Showing papers by "Caroline Freissinet published in 2013"
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Rensselaer Polytechnic Institute1, Goddard Space Flight Center2, California Institute of Technology3, Centre national de la recherche scientifique4, Paris 12 Val de Marne University5, University of Michigan6, University of Maryland, College Park7, École Centrale Paris8, University of Maryland, Baltimore County9, Massachusetts Institute of Technology10, National Autonomous University of Mexico11, University of Hawaii12, University of Minnesota13, Cornell University14, Carnegie Institution for Science15, University of California, Davis16, Georgia Institute of Technology17
TL;DR: 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, suggesting that oxygen is produced from thermal decomposition of an oxychloride compound.
Abstract: 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. H2O, SO2, CO2, and O2 were the major gases released. Water abundance (1.5 to 3 weight percent) and release temperature suggest that H2O is bound within an amorphous component of the sample. Decomposition of fine-grained Fe or Mg carbonate is the likely source of much of the evolved CO2. Evolved O2 is coincident with the release of Cl, suggesting that oxygen is produced from thermal decomposition of an oxychloride compound. Elevated δD values are consistent with recent atmospheric exchange. Carbon isotopes indicate multiple carbon sources in the fines. Several simple organic compounds were detected, but they are not definitively martian in origin.
402 citations
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Goddard Space Flight Center1, Massachusetts Institute of Technology2, University of Maryland, College Park3, École Centrale Paris4, Jacobs Engineering Group5, University of Michigan6, Centre national de la recherche scientifique7, Paris 12 Val de Marne University8, University of Maryland, Baltimore County9, California Institute of Technology10, Rensselaer Polytechnic Institute11, The Catholic University of America12, Ames Research Center13, National Autonomous University of Mexico14, Carnegie Institution for Science15
TL;DR: A single scoop of the Rocknest aeolian deposit was sieved and four separate sample portions, each with a mass of ~50mg, were delivered to individual cups inside the Sample Analysis at Mars (SAM) instrument by the Mars Science Laboratory rover's ample acquisition system.
Abstract: [1] A single scoop of the Rocknest aeolian deposit was sieved (<150 μm), and four separate sample portions, each with a mass of ~50mg, were delivered to individual cups inside the Sample Analysis at Mars (SAM) instrument by the Mars Science Laboratory rover’ ss ample acquisition system. The samples were analyzed separately by the SAM pyrolysis evolved gas and gas chromatograph mass spectrometer analysis modes. Several chlorinated hydrocarbons including chloromethane, dichloromethane, trichloromethane, a chloromethylpropene, and chlorobenzene were identified by SAM above background levels with abundances of ~0.01 to 2.3nmol. The evolution of the chloromethanes observed during pyrolysis is coincident with the increase in O2 released from the Rocknest sample and the decomposition of a product of N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA), a chemical whose vapors were released from a derivatization cup inside SAM. The best candidate for the oxychlorine compounds in Rocknest is a hydrated calcium perchlorate (Ca(ClO4)2·nH2O), based on the temperature release of O2 that correlates with the release of the chlorinated hydrocarbons measured by SAM, although other chlorine-bearing phases are being considered. Laboratory analog experiments suggest that the reaction of Martian chlorine from perchlorate decomposition with terrestrial organic carbon from MTBSTFA during pyrolysis can explain the presence of three chloromethanes and a chloromethylpropene detected by SAM. Chlorobenzene may be attributed to reactionsofMartian chlorine released during pyrolysiswith terrestrial benzene or toluene derived from 2,6-diphenylphenylene oxide (Tenax) on the SAM hydrocarbon trap. At this time we do not have definitive evidence to support a nonterrestrial carbon source for these chlorinated hydrocarbons, nor do we exclude the possibility that future SAM analyses will reveal the presence of organic compounds native to the Martian regolith.
324 citations
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Ames Research Center1, University of Texas at Austin2, University of Arizona3, Indiana University4, United States Geological Survey5, Max Planck Society6, University of Copenhagen7, Cornell University8, University of Guelph9, Lunar and Planetary Institute10, State University of New York System11, California Institute of Technology12, Planetary Science Institute13, Chesapeake Energy14, University of California, Davis15, Centre national de la recherche scientifique16, Oregon State University17, Finnish Meteorological Institute18, Goddard Space Flight Center19, Rensselaer Polytechnic Institute20, Carnegie Institution for Science21, University of Tennessee22, Johns Hopkins University Applied Physics Laboratory23, Princeton University24, Arizona State University25, Search for extraterrestrial intelligence26
TL;DR: The Rocknest aeolian deposit is similar to aeOLian features analyzed by the Mars Exploration Rovers Spirit and Opportunity and implies locally sourced, globally similar basaltic materials or globally and regionally sourced basALTic components deposited locally at all three locations.
Abstract: The Rocknest aeolian deposit is similar to aeolian features analyzed by the Mars Exploration Rovers (MERs) Spirit and Opportunity. The fraction of sand <150 micrometers in size contains ~55% crystalline material consistent with a basaltic heritage and ~45% x-ray amorphous material. The amorphous component of Rocknest is iron-rich and silicon-poor and is the host of the volatiles (water, oxygen, sulfur dioxide, carbon dioxide, and chlorine) detected by the Sample Analysis at Mars instrument and of the fine-grained nanophase oxide component first described from basaltic soils analyzed by MERs. The similarity between soils and aeolian materials analyzed at Gusev Crater, Meridiani Planum, and Gale Crater implies locally sourced, globally similar basaltic materials or globally and regionally sourced basaltic components deposited locally at all three locations.
308 citations
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Goddard Space Flight Center1, Massachusetts Institute of Technology2, University of Maryland, College Park3, École Centrale Paris4, Jacobs Engineering Group5, University of Michigan6, Centre national de la recherche scientifique7, Paris 12 Val de Marne University8, University of Maryland, Baltimore County9, California Institute of Technology10, Rensselaer Polytechnic Institute11, The Catholic University of America12, Ames Research Center13, National Autonomous University of Mexico14, Carnegie Institution for Science15
15 citations
18 Mar 2013
TL;DR: The only previous mission that was designed to search for soil nitrates was the Phoenix mission but was unable to detect evolved N-containing species by TEGA and the MECA WCL.
Abstract: Planetary models suggest that nitrogen was abundant in the early Martian atmosphere as dinitrogen (N2). However, it has been lost by sputtering and photochemical loss to space [1, 2], impact erosion [3], and chemical oxidation to nitrates [4]. Nitrates, produced early in Mars history, are later decomposed back into N2 by the current impact flux [5], making possible a nitrogen cycle on Mars. It is estimated that a layer of about 3 m of pure NaNO3 should be distributed globally on Mars [5]. Nitrates are a fundamental source for nitrogen to terrestrial microorganisms. Therefore, the detection of soil nitrates is important to assess habitability in the Martian environment. The only previous mission that was designed to search for soil nitrates was the Phoenix mission but was unable to detect evolved N-containing species by TEGA and the MECA WCL [6]. Nitrates have been tentatively identified in the Nakhla meteorite [7]. The purpose of this work is to determine if nitrates were detected in first solid sample (Rocknest) in Gale Crater examined by the SAM instrument.
9 citations
18 Mar 2013
TL;DR: For example, during the first 120 sols of the Curiosity rover landing mission on Mars (8/6/2012 to 12/7/2012), SAM sampled the atmosphere 9 times and an eolian bedform named Rocknest 4 times as mentioned in this paper.
Abstract: During the first 120 sols of Curiosity s landed mission on Mars (8/6/2012 to 12/7/2012) SAM sampled the atmosphere 9 times and an eolian bedform named Rocknest 4 times. The atmospheric experiments utilized SAM s quadrupole mass spectrometer (QMS) and tunable laser spectrometer (TLS) while the solid sample experiments also utilized the gas chromatograph (GC). Although a number of core experiments were pre-programmed and stored in EEProm, a high level SAM scripting language enabled the team to optimize experiments based on prior runs.
7 citations
01 Jan 2013
TL;DR: In this paper, the authors discuss the results from these SAM measurements at Rocknest and the steps taken to determine the source of the chlorohydrocarbons detected by Viking and Phoenix Lander missions.
Abstract: The search for organic compounds on Mars, including molecules of either abiotic or biological origin is one of the key goals of the Mars Science Laboratory (MSL) mission. Previously the Viking and Phoenix Lander missions searched for organic compounds, but did not find any definitive evidence of martian organic material in the soils. The Viking pyrolysis gas chromatography mass spectrometry (GCMS) instruments did not detect any organic compounds of martian or exogenous origin above a level of a few parts-per-billion (ppb) in the near surface regolith at either landing site [1]. Viking did detect chloromethane and dichloromethane at pmol levels (up to 40 ppb) after heating the soil samples up to 500 C (Table 1), although it was originally argued that the chlorohydrocarbons were derived from cleaning solvents used on the instrument hardware, and not from the soil samples themselves [1]. More recently, it was suggested that the chlorohydrocarbons detected by Viking may have been formed by oxidation of indigenous organic matter during pyrolysis of the soil in the presence of perchlorates [2]. Although it is unknown if the Viking soils contained perchlorates, Phoenix did reveal relatively high concentrations (~0.6 wt%) of perchlorate salt in the icy regolith [3], therefore, it is possible that the chlorohydrocarbons detected by Viking were produced, at least partially, during the experiments [2,4]. The Sample Analysis at Mars (SAM) instrument suite on MSL analyzed the organic composition of the soil at Rocknest in Gale Crater using a combination of pyrolysis evolved gas analysis (EGA) and GCMS. One empty cup procedural blank followed by multiple EGA-GCMS analyses of the Rocknest soil were carried out. Here we will discuss the results from these SAM measurements at Rocknest and the steps taken to determine the source of the chlorohydrocarbons.
4 citations
18 Mar 2013
TL;DR: In this article, the authors explore Curiosity's ability to detect N compounds using data from the rover's first solid sample, focusing on non-nitrile, reduced-N compounds as inferred from bonded N-H.
Abstract: Nitrogen is the second or third most abundant constituent of the Martian atmosphere [1,2]. It is a bioessential element, a component of all amino acids and nucleic acids that make up proteins, DNA and RNA, so assessing its availability is a key part of Curiosity's mission to characterize Martian habitability. In oxidizing desert environments it is found in nitrate salts that co-occur with perchlorates [e.g., 3], inferred to be widespread in Mars soils [4-6]. A Mars nitrogen cycle has been proposed [7], yet prior missions have not constrained the state of surface N. Here we explore Curiosity's ability to detect N compounds using data from the rover's first solid sample. Companion abstracts describe evidence for nitrates [8] and for nitriles (C(triple bond)N) [9]; we focus here on nonnitrile, reduced-N compounds as inferred from bonded N-H. The simplest such compound is ammonia (NH3), found in many carbonaceous chondrite meteorites in NH4(+) salts and organic compounds [e.g., 10].
3 citations
18 Mar 2013
TL;DR: In this paper, the authors report on the nature of the MTBSTFA derivatization experiment on SAM, the detection of MTBstFA in initial SAM results, and the implications of this detection.
Abstract: For the first time in the history of space exploration, a mission of interest to astrobiology could be able to analyze refractory organic compounds in the soil of Mars. Wet chemistry experiment allow organic components to be altered in such a way that improves there detection either by releasing the compounds from sample matricies or by changing the chemical structure to be amenable to analytical conditions. The latter is particular important when polar compounds are present. Sample Analysis at Mars (SAM), on the Curiosity rover of the Mars Science Laboratory mission, has onboard two wet chemistry experiments: derivatization and thermochemolysis. Here we report on the nature of the MTBSTFA derivatization experiment on SAM, the detection of MTBSTFA in initial SAM results, and the implications of this detection.
2 citations
18 Mar 2013
TL;DR: In this article, a sample analysis at the Mars experiment was carried out using analytical conditions similar to those used for the R============The SAM experiment, with an empty sample sample.
Abstract: A
mongst the Sample Analysis at
Mars (SAM) experiment capabilities,
the GCMS mode
(coupling of the
Gas
-
Chromatograph
and the
q
uadrupole
Mass
-
Spectrometer
instruments)
was
designed for the separation and
ident
ification
of the
chemical
components of the gases evolved from a solid
sample, either processed by heat in pyrolysis or by
chemical react
ant in wet chemistry
[1]
.
Prior to the
three
portioned
samples
already analyzed in pyrolysis
GCMS,
an internal SAM
blan
k
run was carried out
with an empty
quartz
cup. This blank
analysis was
required to understand the
background
signal
intrinsic
to the
GCMS response of the SAM experiment.
With
this aim, it was run using analytical conditions similar
to those used for the R
ocknest samples.
The
identification of the compounds present in the
background
and the understanding of their
origin are
necessary to
perform quantitative analysis and to
aid
the interpretation
of
the solid sample
results.
1 citations
National Autonomous University of Mexico1, Goddard Space Flight Center2, Oak Ridge Associated Universities3, Ames Research Center4, University of Maryland, College Park5, University of Paris6, University of Michigan7, Georgia Institute of Technology8, Carnegie Institution for Science9, École Centrale Paris10, Rensselaer Polytechnic Institute11, California Institute of Technology12
TL;DR: In this article, the results from the Sample Analysis at Mars (SAM) instrument suite aboard the Curiosity rover during the first year of surface operations in Gale Crater were analyzed by MS and GC-MS.
Abstract: Planetary models suggest that nitrogen was abundant in the early Martian atmosphere as N2 but it was lost by sputtering and photochemical loss to space, impact erosion, and chemical oxidation to nitrates. A nitrogen cycle may exist on Mars where nitrates, produced early in Mars' history, may have been later decomposed back into N2 by the current impact flux. Nitrates are a fundamental source of nitrogen for terrestrial microorganisms, and they have evolved metabolic pathways to perform both oxidation and reduction to drive a complete biological nitrogen cycle. Therefore, the characterization of nitrogen in Martian soils is important to assess habitability of the Martian environment, particularly with respect to the presence of nitrates. The only previous mission that was designed to search for soil nitrates was the Phoenix mission but N-containing species were not detected by TEGA or the MECA WCL. Nitrates have been tentatively identified in Nakhla meteorites, and if nitrogen was oxidized on Mars, this has important implications for the habitability potential of Mars. Here we report the results from the Sample Analysis at Mars (SAM) instrument suite aboard the Curiosity rover during the first year of surface operations in Gale Crater. Samples from the Rocknest aeolian deposit and sedimentary rocks (John Klein) were heated to approx 835degC under helium flow and the evolved gases were analyzed by MS and GC-MS. Two and possibly three peaks may be associated with the release of m/z 30 at temperatures ranging from 180degC to 500degC. M/z 30 has been tentatively identified as NO; other plausible contributions include CH2O and an isotopologue of CO, 12C18O. NO, CH2O, and CO may be reaction products of reagents (MTBSTFA/DMF) carried from Earth for the wet chemical derivatization experiments with SAM and/or derived from indigenous soil nitrogenated organics. Laboratory analyses indicate that it is also possible that <550degC evolved NO is produced via reaction of HCl with nitrates arising from the decomposition of perchlorates. All sources of m/z 30 whether it be martian or terrestrial will be considered and their implications for Mars will be discussed.
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TL;DR: In this paper, the detection of reduced sulfur and other S-bearing species evolved from the Rocknest sample in the Sample Analysis at Mars (SAM) experiment and was reported to be successful.
Abstract: Detection of reduced sulfur and other S-bearing species evolved from Rocknest sample in the Sample Analysis at Mars (SAM) experiment
National Autonomous University of Mexico1, Goddard Space Flight Center2, Oak Ridge Associated Universities3, Ames Research Center4, University of Maryland, College Park5, University of Paris6, University of Michigan7, Georgia Institute of Technology8, Carnegie Institution for Science9, École Centrale Paris10, Rensselaer Polytechnic Institute11, California Institute of Technology12
TL;DR: In this article, the results from the Sample Analysis at Mars (SAM) instrument suite aboard the Curiosity rover during the first year of surface operations in Gale Crater were analyzed by MS and GC-MS.
Abstract: Planetary models suggest that nitrogen was abundant in the early Martian atmosphere as N2 but it was lost by sputtering and photochemical loss to space, impact erosion, and chemical oxidation to nitrates. A nitrogen cycle may exist on Mars where nitrates, produced early in Mars' history, may have been later decomposed back into N2 by the current impact flux. Nitrates are a fundamental source of nitrogen for terrestrial microorganisms, and they have evolved metabolic pathways to perform both oxidation and reduction to drive a complete biological nitrogen cycle. Therefore, the characterization of nitrogen in Martian soils is important to assess habitability of the Martian environment, particularly with respect to the presence of nitrates. The only previous mission that was designed to search for soil nitrates was the Phoenix mission but N-containing species were not detected by TEGA or the MECA WCL. Nitrates have been tentatively identified in Nakhla meteorites, and if nitrogen was oxidized on Mars, this has important implications for the habitability potential of Mars. Here we report the results from the Sample Analysis at Mars (SAM) instrument suite aboard the Curiosity rover during the first year of surface operations in Gale Crater. Samples from the Rocknest aeolian deposit and sedimentary rocks (John Klein) were heated to approx 835degC under helium flow and the evolved gases were analyzed by MS and GC-MS. Two and possibly three peaks may be associated with the release of m/z 30 at temperatures ranging from 180degC to 500degC. M/z 30 has been tentatively identified as NO; other plausible contributions include CH2O and an isotopologue of CO, 12C18O. NO, CH2O, and CO may be reaction products of reagents (MTBSTFA/DMF) carried from Earth for the wet chemical derivatization experiments with SAM and/or derived from indigenous soil nitrogenated organics. Laboratory analyses indicate that it is also possible that <550degC evolved NO is produced via reaction of HCl with nitrates arising from the decomposition of perchlorates. All sources of m/z 30 whether it be martian or terrestrial will be considered and their implications for Mars will be discussed.