Valerie Tu
A5009790031- Planetary Science and Exploration
- Astro and Planetary Science
- Geology and Paleoclimatology Research
- Space Exploration and Technology
- Paleontology and Stratigraphy of Fossils
- Isotope Analysis in Ecology
- Geochemistry and Geologic Mapping
- Space Science and Extraterrestrial Life
- Clay minerals and soil interactions
- Biocrusts and Microbial Ecology
- Geological and Geochemical Analysis
- Mineralogy and Gemology Studies
- X-ray Diffraction in Crystallography
- Hydrocarbon exploration and reservoir analysis
- Methane Hydrates and Related Phenomena
- Industrial Engineering and Technologies
- Chalcogenide Semiconductor Thin Films
- Iron oxide chemistry and applications
- Minerals Flotation and Separation Techniques
- Nuclear Physics and Applications
- Radioactivity and Radon Measurements
- Wastewater Treatment and Nitrogen Removal
- Polar Research and Ecology
- Cryospheric studies and observations
- Radioactive contamination and transfer
Johnson Space Center
2018-2025
Jacobs (United States)
2018-2025
Arizona State University
2023
Pacific Northwest National Laboratory
2023
Honeybee Robotics (United States)
2021
Ames Research Center
2021
Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
2021
Centre National de la Recherche Scientifique
2021
Aix-Marseille Université
2021
University of Arizona
2021
Abstract On September 24, 2023, NASA's OSIRIS‐REx mission dropped a capsule to Earth containing ~120 g of pristine carbonaceous regolith from Bennu. We describe the delivery and initial allocation this asteroid sample introduce its bulk physical, chemical, mineralogical properties early analyses. The is very dark overall, with higher‐reflectance inclusions particles interspersed. Particle sizes range submicron dust stone ~3.5 cm long. Millimeter‐scale larger stones typically have hummocky or...
Abstract Evaporation or freezing of water-rich fluids with dilute concentrations dissolved salts can produce brines, as observed in closed basins on Earth 1 and detected by remote sensing icy bodies the outer Solar System 2,3 . The mineralogical evolution these brines is well understood regard to terrestrial environments 4 , but poorly constrained for extraterrestrial systems owing a lack direct sampling. Here we report occurrence salt minerals samples asteroid (101955) Bennu returned...
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 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...
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...
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 The OSIRIS‐REx mission returned a sample of regolith from the carbonaceous asteroid Bennu in September 2023. We present preliminary situ investigations petrology and petrography selected particles ranging size 0.5 to 3 mm. Using combination optical electron beam techniques, we investigate whole specimens polished sections belonging morphologically visually distinct categories particles. find that morphological differences are reflective petrographic petrologic differences, leading...
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Abstract Curiosity investigated active eolian sands near linear dunes during Phase 2 of the Bagnold Dunes campaign in Gale crater, Mars. Ogunquit Beach, a sample scooped from large‐ripple trough within Mount Desert Island ripple field and delivered to Chemistry Mineralogy (CheMin) X‐ray diffraction instrument, is dominated by basaltic igneous minerals amorphous materials. CheMin mineralogy Gobabeb acquired at crest on Namib barchan dune 1 similar Beach. however, contains more plagioclase...
Abstract A systematic survey of 161 known and postulated minerals originating on Mars points to 20 different mineral‐forming processes (paragenetic modes), which are a subset formation modes observed Earth. The earliest martian minerals, as Earth, were primary phases from mafic igneous rocks their ultramafic cumulates. Subsequent associated with products limited fractional crystallization, including alkaline quartz‐normative lithologies. Significant mineral diversification occurred via...
For more than a decade, the CheMin X-ray diffraction instrument on Mars Science Laboratory rover, Curiosity, has been returning definitive and quantitative mineralogical mineral–chemistry data from ~3.5-billion-year-old (Ga) sediments in Gale crater, Mars. To date, 40 drilled rock samples three scooped soil have analyzed during rover’s 30+ km transit. These document mineralogy of over 800 m flat-lying fluvial, lacustrine, aeolian sedimentary rocks that comprise lower strata central mound...
This study presents mineral composition estimates of rock and sediment samples analyzed with the CheMin X-ray diffraction instrument on board NASA Mars Science Laboratory rover, Curiosity, in Gale crater, Mars. Mineral is estimated using crystal-chemically derived algorithms applied to data, specifically unit-cell parameters. The groups characterized include those found major abundance by (i.e., feldspar, olivine, pyroxene, spinel oxide). In addition estimating phases observed we place their...
On 24 September 2023, the NASA OSIRIS-REx mission dropped a capsule to Earth containing approximately 120 g of pristine carbonaceous regolith from Bennu. We describe delivery and initial allocation this asteroid sample introduce its bulk physical, chemical, mineralogical properties early analyses. The is very dark overall, with higher-reflectance inclusions particles interspersed. Particle sizes range sub-micron dust stone about 3.5 cm long. Millimeter-scale larger stones typically have...
Abstract Hydrothermal high sanidine and specular hematite are found within ferric‐rich gray‐colored cemented basaltic breccia occurring horizontal, weathering‐resistant strata exposed in an erosional gully of the Pu'u Poliahu cinder cone summit region Maunakea volcano (Hawai'i). The was extensively altered by hydrothermal, acid‐sulfate fluids at temperatures up to ~400 °C, and, strata, plagioclase removed dissolution from progenitor Hawaiitic basalt, were precipitated. Fe 2 O 3 T...
The Johnson Space Center-Rocknest (JSC-RN) simulant was developed in response to a need by NASA's Advanced Exploration Systems (AES) In-Situ Resource Utilization (ISRU) project for be used component and system testing water extraction from Mars regolith. JSC-RN designed chemically mineralogically similar material the aeolian sand shadow named Rocknest Gale Crater, particularly 1–3 wt% low temperature (<450 °C) release as measured Sample Analysis at (SAM) instrument on Curiosity rover. Sodium...
The Rietveld refinement software Profex is an open-source and platform-independent solution for the processing of powder X-ray diffraction datasets. It based on BGMN kernel uses a description diffractometer configuration to determine instrument-related peak profile. In this article we present file Chemistry Mineralogy (CheMin) (XRD), which on-board Mars Science Laboratory rover Curiosity. For past decade, Curiosity has been mission find out whether planet was once habitable microbial life....
This paper reviews the phosphate phases in meteorites and those measured by landed spacecraft, what they reveal about past igneous aqueous conditions on Mars, important implications for potential prebiotic chemistry, habitability, biosignatures that could be detected samples returned from Mars. A review of 378 martian as 2023 indicate two most common minerals Mars meteorites, merrillite apatites, apatite composition is largely F- Cl-rich, with shergottites containing more OH. The...
Abstract X-ray amorphous material comprises 15-73 wt.% of sedimentary rocks and eolian sediments in Gale crater. This is variably siliceous iron rich but aluminum poor. The presence volatiles consistent with the existence incipient weathering products. To better understand implications this for past aqueous conditions on Mars, here we investigate formation longevity within terrestrial soils varying ages environmental using bulk selective dissolution methods, diffraction, transmission...
Gypsum is a common mineral at Gale crater on Mars, currently being explored by the Mars Science Laboratory (MSL) rover, Curiosity. In this paper, we summarize associations of gypsum with other sulfate minerals (bassanite, anhydrite, jarosite, starkeyite, and kieserite) from lowest levels crater’s northern moat zone (Aeolis Palus) up through ~0.8 km stratigraphic section in lower slopes sedimentary mound developed around central peak, Aeolis Mons (informally, Mount Sharp). The analysis based...
The MSL Curiosity rover investigated dark, Mn-P-enriched nodules in shallow lacustrine/fluvial sediments at the Groken site Glen Torridon, Gale Crater, Mars. Applying all relevant information from rover, are interpreted as pseudomorphs after original crystals of vivianite, (Fe2+,Mn2+)3(PO4)2·8H2O, that cemented sediment soon deposition. appear to have flat faces and linear boundaries stand above surrounding siltstone. ChemCam LIBS (laser-induced breakdown spectrometry) shows MnO abundances...
Phosphate is an essential nutrient for life on Earth, and therefore if exists or ever existed Mars it may have required phosphate. Amorphous Al- Fe-phosphates rapidly precipitate from acidic solutions amorphous Al-phosphates likely control phosphate concentrations in some natural waters Earth. The fraction of martian soils has also been shown to be enriched P, phosphates are important the cycle Mars. Despite this importance, however, few dissolution rates exist Fe-phosphates. In study, were...