A. A. Fraeman
A5006908394- Planetary Science and Exploration
- Astro and Planetary Science
- Space Exploration and Technology
- Geology and Paleoclimatology Research
- Space Science and Extraterrestrial Life
- Paleontology and Stratigraphy of Fossils
- Geochemistry and Geologic Mapping
- Aeolian processes and effects
- Spaceflight effects on biology
- Hydrocarbon exploration and reservoir analysis
- Isotope Analysis in Ecology
- Marine and environmental studies
- Methane Hydrates and Related Phenomena
- Spacecraft Dynamics and Control
- Space Satellite Systems and Control
- Geological and Geochemical Analysis
- Geomagnetism and Paleomagnetism Studies
- Maritime and Coastal Archaeology
- Atmospheric and Environmental Gas Dynamics
- Astronomical Observations and Instrumentation
- Psychological and Educational Research Studies
- Stellar, planetary, and galactic studies
- Geological Studies and Exploration
- Laser-induced spectroscopy and plasma
- Science and Climate Studies
Jet Propulsion Laboratory
2016-2025
California Institute of Technology
2014-2019
Brown University
2009-2015
University of Winnipeg
2015
Washington University in St. Louis
2010-2014
Yale University
2010
The Curiosity rover discovered fine-grained sedimentary rocks, which are inferred to represent an ancient lake and preserve evidence of environment that would have been suited support a martian biosphere founded on chemolithoautotrophy. This aqueous was characterized by neutral pH, low salinity, variable redox states both iron sulfur species. Carbon, hydrogen, oxygen, sulfur, nitrogen, phosphorus were measured directly as key biogenic elements; inference, is assumed available. probably had...
Wind blowing over sand on Earth produces decimeter-wavelength ripples and hundred-meter- to kilometer-wavelength dunes: bedforms of two distinct size modes. Observations from the Mars Science Laboratory Curiosity rover Reconnaissance Orbiter reveal that hosts a third stable wind-driven bedform, with meter-scale wavelengths. These are spatially uniform in typically have asymmetric profiles angle-of-repose lee slopes sinuous crest lines, making them unlike terrestrial wind ripples. Rather,...
Ancient Mars had surface liquid water and a dense carbon dioxide (CO 2 )–rich atmosphere. Such an atmosphere would interact with crustal rocks, potentially leaving mineralogical record of its presence. We analyzed the composition 89-meter stratigraphic section Gale crater, Mars, using data collected by Curiosity rover. An iron carbonate mineral, siderite, occurs in abundances 4.8 to 10.5 weight %, colocated highly water-soluble salts. infer that siderite formed water-limited conditions,...
Abstract We have developed a refined geologic map and stratigraphy for lower Mount Sharp using coordinated analyses of new spectral, thermophysical, morphologic orbital data products. The group consists seven relatively planar units delineated by differences in texture, mineralogy, thermophysical properties. These are (1–3) three spatially adjacent the Murray formation which contain variety secondary phases distinguishable thermal inertia albedo differences, (4) phyllosilicate‐bearing unit,...
Research Article| October 01, 2013 A hematite-bearing layer in Gale Crater, Mars: Mapping and implications for past aqueous conditions A.A. Fraeman; Fraeman 1Department of Earth Planetary Sciences, Washington University St. Louis, Missouri 63130, USA Search other works by this author on: GSW Google Scholar R.E. Arvidson; Arvidson J.G. Catalano; Catalano J.P. Grotzinger; Grotzinger 2Department Geological California Institute Technology, Pasadena, 91125, R.V. Morris; Morris 3NASA Johnson Space...
Abstract Vera Rubin ridge (VRR) is an erosion‐resistant feature on the northwestern slope of Mount Sharp in Gale crater, Mars, and orbital visible/shortwave infrared measurements indicate it contains red hematite. The Mars Science Laboratory Curiosity rover performed extensive campaign VRR to study its mineralogy, geochemistry, sedimentology determine depositional diagenetic history constrain processes by which hematite could have formed. X‐ray diffraction (XRD) data from CheMin instrument...
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...
Abstract Diagenetic silica enrichment in fracture‐associated halos that crosscut lacustrine and unconformably overlying aeolian sedimentary bedrock is observed on the lower north slope of Aeolis Mons Gale crater, Mars. The diagenetic colocated with detrital yet extends into a considerably younger, draping sandstone, implying postdates enrichment. A causal connection between implies water was present subsurface crater long after deposition sediments it mobilized amorphous precipitated along...
Abstract The Mars Science Laboratory Curiosity rover performed coordinated measurements to examine the textures and compositions of aeolian sands in active Bagnold dune field. are rounded subrounded, very fine medium sized (~45–500 μm) with ≥6 distinct grain colors. In contrast examined by a dust‐covered, inactive bedform called Rocknest soils at other landing sites, darker, less red, better sorted, have fewer silt‐sized or smaller grains, show no evidence for cohesion. Nevertheless,...
After landing in Gale Crater on August 6, 2012, the Mars Science Laboratory Curiosity rover traveled across regolith‐covered, rock‐strewn plains that transitioned into terrains have been variably eroded, with valleys partially filled windblown sands, and intervening plateaus capped by well‐cemented sandstones fractured shaped wind outcrops numerous sharp rock surfaces. Wheel punctures tears caused rocks while traversing led to directing traverse where sands would cushion wheel loads. This...
Abstract For ~500 Martian solar days (sols), the Mars Science Laboratory team explored Vera Rubin ridge (VRR), a topographic feature on northwest slope of Aeolis Mons. Here we review sedimentary facies and stratigraphy observed during sols 1,800–2,300, covering more than 100 m stratigraphic thickness. Curiosity's traverse includes two transects across ridge, which enables investigation lateral variability over distance ~300 m. Three informally named members Murray formation are described:...
Abstract This paper provides an overview of the Curiosity rover's exploration at Vera Rubin ridge (VRR) and summarizes science results. VRR is a distinct geomorphic feature on lower Aeolis Mons (informally known as Mount Sharp) that was identified in orbital data based its texture, topographic expression, association with hematite spectral signature. conducted extensive remote sensing observations, acquired dozens contact targets, drilled three outcrop samples from ridge, well one sample...
Modified clay minerals on Mars Sedimentary rocks exposed in Gale crater contain extensive minerals. Bristow et al. analyzed drill samples collected by the Curiosity rover as it climbed up sedimentary layers crater. They found evidence of past reactions with liquid water and sulfate brines, which could have percolated through from an overlying deposit. Similar deposits are widespread across planet represent some last to form before lost its surface water, so results inform our understanding...
The Mars Science Laboratory rover, Curiosity, explored the clay mineral-bearing Glen Torridon region for 1 Martian year between January 2019 and 2021, including a short campaign onto Greenheugh pediment. sought to characterize geology of area, seek evidence habitable environments, document onset potentially global climatic transition during Hesperian era. Curiosity roved 5 km in total throughout Torridon, from Vera Rubin ridge northern margin acquired samples 11 drill holes this conducted...
Abstract The Glen Torridon (GT) region within Gale crater, Mars, occurs in contact with the southern side of Vera Rubin ridge (VRR), a well‐defined geomorphic feature that is comparatively resistant to erosion. Prior detailed ground‐based investigation GT, its geologic relationship VRR was unknown. Distinct lithologic subunits Jura member (Murray formation), which forms upper part VRR, made it possible be also identified GT. This indicates strata pass across divide between regions....
Abstract For the first time on Mars, crystalline magnesium‐sulfate mineral starkeyite (MgSO 4 ‧4H 2 O) was definitively identified using CheMin X‐ray diffraction instrument at Gale crater. At Canaima drill site, along with amorphous MgSO ‧ n H O are among “polyhydrated Mg‐sulfates” interpreted in orbital reflectance spectra. Mg‐sulfates good climate indicators as they very responsive to changes temperature and relative humidity. We hypothesize that, through evaporation, formed end of brine...
Abstract During its ascent up Mount Sharp, the Mars Science Laboratory Curiosity rover traversed Bagnold Dune Field. We model sand modal mineralogy and grain size at four locations near traverse, using orbital shortwave infrared single‐scattering albedo spectra a Markov chain Monte Carlo implementation of Hapke's radiative transfer theory to fully constrain uncertainties permitted solutions. These predictions, evaluated against in situ measurements one site from rover, show that X‐ray...
Abstract Orbital data acquired by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and High Resolution Science Experiment instruments on Orbiter (MRO) provide a synoptic view of compositional stratigraphy floor Gale crater surrounding area where Laboratory (MSL) Curiosity landed. Fractured, light‐toned material exhibits 2.2 µm absorption consistent with enrichment in hydroxylated silica. This may be distal sediment from Peace Vallis fan, cement fracture fill containing unit...
Abstract Geochemical results are presented from Curiosity's exploration of Vera Rubin ridge (VRR), in addition to the full chemostratigraphy predominantly lacustrine mudstone Murray formation up and including VRR. VRR is a prominent flanking Aeolis Mons (informally Mt. Sharp), central mound Gale crater, Mars, was key area interest for Mars Science Laboratory mission. ChemCam data show that overall geochemically similar lower‐lying members formation, even though top shows strong hematite...