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Project Reports

• Biosignatures in Chemosynthetic and Photosynthetic Systems

  Our work examines the microbiology and geochemistry of microbial ecosystems on Earth in order to better understand the production of “biosignatures” — chemical or physical features or patterns that can only have been formed by the activities of life. More specifically, in photosynthetic (light-eating) microbial mats, we examine the factors that control the formation of biosignature gases (such as could be seen by telescope in the atmospheres of planets orbiting other stars) and isotopic and morphological features that could be preserved in the rock record (such as could be examined by rovers on Mars). Additionally, we study the formation of morphological and mineral signatures in chemotrophic (chemical-eating) systems that have no direct access to light or the products of photosynthesis. Such systems likely represent the only viable possibility for extant life on modern day Mars or Europa.

  ROADMAP OBJECTIVES: 2.1 4.1 5.1 5.2 6.1 7.1 7.2

• Module 1: The Building Blocks of Life

  Molecular material that may lead to life on planet surfaces has its origin in interstellar space. Using a combination of laboratory spectroscopic measurements and radio astronomical observations, this module has been tracing the life cycle of carbon and phosphorus containing compounds from their formation in outflows around old stars to their arrival on planet surfaces via exogenous delivery. We have been investigating what carbon and phosphorus compounds are found in matter lost from stars, and how the chemical composition changes as this material flows into the interstellar medium and forms dense clouds
  in space. We are following what happens to these compounds as these clouds evolve into solar systems, and how comets, meteorites, and dust particles may have brought interstellar pre-biotic material to Earth and other planets.

  ROADMAP OBJECTIVES: 3.1 3.2 4.2 7.1

• Amino Acid Preservation in Saline-Lake Sediments and Mars-Simulant Regolith

  Potentially habitable environments on the Martian surface have been identified by orbital spectroscopy and by landed instruments on the Mars Exploration Rovers (MERs). Identification of evaporite mineral assemblages on Mars provides strong evidence for the widespread role of evaporitic water bodies of water in the past. Evaporite minerals may provide enhanced preservation of biomolecules by sequestration of organic constituents into mineral matrices during crystallization. The utilization of amino acids, the building blocks of proteins, as a distinct biosignature that could be extracted from evaporite phases would provide a strong biosignature for life having existed in the past or persisting to the present on Mars.

  ROADMAP OBJECTIVES: 2.1 3.2 5.1 5.3 7.1

• Biogenic Formation of High-Magnesium Calcite in Sulfide-Rich Systems

  Calcite minerals that contain high proportions of magnsium are well-known biogneic minerals in modern marine environments, reflecting metastable incorporation of Mg in the calcite lattice. In the modern oceans, calcite may form in the presence of sulfide in hydrothermal systems, or, in the ancient Earth, high-magnesium calcite may have formed in the presence of high ambient sulfide (produced by bacterial sulfate reduction or hydrothermal systems), and this project is aimed at understanding the mechamisms involved in producing high-magnesium calcite in the presence of high dissolved sulfide.

  ROADMAP OBJECTIVES: 4.1 6.1 7.1

• Biomimetic Cluster Synthesis: Bridging the Structure and Reactivity of Biotic and Abiotic Iron-Sulfur Motifs

  Synthetic approaches are being utilized to bridge the gap between Fe-S minerals and highly evolved biological Fe-S metalloenzymes. These studies are focusing on organic template (protein) mediated cluster assembly (biomineralization), probing properties of synthetic clusters, both as homogeneous and heterogeneous catalysts, investigating the impact of size scale on the properties of synthetic Fe-S clusters, and computational modeling of the structure and catalytic properties of synthetic Fe-S nanoparticles in the 5-50 nm range.

  ROADMAP OBJECTIVES: 3.1 3.2 3.3 3.4 7.1 7.2

• Application of U-Tube and Fiber-Optic Distributed Temperature Sensor to Characterize the Chemical and Physical Properties of a Deep Permafrost and Sub-Permafrost Environment at High Lake, Nunavut, Canada.

  Acquiring water samples for microbial and geochemical analyses from beneath hundreds of meters of frozen rock by conventional approaches are impossible because the water freezes in the tubing while transiting the permafrost and most down-hole pumps or bailers lack sufficient power to push up water that distance. Furthermore, to collect samples with representative trace gas concentrations the water needs to be kept under pressure as it rises to the surface. We utilized a new technology that combines a gas-lifting U-tube device with heat tracer tapes and a fiber-optic distributed temperature sensor (DTS) and successfully acquired a mixture of drilling water and fracture water from beneath 420 meters of permafrost. We also performed a thermal perturbation experiment and obtained a high resolution profile of the thermal conductivity of the permafrost zone, which in turn enabled us to invert the ambient geothermal profile to obtain this ground surface temperature history for the past 1000 years.

  ROADMAP OBJECTIVES: 2.1 5.2 5.3 7.1

• Iron Isotope Biosignatures: Laboratory Studies and Modern Environments

  This project seeks to define the biotic and abiotic mechanisms of Fe isotope fractionation in modern sedimentary environments and laboratory model systems. Such information is required to evaluate the potential role of Fe isotopes in understanding the evolution of microbial redox metabolism on the early Earth, and to evaluate their ability to serve as biosignatures of microbial metabolism on other planets (e.g. Mars).

  ROADMAP OBJECTIVES: 4.1 6.1 7.1

• Computational Chemical Modeling the Link Between Structure and Reactivity of Iron-Sulfur Motifs

  The Fe-S mineral catalysis, Fe-S enzyme catalysis, and a biomimetic thrust areas of ABRC have their own unique ways to probe the relationships between structure and reactivity at the active sites of iron-sulfur enzymes and the structure and reactivity of iron-sulfur minerals. We have developed a cohesive link among these thrust areas through bridging the enzymatic/mineral catalysis and molecular structure/chemical reactivity by computational chemistry.

  ROADMAP OBJECTIVES: 3.1 3.2 3.3 7.1 7.2

• Advancing Techniques for in Situ Analysis of Complex Organics

  Our research in laser mass spectrometry is part of the overall program of the Goddard Center for Astrobiology to investigate the origin and evolution of organics in planetary systems. Laser mass spectrometry is a technique that is used to determine the chemical composition of sample materials such as rocks, dust, ice, meteorites in the lab. It also may be miniaturized so it could fit on a robotic spacecraft to an asteroid, a comet, or even Mars. On such a mission it could be used to discover any organic compounds preserved there, which in turn would give us insight into how Earth got its starting inventory of organic compounds that were necessary for life. The technique uses a high-intensity laser to “zap” atoms and molecules directly off the surface of the sample. The mass spectrometer instantly captures these particles and provides data that allow us to determine their molecular weights, and therefore their chemical composition. We are developing this technique to understand the mass spectra that would be obtained from a meteorite or an unknown rock sample encountered on a remote planetary mission.

  ROADMAP OBJECTIVES: 2.1 2.2 3.1 3.2 7.1

• Climate, Habitability, and the Atmosphere on Early Mars

  Atmospheric chemistry has profound implications for the climate and habitability of Mars throughout its history. The presence and stability of greenhouse gases and aerosols, for example, may regulate climate or force climate change. Chemical reactions in the atmosphere initiated by light (“photochemistry”) may also produce gases or aerosols that serve as a shield against ultraviolet light (as stratospheric ozone does on earth) and possibly warm or cool the surface, which, in turn, has implications for the presence and stability of water on Mars. Thus, understanding the chemical composition and physical properties of possible Martian atmospheres over time is vital to the understanding of the opportunities and challenges for early life on Mars, as well as the importance of habitat features that provide radiation protection. In this project, we are investigating in laboratory experiments how quickly photochemistry can destroy and produce various greenhouse gases and aerosols and whether or not the aerosols may serve to warm or cool the surface. We are also investigating whether or not these photochemical reactions can produce carbon-rich aerosols that might be depleted in the stable isotope carbon-13 relative to carbon-12, and thus might be mistaken for an isotopic signature produced by biological processes after the aerosols settle out of the atmosphere and become incorporated into the martian rock record or meteorites that have made it to earth.

  ROADMAP OBJECTIVES: 1.1 1.2 3.1 6.1 7.1 7.2

• Microbial Pyrite Oxidation in Nature and the Lab: Sulfate Mineral Biosignature Investigation

  In the laboratory the project aims to culture bacteria that oxidize iron and sulfur under various conditions (a range of temperatures and different degrees of acidity). The goal is to develop criteria to distinguish minerals that formed as indirect result of bacterial activity from those that form with no biological association. It s anticipated that such distinctions may involve subtle, but distinctive differences in chemical and isotopic compositions, including variations in the ratios of the naturally occurring stable (non-radioactive) isotopes of iron, sulfur and oxygen. Analyses will be made of similar minerals, formed naturally in an acid mine drainage area of SW Spain, that may be an analog for processes that are believed to have happened on the surface of Mars four billion years ago.

  ROADMAP OBJECTIVES: 2.1 4.1 7.1

• Molecular Beam Studies of Nitrogen Reactions on Iron-Sulfur Surfaces

  It is generally accepted that surface-mediated reactions occur on defect sites. The role of defects in the formation of ammonia is being evaluated using molecular beam-surface scattering experiments in which a deuterium atom plasma source is used to hydrogenate a pyrite surface with D atoms. The hydrogenated surface is subsequently bombarded with a molecular beam of energetic N2 molecules and the conversion of N2 to products such as ammonia is probed through mass spectrometry.

  ROADMAP OBJECTIVES: 3.1 3.2 3.3 7.1 7.2

• 3. Prebiotic Chemical and Isotopic Evolution on Earth

  ROADMAP OBJECTIVES: 3.1 4.1 4.2 7.1

• Challenges for Coring Deep Permafrost on Earth and Mars: Drilling Project at High Lake, Nunavut, Canada

  Accessing liquid water environments and searching for life in the subsurface of Mars during future space missions will require drilling through hundreds of meters of permafrost and frozen rock. Many coring expeditions with the goal of acquiring uncontaminated cores for microbial studies have been performed on Earth, but none in deep permafrost, hard rock terranes. The goal of this project was to determine the requirements for obtaining permafrost core samples that are useful for microbial analyses and to acquire experience in coring through permafrost into the underlying liquid water, fractured rock system at High Lake, Nunavut, Canada.

  ROADMAP OBJECTIVES: 2.1 5.1 7.1

• 4. Prebiotic Molecular Selection and Organization

  ROADMAP OBJECTIVES: 3.1 3.2 3.4 4.1 7.1

• Examination of the Microbial Diversity Found in Ice Cores (Brenchley)

  Our goal is to discover microorganisms surviving in cold or frozen environments and to use this information to understand how different microorganisms survive extreme habitats. Our recent results demonstrated that abundant populations, including many bacteria representing novel taxa, exist frozen in a Greenland glacier ice core for at least 120,000 years. Current isolates are being characterized as new species of ultra-small celled bacteria. This research provides insight into microbial survival in extreme environments that might exist elsewhere in the solar system.

  ROADMAP OBJECTIVES: 2.1 5.1 5.2 5.3 6.1 6.2 7.1

• Design, Construction and Testing of a Cavity-Ring Down Spectrometer for Determination of the Concentration and Isotopic Composition of Methane

  The recent detection of CH₄ in the Martian atmosphere and observations suggesting that it varies both temporally and spatially argues for dynamic sources and sinks. CH₄ is a gaseous biomarker on Earth that is readily associated with methanogens when its H and C isotopic composition falls within a certain range. It is imperative that a portable instrument be developed that is capable of measuring the C and H isotopic composition of CH₄ at levels comparable to that on Mars with a precision similar to that of an isotope ratio mass spectrometer and that such an instrument be space flight capable. Such an instrument could guide a rover to a site on Mars where emission of biogenic gases is occurring and samples could be collected for Mars sample return.

  ROADMAP OBJECTIVES: 2.1 2.2 3.3 4.1 5.1 5.2 5.3 6.1 6.2 7.1 7.2

• Pearson Project

  ROADMAP OBJECTIVES: 3.2 4.2 6.1 7.1

• Nano-Structured Minerals as Tracers of Microbial Activities

  Biologically produced mineral formation at the nanometer scale often produces unique morphologies and compositions relative to abiologic imineral formation. For example, calcite nano-fibers in arid and semi-arid soils are demonstrably products of microbial activities, where bioorganics derived from microorganism have controlled growth of nano-fibrous calcite. Other examples of bioorganic control on nano minerals include ttitanium-free magnetite / maghemite nano-fibers that are closely associated with Fe-bearing smectite in a weathered basaltic glass, and it is possible that these minerals were produced by bacterial dissimilatory iron reduction of ferrihydrite nano-crystals through topotactic transformation to magnetite. Both calcite nano-fibers and Ti-free maghemite nano-crystals are likely biosignatures in dry soils and weathered basalt tuff deposits, raising the possibility that such features may be found in sedimentary rocks on other planetary bodies.

  ROADMAP OBJECTIVES: 7.1

• DDF: Geomicrobiology of a Unique Ice-Sulfur Spring Ecosystem in the High Arctic

  A glacial, active sulfide spring environment at Borup Fiord Pass on Ellesmere Island in the Canadian High Arctic provides an excellent opportunity to study microbial life at a site that may be an analog to Europa, an ice-covered moon of Jupiter. During the past year we have collected samples from the extensive mats of sulfur-minerals that precipitate in discharge channels to identify the microbial communities hosted in the sulfur-ice, and to cultivate key key organisms mediating the oxidation of H2S to elemental sulfur.

  ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 7.1 7.2

• 5. Life in Extreme Environments

  ROADMAP OBJECTIVES: 3.1 5.1 5.3 6.2 7.1

• Probing the Structure and Nitrogen Reduction Activity of Iron-Sulfur Minerals

  Fe-S compounds are common in both biological and geological systems. The adaptation of Fe-S clusters from the abiotic world to the biological world may have been an early event in the development of life on Earth and possibly a common feature of life elsewhere in the universe. The Iron-sulfur mineral thrust of the ABRC is focused on examining the structure and reactivity of FeS minerals using nitrogen fixation as a model reaction.

  ROADMAP OBJECTIVES: 3.1 3.2 3.3 3.4 7.1 7.2

• 6. Molecular and Isotopic Biosignatures

  ROADMAP OBJECTIVES: 2.1 3.1 4.1 4.2 5.3 6.1 7.1 7.2

• Structure, Function, and Biosynthesis of the Complex Iron-Sulfur Clusters at the Active Sites of Nitrogenases and Hydrogenases

  Iron-sulfur clusters are thought to be among the most ancient cofactors in living systems. The Fe-S enzyme thrust is focused on examining the structure, mechanism, and biosynthesis of the complex Fe-S enzymes nitrogenase and hydrogenase.

  ROADMAP OBJECTIVES: 3.1 3.2 3.3 7.1 7.2

• Iron and Sulfur-Based Biospheres and Their Biosignatures

  This project focuses on the geochemical and microbiological properties of iron (Fe) and sulfur (S) based lithotrophic microbial ecosystems. Recent aspects of this research have been supported by a Director’s Discretionary Fund (DDF) project entitled “Biogeochemical forensics of Fe-based microbial systems: defining mission targets and tactics for life detection on Mars”. The Banfield group is examining Fe concretions at the hypersaline Lake Tyrell in Victoria, Australia as analogs for those which formed at Meridiani Planum on Mars, as well as novel uncultivated, ultra-small Archaea in pyrite oxidation-based microbial communities at Iron Mountain, CA. The latter organisms have only a very small number of ribosomes per cell (ca. 92, compared to ca. 10,000 for E. coli in culture), which are positioned around the inside of the inner membrane. The size and highly organized internal structure of these organisms provide clues to the strategies of life at its lower size limits. The Emerson group is investigating natural populations and pure cultures of Fe(II)-oxidizing bacteria in an attempt to better understand how their physiology and ecology influences the mineralogy and geochemistry that are hallmarks of these organisms in the environment. A major focus of this work, in collaboration with the Luther group, has been to gain a better understanding the contribution that neutrophilic, oxygen-dependent Fe(II)-oxidizing bacteria make to Fe(II) oxidation kinetics both in situ and in the laboratory. Additional work has focused on the ultrastructure and behavior of a unique Fe-oxidizing bacterium, Mariprofundus ferrooxydans, isolated from a deep-sea hydrothermal vent that had extensive mats of Fe(II)-oxidizing bacteria. The Luther group has been examining a variety of environments where microbially-driven Fe(II) oxidation occurs, including areas where free sulfide is not present (creeks in VA and Chocolate Pots, Yellowstone National Park) and locations where free sulfide is present [local Delaware Inland Bays and the hydrothermal vents at Kilo-Moana (20°3’S, 176°8’W), located on the East Lau Spreading Centre (ELSC), in the Lau Basin, SW Pacific Ocean]. These studies demonstrate that it is possible to distinguish between abiotic and biotic mechanisms for Fe(II) oxidation using real time measurements. Roden’s group has examined microbial communities and biosignatures in several different Fe-dominated natural systems, including circumneutral pH groundwater Fe seeps in Tuscaloosa, AL; a Pliocene-age weathered volcanic tuff unit in Box Canyon, ID; hypersaline Lake Tyrell; and chemically-precipitated sediments in the Spring Creek Arm of the Keswick Reservoir downstream of the Iron Mountain acid mine drainage site in northern CA. We have also evaluated the composition and function of an anaerobic, nitrate-dependent Fe(II)-oxidizing enrichment culture which is capable of chemolithoautotrophic growth coupled to oxidation of the insoluble ferrous iron-bearing phyllosilicate mineral biotite.

  ROADMAP OBJECTIVES: 4.1 6.1 7.1 7.2

• High Lake Gossan Deposit: An Arctic Analogue for Ancient Martian Surficial Processes?

  The massive sulfide deposit at High Lake is covered by a ~1 meter thick layer of Fe oxides and sulfate minerals. The minerals have formed within the last 8,000 years in the active zone of the permafrost and as such the site provides a good analog to those terranes on Mars that contain similar mineral assemblages, e.g. Terra Meridiana, and may have formed under similar, acidic conditions. The minerals present in the High Lake gossan were characterized by XRD, SEM and Mössbauer.

  ROADMAP OBJECTIVES: 2.1 5.1 5.2 5.3 6.1 7.1

• Recognition of Theoretical Environments on Mars

  Our goal is to develop remotely sensed signatures that provide guideposts to analyzing remotely sensed data from Mars to explore for habitable environments. We are working with the biologically diverse, iron-rich environments of Rio Tinto and their mineral deposits to develop strategies for interpreting data from Mars.

  ROADMAP OBJECTIVES: 2.1 7.1

• New Frontiers in Micro-Analysis of Isotopic Compositions of Natural Materials: Development of O, Si, and Li Isotopes

  The isotope ratios of oxygen and silicon are a sensitive monitor of sedimentary and hydrothermal processes for deposition of banded iron formation. Our focus on banded iron formations reflects the importance these unusual units have in biogeochemical cycling in the early Earth. In particular, we are examining the deposition of microlaminated sections of the Dales Gorge member of the Brockman Iron Formation from the Hamersley basin, which have alternatively been interpreted to represent annual varves in chemical precipitates from seawater, or variations in a sub-surface hydrothermal system. These conflicting models have relevance for interpreting the role of microbial life in precipitation of the Fe-oxides. In addition, δ18O and δ³⁴S values from coexisting minerals can be used to estimate the temperature of the Archean ocean, or of the hydrothermal system. δ⁷Li and δ18O values in zircons allow these tests to be applied to magmas that may have assimilated sedimentary materials, and, in the case of Jack Hills samples from SW Australia, provide a record of the earliest Earth (4.4 to 4.0 Ga), before the formation of all known rocks.

  ROADMAP OBJECTIVES: 4.1 7.1

• Isotopic Signatures of Methane and Higher Hydrocarbon Gases From Precambrian Shield Sites: A Model for Abiogenic Polymerization of Hydrocarbons

  Methane and higher hydrocarbon gases in ancient rocks on Earth originate from both biogenic and abiogenic processes. The measured carbon isotopic compositions of these natural gases are consistent with formation of polymerization of increasing long hydrocarbon chains starting with methane. Integration of carbon isotopic compositions with concentration data is needed to delineate the origin of hydrocarbon gases.

  ROADMAP OBJECTIVES: 1.1 2.1 3.1 4.1 4.2 6.1 7.1 7.2

• 7. Astrobiotechnology

  ROADMAP OBJECTIVES: 2.1 2.2 3.1 3.2 5.3 6.2 7.1

• Production of Mixed Cation Carbonates in Abiologic and Biologic Systems

  Carbonate minerals commonly occur in terrestrial environments and they are found in extraterrestrial materials, such as meteorites and interplanetary dust particles. On earth, carbonates hold one of the earliest records of seawater chemistry. Carbonate minerals that form in thermodynamic equilibrium (abiotic formation) are constrained in Ca-Mg-Fe composition by the solvi that limit solid-solution to the magnesite-siderite join, the dolomite-ankerite join, and the calcite end member. However, it is now known that microorganisms may produce Ca-Mg-Fe compositions that lie between these solvi, and are therefore out of thermodynamic equilibrium, and such compositions may represent a biosignature for microbially mediated formation. The goal of this project is to understand the mechanisms by which carbonate minerals of unusual chemistry form at relatively low temperature so that we may better understand the processes that may form these minerals in the early Earth, on Mars, and other planetary bodies of the Solar System.

  ROADMAP OBJECTIVES: 4.1 7.1

• Prebiotic Organics From Space

  This project has three components, all aimed to better our understanding of the connection between chemistry in space and the origin of life on Earth and possibly other worlds. Our approach is to trace the formation and evolution of compounds in space, with particular emphasis on identifying those that are interesting from a prebiotic perspective, and understand their possible roles in the origin of life on habitable worlds. We do this by first measuring the spectra and chemistry of materials under simulated space conditions in the laboratory. We then use these results to interpret astronomical observations made with ground-based and orbiting telescopes. We also carry out experiments on simulated extraterrestrial materials to analyze extraterrestrial samples returned by NASA missions or that fall to Earth in as meteorites.

  ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 3.4 4.3 7.1 7.2

• Isotopic Fingerprints of Past Life and Surface Conditions on Mars

  The isotopic composition of calcium is being investigated as a possible indicator the presence of past life on Mars. The research seeks to separate biological from non-biological effects, estimate the magnitude of the effects, and investigate terrestrial environments that may be analogues of early Martian surface environments. Unexpected results have led to evidence concerning the earliest stages of the formation of Mars.

  ROADMAP OBJECTIVES: 1.1 2.1 7.1

• Laboratory Microbial Simulations: Astrobiological Signatures

  We aim to use laboratory and field environments to investigate microorganisms and their biogeochemical signatures. We have investigated methanotrophic seeps and deeply-buried marine environments, as well as used laboratory pure-cultures to further our understanding of diverse metabolisms.

  ROADMAP OBJECTIVES: 2.1 4.1 5.1 5.2 5.3 7.1

• The High Lakes Project (HLP)

  The High Lakes Project is a multi-disciplinary astrobiological investigation studying high-altitude lakes between 4,200 m and 5,916 m elevation in the Central Andes of Bolivia and Chile. Its primary objective is to understand the impact of increased environmental stress on lake habitats and their evolution during rapid climate change as an analogy to early Mars. Their unique geophysical environment and mostly uncharted ecosystems have added new objectives to the project, including the assessment of the impact of low ozone/high solar irradiance in non-polar aquatic environments, the documentation of poorly known ecosystems, and the quantification of the impact of climate change on lake environment and ecosystem.
  Data from 2003 to 2007 show that solar irradiance is 165% that of sea level with instantaneous UV-B flux reaching 17W/m2. Short UV wavelengths (260-270 nm) were recorded and peaked at 14.6 mW/m2. High solar irradiance occurs in an atmosphere permanently depleted in ozone falling below ozone hole definition for 33-36 days and between 30-35% depletion the rest of the year. The impact of strong UV-B and UV erythemally-weighted daily dose on life is compounded by broad daily temperature variations with sudden and sharp fluctuations. Lake habitat chemistry is highly dynamical with notable changes in yearly ion concentrations and pH resulting from low and variable yearly precipitation. The year-round combination of environmental variables define these lakes as end-members. In such an environment, they host surprisingly abundant and diverse ecosystems including a significant fraction of previously undescribed species of zooplankton, cyanobacterial, and bacterial populations.

  ROADMAP OBJECTIVES: 1.1 2.1 4.1 4.3 5.1 5.2 5.3 6.1 6.2 7.1

• Mars Forward Contamination Studies Utilizing a Mars Environmental Simulation Chamber

  A variety of microorganisms have been selected for experimental culturing in a Mars environmental simulation chamber. The test organisms are adapted on Earth to desiccation resistance and cold tolerance so they are suitable for exposure to simulated surface conditions on Mars. The test chamber is capable of reproducing temperatures, solar radiation, and atmospheric conditions inferred for Mars. Results from these tests will provide critical information for the design and engineering of sampling and caching equipment on a future mission to sample rocks and sediments on Mars and return those samples to Earth for laboratory study.

  ROADMAP OBJECTIVES: 2.1 3.2 3.3 5.1 5.2 5.3 6.1 6.2 7.1

• Microbial Communities in Subpermafrost Saline Fracture Water at the Lupin Au Mine, Nunavut, Canada

  As scientists prepare to search for life in the subsurface of Mars, it is increasingly clear that we have little experience characterizing microbial life in permafrost environments on Earth. Lupin gold mine in Nunavut Territory Canada provides scientists with an opportunity to collect samples of ground water beneath 500 meters of permafrost. These subpermafrost water samples contain extant microbial communities that are dominated by sulfate-reducing bacteria. It remains to be determined how and when this microbial community became established.

  ROADMAP OBJECTIVES: 2.1 5.1 5.2 5.3 7.1

• Molecular Signatures of Life on the Edge (DDF Project)

  We have investigated the Dead Sea, as a possible analog of early Mars environments — slightly acidic and highly saline. We have used metagenomics, lipid analysis, and amino acid analysis.

  ROADMAP OBJECTIVES: 2.1 5.1 5.2 5.3 7.1

• Organic and Inorganic Acids From Ion-Irradiated Ices

  Scientists at the Cosmic Ice Laboratory with the Goddard Center for Astrobiology study the formation and stability of molecules under conditions found in outer space. During the past year, amino acids found in meteorites were investigated, including some acids not found in terrestrial biology. Carbonic acid, a very unstable molecule on Earth, also was studied since it will be stable under Martian conditions and environments in the outer solar system. These projects are part of the Comic Ice lab’s continuing contributions to understanding the chemistry of biologically-related molecules and chemical reactions in extraterrestrial environments.

  ROADMAP OBJECTIVES: 2.2 3.1 7.1

• Saline Lakes and Gypsum Dunes in the Rio Grande Rift System as Analogues for Sulfate Deposits on Mars

  Sulfates are a critical component of rocks and regolith exposed at or near the surface of Mars. We are pursuing, therefore, a latitudinal study of salt basins developed along the Rio Grande rift in North America as a terrestrial analog for sulfate deposition in down-dropped basins and craters on Mars. This project addresses local and regional influences of volcanism on sulfur cycling, biogeochemical roles of organism in sulfate-dominated playa lakes, and climatic controls on formation of gypsum dunes.

  ROADMAP OBJECTIVES: 2.1 5.3 7.1

• Untitled

  We are exploring the geological and geochemical record of ancient Earth for clues about the co-evolution of life and environment. We’re focusing on three events in Earth history: the apparent rise of atmospheric oxygen at 2.45 billion years ago, the establishment of life on land during the Cambrian (about 540 milliion years ago), and the greatest mass extinction of all time at the end of the Permian, 252 million years ago. We use a combination of computer modeling, field work, and laboratory analysis.

  ROADMAP OBJECTIVES: 4.1 6.1 7.1 7.2

• Stability of Methane Hydrates in the Presence of High Salinity Brines on Mars

  Laboratory experiments were used to monitor the influence of increasing salinity on the stability of ices composed of water, methane, and carbon dioxide. New data show that these types of hydrates decease in stability as salinity increases, suggesting that lateral or vertical migration of brines in the subsurface of Mars could cause release of methane and carbon dioxide to surface sediments and the atmosphere. These experimental results are important for interpreting reports of methane in the Martian atmosphere.

  ROADMAP OBJECTIVES: 2.1 2.2 3.1 7.1 7.2

• The Diversity of the Original Prebiotic Soup: Re-Analyzing the Original Miller-Urey Spark Discharge Experiments

  Recently obtained samples from some of the original Stanley Miller spark discharge experiments have been reanalyzed using High Pressure Liquid Chromatography-Flame Detection and Liquid Chromatography-Flame Detection/Time of Flight-Mass Spectrometry in order to identify lesser constituents that would have been undetectable by analytical techniques 50 years ago. Results show the presence of several isoforms of aminobutyric acid, as well as several serine species, isomers of threonine, isovaline, valine, phenylalanine, ornithine, adipic acid, ethanolamine and other methylated and hydroxylated amino acids. Diversity and yield increased in experiments utilizing an aspirating device to increase the gas flow rates; this could be applied as a simulation of prebiotic chemistry during a volcanic eruption. The variety of products formed in these experiments is significantly greater than previously published and mimic the assortment of compounds detected in Murchison and CM meteorites.

  ROADMAP OBJECTIVES: 2.1 3.1 3.2 3.4 4.1 4.2 5.1 6.2 7.1 7.2

• Sulfur Biogeochemistry of the Early Earth

  Sulfur is widespread in surface geochemical systems and is abundant in many rock types. It is present in volcanic gases and marine waters, and has served a key role in geobiological processes since the origin of life. Like other low atomic number elements, sulfur isotope ratios in various compounds usually follow predictable mass-dependent fractionation laws; these different mass-dependent isotope fractionations serve as powerful tracers for igneous, metamorphic, sedimentary, hydrothermal and biological processes. Mass-independent sulfur isotope fractionation is a short-wavelength photolytic effect that occurs in space, as well as in gas-phase reactions in atmospheres transparent to deep penetration by ultraviolet light. Crucial aspects of the chemical evolution of the early atmosphere — and the surface zone as a whole — can be followed by mass-independent sulfur isotopes in Archean metasedimentary rocks. Metabolic styles of organisms in response to global changes in surface redox over geologic time can also be traced with multiple S isotopes.

  We have concluded from our various studies over the last year and before to the very inception of the NAI node at Colorado, that all Archean sulfur minerals previously documented for their 34S/32S compositions warrant a comprehensive re-examination of their 32S, 33S, 34S (and 36S), sulfur isotope systematics.

  ROADMAP OBJECTIVES: 1.1 1.2 4.1 4.2 5.1 5.2 5.3 6.1 7.1 7.2

• Research Activities in the Astrobiology Analytical Laboratory

  A little over 4.5 billion years ago, our solar system was a disk of gas and dust, newly collapsed from a molecular cloud, surrounding a young and growing protostar. Today most of the gas and dust is in the spectacularly diverse planets and satellites of our solar system, and in the Sun. How did the present state of the planetary system come to be from such undistinguished beginnings? The telling of that story is an exercise in forensic science. The “crime” occurred a long time ago and the “evidence” has been tampered with, as most planets and satellites display a rich variety of geological evolution over solar system history.

  Fortunately, not all material has been heavily processed. Comets and asteroids represent largely unprocessed material remnant from the early solar system and they a represented on Earth by meteorites and interplanetary dust particles (IDPs). Furthermore, telescopic studies of the birth places of other solar systems allow researchers to simulate those environments in the laboratory so that we may characterize the organic material produced.

  We are a laboratory dedicated to the study of organic compounds derived from Stardust and future sample return missions, meteorites, lab simulations of Mars, interstellar, proto-planetary, and cometary ices and grains, and instrument development. Like forensic crime shows, the Astrobiology Analytical Laboratory employs commercial analytical instruments. However, ours are configured and optimized for small organics of astrobiological interest instead of blood, clothing, etc.

  ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 7.1