nai

Project Reports

• 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

• 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

• Detectability of Life

  Detectability of Life investigates the detectability of chemical and biological signatures on the surface of icy worlds, with a focus on spectroscopic techniques, and on spectral bands that are not in some way connected to photosynthesis.Detectability of life investigation has three major objectives: Detection of Life in the Laboratory, Detection of Life in the Field, and Detection of Life from Orbit.

  ROADMAP OBJECTIVES: 1.2 2.1 2.2 4.1 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  The Astrobiology Integrative Research Framework (AIRFrame) analyzes published and unpublished documents to identify and visualize implicit relationships between astrobiology’s diverse constituent fields.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

• 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

• 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

• Extremophile Ribosomes

  We will compare biochemistry and the three-dimensional structures of ribosomes from modern organisms on particular lineages of the tree of life. Extremophiles are of special interest due to their ability to thrive in environments that reminiscent of early biotic earth.

  ROADMAP OBJECTIVES: 5.3

• 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

• 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. Our efforts are focused 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 3.2 3.4 4.1 5.2 5.3 7.1 7.2

• High Level Theory – the Role of Mg2+ in Ribosome Assembly

  We investigated a unique role of Mg2+ ions to form stable complexes with ribosomal RNA, and specifically their role in a formation of ancestral peptidyl transferase center using modern quantum mechanics methods. The interaction energies of ribosomal RNA with single and multiple Mg2+ cations are computed in the gas phase and water, and partitioned into specific tems. RNA-Mg interactions are compared to those with other metals, to determine why Mg2+ plays a special role in RNA folding. Additionally, we hypothesize a possible unique role of Fe2+ in a formation of ribosomal catalytic centers during early stages of life. The project is performed using NASA’s HEC supercomputer recourses.

  ROADMAP OBJECTIVES: 3.2 5.3

• 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

• 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

• 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

• Deep (Sediment-Buried Basement) Biosphere

  The ocean crust comprises the largest aquifer on earth and there is increasing evidence that supports the presence of actively growing microbial communities within basaltic porewaters.

  Advanced Integrated Ocean Drilling Program (IODP) circulation obviation retrofit kit (CORK) observatories provide a unique opportunity to sample these otherwise inaccessible deep subseafloor habitats at the basalt-sediment transition zone. Aging porewaters remain isolated within this sediment-buried upper oceanic basement, subjected to increasing temperatures and pressures as plates move away from spreading ridges.

  ROADMAP OBJECTIVES: 4.1 4.2 5.2 5.3 6.1 6.2 7.1 7.2

• RNA Folding and Assembly

  We will characterize the assembly, structure and thermodynamics of the a-PTC by chemical mapping, including hydroxyl radical footprinting1,2 and SHAPE analysis,3 RNase H cleavage, temperature dependent hydrodynamics,4 and computational folding algorithms. In addition we will investigate the effect of freezing aqueous solutions of RNA and DNA molecules on their ability to assemble into larger more complex structures. Freezing nucleic acid solutions concentrates non-water molecules into small liquid pockets in the ice. This enables reactions that can promote the assembly of small segments of nucleic acids into larger complexes.

  ROADMAP OBJECTIVES: 3.2 5.3

• 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

• 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 looked at how the Sun’s brightness would have changed with time. We also model how stars with different masses, temperatures and flare activity affect the habitability of planets, including looking at the effect of a very big flare on a planet’s atmosphere and surface. We find that a planet with an atmosphere like Earth orbiting around a cool red star is fairly well protected from UV radiation, but particles associated with the flare can produce damaging chemistry in the planetary atmosphere that severely depletes the planet’s ozone layer.

  ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1 4.3 5.3 6.1 7.2

• Stromatolites in the Desert: Analogs to Other Worlds

  In this task biologists go to field sites in Mexico to better understand the environmental effects on growth rates for freshwater stromatolites. Stromatolites are microbial mat communities that have the ability to calcify under certain conditions. They are believed to be an ancient form of life, that may have dominated the planet’s biosphere more than 2 billion years ago. Our work focuses on understanding these communities as a means of characterizing their metabolisms and gas outputs, for use in planetary models of ancient environments.

  ROADMAP OBJECTIVES: 4.1 4.2 5.2 5.3 6.1 6.2

• 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

• 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 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

• 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

• 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

• The Deep Hot Biosphere: Expedition 331 of the Integrated Ocean Drilling Program (IODP)

  Hydrothermal systems on the seafloor, and their associated submarine hot springs, are one of the leading candidates for the setting in which life originated on planet Earth some 4 billion years ago. Today these systems are known to harbor active and diverse communities of microbes, both bacteria and archaea, which thrive on the high temperatures and the abundant sources of chemical energy supplied by reduced chemical species generated from magma and by water-rock reactions within the hydrothermal system. From September 1 through October 4, 2010, we drilled into an active high-temperature hydrothermal system in the Okinawa Trough, an actively rifting back-arc basin that lies in a transitional region between continental and oceanic crust, northwest of the island of Okinawa in the western Pacific Ocean. The objectives of this drilling were to investigate microbial communities with the hydrothermal system and their geochemical and geophysical setting.

  ROADMAP OBJECTIVES: 5.3 7.1