P. G. Conrad
A5041363339- Planetary Science and Exploration
- Astro and Planetary Science
- Space Exploration and Technology
- Space Science and Extraterrestrial Life
- Isotope Analysis in Ecology
- Spaceflight effects on biology
- Geology and Paleoclimatology Research
- Atmospheric and Environmental Gas Dynamics
- High-pressure geophysics and materials
- Spacecraft Design and Technology
- Scientific Research and Discoveries
- Geological and Geochemical Analysis
- Crystal Structures and Properties
- Methane Hydrates and Related Phenomena
- Nuclear Physics and Applications
- Polar Research and Ecology
- Marine and environmental studies
- Microbial Community Ecology and Physiology
- Spacecraft and Cryogenic Technologies
- Paleontology and Stratigraphy of Fossils
- Chemical Analysis and Environmental Impact
- Advanced Chemical Sensor Technologies
- Pleistocene-Era Hominins and Archaeology
- Mass Spectrometry Techniques and Applications
- Space exploration and regulation
Carnegie Institution for Science
1998-2023
Jet Propulsion Laboratory
2001-2022
Goddard Space Flight Center
2011-2022
University of the Basque Country
2022
Finnish Meteorological Institute
2022
Instituto Nacional de Técnica Aeroespacial
2022
National Institute of Aerospace
2022
Instituto de Química Física Blas Cabrera
2022
Ames Research Center
2022
Johns Hopkins University Applied Physics Laboratory
2022
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...
Scheduled to land in August of 2012, the Mars Science Laboratory (MSL) Mission was initiated explore habitability Mars. This includes both modern environments as well ancient recorded by stratigraphic rock record preserved at Gale crater landing site. The Curiosity rover has a designed lifetime least one year (∼23 months), and drive capability 20 km. Curiosity's science payload specifically assembled assess gas chromatograph-mass spectrometer analyzer that will search for organic carbon...
Sedimentary rocks at Yellowknife Bay (Gale crater) on Mars include mudstone sampled by the Curiosity rover. The samples, John Klein and Cumberland, contain detrital basaltic minerals, calcium sulfates, iron oxide or hydroxides, sulfides, amorphous material, trioctahedral smectites. smectite has basal spacing of ~10 angstroms, indicating little interlayer hydration. Cumberland both ~13.2 angstroms. larger suggests a partially chloritized magnesium facilitating H2O retention. Basaltic minerals...
Ancient lake system at Gale crater Since 2012, the Curiosity rover has been diligently studying rocky outcrops on Mars, looking for clues about past water, climate, and habitability. Grotzinger et al. describe analysis of a huge section sedimentary rocks near crater, where Mount Sharp now stands (see Perspective by Chan). The features within these sediments are reminiscent delta, stream, deposits Earth. Although individual lakes were probably transient, it is likely that there was enough...
The Sample Analysis at Mars (SAM) investigation of the Science Laboratory (MSL) addresses chemical and isotopic composition atmosphere volatiles extracted from solid samples. SAM is designed to contribute substantially mission goal quantitatively assessing habitability as an essential step in search for past or present life on Mars. a 40 kg instrument suite located interior MSL's Curiosity rover. instruments are quadrupole mass spectrometer, tunable laser 6-column gas chromatograph all...
Abstract The Sample Analysis at Mars (SAM) instrument on board the Science Laboratory Curiosity rover is designed to conduct inorganic and organic chemical analyses of atmosphere surface regolith rocks help evaluate past present habitability potential Gale Crater. Central this task development an inventory any molecules elucidate processes associated with their origin, diagenesis, concentration, long‐term preservation. This will guide future search for biosignatures. Here we report...
Establishing the presence and state of organic matter, including its possible biosignatures, in martian materials has been an elusive quest, despite limited reports existence matter on Mars. We report situ detection preserved lacustrine mudstones at base ~3.5-billion-year-old Murray formation Pahrump Hills, Gale crater, by Sample Analysis Mars instrument suite onboard Curiosity rover. Diverse pyrolysis products, thiophenic, aromatic, aliphatic compounds released high temperatures (500° to...
Reports of plumes or patches methane in the martian atmosphere that vary over monthly time scales have defied explanation to date. From situ measurements made a 20-month period by tunable laser spectrometer Sample Analysis at Mars instrument suite on Curiosity Gale crater, we report detection background levels atmospheric mean value 0.69 ± 0.25 parts per billion volume (ppbv) 95% confidence interval (CI). This abundance is lower than model estimates ultraviolet degradation accreted...
Samples from the Rocknest aeolian deposit were heated to ~835°C under helium flow and evolved gases analyzed by Curiosity’s Sample Analysis at Mars instrument suite. H 2 O, SO , CO O major released. Water abundance (1.5 3 weight percent) release temperature suggest that is bound within an amorphous component of sample. Decomposition fine-grained Fe or Mg carbonate likely source much . Evolved coincident with Cl, suggesting oxygen produced thermal decomposition oxychloride compound. Elevated...
Volume mixing and isotope ratios secured with repeated atmospheric measurements taken the Sample Analysis at Mars instrument suite on Curiosity rover are: carbon dioxide (CO2), 0.960(±0.007); argon-40 ((40)Ar), 0.0193(±0.0001); nitrogen (N2), 0.0189(±0.0003); oxygen, 1.45(±0.09) × 10(-3); monoxide, < 1.0 (40)Ar/(36)Ar, 1.9(±0.3) 10(3). The (40)Ar/N2 ratio is 1.7 times greater (40)Ar/(36)Ar 1.6 lower than values reported by Viking Lander mass spectrometer in 1976, whereas other are generally...
The Mars Science Laboratory rover Curiosity scooped samples of soil from the Rocknest aeolian bedform in Gale crater. Analysis with Chemistry and Mineralogy (CheMin) x-ray diffraction (XRD) instrument revealed plagioclase (~An57), forsteritic olivine (~Fo62), augite, pigeonite, minor K-feldspar, magnetite, quartz, anhydrite, hematite, ilmenite. phases are present at, or near, detection limits. also contains 27 ± 14 weight percent amorphous material, likely containing multiple Fe 3+ -...
H 2 O, CO , SO O S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, amorphous materials. Thermal decomposition carbonates combustion organic materials are candidate sources for . Concurrent evolution hydrocarbons suggests presence oxychlorine phase(s). Sulfides likely...
A single scoop of the Rocknest aeolian deposit was sieved (< 150 µm), and four separate sample portions, each with a mass ~50 mg, were delivered to individual cups inside Sample Analysis at Mars (SAM) instrument by Science Laboratory rover's acquisition system. The samples analyzed separately SAM pyrolysis evolved gas chromatograph spectrometer analysis modes. Several chlorinated hydrocarbons including chloromethane, dichloromethane, trichloromethane, chloromethylpropene, chlorobenzene...
Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved an approximately average martian crustal composition to one influenced alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion deposition. The absence predicted geochemical variations indicates magnetite phyllosilicates formed diagenesis under low-temperature, circumneutral pH, rock-dominated aqueous...
We determined radiogenic and cosmogenic noble gases in a mudstone on the floor of Gale Crater. A K-Ar age 4.21 ± 0.35 billion years represents mixture detrital authigenic components confirms expected antiquity rocks comprising crater rim. Cosmic-ray-produced (3)He, (21)Ne, (36)Ar yield concordant surface exposure ages 78 30 million years. Surface occurred mainly present geomorphic setting rather than during primary erosion transport. Our observations are consistent with deposition shortly...
Significance We present data supporting the presence of an indigenous source fixed nitrogen on surface Mars in form nitrate. This may indicate first stage development a primitive cycle ancient and would have provided biochemically accessible nitrogen.
Abstract The Scanning Habitable Environments with Raman and Luminescence for Organics Chemicals (SHERLOC) is a robotic arm-mounted instrument on NASA’s Perseverance rover. SHERLOC has two primary boresights. Spectroscopy boresight generates spatially resolved chemical maps using fluorescence spectroscopy coupled to microscopic images (10.1 μm/pixel). second Wide Angle Topographic Sensor Operations eNgineering (WATSON); copy of the Mars Science Laboratory (MSL) Hand Lens Imager (MAHLI) that...
The Perseverance rover landed in Jezero crater, Mars, February 2021. We used the Scanning Habitable Environments with Raman and Luminescence for Organics Chemicals (SHERLOC) instrument to perform deep-ultraviolet fluorescence spectroscopy of three rocks within crater. identify evidence two distinct ancient aqueous environments at different times. Reactions liquid water formed carbonates an olivine-rich igneous rock. A sulfate-perchlorate mixture is present rocks, which probably by later...
Abstract The presence and distribution of preserved organic matter on the surface Mars can provide key information about Martian carbon cycle potential planet to host life throughout its history. Several types molecules have been previously detected in meteorites 1 at Gale crater, 2–4 . Evaluating diversity detectability elsewhere is important for understanding extent processes availability sources 1,5,6 Here we report detection Raman fluorescence spectra consistent with several species...
We present near edge X-ray absorption spectra of manganese oxides at the Mn L2,3, K, and O K edges to investigate relative sensitivity bonding structure. Collectively, probe local electronic structure intermediate range crystal Spin independent full multiple scattering calculations give good agreement with data above threshold qualitatively reproduce prepeak that is observed for each compound. show apparent MnO not due p−d hybridization atom (in accordance symmetry principles) or quadrupolar...
Abiotic Martian Organics Understanding the sources and formation mechanisms of organic carbon compounds on Mars has implications for our understanding martian cycle. Steele et al. (p. 212 , published online 24 May) present measurements material in 11 meteorites, including Tissint meteorite, which fell Moroccan desert July 2011. Ten meteorites contain complex hydrocarbons encased within igneous minerals. The results imply that organics formed as magma melt crystallized are thus abiotic origin.
The deuterium-to-hydrogen (D/H) ratio in strongly bound water or hydroxyl groups ancient martian clays retains the imprint of formation these minerals. Curiosity's Sample Analysis at Mars (SAM) experiment measured thermally evolved and hydrogen gas released between 550° 950°C from samples Hesperian-era Gale crater smectite to determine this isotope ratio. D/H value is 3.0 (±0.2) times standard mean ocean water. ~3-billion-year-old mudstone, which half that present atmosphere but...