2009 Annual Science Report

Astrobiology Roadmap Objective 5.1 Reports Reporting  |  JUL 2008 – AUG 2009

Project Reports

  • Biosignatures in Ancient Rocks

    The Earth’s Archean and Proterozoic eons offer the best opportunity for investigating a microbial world, such as might be found elsewhere in the cosmos. The ancient record on Earth provides an opportunity to see what geochemical signatures are produced by microbial life and how these signatures are preserved for geological time. Researchers have recognized a variety of mineralogical and geochemical characteristics in ancient rocks (sedimentary and igneous rocks; paleosols) that may be used as indicators of: (i) specific types of organisms that lived in the oceans, lakes and on land; and (ii) their environmental conditions (e.g., climate; atmospheric and oceanic chemistry). Our project addresses the following questions: Are some or all of these characteristics true or false signatures of organisms and/or indicators of specific environmental conditions? Do a “biosignature” in a specific geologic formation represent a local or global phenomenon? How are the biosignatures on Mars and other planets expected to be similar to (or different from) those in ancient terrestrial rocks?

    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
  • AbGradCon 2009

    The Astrobiology Graduate Student Conference (AbGradCon) was held on the UW campus July 17 – 20 2009. AbGradCon supports NAI’s mission to carry out, support and catalyze collaborative, interdisciplinary research, train the next generation of astrobiology researchers, provide scientific and technical leadership on astrobiology investigations for current and future space missions, and explore new approaches using modern information technology to conduct interdisciplinary and collaborative research amongst widely-distributed investigators. This was done through a diverse range of activities, ranging from formal talks and poster sessions to free time for collaboration-enabling discussions, social activities, web 2.0 conference extensions, public outreach and grant writing simulations.

    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
  • AIRFrame Technical Infrastructure and Visualization Software Evaluation

    To create visualizations of interdisciplinary relationships in the field of astrobiology, this component of the AIRFrame project involves creating a data model for source documents, a database structure, and evaluating off-the-shelf visualization software for possible application to the final project.

    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
  • Astrobiology of Icy Worlds

    Icy worlds such as Titan, Europa, Enceladus, and others may harbor the greatest volume of habitable space in the Solar System. For at least five of these worlds, considerable evidence exists to support the conclusion that oceans or seas may lie beneath the icy surfaces. The total liquid water reservoir within these worlds may be some 30 to 40 times the volume of liquid water on Earth. This vast quantity of liquid water raises two questions: Can life emerge and thrive in such cold, lightless oceans beneath many kilometers of ice? And if so, do the icy shells hold clues to life in the subsurface? We will address these questions through four major investigations namely, the habitability, survivability, and detectability of life of icy worlds coupled with “Path to Flight” Technology demonstration. We will also use a wealth of existing age-appropriate educational resources to convey concepts of astrobiology, spectroscopy, and remote sensing; develop standards-based, hands-on activities to extend the application of these resources to the search for life on icy worlds.

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

    Eigenbrode’s GCA work over the past year has largely focused on advancing protocols for the extraction and analysis of complex organics molecules in iron-oxide rich samples regarded as analogs to groundwater seeps and ancient surface water environments on Mars and ancient Earth. Eigenbrode has succeeded with some advance in methods for organic extraction and analysis for samples that include iron seep sediments, cultured iron bacteria, and terrace sediments of the Rio Tinto. In addition, Eigenbrode has been part of a successful study aimed at understanding microbial metabolisms and ecological evolution of Neoarchean using Fe, S, and C isotopic records.

    ROADMAP OBJECTIVES: 2.1 4.1 5.1 5.2 5.3 6.1 7.1
  • Amino Acid Alphabet Evolution

    All life on earth uses a standard “alphabet” of just 20 amino acids. Members of this alphabet links together into different sequences to form proteins that then interact to produce living metabolism (rather like the English of 26 letters can be linked into words that interact in sentences and paragraphs to produce meaningful writing). However, a wealth of scientific research from diverse disciplines points to the idea that many other amino acids are made by non-biological processes throughout the universe: put simply, we have no idea why life has “chosen” the members of its standard alphabet. Our project seeks to gather and organize the disparate information that describes these non-biological amino acids, to understand their properties and potential for making proteins and thus to understand better whether the biology that we know is a clever, predictable solution to making biology – or just one of countless possible solutions that may exist elsewhere.

    ROADMAP OBJECTIVES: 1.1 3.1 3.2 3.4 4.1 4.3 5.1 5.3 6.2 7.1 7.2
  • Co-Evolution of Microbial Metabolisms in the Neoarchean and Paleoproterozoic

    The interplay between the biosphere, lithosphere, hydrosphere, and atmosphere has produced a complex evolution of microbial metabolisms that significantly affect the geochemical and mineralogical compositions of surface environments. One approach to tracing the evolution of very ancient microbial metabolisms is through studies of the isotopic compositions of elements that are cycled by life and preserved in the rock record. The Neoarchean and Paleoproterozoic (~3.1 to 2.4 billion years ago) record very large changes in C, S, and Fe isotope compositions in marine sedimentary rocks that are interpreted to reflect an explosion in microbial diversity, including establishment of oxygenic and anaerobic photosynthesis, aerobic methanotrophy, methanogenesis, and dissimilatory sulfate and iron reduction. The ecosystems on Earth in the Neoarchean and Paleoproterozoic juxtaposed oxidized and reduced environments, reflecting unique conditions during the time leading up to the first significant increase in atmospheric oxygen at ~2.4 b.y. ago.

    ROADMAP OBJECTIVES: 4.1 5.1 6.1 7.1
  • Biosignatures in Relevant Microbial Ecosystems

    In this project, PSARC team members explore the isotope ratios, gene sequences, minerals, organic biomarkers, and other biosignatures in modern ecosystems that function as analogs for early earth ecosystems, or for 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
  • Evolution of Nitrogen Fixation, Photosynthesis, Hydrogen Metabolism, and Methanogenesis

    We have developed a new line of investigation to complement our work on the biochemistry of complex iron-sulfur cluster enzyme structure, function and biosynthesis with the aim of probing complex iron-sulfur enzyme evolution. We are studying the phylogenetic trajectory of multiple genes involved in complex iron-sulfur cluster function and biosynthesis to probe the evolutionary origin of aspect of hydrogen metabolism and modes of biological nitrogen fixation.

    ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Bioastronomy 2007 Meeting Proceedings

    The 9th International Bioastronomy coneference: Molecules, Microbes and Extraterrestrial Life was organized by Commission 51 (Bioastronomy) of the International Astronomical Union, and by the UH NASA Astrobiology team. The meeting was held in San Juan, Puerto Rico from 16-20 July 2007. During the reporting period the Proceedings were finalized and will have a publication date of 2009.

    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
  • CASS Planning

    The computational astrobiology summer school (CASS) is a two week program, followed by a semester of mentored independent work, which has the following goals:

    - To introduce computer science and engineering (CS&E) graduate students to the field of astrobiology, – To introduce astrobiologists to the tools and techniques that current methods in CS&E can provide, and – To encourage interdisciplinary projects that will result in advances in astrobiology.

    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 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
  • 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
  • Subglacial Methanogenesis and Its Role in 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 6.1 6.2 7.1 7.2
  • Viral Ecology and Evolution

    This project is aimed at probing the occurrence and evolution of archaeal viruses in the extreme environments in the thermal areas in Yellowstone National Park. Viruses are the most abundant life-like entities on the planet and are likely a major reservoir of genetic diversity for all life on the planet and these studies are aimed at providing insights into the role of viruses in the evolution of early life on Earth.

    ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • 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
  • Stoichiometry of Life, Task 1: Laboratory Studies in Biological Stoichiometry

    Living things require a broad menu of chemical elements to function. This project aims to quantify the chemical elements required by prokaryotes – the class of terrestrial organisms thought most similar to those that might be present in extraterrestrial settings – through laboratory experiments. These experiments will also teach us the ways in which such organisms cope with scarcity of the bioessential elements nitrogen, phosphorus and iron. We are also conducting experiments to isolate micro-organisms that use the element arsenic in place of phosphorus, if they exist. In Year 1 we initiated the first stage of these experiments.

    ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 6.2 7.1
  • Stoichiometry of Life, Task 2a: Field Studies – Yellowstone National Park

    We are investigating how the element requirements of microbes are affected by element availability in their environment in Yellowstone National Park, where there are extreme variations in the abundances of bioessential elements in addition to extremes of temperature and pH. In Year 1 we organized a multi-disciplinary field expedition to collect samples and conduct experiments. Analyses of these samples is now underway.

    ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 6.2 7.2
  • Thermodynamic Efficiency of Electron-Transfer Reactions in the Chlorophyll D-Containing Cyanobacterium, Acharyochloris Marina

    Photosynthesis is the only known process that produces planetary-scale biosignatures – atmospheric oxygen and the color of photosynthetic pigments — and 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 studying a recently discovered cyanobacterium, Acaryochloris marina, which performs oxygenic photosynthesis in environments depleted in visible light but enriched in far-red/near-infrared light. A. marina is the only known organism to have chlorophyll d (Chl d) to use photons in the far-red and near-infrared, whereas all other oxygenic photosynthetic organisms use chlorophyll a (Chl a) to utilize red photons. 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. We have been conducting lab measurements of energy storage in whole A. marina cells using pulsed, time-resolved photoacoustics (PTRPA, or PA), a laser technique that allows us to control the wavelength, amount, and timing of energy received by a sample of cells.

    ROADMAP OBJECTIVES: 3.2 4.2 5.1 5.3 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.

    ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 6.2
  • Understanding Past Earth Environments

    This project examines the evolution of the Earth over time. This year we examined and expanded the geological record of Earth’s history, and ran models to help interpret those data. Models were also used to simulate what the early Earth would look like if viewed remotely through a telescope similar to NASA’s Terrestrial Planet Finder mission concept. We focused our efforts on the Earth as it existed in prior to and during the rise of atmospheric oxygen 2.4 billion years ago, as this was one of the most dramatic and important events in the evolution of the Earth and its inhabitants.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1 4.2 4.3 5.1 5.2 5.3 6.1
  • Stoichiometry of Life, Task 3b: Ancient Records – Genomic

    The genomic records of modern organisms carry clues to the evolution of the use of elements in biology. We are investigating these records in several ways, with a particular emphasis on the use of metals in enzyme active sites and nitrogen fixation.

    ROADMAP OBJECTIVES: 5.1 5.2 5.3
  • Microbial Ecology in Hawaiian Lava Caves

    We have been studying a microbial biofilm growing at very low light intensities and high temperature and humidity below the entrance of a lava cave in Kilauea Crater, Hawai’i Volcanoes National Park. The cave presents an oligotrophic environment, but condensation of geothermally heated groundwater that vents at the rear of the cave has promoted the development of a complex microbial community, similar in higher order taxonomic structure to copiotrophic soil environments. Given the existence of lava tubes of similar geologic composition on Mars, geothermal activity there may have allowed the existence, or persistence, of complex microbial communities in similar Martian environments, wherein they would be shielded from the effects of harmful UV radiation.

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

    The questions of astrobiology span many scientific fields. This project analyzes databases of scientific literature to determine and quantify the diverse disciplinary roots of astrobiology. This is one component of a wider study to build a map of relationships between the constituent fields of astrobiology, so relevant knowledge in diverse fields can be most efficiently inform the study of life in the universe.

    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