex craters to peak-ring basins. At crater diameters larger than ~200 km, central positive Bouguer anomaly is seen within innermost peak ring, an annular negative extends outward this ring outer topographic rim crest. These observations demonstrate that basin-forming impacts...
The earliest history of the Moon is poorly preserved in surface geologic record due to high flux impactors, but aspects that may be subsurface structures. Application gravity gradiometry observations by Gravity Recovery and Interior Laboratory (GRAIL) mission results identification a population linear anomalies with lengths hundreds kilometers. Inversion indicates elongated positive-density are interpreted ancient vertical tabular intrusions or dikes formed magmatism combination extension...
High-resolution gravity data from the Gravity Recovery and Interior Laboratory spacecraft have clarified origin of lunar mass concentrations (mascons). Free-air anomalies over impact basins display bull's-eye patterns consisting a central positive (mascon) anomaly, surrounding negative collar, outer annulus. We show that this pattern results basin excavation collapse followed by isostatic adjustment cooling contraction voluminous melt pool. used hydrocode to simulate self-consistent...
New results from the Compact Reconnaissance Imaging Spectrometer for Mars and High Resolution Science Experiment Context Imager cameras on Orbiter provide insights into origin of interior layered deposits in Valles Marineris analysis a thick, well‐exposed section western Candor Chasma. Most deposit is dominated spectrally by nanophase ferric oxide like that found globally distributed eolian dust, with addition prevalent component monohydrated sulfates. A rippled mantle containing both...
[1] Columbus crater in the Terra Sirenum region of Martian southern highlands contains light-toned layered deposits with interbedded sulfate and phyllosilicate minerals, a rare occurrence on Mars. Here we investigate detail morphology, thermophysical properties, mineralogy, stratigraphy these deposits; explore their regional context; interpret crater's aqueous history. Hydrated mineral-bearing occupy discrete ring around walls are also exposed beneath younger materials, possibly lava flows,...
The Meridiani Planum region of Mars has been identified as a past aqueous activity by combination orbital and in situ observations that revealed evidence for sulfate‐rich dirty evaporites formed playa setting. We investigate the hydrology sedimentary record this area using global regional hydrological models which groundwater flow is driven precipitation, evaporation, surface topography. Groundwater evaporation results evaporite precipitation cementation aeolian sediments, allowing...
[1] Mars was warmer and wetter during the early to middle Noachian, before a hydrologic climatic transition in late Noachian led decrease erosion rates, change valley network morphology, geochemical shift from phyllosilicate sulfate formation that culminated of widespread sulfate-rich sedimentary deposits Meridiani Planum surrounding Arabia Terra region. This secular evolution overprinted by episodic periodic variability, as recorded fluvial record, layering, erosional discontinuities. We...
Abstract We analyzed data from the Gravity Recovery and Interior Laboratory (GRAIL) mission using a localized admittance approach to map out spatial variations in vertical density structure of lunar crust. Mare regions are characterized by distinct decrease with depth, while farside is an increase depth at average gradient ∼35 kg m −3 km −1 typical surface porosities least 20%. The Apollo 12 14 landing site region has similar farside, permitting comparison seismic velocity profiles. interior...
Abstract What allows a planet to be both within potentially habitable zone and sustain habitability over long geologic time? With the advent of exoplanetary astronomy ongoing discovery terrestrial‐type planets around other stars, our own solar system becomes key testing ground for ideas about what factors control planetary evolution. Mars provides system's longest record interplay physical chemical processes relevant on an accessible rocky with atmosphere hydrosphere. Here we review current...
titOn the origin of Orientale basinle basin is a major impact crater on Moon, which hard to see from Earth because it right western edge lunar nearside. Relatively undisturbed by later events, serves as prototype for understanding large craters throughout solar system. Zuber et al. used Gravity Recovery and Interior Laboratory (GRAIL) mission map gravitational field around in great detail flying twin spacecraft little 2 km above surface. Johnson performed sophisticated computer simulation...
The Martian outflow channels were carved by the eruption of catastrophic floods from groundwater aquifers. This study models time evolution a typical channel flood originating within chaos region. initiates when superlithostatic pore pressures confined aquifer lead to propagation hydrofractures through confining cryosphere surface. peak discharges are modulated diffusion pulse region, resulting in rapid rise discharge immediately after initiation. Later flow is limited and sensitive...
We develop a hydrological model of the Martian crust, including both ancient heavily cratered terrains and younger basaltic sedimentary terrains. The porosity, permeability, compressibility are represented as interdependent functions effective stress state aquifer, determined by combination lithostatic pressure fluid pore pressure. In megaregolith aquifer model, crust is modeled 2 km thick megaregolith, composed lithified fractured impact ejecta, overlying impact‐fractured partially...
Sedimentary deposits within the 280 km wide crater containing Aram Chaos (∼3°N, 339°E) have been differentially eroded by wind to expose a stratigraphic column 900–1000 m thick that unconformably overlies chaos bedrock. A detailed and mineralogical description of is presented based on data from Mars Reconnaissance Orbiter Compact Imaging Spectrometer for Mars, Context Imager, High Resolution Science Experiment. Two sedimentary units overlie basement material representing original plains fill...
We present detailed stratigraphic and spectral analyses that focus on a region in northern Sinus Meridiani located between 1°N to 5°N latitude 3°W 1°E longitude. Several stratigraphically distinct units are defined mapped using morphologic expression, properties, superposition relationships. Previously unreported exposures of hydrated sulfates Fe/Mg smectites identified MRO CRISM MEX OMEGA near‐infrared (1.0 2.5 μ m) reflectance observations. Layered deposits with monohydrated polyhydrated...