DENVER, Aug. 30, 2011 — Scientists are expressing confidence that questions about life on Mars, which have captured human imagination for centuries, finally may be answered, thanks in part to new life-detection tools up to 1,000 times more sensitive than previous instruments.
"The bottom line is that if life is out there, the high-tech tools of chemistry will find it sooner or later," said Jeffrey Bada, Ph.D., co-organizer of a special two-day symposium on the Red Planet, which began here today during the 242nd National Meeting & Exposition of the American Chemical Society (ACS). "It certainly is starting to look like there may be something alive out there somewhere, with Mars being the most accessible place to search," Bada added.
The symposium included more than two dozen presentations by experts concerned with whether life exists, or existed, on Mars. Abstracts of the presentations appear below.
"One reason that the questions linger is that they haven't had the right instruments," said Bada, a noted authority on the topic at the Scripps Institution of Oceanography at the University of California-San Diego. "We have the instruments now or are in the process of developing and refining them. The challenge is getting them onboard future spacecraft, knowing what kinds of compounds to look for and knowing exactly where to look."
Bada is a strong advocate for postponing future manned missions to Mars until the unmanned missions get enough information to land astronauts in an area most hospitable to life. He expressed concern, however, that NASA budget cuts could jeopardize such future unmanned missions.
One forthcoming unmanned mission is the new Mars Science Laboratory rover, called Curiosity, scheduled for launch in November. The $2.5 billion nuclear-powered machine will land on Mars' surface with a suite of 10 science instruments to try to determine if conditions are favorable for life. Another key Mars mission is scheduled for 2016. Called the ExoMars Trace Gas Orbiter, it will carry five science instruments and will study gases in Mars' atmosphere, including methane, for evidence of biological or geological activity. It is a joint mission of the European Space Agency and NASA.
"The instruments on that atmospheric mission have a factor of 100 to 1,000 increase in sensitivity over what is currently available from Mars orbiters or from ground observations," noted symposium co-organizer Mark Allen, Ph.D., who is the U.S. project scientist for the 2016 Mars mission. He is with the Jet Propulsion Laboratory at the California Institute of Technology in Pasadena.
Among the most important instruments flown onboard future missions will be those that can detect organic nitrogen, Bada said. Nitrogen is essential for life on Earth. Scientists are convinced that if there's life on Mars, it will contain nitrogen.
Scientists also should look for signs of life deep underneath Mars' surface, Bada said. He noted that powerful ultraviolet and cosmic rays have bombarded the planet's surface for billions of years, likely destroying organic matter so that traces of these materials are no longer detectable. But studies suggest that organic materials buried beneath the surface of Mars, perhaps a meter or so deep, may somehow be protected against this radiation.
Researchers are also planning to use high-tech instruments to search Mars' atmosphere for signs of life. Among the substances they'll be searching for in the future is methane, the largest component of natural gas. NASA scientists have reported that Mars appears to be emitting plumes of methane on parts of the planet. If so, scientists suggest that the possible sources include bacteria and other organisms.
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Selected abstracts from the symposium "Chemistry as a Tool for Space Exploration and Discovery at Mars" are below.
ABSTRACTS:
Searching for organic compounds on Mars: Intensive in situ investigations are required prerequisites to a sample return mission
Jeffrey L Bada1 , Professor, University of California, San Diego, Scripps Institution of Oceanography, 8615 Kennel Way, La Jolla, CA, 92093-0212, United States, 858 534-4258, jbada@ucsd.edu
A campaign of in situ analytical exploration missions is needed to identify sites on Mars that demonstrate an unequivocal presence of organic compounds. This in situ campaign would best be realized through a Follow the Nitrogen strategy before sample return is attempted. Organic nitrogen compounds are readily synthesized in model prebiotic experiments, are abundant in carbonaceous meteorites and are the core compounds associated with biology as we know it on Earth. Instruments with exquisite sensitivity for nitrogen-containing organic compounds and nondestructive extraction techniques have been developed, and their continuing advancement will result in the enhancement of present in situ capabilities. Landing-site selection must be carefully evaluated and emphasize sequestration potential of various mineral types such as gypsum, clays and halites. Following intensive in situ exploration, Mars sample return would then be the required and justified follow-on to provide for scientific discovery beyond the capabilities of in situ methods.
Remote sensing for atmospheric evidence of Martian habitability and habitancy
Mark Allen1 , California Institute of Technology, Jet Propulsion Laboratory, 4800 Oak Grove Drive, MS 301-345, Pasadena, CA, 91109, United States, 818-317-6346, Mark.Allen@jpl.nasa.gov
The joint ESA/NASA ExoMars Trace Gas Orbiter is planned for launch in 2016. It will provide an intensive, remote sensing investigation of the chemical composition and dynamics of the Mars atmosphere. It will be the most sensitive survey of atmospheric composition that is practical to place into orbit around another planet. Coupled with the measurements of atmospheric properties, the observations to be acquired by the five-instrument international payload should allow a characterization of atmospheric sources and sinks for trace gases and possible surface sources and sinks. Thus signatures of subsurface habitable oases due to extant geological activity and of subsurface areas of inhabitance (albeit microbial life) may be detected and localized.
Novel electroanalytical instrument for soil samples: CHEMSENS
Kyle McElhoney1 , Tufts University, Department of Chemistry, 62 Talbot Ave., Medford, MA, 02155, United States, 6176274962, kyle.mcelhoney@tufts.edu
In this presentation a new instrument will be introduced based on the previous knowledge of the 2007 Phoenix Mars Scout Lander, and in particular the Wet Chemical Laboratory (WCL). The In-Situ Chemical Analysis Laboratory & Sensor Array (CHEMSENS) under development is to further characterize soil samples via wet chemistry experiments in remote sites both on Earth and other planets. CHEMSENS has been designed with an increased number of sensors in order to increase the accuracy and reproducibility of the measurements, as well as to increase the number of samples that can be analyzed remotely when mounted onto a rover. CHEMSENS will include sensors for the measurement of Na+, K+, NH4+, Ca2+, Mg2+, pH, Cl-, NO3-/ClO4- and conductivity. A challenge of this project has been the development of potentiometric microsensors in order to minimize sample cell volume and increase the number of sensors. Results to overcome this challenge will be presented.
In-situ planetary chemical analysis of aqueous geochemistry: Results of the Phoenix Mars lander Wet Chem Lab and the global implications for both Mars and Earth
Samuel P. Kounaves1 , Professor, PhD, Tufts University, Department of Chemistry, 62 Talbot Avenue, Medford, MA, 02155, United States, 617-627-3124, samuel.kounaves@tufts.edu
The Wet Chemistry Laboratory (WCL) onboard the Phoenix Mars Lander used both classical titration and a sophisticated sensor array to provide on-site chemical analyses of soluble components in the soil. The discoveries of SO4=, which models show to most likely be epsomite (MgSO4•7H2O), and soil buffered by percent-levels of Ca and Mg carbonates, has altered our understanding of Mars' aqueous chemistry. The detection of 1wt% perchlorate as Mg(ClO4)2 •7H2O, has not only impacted our understanding of the atmospheric and geo-chemistry of Mars, but has lead to its serendipitous discovery in Antarctica, pointing to global atmospheric production and distribution of ClO4- on Earth, with direct implications for its interactions with microbial ecology, human health and environmental policy. Analyses, including the WCL, have also identified ClO4- in the Martian meteorite EETA79001, implying its potentially widespread distribution on Mars. The Phoenix results have provoked a reassessment of Mars' biohabitability and future analytical instrumentation for organics and life detection.
Search for chemical biomarkers on Mars using the sample analysis at Mars Instrument Suite on the Mars Science Laboratory
Daniel P Glavin1 , Dr., NASA Goddard Space Flight Center, Planetary Environments Laboratory, 8800 Greenbelt Rd., Code 699, Bldg. 33, Room D204, Greenbelt, MD, 20771, United States, 301-614-6361, 301-614-6406, daniel.p.glavin@nasa.gov
One key goal for future exploration of Mars is the search for chemical biomarkers including complex organic compounds important in life on Earth. The Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) will provide the most sensitive measurements of the organic composition of rocks and regolith samples ever carried out in situ on Mars. SAM consists of a gas chromatograph (GC), quadrupole mass spectrometer (QMS), and tunable laser spectrometer to measure volatiles in the atmosphere and released from rock powders heated up to 1000°C. The measurement of organics in solid samples will be accomplished by three experiments: (1) pyrolysis QMS to identify alkane fragments and simple aromatic compounds; (2) pyrolysis GCMS to separate and identify complex mixtures of larger hydrocarbons; and (3) chemical derivatization and GCMS to extract less volatile compounds, including amino and carboxylic acids that are not detectable by the other two experiments.
Automated analysis of carbonaceous biomarkers with the Mars Organic Analyzer microchip capillary electrophoresis system: Amines, amino acids, aldehydes, ketones, carboxylic acids, and polycyclic aromatic hydrocarbons
Richard A. Mathies1 , Professor, University of California, College of Chemistry, 307 Lewis Hall, Berkeley, CA, 94720, United States, 510-642-3599, 510-642-3599, ramathies@berkeley.edu
The Mars Organic Analyzer (MOA) microcapillary electrophoresis (μCE) technology (Skelley et al., PNAS, 2005, 102, 1041) enables rapid, automated and extremely sensitive (sub pptr) analyses of organic biomarkers including amines, amino acids and PAHs by microchip capillary electrophoresis. Recent work developed labeling and separation methods for highly oxidized organic molecules including aldehydes, ketones and carboxylic acids that may be present on the Martian surface. These methods enable low limit of detection (70 pM formaldehyde) analysis of oxidized organics in astrobiologically relevant samples. We now report the development of a programmable microfluidic Automaton array of microvalves that enables rapid automated fluorescent derivitization, serial dilution, spiking with standards and μCE channel loading for analysis of all desired classes of molecules. Automated autonomous performance of carboxylic acid labeling and processing on-chip results in labeling efficiencies and peak efficiencies comparable to manual results. These advances provide a completely integrated and autonomous MOA technology for extraterrestrial sample analyses.
Extended view of ozone and chemistry in the atmosphere of Mars
Ramsey L Smith1 , PhD, NASA Goddard Space Flight Center, Planetary Systems Laboratory, 8800 Greenbelt Rd, MS 693, Greenbelt, MD, 20771, United States, 301-286-4303, Ramsey.L.Smith@nasa.gov
We present an ongoing effort to characterize chemistry in Mars' atmosphere in multiple seasons on timescales longer than spaceflight missions through coordinated efforts by GSFC's HIPWAC spectrometer and Mars Express SPICAM, archival measurements and tests/application of photochemical models. The trace species ozone (O3) is an effective probe of Mars' atmospheric chemistry because it is destroyed by odd-hydrogen species (HOX, from water vapor photolysis). Observed ozone is a critical test for specific predictions by 3-D photochemical models (spatial, diurnal, seasonal). Coordinated measurements by HIPWAC and SPICAM quantitatively linked mission data to the 23-year GSFC ozone data record and also revealed unanticipated inter-decadal variability of same-season ozone abundances, a possible indicator of changing cloud activity (heterogeneous sink for HOX). A detailed study of long-term conditions is critical to characterizing the predictability of Mars' seasonal chemical behavior, particularly in light of the implications of and the lack of explanation for reported methane behavior.
Liquid water on Mars? Laboratory studies of low temperature, metastable perchlorate phase transitions
Raina V Gough1 , University of Colorado, Dept. of Chemistry and Biochemistry and CIRES, Campus Box 216, Boulder, CO, 80309, United States, 3034921433, raina.gough@colorado.edu
Perchlorate salts discovered at the Phoenix landing site are known to readily absorb water vapor from the atmosphere and deliquesce into aqueous solutions at room temperature. Here we examine the deliquescence (transition from crystalline solid to liquid) and efflorescence (transition from liquid to crystalline solid) of perchlorate salts at low temperatures relevant to Mars. A Raman microscope with an environmental cell was used to determine the deliquescence relative humidity (DRH) and efflorescence relative humidity (ERH) of Na+ and Mg2+ perchlorate salts as a function of temperature (-50 to 0C) and hydration state. The measured DRH can be as low as 40% and the ERH is even lower due to the kinetic inhibition of crystallization. Our results indicate that perchlorate salts can exist as metastable, aqueous solutions under current-day RH and temperature conditions on Mars. Implications for the current habitability and aqueous history of the Martian subsurface are discussed.
Physical properties and seasonal behavior of H2O, HDO, CO2 and trace gases on Mars: Quantitative mapping from Earth-based observatories
Robert E Novak1 , Professor of Physics, Ph.D., Iona College, Department of Physics, 715 North Avenue, New Rochelle, NY, 10801, United States, 914-633-2239, 914-633-2240, rnovak@iona.edu
Since 1997, we have used high-resolution (R > 40000) spectrometers on ground based-telescopes to study molecules that have astrobiological significance in Mars' atmosphere. We have used the NASA-IRTF, Keck II and VLT telescopes in the 1.0-5.0 micron range. The spectrometer is set at a wavelength to detect specific molecules. Spectral/spatial images are produced. Extracts from these images provide column densities centered at latitude/longitude locations (resolution ~400km at sub-Earth point). We have mapped the O2 singlet-Delta emission (a proxy for ozone), HDO and H2O for seasonal dates throughout the Martian year. Previously undiscovered isotopic bands of CO2 have been identified along with isotopic forms of CO. We are searching for other molecules that have astrobiological importance and have successfully measured methane in Mars' atmosphere.
Characterization of the geochemistry on Mars using LIBS and Raman spectroscopy: Implications for habitability
Pablo Sobron1 , Dr., Canadian Space Agency, Space Science and Technology, 6767, route de l'Aéroport, Saint-Hubert, Quebec, J3Y 8Y9, Canada, (450) 926-5154, psobron@gmail.com
Hydrous sulfates are a major type of secondary mineral on Mars that, because of their association with aqueous environments, can provide information about habitability. Iron Mountain, California, is an analogous site that contains hydrous iron-sulfate minerals (e.g., rhomboclase, copiapite and jarosite [1]) also identified on Mars [2]. The mineralogy and hydrochemistry make this site a useful analogue for sulfate formation and habitability investigations. Here we have explored the potential of Raman spectroscopy and Laser-Induced Breakdown Spectroscopy to characterize habitable environments based on the geochemistry of Iron Mountain. Both techniques, which are onboard the ExoMars and MSL missions, respectively, have been previously used to study Mars analogue samples [3,4]. LIBS provides the elemental abundances of most elements (10 ppm detection for some); Raman reveals information on the individual mineral species and their chemical and structural nature, e.g., hydration state, which is an indicator of water activity and habitability [5].
Probing the chemical composition of the Martian atmosphere with solar occultation Fourier transform infrared spectrometry
Paul O Wennberg1 , California Institute of Technology, Planetary Science, MC150-21, 1200 E. California Blvd, Pasadena, California, 91104, United States, 626-395-2447, wennberg@caltech.edu
We describe the Mars Atmospheric Trace Molecule Occultation Spectrometer (MATMOS) investigation, selected for the 2016 Mars Trace Gas Orbiter (TGO). The MATMOS instrument is a solar occultation Fourier Transform InfraRed spectrometer that will detect, profile and map with parts per trillion sensitivity a large suite of trace gases. A boresighted color imager will provide properties of dust and cloud layers. The MATMOS measurements will provide important new constraints on the exchange of volatiles across the surface of the planet. MATMOS will be situated on the "Sun Deck" of the TGO spacecraft. As the orbiter enters and exits the shadow of Mars, FTIR spectra will be acquired as the sun sets (or rises) by approximately 3 km tangent altitude. The spectra will be obtained from 850 – 4300 cm-1 with S/N greater than 200 and with a spectral resolution of 0.02 cm-1. The high S/N and high spectral resolution will allow precise and accurate measurements of a large suite of compounds. Shown in the figure are examples of the limits of detection for trace gas profiles from an average of 100 occultations obtained under high (least sensitive) and low (most sensitive) dust loading. MATMOS will also provide precise retrievals of the isotopic ratios of oxygen and carbon in major and minor gases.
NERNST: An electrofluidic platform for planetary surface analysis
Glen D. O'Neil1 , Tufts University, Department of Chemistry, 62 Talbot Avenue, Medford, MA, 02155, United States, 617-627-4962, Glen.O_Neil@tufts.edu
NASA's 2007 Phoenix mission performed the first wet chemical analysis of Martian soil using an array of ion-selective electrodes (ISEs). Due to size limitations, only 14 different ISEs were used in each beaker assembly. The suite included sensors for Na+, K+, NH4+, Ca2+, Mg2+, Ba2+, pH, Cl-, Br-, I- and NO3- / ClO4-, as well as metal electrodes for voltammetry and chronopotentiometry (CP). Efforts are underway to develop a platform that improves on the Phoenix experiments by using a more complete array of ion-selective microelectrodes (µISE) coupled with mesofluidic / microfluidic sample handling and processing. This design offers improvements over the Phoenix MECA experiments: flow-system configuration to increase analytical sample capacity, sensor redundancy for more complete and reliable analysis, and the ability to perform more advanced chemical characterization through reagent addition. These improvements will allow a more rigorous chemical characterization in future deployment in landed planetary science missions.
Multi oxygen isotopes in carbonates: Martian and terrestrial atmospheric observations and mechanisms for productions
Mark H. Thiemens1 , Professor, PhD, university calfornia san diego, Chemistry 0356, 9500 Gilman Drive, La Jolla, CA, 92093-0356, United States, 858 534 6882, mthiemens@ucsd.edu
Oxygen isotopic anomalies have been observed in terrestrial atmospheric and Martian carbonates. A new mechanism for their chemical production has been observed which has previously not been recognized. This new mechansim produces carbonates on atmospheric aerosols is a purely surface process. The synthesis route that occurs on an outer tens of nanometer liquid layer occurs in the Earth's atmosphere and reflects ozone concentration and chemical transformational processes. On Mars, the same route may occur on dust particles and with ozone carbon dioxide interactive process could produce an anomalous water reservoir. Along with our Mars meteorite isotopes measurements, a way to quantify past water levels may be available.
Mineralogical constraints on the chemistry and temporal footprint of Martian water
Nicholas J Tosca1 , PhD, University of Cambridge, Department of Cambridge, Downing Street, Cambridge, Cambs, CB2 3BE, United Kingdom, 44 1223 333442, njt41@cam.ac.uk
Water's footprint is clearly recorded by extensive deposits of clay minerals and evaporites in the early Martian crust. The geology of clay bearing strata supports a significant role for magma-volatile interaction in the formation and distribution of clay minerals, while leaving unanswered the contribution of surface water to early clay formation. At ~3.5 Ga, the earliest geomorphic expressions of surface water and its chemical precipitates record excursions in salinity that would have challenged the handful of microorganisms known to exhibit halo-tolerance on Earth through osmotic stress and loss of biopolymer functionality. Collectively, these data tell the story of water's limited persistence on the early Martian surface and indicate that local aqueous chemistry was principally controlled by water's episodic nature. Little is known about the boundaries of pre-biotic or early biologic environments, but when compared to Earth, the story of water on Mars appears to have been much shorter.
Aqueous soil chemistry on a not-so-dry planet: Retrospective on the Phoenix Wet Chemistry Laboratory
Michael H Hecht1 , Jet Propulsion Laboratory, Caltech, M/S 306-431, 4800 Oak Grove Dr., Pasadena, CA, 91109, United States, 818-653-9160, michael.h.hecht@jpl.nasa.gov
Compared to routine laboratory techniques, options for chemical analysis on the surfaces of other planets are severely limited. The 1976 Viking mission, the TEGA instrument on Phoenix and the SAM instrument on MSL all relied on analysis of volatiles produced by pyrolysis or humidification. In contrast, by employing electrochemical detection of soluble constituents in an aqueous solution, the Wet Chemistry Laboratory on Phoenix identified soil constituents that would be severely modified or destroyed by heating – notably perchlorate salts that seem to be the predominant form of chlorine. pH was measured for the first time (slightly alkaline, surprising most Mars scientists, as a result of carbonate buffering), and the sulfate concentration inferred from titration was within the expected range. The cation mix of Mg, Ca, Na and some K was not a surprise. Implications for the geochemical evolution of Mars, the global distribution of water and the likelihood of aqueous alteration will be discussed.
Isotopic expansion of traditional biogenic methane boundaries obtained from data collected from Mars analog hypersaline ponds
Amanda M Tazaz1 , Florida State University, Earth, Ocean and Atmospheric Science, PO Box 3064320, 117 North Woodward Ave, Tallahassee, Florida, 32306, United States, 954-445-5309, amt02e@fsu.edu
Recent discoveries of atmospheric CH4, widespread chloride rich deposits and evidence for past liquid water on the surface of Mars, have raised questions about the character of biogenic methane in similar Earth environments. We investigated CH4 production in hypersaline ponds with salinities ranging from 55 to 320 ppt. At lower salinities, microbial mats dominated, whereas at salinities above ~150 ppt, endoevaporitic communities occurred. High methane concentrations in bubbles, up to 40% by volume, were located in microbial mats and underlying sediments, as well as locked within the evaporitic minerals. This methane δ13C and δ2H ranged from -60 to -30 ‰ and -350 to -140 ‰ respectively. Higher salinity locations yielded isotopic values and methane/ethane ratios that were previously considered outside the range of biogenic methane (greater than about -50‰). Incubations of these crustal and mat samples resulted in methane production utilizing methylamine and methanol as the dominant substrates.
Assessing the habitability of past and future Mars landing sites
Richard Quinn1 , SETI Institute, Carl Sagan Center, NASA Ames Research Center, Moffett Field, CA, 94035, United States, 650-604-6501, Richard.C.Quinn@nasa.gov
Mars exploration strategies have generally focused on habitability assessment and in particular, the search for evidence of aqueous processes and the presence of complex organic molecules. However, quantitative in situ determination of these and other factors that are thought to constrain habitability on Mars has proven to be a challenge. Field research on Earth can provide important insights for the development of Mars exploration strategies. Results from field campaigns in the Chilean Atacama Desert and the recent EuroGeoMars 2009 campaign in the Utah desert have been used to develop strategies to overcome some of the analytical challenges faced during Mars exploration.
Measuring stable isotope ratios in the Martian atmosphere sampled by balloon, aircraft and surface rover
Christopher R Webster1 , Dr., Jet Propulsion Laboratory (JPL), Planetary Science Instruments Office, 4800 Oak Grove Drive, Pasadena, CA, 91109, United States, (818) 354-7478, Chris.R.Webster@jpl.nasa.gov
Scientific advancements for understanding the Martian atmosphere and surface composition place demanding requirements on precisions needed for measuring stable isotope ratios in CHNOPS. We will summarize the capability and limitations of tunable laser spectrometers to make those measurements from three platforms: balloon, aircraft and surface rover, and describe the limiting factors. We will also present recent results from extensive calibrations of the Tunable Laser Spectrometer (TLS) on the Sample Analysis at Mars (SAM) analytical chemistry lab on NASA's 2011 Mars Science Laboratory (MSL) mission. TLS has unprecedented capability for measuring methane, water and carbon dioxide abundances in the Martian atmosphere and evolved from heated soil samples. In addition, TLS will measure the 13C/12C isotope ratios in both CH4 and CO2, and the 16O/17O/18O isotope ratios in CO2.
Atmospheric chemistry and airglow on Mars: Probes of multiscale temporal and spatial scales of planetary processes
John (Jack) C McConnell1 , York University, Earth and Space Science and Engineering, 419 Petrie Bld, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada, 416-736-2100 ex 77709, jcmcc@yorku.ca
One of the puzzles when observing a planet is whether or not we are seeing the planet as it has been for millennia or as a snapshot in time. At the end of the 1960s and early 70s it was realized that the stability of the Martian atmosphere presented a problem, viz. the CO observed could be produced in a few years while the major constituent, CO2, without recombination, would last only a few thousand years. More recently it is very likely that CH4 has been discovered by ground-based and satellite instruments. But its spatial and temporal heterogeneity also imposed important constraints on Martian photochemistry. In this talk I will review past and current problems of the Martian atmosphere with a chemical flavor touching on airglow, heterogeneous chemistry, isotopic enhancement and planetary escape.
Formation and preservation of evidence for habitable environments on Mars
David J Des Marais1 , NASA Ames Research Center, Exobiology Branch, Mail Stop 239-4, Moffett Field, California, 94035-0001, United States, 650-604-3220, 650-604-1088, David.J.DesMarais@nasa.gov
The search for evidence of life on Mars requires the identification of environments (hence landing sites) that have been favorable both for life or its chemical precursors, and also for the preservation of any remains. Elemental and mineralogical measurements by the Mars Exploration Rover Mission found aqueous evaporites and hydrothermal deposits, consistent with past habitable environments. The rovers identified sulfates, carbonates and silica; these mineral groups can preserve evidence of past environments and life. Spirit rover found ultramafic rocks (Fe- and Mg-rich, relatively Si-poor); these can react with water to produce methane. Both Spirit and Opportunity found evidence that subsurface liquid water persisted at some period in the distant past. Recent observations of phyllosilicates by orbital spacecraft also indicate the former presence of near-subsurface water. These findings are consistent with the presence of subsurface habitable environments producing reduced gases sometime in the past, and perhaps even today.
MOMA: Analytical chemistry on Mars
Harald Steininger1 , Max Planck Institute for Solar System Research, Planetary Department, Max-Planck-Strasse 2, Katlenburg-Lindau, Lower Saxony, 37191, Germany, 0049-5556-979-321, steininger@mps.mpg.de
Characterizing the organic inventory of Mars is an important science goal in the field of astrobiology. On Earth, the analysis of trace amounts of organic material on a mineral matrix requires complex sample preparation, while in-situ measurements on Mars have to be relatively simple. The use of pyrolysis-GC-MS systems to analyze Martian soil samples was part of the Viking missions and will be part of the upcoming MSL and ExoMars missions. The composition of any organic compounds on Mars is unknown and could range from abiotic polycyclic aromatic hydrocarbons (PAHs), to complex organics, including biogenic compounds if life is or was ever present. The temperature during pyrolysis and the interaction with the mineral matrix leads to chemical reactions. Pyrolysis products will interact with oxygen and chlorine released by thermal decomposition of perchlorates. The use of derivatization reagents for access to less volatile amino acids and other polar substances also leads to complex chemical reactions.
Mars organic molecules irradiation and evolution (MOMIE): Assessing the processes impacting organic matter at Mars surface and subsurface
Patrice Coll1 , Prof, LISA, Department of Chemistry, CMC, 61 avenue du Général de Gaulle, CRETEIL cedex, Ile de France, 94010, France, (33)-145171554, (33)-145171564, pcoll@lisa.u-pec.fr
The search for organic relics from the early Mars is one of the major science objectives of the next missions to Mars: NASA MSL 2011 and ESA ExoMars 2018. To fulfill these mission goals, the MOMIE project has been developed to study the processes which potentially drive the evolution of organics and evaluate the stability of organic molecules under current environmental conditions at the Mars surface. An experimental set-up enabling to simulate various interactions encountered by organic matter on Mars is the heart of the project. For instance, the relative influence of hydrogen peroxide (H2O2) diffusion in the soil and of oxidants formed by UV-water ice or UV-minerals interactions can be studied by monitoring an organic sample with infrared spectroscopy. The more complex synergy of different processes will be the UV irradiation of an organic compound adsorbed on a mineral matrix in contact with water ice and/or oxidants.