2010 Annual Science Report

Astrobiology Roadmap Objective 5.1 Reports Reporting  |  SEP 2009 – AUG 2010

Project Reports

  • Advancing Methods for the Analyses of Organics Molecules in Microbial Ecosystems

    Eigenbrode’s GCA work over the past year has largely focused on developing thermochemolysis methodologies for extracting components of complex organics molecules from samples that pose unique analytical challenges because of their mineral composition. These include iron-oxide rich samples regarded as analogs to ancient aqueous environments on Mars and ancient Earth, as well as perchlorate-laden samples. Eigenbrode is making progress with the method development and has observed some interesting biosignatures relevant to understanding microbial contributions and sedimentary preservation. In addition, Eigenbrode has begun a new collaboration with MIT and Wisconsin teams with the intention of applying innovative techniques to understanding the distribution of stable carbon isotopes in the Archean rock record.

    ROADMAP OBJECTIVES: 4.1 5.1 5.2
  • Biosignatures in Ancient Rocks

    This team of geologists, geochemists, paleontologists and biologists seeks signs of early life in ancient rocks from Earth. Working mostly on that part of Earth history before the advent of skeletons and other preservable hard parts in organisms, our group focuses on geochemical traces of life and their activities. We also investigate how life has influenced, and has been influenced by changes in the surface environment, including the establishment of an oxygen-rich environment and the initiation of extreme climate states including global glaciations. For this we use a combination of observations from modern analogous environments, studies of ancient rocks, and numerical modeling.

    ROADMAP OBJECTIVES: 1.1 3.2 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • AIRFrame Technical Infrastructure and Visualization Software Evaluation

    The Astrobiology Integrative Research Framework (AIRFrame) analyzes published and unpublished documents to identify and visualize implicit relationships between astrobiology’s diverse constituent fields. The main goal of the AIRFrame project is to allow researchers and the public to discover and navigate across related information from different disciplines.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • AbGradCon 2010

    The Astrobiology Graduate Student conference is a conference organized by astrobiology graduate students for astrobiology grad students. It provides a comfortable peer forum in which to communicate and discuss research progress and ideas.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Project 1B: Proto-Cell Membrane Evolution May Have Been Directed by Mineral Surface Properties

    In the present project, we used both experimental and classical modeling approaches to examine the novel hypothesis that the surface chemistry of minerals in contact with self-assembling lipid vesicles (i.e., model protocells) controlled the stability of the vesicle membrane, causing membranolysis and preventing self-assembly in the case of minerals with certain surface properties, while other minerals were relatively inert. We also examined the role of solution chemistry and temperature cycling on lipid vesicle stability in contact with mineral surfaces. By understanding the role of natural geochemical parameters such as mineral surface chemistry, solution chemistry (pH, ionic strength, presence or absence of Ca2+), and temperature cycling on protocell membrane stability under variable conditions, we attempted to model potential aqueous environments where life may have originated such as lacustrine, tidal pool, and sub-aerial or submarine hydrothermal vents. Our project addresses NASA Astrobiology Institute’s (NAI) Roadmap goals of understanding the origins of cellularity and the evolution of mechanisms for survival at environmental limits, and NASA’s Strategic Goal of advancing scientific knowledge of the origin and evolution of the Earth’s biosphere and the potential for life elsewhere.

    ROADMAP OBJECTIVES: 3.4 5.1
  • Habitability of Icy Worlds

    Habitability of Icy Worlds investigates the habitability of liquid water environments in icy worlds, with a focus on what processes may give rise to life, what processes may sustain life, and what processes may deliver that life to the surface. Habitability of Icy Worlds investigation has three major objectives. Objective 1, Seafloor Processes, explores conditions that might be conducive to originating and supporting life in icy world interiors. Objective 2, Ocean Processes, investigates the formation of prebiotic cell membranes under simulated deep-ocean conditions, and Objective 3, Ice Shell Processes, investigates astrobiological aspects of ice shell evolution.

    ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 3.2 3.3 3.4 4.1 5.1 5.3 6.1 6.2 7.1 7.2
  • Project 1C: Extra-Cellular Polymeric Substances as Armor Against Cell Membrane Rupture on Mineral Surfaces

    Our interdisciplinary project examined the hypotheses that bacterial cell membranes are ruptured in contact with specific mineral surfaces, and that biofilm-forming extra-cellular polymeric substances (EPS) may have evolved to shield against membrane rupture (cell lysis). Furthermore, we proposed that mineral reactivity towards membranolysis should depend on its surface properties such as charge, reactive area, or free radicals generated by radiation and impacts on early Earth, Mars, and other worlds. The effect of EPS on preservation in the rock record will also be examined. By understanding the mechanisms for membranolysis, especially under the extreme conditions of high radiation and heavy impacts during early planetary history, the project addresses the NASA Astrobiology Institute’s (NAI) Roadmap goals of understanding the origins of cellularity, the evolution of mechanisms for survival at environmental limits, and preservation of biosignatures, and NASA’s Strategic Goal of advancing scientific knowledge of the origin and evolution of the Earth’s biosphere and the potential for life elsewhere.

    ROADMAP OBJECTIVES: 3.4 5.1 7.1
  • Functional Based Habitability – Defining the Environmental Factors That Constrain Modes of Microbial Metabolism

    To set the stage for space exploration and the search for life in the universe, it is necessary to establish the boundaries that define habiltability on Earth. Previous studies have emphasized using simple binary parameters to establish where life occurs and where life does not occur on Earth. We are attempting to take this to another level and establish through mutlivariable statistics the parameters that not only constrain the life but what parameters constrain the set of metabolic processes that sustain life as a function of environment.

    ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 6.2
  • Biosignatures in Relevant Microbial Ecosystems

    In this project, PSARC team members explore the isotope ratios, gene sequences, minerals, organic molecules, and other signatures of life in modern environments that have important similarities with early earth conditions, or with life that may be present elsewhere in the solar system and beyond. Many of these environments are “extreme” by human standards and/or have conditions that are at the limit for microbial life on Earth.

    ROADMAP OBJECTIVES: 4.1 4.3 5.1 5.2 5.3 6.1 7.1 7.2
  • Survivability of Icy Worlds

    As part of our Survivability of icy Worlds investigation, we examine the similarities and differences between the abiotic chemistry of planetary ices irradiated with ultraviolet photons (UV), electrons, and ions, and the chemistry of biomolecules exposed to similar conditions. Can the chemical products resulting from these two scenarios be distinguished? Can viable microbes persist after exposure to such conditions? These are motivating questions for our investigation.

    ROADMAP OBJECTIVES: 2.2 3.2 5.1 5.3 7.1 7.2
  • Bioastronomy 2007 Meeting Proceedings

    This is the published volume of material from an astrobiology meeting hosted by our lead team in 2007 in San Juan Puerto Riceo. The book includes 60 papers covering the breadth of astrobiology, and developed a new on-line astrobiology glossary.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Molecular Paleontology of Iron-Sulfur Enzymes

    In this project we are attempting to trace back in the evolutionary record using specific genetic events as markers. We are using specific gene fusion and gene duplication events in the genetic record to place a chronological sequence to the advent of nitrogen fixation, certain modes of hydrogen metabolism, and both anoxygenic and oxygenic photosynthesis.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3 3.4 4.1 5.1 5.2 5.3 6.1
  • Project 5: Geological-Biological Interactions

    This project focuses on a wide range of questions spanning understanding microbial diversity in extreme environments to the identification of biosignatures in modern and ancient rocks. In terms of environments, research in this project focuses on research at deep sea hydrothermal vents, desert sulfate deposits, arctic hydrothermal fields, as well as Paleoproterozoic terrains of Australia, Canada, and India. By learning more how life adapts to extreme environments on Earth, we hope to gain a better understanding of the limits of life on other worlds. By understanding better the signature of life recorded in ancient rocks, we hope to better refine our search stategies for the presence of life on other worlds.

    ROADMAP OBJECTIVES: 4.1 5.1 6.1 6.2 7.1
  • Computational Astrobiology Summer School

    The Computational Astrobiology Summer School (CASS) is an excellent opportunity for graduate students in computer science and related areas to learn about astrobiology, and to carry out substantial projects related to the field.

    The two-week on-site part of the program is an intensive introduction to the field of astrobiology. NASA Astrobiology Institute scientists present their work, and the group discusses ways in which computational tools (e.g. models, simulations, data processing applications, sensor networks, etc.) could improve astrobiology research. Also during this time, participants define their projects, with the help of the participating NAI researchers. On returning to their home institutions, participants work on their projects, under the supervision of a mentor, with the goal of presenting their completed projects at an astrobiology-related conference the following year.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • PHL 278: A Gateway Course for a Minor in Astrobiology

    We have recently developed obtained Montana Board of Regents for an undergraduate minor in Astrobiology at Montana State University. The Minor includes courses in Earth Sciences, Physics, Astronomy, Microbiology, Ecology, Chemistry, and Philosophy. Two new courses have been developed as part of the minor, one of which is a gateway or introductory course examines the defining characteristics of life on earth as well as the challenges of a science that studies life and its origin. The other course which will be offered fall 2011 is the capstone course for the minor which will delved into the science of Astrobiology in more detail and targeted for Juniors and Seniors that have fulfilled the majority of the requisite course requirements for the curriculum.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Metabolic Networks From Single Cells to Ecosystems

    We use mathematical and computational approaches to study the dynamics and evolution of metabolism in individual microbes and in microbial ecosystems. In particular, we take advantage of sequenced genomes to study the complete network of biochemical reactions present in an organism. We have been extending these approaches from single genomes to multiple genomes, generating ecosystem-level models of metabolism, which can help us understand some of the key transitions in the history of life on our planet.

    ROADMAP OBJECTIVES: 4.1 4.2 5.1 5.2 6.1
  • Postdoctoral Fellow Report: Steven Mielke

    This project seeks to resolve the long-wavelength limit of oxygenic photosynthesis in order to constrain the range of extrasolar environments in which spectral signatures of biogenic oxygen might be found, and thereby guide future planet detecting and characterizing observatories.

    ROADMAP OBJECTIVES: 5.1 6.1 6.2 7.2
  • Subglacial Methanogenesis and Implications for Planetary Carbon Cycling

    Methanogens are thought to be among the earliest emerging life forms. Today, the distribution of methanogens is narrowly constrained, due in part to the energetics of the reactions which support this functional class of organism (namely carbon dioxide reduction with hydrogen and acetate fermentation). Methanogens utilize a number of metalloenzymes that have active site clusters comprised of a unique array of metals. The goals of this project are 1) identifying a suite of biomarkers indicative of biological CH4 production 2). quantifying the flux of CH~4~ from sub-ice systems and 3). developing an understanding how life thrives at the thermodynamic limits of life. This project represents a unique extension of the ABRC and bridges the research goals of several nodes, namely the JPL-Icy Worlds team and the ASU-Follow the Elements team.

    ROADMAP OBJECTIVES: 2.1 5.1 5.2 5.3 7.1 7.2
  • Viral Ecology and Evolution

    We are interested in studying the viruses inhabiting the acidic hot springs within Yellowstone. We hypothesize that further understanding the viral dynamics, diversity, and composition will aid in the understanding of early Earth and how cellular life may have evolved.

    ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 6.2
  • Stoichiometry of Life, Task 1a: Experimental Studies – Cellular Stoichiometry Under Nutrient Limitation in Chemostats

    In this project we are raising several species of “extremophile” microbes at different growth rates under different kinds of element limitation (N, P, and Fe) in order to determine how their “elemental recipes” (in terms of C, N, P, Fe, and other metals) change with environmental conditions. These data will help us understand similar data to be obtained from microbes in natural ecosystems.

    ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 6.2 7.1
  • Thermodynamic Efficiency of Electron-Transfer Reactions in the Chlorophyll D-Containing Cyanobacterium, Acharyochloris Marina

    Photosynthesis produces planetary-scale biosignatures – atmospheric oxygen and the color of photosynthetic pigments. It is expected to be successful on habitable extrasolar planets as well, due to the ubiquity of starlight as an energy source. How might photosynthetic pigments adapt to alternative environments? Could oxygenic photosynthesis occur at much longer wavelengths than the red? This project is approaching these questions by using a laser technique to study the recently discovered cyanobacterium, Acaryochloris marina, which uses the chlorophyll d pigment to perform its photosynthesis at wavelengths longer than those used by the much more prevalent chlorophyll a. Whether A. marina is operating more efficiently or less than Chl a-utilizing organisms will indicate what wavelengths are the ultimate limit for oxygenic photosynthesis.

    ROADMAP OBJECTIVES: 3.2 4.2 5.1 5.3 6.2 7.2
  • Stoichiometry of Life – Task 1c – Laboratory Studies – the Role of Arsenic in Microbial Physiology, Ecology, and Evolution

    It has previously been assumed that arsenic (or its more common form, arsenate) acts only as a poison for living things. However, As is very close to the nutrient element phosphorus (P; phosphate) in the Periodic Table suggesting that possibility that under some conditions organisms might use arsenate instead of phosphate in key molecules. This study examines microbes isolated from a high arsenate, low phosphate environment (Mono Lake, CA) to see whether or not they can grow on arsenate in the absence of phosphate and if As is incorporated into major molecules.

    ROADMAP OBJECTIVES: 3.2 5.1 5.3 6.1
  • Understanding Past Earth Environments

    We study the chemical and climate evolution of the Earth as the best available proxy for what other inhabited planets might be like. A particular focus is on the “Early Earth” (formation through to the 1.6 billion years ago) which is poorly represented in the geological record but comprises half of Earth’s history. We have studied the total pressure of the Archean atmosphere (prior to 2.5 billion years ago), developed constraints on CO2 concentration, studied the oxygen and nitrogen cycles, the fractionation of sulfur isotopes and explored the effect of hazes on early Earth climate.

    ROADMAP OBJECTIVES: 1.1 1.2 4.1 4.2 5.1 5.2 6.1
  • Project 5A: Astrobiology Studies at the Utah Mars Desert Research Station in Support of Current and Future Mars Missions

    Pascale Ehrenfreund participated to Crew #77 at the Mars Desert Research Station (MDRS) in Utah in February 2009. The MDRS project was initiated by the Mars Society in 2000 and consists of a habitat complex optimized for a 6-person crew and includes a greenhouse and astronomical observatory. The goal of this field campaign sponsored by ESA, NASA and the international lunar exploration working group (ILEWG) was to demonstrate instrument capabilities in support of current and future planetary missions, to validate a procedure for Martian surface in-situ and return science, and to study human performance aspects. Special emphasis was given to sample collection in the geologically rich vicinity of MDRS and subsequent analysis of organic molecules and microorganisms in the soil to simulate the search for life with field instrumentation.

    ROADMAP OBJECTIVES: 2.1 5.1
  • Stoichiometry of Life – Task 1d – Experimental Studies – the Role of Molybdenum in the Nitrogen Cycle, Past and Present

    The element molybdenum (Mo) is critical for key processes in the cycling of nitrogen (N); for example, it is essential for the enzyme nitrogenase which bacteria use to convert gaseous N to “fixed” N that can be used in biological processes. This project seeks to understand how Mo might limit N processing in modern ecosystems (lakes and oceans) and infer its potential role in the past.

    ROADMAP OBJECTIVES: 4.1 5.1 6.1
  • Stoichiometry of Life – Task 1f – Concept Studies – Nickel-Molybdenum Co-Limitation and Evolution of Mo-Nitrogenase

    The element molybdenum (Mo) is critical for key processes in the cycling of nitrogen (N); for example, it is essential for the enzyme nitrogenase which bacteria use to convert gaseous N to “fixed” N that can be used in biological processes. However, this process costs a lot of energy. In some microbes, this energy can be captured and used via enzymes that involve both Mo and nickel (Ni). This project investigates the role of these Ni-Fe enzymes in making nitrogenase-driven processes more energetically efficient and how these enzymes may have evolved in the deep past when Ni concentrations were lower.

    ROADMAP OBJECTIVES: 4.1 5.1 5.2 6.1
  • Stoichiometry of Life, Task 2a: Field Studies – Yellowstone National Park

    Field work and subsequent laboratory analysis is an integral part of following the elements. One of our field areas is the hot spring ecosystems of Yellowstone, which are dominated by microbes, and where reactions between water and rock generate diverse chemical compositions.
    These natural laboratories provide numerous opportunities to test our ideas about how microbes respond to different geochemical supplies of elements. Summer field work and lab work the rest of the year includes characterizing the natural systems, and controlled experiments on the effects of changing nutrient and metal concentrations (done so as to not impact the natural features!).

    ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 6.2 7.2
  • Stoichiometry of Life, Task 2b: Field Studies – Cuatro Cienegas

    Cuatro Cienegas is a unique biological preserve in which there is striking microbial diversity, potentially related to extreme scarcity of phosphorus. We aim to understand this relationship via field sampling of biological and chemical characteristics and a series of enclosure and whole-pond fertilization experiments.

    ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 6.2
  • Stoichiometry of Life, Task 3b: Ancient Records – Genomic

    The goal of Task 3b is to advance understanding of elemental cycling in ancient ecosystems. Team members are developing experimental and computational approaches aimed at genomic analysis of modern ecosystems, and extending these approaches in novel ways to infer the function and composition of ancient communities.

    ROADMAP OBJECTIVES: 5.1 5.2 5.3
  • Quantification of the Disciplinary Roots of Astrobiology

    While astrobiology is clearly an interdisciplinary science, this project seeks to address the question of how interdisciplinary it is. We are reviewing published works across a broad range of scholarly databases, comparing disciplinary indicators such as subject terms, journal titles and author affiliations, and creating a computational model to identify and compare the makeup of astrobiological research literature in terms of the proportion of work that come from constituent fields.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2