nai

Project Reports

• 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

• 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

• 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

• 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

• Radiolytic Oxidation of Sulfide Minerals as a Source of Sulfate and Hydrogen to Sustain Microbial Metabolism

  Microbial ecosystems have been discovered in crustal environments up to 2.8 kilometers below the surface of Earth. Life in this extreme environment apapears to be sustained by high concentrations of dissolved sulfate and hydrogen. Splitting of water molecules by radiation from uranium can produce oxidation gradients that result in simple ionic products usable for maintenance and growth of microbial organisms. A set of experiments exposing water and common sulfide minerals to radiation in a laboratory reactor were conducted to test this hypothesis.

  ROADMAP OBJECTIVES: 1.1 2.1 3.3 4.1 5.1 5.3 6.2

• 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

• 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

• 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

• 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

• 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

• 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

• 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

• Environmental Genomics Reveals a Single Species Ecosystem Deep Within the Earth.

  The first metagenome sequence from a deep subsurface environment of South Africa has not only described the genetic composition of a new genera/species of sulfate reducing bacteria, Desulforudis Audaxviator, but has also revealed that it is by far the most dominant and most likely the sole resident of its environment. A single species ecosystem has never been reported before and runs counter to the prevalent concept that microorganisms live and evolve as communities of mixed species. Whether this bacterial species occurs in other deep subsurface environments around the world or whether other deep subsurface environments are also occupied by single species remains to be determined.

  ROADMAP OBJECTIVES: 2.1 5.1 5.2 5.3 6.2