2009 Annual Science Report

Astrobiology Roadmap Objective 7.2 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
  • 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
  • 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
  • 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
  • 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
  • Cosmic Distribution of Chemical Complexity

    This project seeks to improve 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 development of chemical complexity in space, with particular emphasis on understanding the evolution from simple to complex species focusing on those that are interesting from a biogenic perspective and also understanding 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 meteorites.

    ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 3.2 3.4 4.3 7.1 7.2
  • 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
  • Computational Chemical Modeling the Link Between Structure and Reactivity of Iron-Sulfur Motifs

    Traditionally, the iron-sulfur mineral catalysis, iron-sulfur enzyme catalysis, and biomimetic thrust areas of ABRC have their own unique ways to probe the structure/function relationships at the surface defect sites, at the enzymatic active sites, or at the interface of biomacromolecular and iron-sulfur particle layers, respectively. Computation chemistry can provide a cohesive link among these thrust areas through bridging the enzymatic/mineral catalysis and molecular structure/chemical reactivity via fundamental physico-chemical properties at the molecule level.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3 3.4 7.1 7.2
  • 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
  • Developing New Biosignatures

    The development and experimental testing of potential indicators of life is essential for providing a critical scientific basis for the exploration of life in the cosmos. In microbial cultures, potential new biosignatures can be found among isotopic ratios, elemental compositions, and chemical changes to the growth media. Additionally, life can be detected and investigated in natural systems by directing cutting-edge instrumentation towards the investigation of microbial cells, microbial fossils, and microbial geochemical products. Over the next five years, we will combine our geomicrobiological expertise and on-going field-based environmental investigations with a new generation of instruments capable of revealing diagnostic biosignatures. Our efforts will focus on creating innovative approaches for the analyses of cells and other organic material, finding ways in which metal abundances and isotope systems reflect life, and developing creative approaches for using environmental DNA to study present and past life.

    ROADMAP OBJECTIVES: 2.1 2.2 3.1 3.4 4.1 5.2 5.3 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
  • Development of Laser Ablation-Electron Impact Ionization-Miniature Mass Spectrometer (LA-EI-MMS) for In-Situ Chemical and Isotopic Measurements of Martian Rocks

    Our goal is to develop instrumentation capable of being deployed on a lander style space craft that can measure the chemical and isotopic composition of Martian samples. The instrumentation is based on the technologies of (i) laser ablation (LA) sampling of minerals, (ii) electron-impact ionization (EI) of ablated neutrals, and (iii) mass spectral measurement using JPL-developed miniature mass spectrometer (MMS) of focal plane geometry with modified-CCD array detector.

    ROADMAP OBJECTIVES: 2.1 7.2
  • 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 systematically evaluated using molecular beam-surface scattering experiments in which a hydrogen atom plasma source (deuterium due to easier detection) is used to hydrogenate a pyrite surface. The hydrogenated surface is subsequently bombarded with a molecular beam of energetic nitrogen molecules and the conversion of nitrogen to products, such as ammonia is probed through mass spectrometry.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3 7.1 7.2
  • Earth as an Extrasolar Planet

    Earth is the only known planet that can support life on its surface, and serves as our only example of what a habitable planet looks like. This task uses distant observations of the Earth taken from spacecraft combined with a sophisticated computer model of the Earth to understand the appearance and characteristics of a habitable planet. With our model, we can generate accurate simulations of the Earth’s brightness, color and spectrum, when viewed at different time-intervals, and from different vantage points. We are using these simulations to understand how we might detect signs of an ocean on a distant planet, and to understand the limitations of surface temperature measurements when a planet has significant cloud cover.

    ROADMAP OBJECTIVES: 1.2 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
  • Probing the Structure and Nitrogen Reduction Activity of Iron-Sulfur Minerals

    Iron-sulfur 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 7.1 7.2
  • Modelling Planetary Albedo

    What kind of environments could provide opportunities for life in general and for the advent of complex life specifically to emerge? If there were complex life present, what features would it produce? Could we remotely characterize such habitats and the features of complex life on extrasolar planets light-years away with current and future NASA missions?
    These are the three main questions we work on in this part of the project.

    ROADMAP OBJECTIVES: 1.1 1.2 4.1 4.2 6.2 7.2
  • Iron Isotope Biosignatures: Laboratory Studies and Modern Environments

    The isotopic fingerprints of biological carbon and sulfur cycling in modern and ancient marine environments is well established by research over several decades, but, until recently, potential iron isotope fingerprints of microbial iron cycling in the ancient Earth have not been pursued. Next to carbon, iron was probably the most important element cycled by early life, given the high abundance of iron in early Earth environments and the energy gains that may be obtained by microbes during iron redox changes. Our new laboratory studies moved away from simple systems to those more analogous to nature, and we demonstrated that iron isotope fractionations can be produced by biological cycling in complex systems. Moreover, in a field study, we isolated natural iron cycling microbes and demonstrated that the iron isotope fractionations produced by natural microbial ecosystems are the same as those produced by pure strains in the laboratory; these are key components to confidently applying Fe isotopes as a biosignature for ancient life.

    ROADMAP OBJECTIVES: 2.1 4.1 5.2 6.1 7.1 7.2
  • Project 6: Application of Laboratory Experimentation to Flight Instrument Testing

    The Arctic Mars Analogue Svalbard Expedition (AMASE) tests instruments, procedures and protocols to answer critical science questions on Mars. NAI sponsored researchers undertake science tasks alongside scientists developing instruments for Mars missions (MSL and ExoMars).

    ROADMAP OBJECTIVES: 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 iron-sulfur enzyme thrust is focused on examining the structure, mechanism, and biosynthesis of the complex Fe-S enzymes nitrogenase and hydrogenase. Biochemical, biophysical, and structure biology approaches are being employed to provide insights into complex iron-sulfur biosynthesis to establish paradigms for complex iron-sulfur cluster biosynthesis that can be placed in the context of the evolution of iron-sulfur motifs from the abiotic to biotic systems.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3 6.1 6.2 7.1 7.2
  • Astrophysical Controls on the Elements of Life, Task 7: Update Catalog of Elemental Ratios in Nearby Stars

    We are making 3D maps of the elements in stars within 1000 light-years of the Sun. When completed, these maps will be useful for discovering whether there are neighborhoods or streams of stars more favorable to Earth-like planets and life as we know it.

    ROADMAP OBJECTIVES: 1.1 7.2
  • 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: Mark Claire

    I am interested in how biological gases affect the atmosphere of Earth (and possibly other planets.) Specifically, I use computer models to investigate how biogenic sulfur gases might build up in a planetary atmosphere, and if this would lead to observable traces in Earth’s rock record or in the atmospheres of planets around other stars. I’m also working on how anaerobic oxidizers of methane affected the rise of oxygen on Earth, and if evolutionary changes in nitrogen-using bacteria may have changed global N2 levels and planetary climate.

    ROADMAP OBJECTIVES: 1.1 1.2 4.1 7.2
  • New Frontiers in Micro-Analysis of Isotopic Compositions of Natural Materials: Development of Fe Isotopes

    We are developing micro-analytical techniques to perform in situ Fe isotope analysis of Fe-bearing minerals by ion microprobe and laser ablation mass spectrometry. Iron isotope compositions are important signatures in tracking redox processes, chemical weathering, and dissimilatory iron reduction by bacteria. In situ micro analysis procedures will allow us to better apply the Fe isotope system by allowing one to determine Fe isotope compositions within a petrographic framework, minimize sample requirements, evaluate microscale heterogeneity, and inter-mineral isotopic equilibrium. Such in situ procedures are critical for analysis of samples that may be returned from future space missions or for analysis by instruments that can be deployed on space craft.

    ROADMAP OBJECTIVES: 2.1 4.1 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
  • Stellar Effects on Planetary Habitability

    Habitable environments are most likely to exist in close proximity to a star, and hence a detailed and comprehensive understanding of the effect of the star on planetary habitability is crucial in the pursuit of an inhabited world. We model how stars with different masses, temperatures and flare activity affect the habitability of planets. We also address the effect that tides between a star and a planet have on planetary habitability, including the power to turn potentially habitable planets like Earth into extremely volcanically active bodies like Io.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 4.1 4.3 5.3 6.1 7.2
  • The Role of Dissolved Sulfide in Controlling Carbonate Mineral Compositions

    Role of microbes in dolomite formation is still under debate. It was proposed that sulfate-reducing bacteria (SRB) can results in dolomite precipitation. We investigated the role of dissolved sulfide (a product of SRB metabolism) in controlling carbonate mineral compositions and even dolomite crystallization at low temperatures. Our results show that very high-magnesium calcite (VHMC) and disordered dolomite can precipitate from aqueous sulfide-bearing solutions at low temperature.

    ROADMAP OBJECTIVES: 4.1 7.1 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 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
  • The VPL Life Modules

    The Life Modules of the VPL are concerned with the modeling of biosphere processes for coupling with the VPL’s atmospheric and planetary models. These coupled models enable simulation of the impact of biogenic gases on atmospheric composition, of biota on the surface energy balance, and of the detectability of these in planetary spectra. The Life Modules team has engaged in previous work coupling 1D models in the VPL’s suite of planetary models, and current work now focuses on biosphere models coupled to 3D general circulation models (GCMs). Current project areas are: 1) development of a model of land-based ecosystem dynamics suitable for coupling with GCMs and generalizable for alternative planetary parameters, and 2) coupling of an ocean biogeochemistry model to GCMs.

    ROADMAP OBJECTIVES: 1.2 6.1 6.2 7.2
  • Stoichiometry of Life, Task 4: Biogeochemical Impacts on Planetary Atmospheres

    The abundance of molecular oxygen in planetary atmospheres may be a useful way to look for evidence of life. The amount of photosynthetically produced oxygen that accumulates in an atmosphere depends in part on the export of photosynthetically produced organic carbon from the ocean surface to the seafloor, which in turn may depend on the availability of bioessential elements. We are using a computer model to determine how this carbon export processes might operate in an ocean dominated by prokaryotes rather than eukaryotes, as may have been common in Earth’s past and as an analog for hypothetical extrasolar planets.

    ROADMAP OBJECTIVES: 4.1 4.2 5.2 6.1 7.2
  • Kavli Symposium (Fall 2008)

    The Kavli Frontiers of Science symposia are jointly sponsored by the Kavli Foundation and the US National Academy of Sciences to bring together top young scientists in an interdisciplinary conference environment that encourages in-depth discussions related to exciting advances in the fields of astronomy and astrophysics, computer sciences, neurosciences and physics. As a Kavli fellow, and participant in these seminars, the UHNAI PI has organized a special astrobiology session at the fall 2008 Kavli symposium on the topic of Extrasolar planets, drawing participants from within the NAI. The purpose is to highlight the cutting edge science that is being accomplished in astrobiology through the NAI.

    ROADMAP OBJECTIVES: 1.2 6.2 7.2
  • Mineral-Catalyzed Coupling of Amino Acids to Polypeptides

    Enzymes carry out chemical functions within our body, and are produced from long chains of amino acids called polypeptides. Today, the manufacture of these long chains is made possible within our bodies by large 'machinery’ known as polymerases. However, these are vastly complex, and were almost certainly not present in the early stages of life. One question we are trying to answer here is whether or not it is possible to produce long chains of polypeptides under certain conditions which may be relevant to the origin of life, such as on the surface of a mineral.

    ROADMAP OBJECTIVES: 3.1 3.2 7.1 7.2
  • 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
  • Rare Subduction Zone Carbonate Mineral May Hold Clues to Early Life

    Recent work performed by Erik Melchiorre as part of a NASA Minority
    Institution Research Sabbatical indicates that the rare purple mineral
    stichtite Mg6Cr2[(OH)16|CO3] . 4H2O may provide a record of
    the carbon, hydrogen and ocygen isotope values of serpentizing fluids
    from ancient subduction zones. This could be of significant interest
    in the study of methane signatures on Mars, as well as the study of
    early life on Earth.

    ROADMAP OBJECTIVES: 4.1 4.3 7.1 7.2