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2011 Annual Science Report

Astrobiology Roadmap Objective 3.1 Reports Reporting  |  SEP 2010 – AUG 2011

Project Reports

  • Astrophysical Controls on the Elements of Life, Task 1: High-Precision Isotopic Studies of Meteorites

    The elemental abundances of planetary systems potentially are affected by contributions from nearby supernovae. Injection of supernova material can be studied by isotopic analyses of meteorites, especially calcium-rich, aluminum-rich inclusions (CAIs) within them, which reveal the presence in the forming Solar System of short-lived radionuclides. Initial abundances of these radionuclides not only signal contributions from a supernova but also provide a chronometer to date the injection and other formation events. Radionuclides, especially 26Al, also can affect the thermal evolution and volatile retention within planetary bodies. In this task we seek to measure initial abundances of radionuclides in meteorites, especially CAIs, and to constrain the timing of early Solar System events.

  • Project 1: Interstellar Origins of Preplanetary Matter

    Interstellar space is rich in the raw materials required to build planets and life, including essential chemical elements (H, C, N, O, Mg, Si, Fe, etc.) and compounds (water, organic molecules, planet-building minerals). This research project aims to characterize the composition and structure of these materials and the chemical pathways by which they form and evolve. The long-term goal is to determine the inventories of proto-planetary disks around young sun-like stars, leading to a clear understanding of the processes that led to our own origins and insight into the probability of life-supporting environments emerging around other stars.

  • AIRFrame Technical Infrastructure and Visualization Software Evaluation

    We have analyzed over four thousand astrobiology articles from the scientific press, published over ten years to search for clues about their underlying connections. This information can be used to build tools and technologies that guide scientists quickly across vast, interdisciplinary libraries towards the diverse works of most relevance to them.

    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
  • Task 1.1.1 Models of the Internal Dynamics: Formation of Liquids in the Subsurface and Relationships With Cryovolcanism

    The internal and external geologic evolution of Titan was investigated so as to constrain the environment in which organic evolution has proceeded over time.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • BioInspired Mimetic Cluster Synthesis: Bridging the Structure and Reactivity of Biotic and Abiotic Iron-Sulfur Motifs

    Bioinspired synthetic approaches are being utilized to bridge the gap between Fe-S minerals and highly evolved biological Fe-S metalloenzymes. Biology builds complex Fe-S clusters by first synthesizing standard Fe-S clusters and then modifying them through radical chemistry catalyzed by radical SAM enzymes. In an effort to examine hypothetical early biocatalysts, we probing simple Fe-S motifs capable of coordinating Fe-S clusters in aqueous solutions that can initiate radical chemistry.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3 3.4 7.1 7.2
  • Project 1: Looking Outward: Studies of the Physical and Chemical Evolution of Planetary Systems

    This project five main objectives focused broadly on understand the origin and early evolution of our solar system. First, we have employed a new planet finding spectrometer to aid in detecting planetary systems surrounding neighboring stars. Second, we have begun the Carnegie Astrometric Planet Search project to detect giant planets around nearby loss mass dwarf stars. Third, we focused on understanding of radial transport and mixing of matter in protoplanetary disks. Fourth, we have continued to survey of small planetary size objects in the Kuiper belt. Fifth, we have continued our studies of the composition, structure, and ages of circumstellar disks.

    ROADMAP OBJECTIVES: 1.1 1.2 2.2 3.1
  • Cosmic Distribution of Chemical Complexity

    The central theme of this project is to explore the possible connections between chemistry in space and the origins of life. We start by tracking the formation and development of chemical complexity in space from simple molecules such as formaldehyde to complex species including amino and nucleic acids. The work focuses on molecular species that are interesting from a biogenic perspective and on understanding their possible roles in the origin of life on habitable worlds. We do this by measuring the spectra and chemistry of analog materials in the laboratory, by remote sensing in small spacecraft and by analysis of extraterrestrial samples returned by spacecraft or that fall to Earth as meteorites. We then use these results to interpret astronomical observations made with ground-based and orbiting telescopes.

    ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 3.2 3.4 4.3 7.1 7.2
  • Astrophysical Controls on the Elements of Life, Task 2: Model the Chemical and Dynamical Evolution of Massive Stars

    The elemental ratios in stars and their planets will differ because each star has a different contributions from sources of stellar nucleosynthesis. The dominant contributions of heavy elements to molecular clouds come from supernova explosions, which may also contribute material just prior to star formation. To quantify what elements might be contributed by supernovae, in this task we first perform numerical simulations of stellar evolution, predicting how stellar properties (e.g., luminosity, temperature, internal composition, stellar winds, etc.) change over time. These results are made available to the public. We then simulate the explosions of massive stars as supernovae, to determine what elements are ejected. As a complementary study, we are also using spectra of stars, obtained during radial velocity planet searches, to find the chemical abundances of hundreds of nearby, potentially habitable stars, to assess the variability of starting compositions, and we are also modeling how the habitable zones of stars with these starting compositions might vary over time.

  • Task 1.1.2 Models of the Reaction Between Hydrocarbons and Water Ice

    Reactions between hydrocarbons and water ice was modeled to assess the possible extent of prebiotic compound formation in this context. Various environments where organics and liquids could be in contact were considered.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Project 2: Processing of Precometary Ices in the Early Solar System

    The discovery of numerous planetary systems still in the process of formation gives us a unique opportunity to glimpse how our own solar system may have formed 4.6 billion years ago. Our goal is to test the hypothesis that the building blocks of life were synthesized in space and delivered to the early Earth by comets and asteroids. We use computers to simulate shock waves and other processes that energize the gas and dust in proto-planetary disks and drive physical and chemical processes that would not otherwise occur. Our work seeks specifically to determine (i) whether asteroids and comets were heated to temperatures that favor prebiotic chemistry; and (ii) whether the requisite heating mechanisms operate in other planetary systems forming today.

    ROADMAP OBJECTIVES: 1.1 3.1 3.2
  • 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
  • Amino Acid Alphabet Evolution

    We study the question why did life on this planet “choose” a set of 20 standard building blocks (amino acids) for converting genetic instructions into living organisms? The evolutionary step has since been used to evolve organisms of such diversity and adaptability that modern biologists struggle to discover the limits to life-as-we-know-it. Yet the standard amino acid alphabet has remained more or less unchanged for 3 billion years.
    During the past year, we have found that the sub-set of amino acids used by biology exhibits some surprisingly simple, strikingly non-random properties. We are now building on this finding to solidify a new insight into the emergence of life here, and what it can reveal about the distribution and characteristics of life elsewhere in the universe.

    ROADMAP OBJECTIVES: 3.1 3.2 4.1 4.2 4.3 5.2 5.3 6.2 7.1
  • Project 2: Origin and Evolution of Organic Matter in the Solar System

    This project focuses on understanding the origin and evolution primitive bodies in the solar system (e.g. comets, interplanetary dust particles [IDPs], and primitive, undifferentiated, meteorites). The first focus area involves detailed studies of the water/ice content of bodies in the outer solar system. We seek to learn more about the mechanism by which water is retained in these bodies and learn more about what water(ice)/rock ratios tell us about the evolution of the early solar system. The second part of this study involves understanding the origin and evolution of organic solids in comets, IDPs, and primitive meteorites. These organic solids are one of the largest reservoirs of carbon, outside of the Sun, and are only now being understood from the perspective of their origin and the unique history they record of processes that occurred in the early solar system.

    ROADMAP OBJECTIVES: 2.2 3.1 7.1
  • Delivery of Volatiles to Terrestrial Planets

    This project uses computer models and laboratory work to better understand how volatile materials that are important for life, like water, methane, and other organic molecules, are delivered to terrestrial planets. Habitable planets are too small to gravitationally trap these volatiles directly from the gas disk from which they formed, and instead they must be delivered as solids or ices at the time of the planet’s formation, or ongoing as the planet evolves. These trapped volatiles are eventually released to form our oceans and atmosphere. In this task we use computer models of planet formation and migration to understand how the asteroid belt, which is believed to be the source of the Earth’s oceans, was formed. We also use models to understand what happens to meteoritic material as it enters a planet’s atmosphere, especially where it gets deposited in the atmosphere, what happens to it chemically, and how it interacts with the light from the parent star. .

    ROADMAP OBJECTIVES: 1.1 3.1 4.1 4.3
  • An Encyclopedia of Astrobiology and Using the Large Millimeter Telescope for Astrobiological Observations

    Irvine and colleagues at the University of Massachusetts have begun commissioning the Large Millimeter Telescope, the largest single-dish radio telescope in the world operating at short millimeter wavelengths. This is a joint project with the country of Mexico.

  • Project 3: Pathways for Exogenous Organic Matter to the Early Earth and Mars

    This project focuses on investigating the asteroidal contribution of organic molecules to the terrestrial planets in the early Solar System – molecules that may have contributed to the rise of life on Earth and potentially on Mars. Some types of meteorites contain significant amounts of organic compounds, including amino acids. These compounds are presumed to have formed by non-biological processes, either in the solar nebula (with subsequent incorporation into asteroids during their formation), or within the asteroids themselves by liquid water acting on the original minerals. Fragments from asteroids arrive at the Earth (and Mars) at comparably low velocities and can efficiently deliver intact organic molecules to the surfaces of these planets.

  • Task 1.2 Interaction of Methane/ethane With Water Ice

    Laboratory work led to several results. Tholins are entrained in the subsurface during a methane rain. As the liquid evaporates, the tholins remain trapped in the subsurface. The JPL Titan chamber (Figure 1) also was used to test a rain drop sensor developed by a group of students at University of Idaho that could be embarked on future missions to Titan.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Minerals to Enzymes: The Path to CO Dehydrogenase/Acetyl – CoA Synthase

    We have through NAI Director’s discretionary initiated a project to probing the structural determinants for nickel-iron-sulfur based reversible carbon monoxide oxidation. We are probing whether we can mimic the reactivity of carbon monoxide dehydrogenase to some extent by simple organic nesting and synthesis of nickel-iron-sulfur clusters using a model system we have developed.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3 3.4 7.1 7.2
  • Astrophysical Controls on the Elements of Life, Task 3: Model the Injection of Supernova Material Into Star-Forming Molecular Clouds

    Our Solar System is known to have contained short-lived radionuclides such as 26Al and 60Fe when it formed. These must have been created either during or just before Solar System formation. A supernova explosion is thought to be the most likely source. Depending on the manner of supernova injection, other elements relevant to life may accompany the radionuclides. In this task we study how a supernova might inject material into the molecular cloud from which the Solar System formed, before formation of the protostar. This tests the hypothesis of supernova injection and quantifies its contributions to radionuclides and other elements.

  • Project 3: The Origin, Evolution, and Volatile Inventories of Terrestrial Planets

    This research project brings together a large team of scientists with a unified goal understanding the origin and evolution of volatiles (C, H, O, and N) in planetary interiors. It includes a theoretical study of planet formation with focus of addressing the abundance of volatiles in objects that ultimately combine to form the terrestrial planets. The project gains from information being currently revealed through the NASA Messenger mission in orbit around Mercury. The project has an experimental component that focuses on studying volatiles deep in planetary interiors using ultra-high pressure devices and molecular spectroscopy for species interrogation. Finally, it includes a systematic study of the chemistry of mineral inclusions in diamonds, where diamond serves to trap minerals in a natural high pressure container. These studies allow CIW NAI scientists probe the chemistry of Earth’s deep mantle and help reveal how Earth’s plate tectonics may have started.

    ROADMAP OBJECTIVES: 1.1 3.1 4.1
  • Path to Flight

    Our technology investigation, Path to Flight for astrobiology, utilizes instrumentation built with non-NAI funding to carry out three science investigations namely habitability, survivability and detectability of life. The search for life requires instruments and techniques that can detect biosignatures from orbit and in-situ under harsh conditions. Advancing this capacity is the focus of our Technology Investigation.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 7.1 7.2
  • Project 4: Geochemical Steps Leading to the Origins of Life

    This project involves research designed to aid understanding the geochemical roots of life focusing in particular on the role of mineral surfaces play in catalyzing organic reactions that may have biochemical utility.

  • Astrophysical Controls on the Elements of Life, Task 4: Model the Injection of Supernova Material Into Protoplanetary Disks

    Our Solar System is known to have contained short-lived radionuclides such as 26Al and 60Fe when it formed. These must have been created either during or just before Solar System formation. A supernova explosion is thought to be the most likely source. Depending on the manner of supernova injection, other elements relevant to life may accompany the radionuclides. In this task we study how a supernova might inject material into the protoplanetary disk from which the planets in the Solar System formed, after the formation of the protostar. This tests the hypothesis of supernova injection and quantifies its contributions to radionuclides and other elements.

  • Task 2.1.1 Master Atmospheric Chemistry Simulation

    The development of a master atmospheric model is nearing completion. Based on an older Titan model, the current model has been updated this year to include a treatment of chemical equilibrium, a description of aerosols, and a numerical model for condensation on and sublimation of atmospheric organic molecules from aerosol particles. To allow a global simulation of Titan atmospheric organic chemistry, the computer model is being recoded to support parallel processing.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Dynamical Effects on Planetary Habitability

    The Earth’s orbit is near-circular and has changed little since its formation. The Earth is also far enough away from the Sun, that the Sun’s gravity doesn’t seriously affect the Earth’s shape. However, exoplanets have been found to have orbits that are elliptical, rather than circular, and that evolve over time, changing shape and/or moving closer or further to the parent star. Many exoplanets have also been found sufficiently close to the parent star that the star can deform the planet’s shape and transfer energy to the planet in a process called tidal heating. In this VPL task we investigate how interactions between a planet’s orbit, spin axis, and tidal heating can influence our understanding of what makes a planet habitable. Scientific highlights include the finding that tidal effects could be strong enough to cause a planet to overheat and ultimately lose its ocean, that large changes in the direction of the spin-axis of a planet could potentially increase the range of distances from the star in which the planet could remain habitable, and that the Sun may have moved significant distances outward through the Galaxy during its lifetime, changing the rate of at which large bodies have hit the Earth.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1 4.3
  • Collisional Evolution of Planetesimal Systems and Debris Disk Patterns

    Marc Kuchner and his graduate student Erika Nesvold are working on a new tool for modeling the collisional evolution and 3-D distribution of planetesimals in planetary systems and debris disks. We plan to use this tool for interpreting images of planetary systems: modeling images and other data on circumstellar disks. We expect to be able to use this approach to locate hidden exoplanets via their dynamical influence on the shapes of the disks. We also expect to use our new models to understand the evolution of planetesimals in the solar system during the time when these planetesimals probably delivered the Earth’s ocean water.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1
  • Comet Activity and Composition

    The study of primitive bodies as building blocks of the Solar System, and what they contribute to
    the understanding of how the Solar System was constructed is central to the science goals laid out in the Planetary Decadal Survey. Objects in the Kuiper belt (KBOs) are remnant planetesimals with orbits beyond Neptune, with sizes small enough that they are relatively well preserved since the era of solar system formation. KBO surfaces exhibit a wide variety of colors, ranging from blue-neutral to reddish. This reflects both the underlying primordial chemical differences as well as radiation processing on their surfaces. Some of this population gets scattered into the inner solar system through dynamical interactions, and these, when observable form the Centaur class of objects. Comets, depending on their source region may have formed at a variety of distances and scattered early in the solar system’s history; some are now captured in the inner solar system due to the influence of Jupiter. Understanding the chemistry of these primordial leftovers is important as a clue to the early conditions in the solar system during the planet formation era. Our team is actively studying the composition of these objects through spectroscopy of their surfaces and the materials outgassed, by observing the level of dust and gas objects produce when they move into the inner solar system and through modeling their outgassing behavior.

  • Task Atmospheric State and Dynamics

    The chemical model requires a description of the background state of the atmosphere, specifically temperature and circulation as a function of latitude and longitude.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Composition of Parent Volatiles in Comets

    During the period covered by this progress report we conducted an extensive observing campaign on the Jupiter-family comet 103P/Hartley-2 – the target of the EPOXI fly-by mission. We studied the volatile composition of two other Jupiter-family comets – 10P/Tempel-2 and 21P/Giacobini-Zinner. We continued our multi-comet surveys of spin temperatures and searches for deuterated species. We characterized the abundances of several prebiotic molecules in comet C/2007 N3 Lulin. We also organized NAI-funded “Workshop on cometary taxonomies” held in Annapolis, MD

    ROADMAP OBJECTIVES: 2.2 3.1 4.1
  • Nitrate and Nitrate Conversion to Ammonia on Iron-Sulfur Minerals

    Conversion of nitrate and nitrite may have contributed to the formation of ammonia—a key reagent in the formation of amino acids—on the prebiotic Earth. Results suggest that the presence of iron mono sulfide facilitates the conversion of nitrate and nitrite. Nitrite conversion is, however, much faster than the conversion of nitrate.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3 7.1 7.2
  • Astrophysical Controls on the Elements of Life, Task 5: Model the Variability of Elemental Ratios Within Clusters

    In Tasks 3 and 4 we study how supernovae may enrich indvidual solar systems at the peripheries of high-mass star-forming regions. In this task we study in a statistical sense how stars of a variety of masses at the ends of their lives enrich star-forming molecular clouds and stellar clusters. Through detailed numerical hydrodynamic simulations we are studying the mixing of heavy elements into the surrounding medium and comparing our predictions to variable abundance ratios in present-day clusters. We also apply this research to star formation in the early universe, studying the transition between pristine (very low metallicity) and enriched star formation.

  • Project 2A: Estimation of Pre-Biotic Amino Acids Delivery to Earth by Carbonaceous Chondrite Meteorites

    The role of mineral surfaces in extraterrestrial organic synthesis, pre-biotic chemistry, and the early evolution of life remains an open question. Mineral surfaces could promote synthesis, preservation, or degradation of chiral excesses of organic small molecules, polymers, and cells. Different minerals, crystal faces of a mineral, or defects on a face may selectively interact with specific organics, providing an enormous range of chemical possibilities. We focus here on amino-acid isomer adsorption, conformation, and racemization on minerals representing primitive and altered peridotite found in chondritesand on planetary bodies. The study is inspired by the discovery of an excess of L-isovaline, a non-biologic amino acid, in a few carbonaceous meteorites by (Glavin and Dworkin, 2009), which suggests that the chiral nature of biology may have been due to excess L-amino acids delivered pre-biotically by meteorites.

    In the present year of funding, we expanded our study to determine the conformation and binding modes of the acidic amino-acids, glutamate (Glu) and aspartate (Asp), adsorbed on model oxide, γ-Al2O3, using Attenuated Total Reflectance-Fourier Transform Infra-Red Spectroscocpy (ATR-FTIR) and the Triple Layer surface complexation model fits to bulk adsorption data over a wide range of pHs and amino-acid concentrations.

    We also examined adsorption of L- and D- Glu, Asp, and a non-biological; amino acid, iso-valine on peridotite and serpentinte as pristine and altered analogs of carbonaceous chondrites, using LC-FD/ToF-MS. Preliminary results do not indicate preferential adsorption of either L- or D-amino-acids on peridotite and serpentinite, within detection limits. More detailed studies are required to improve the sensitivity and accuracy of the experiments involving the chiral amino-acids adsorption on chondritic analog materials.

    The project addresses NASA Astrobiology Institute’s (NAI) Roadmap Goal 3 of understanding how life emerges from cosmic and planetary precursors , and Goal 4 of understanding organic and biosignature preservation mechanisms. The work is relevant to NASA’s Strategic Goal of advancing scientific knowledge on the origin and evolution life on Earth and potentially elsewhere, and of planning future Missions by helping to identify promising targets for the discovery of organics.

    ROADMAP OBJECTIVES: 3.1 3.2 4.1
  • Paradigms for Complex Iron-Sulfur Cluster Assembly and the Origin and Evolution of Iron-Sulfur Enzymes

    We have presented seminal results in the past year that define paradigms for iron-sulfur cluster assembly in biology that are shared between several important enzymes systems. This work has allowed for the formulation of new models for the origin and evolution of iron sulfur enzymes. An evolutionary origin that involves a mineral beginning and the stepwise refinement of catalytic function in response to selective pressure.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3
  • Task Atmospheric Observations

    A previously unsuspected seasonal change in the altitude of Titan’s detached haze layer was discovered and used to test current models of the formation of the haze and related dynamical and microphysical processes.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Cosmochemical Search for the Origin of Water in Planetary Bodies

    The ultimate goal of our study is to understand the origin of water in planetary bodies (asteroids, comets and terrestrial planets). In particular we want to understand better the water-based chemis-try that happens on these bodies. This gives important insights into the role(s) played by water dur-ing the origin of our Solar System. We are taking a new approach to understanding aqueous altera-tion processes in carbonaceous chondrites by investigating the distribution and composition of or-ganic compounds in aqueously altered chondrites. This research will also shed light on the nature of organic compounds in asteroids and in planetesimals that might have delivered organic compounds to the early Earth. This research will use a variety of micro-analytical techniques (optical microscopes, scanning electron microscope, electron microprobe, transmission electron microscope, ion microprobe, Raman spectroscopy) to investigate the aqueous alteration that has affected the CR chondrites. These meteorites were chosen because they exhibit a complete series of alteration, from very lightly altered to completely altered, and they have experience almost no thermal metamorphism.

    ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 3.2
  • Composition of Parent Volatiles in Comets: Oxidized Carbon

    GCA Co-Investigator Dr. Michael DiSanti continued his work on measuring parent volatiles in comets using high-resolution near-infrared spectroscopy at world class observatories in Hawai’i and Chile. The goal of this work is to build a taxonomy of comets based on ice compositions, which show considerable variation among comets measured to date. DiSanti’s research emphasizes the chemistry of volatile oxidized carbon, in particular the efficiency of converting CO to H2CO and CH3OH on the surfaces of icy interstellar grains, through H-atom addition reactions prior to their incorporation into comets. The work requires planning and conducting observations, processing of spectra, and development and application of fluorescence models for interpretation of observed line intensities. Major strides in these areas were realized during this period of performance.

  • Astrophysical Controls on the Elements of Life, Task 6: Determine Which Elemental or Isotopic Ratios Correlate With Key Elements

    In this task we explore how key elements and radioactive isotopes are created by nucleosynthesis during the explosions of massive stars. We also study the formation and composition of structures in supernova explosions that may be relevant to delivery of bioessential elements to forming solar systems. In particular, we have investigated how the bioessential elements Ca and Fe are produced during supernovae. We have discovered that they are produced by 6 distinct nucleosynthetic pathways, and that their relative abundances can be probed by observations of the gamma-ray radiation from the radioactive decay of the isotopes 44Ti and 56Ni into 44Ca and 56Fe. We also have investigated the co-production of O isotopic anomalies with the short-lived radionuclide 26Al. We find that delivery of 26Al to the early solar system would not necessarily have altered significantly its O isotopic composition.

  • Radical SAM Chemistry and Biological Ligand Accelerated Catalysis

    A number of key reactions in biological systems are catalyzed by iron-sulfur enzymes. Iron-sulfur clusters in biology have a number of features in common with iron-sulfur minerals and their derivatives. We are using iron sulfur motifs as a model system to understand how chemistry in the abiotic mineral world was incorporated into biology on a path to the origin of life. We have found that iron-sulfur motifs in biology are synthesized and modified by reactions and mechanisms that we envision minerals could have been modified on the early prebiotic Earth. The results have had a profound impact on our ability to understand a stepwise trajectory from the nonliving to the living Earth.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3
  • Task 2.2.1 Characterization of Aerosol Nucleation and Growth

    A quantitative understanding of the particle formation and growth in the Titan atmosphere is still unrealized. Laboratory work is being conducted to clarify these processes.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Cosmic Ice Laboratory Progress Report

    Scientists at the Cosmic Ice Laboratory with the Goddard Center for Astrobiology study the formation and stability of molecules under conditions found in outer space. During the past year, studies of amino-acid destruction were continued with a manuscript in preparation. Projects on sulfuric-acid hydrates were completed, and a new project involving thermal chemistry at Europa-like temperatures was begun. All of this work is part of the Comic Ice Laboratory’s continuing contributions toward understanding the chemistry of biologically-related molecules and chemical reactions in extraterrestrial environments.

  • Project 7: Prebiotic Chemical Catalysis on Early Earth and Mars

    The “RNA World” hypothesis is the current paradigm for the origins of terrestrial life. Our research is aimed at testing a key component of this paradigm: the efficiency with which RNA molecules form and grow under realistic conditions. We are studying abiotic production and polymerization of RNA by catalysis on montmorillonite clays. The catalytic efficiency of different montmorillonites are determined and compared, with the goal of determining which properties distinguish good catalysts from poor catalysts. We are also investigating the origin of montmorillonites, to test their probable availability on the early Earth and Mars, and the nature of catalytic activity that could have led to chiral selectivity on Earth.

  • Project 8: Survival of Sugars in Ice/Mineral Mixtures on High Velocity Impact

    Understanding the delivery and preservation of organic molecules in meteoritic material is important to understanding the origin of life on Earth. Though we know that organic molecules are abundant in meteorites, comets, and interplanetary dust particles, few studies have examined how impact processes affect their chemistry and survivability under extreme temperatures and pressures. We are investigating how impact events may change the structure of simple sugars, both alone and when combined with ice mixtures. The experiments will allow us to understand how sugar chemistry is affected by high pressure events and to contrast the survival probabilities of sugars in meteorite and comet impacts. This will lead to a better understanding of how organic molecules are affected during their delivery to Earth. This project leverages expertise in two different NAI nodes, increasing the collaborative interaction among the NAI investigators

    ROADMAP OBJECTIVES: 1.1 3.1 4.1 4.3
  • Task 2.2.2 Ultraviolet/infrared Spectroscopy and Photoprocessing of Ice Films

    Only near-ultraviolet light at long wavelengths can penetrate to the deep Titan atmosphere, not being absorbed by atmospheric gas-phase species. Large hydrocarbons can absorb at these longer wavelengths. Condensed onto atmospheric particles, such hydrocarbons can undergo photochemical reactions initiated by absorption of near-ultraviolet photons.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Task 3.1.1 Reactions of Organics With Ices and Mineral Grains

    A goal is to determine the potential role of mineral surfaces (i.e. meteorite fragments) in catalyzing reactions on Titan’s surface. There is also the possibility of low-energy electron and visible/UV photon stimulated chemistry on aggregates and organic aerosol surfaces.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Surface Chemistry of Iron-Sulfur Minerals

    The exposure of pyrite surfaces to energetic particle beams creates an activated surface that is capable of facilitating the reduction of nitrogen molecules to ammonia. Experimental results and complementary theoretical calculations indicates that the exposure of pyrite surfaces creates anomalously reduced iron atoms. The chemical state of the surface iron atoms is somewhat similar to iron in the active center of several key enzymes. The triple bond in dinitrogen sorbed onto these reduced surface iron atoms weakens, which is a key step in the conversion to ammonia, a key reagent in the formation of amino acids on the prebiotic Earth

    ROADMAP OBJECTIVES: 3.1 3.2 3.3 7.1 7.2
  • Project 2E: The ORGANIC Experiment on EXPOSE-R – Space Exposure on the International Space Station (ISS)

    In March of 2009, the Organic experiment integrated into the European multi-user facility EXPOSE-R, containing experiments dedicated to Astrobiology, was mounted through Extra Vehicular Activity (EVA) externally on the International Space Station (ISS). The experiment exposed organic samples of astronomical interest for a duration of 97 weeks (~22 months) to the space environment. The samples that were returned to Earth in spring 2011, received a total UV radiation dose during their exposure including direct solar irradiation of >2500h (>42.1 kJ per sample, based on ASTM E-490 AM0 standard solar spectrum between 119 and 400 nm), exceeding the limits of laboratory simulations. The Organics experiment on EXPOSE-R consists of thin films of polycyclic aromatic hydrocarbons (PAHs) and fullerenes that were exposed to solar UV under vacuum or controlled atmosphere. Samples were deposited in thin (~few hundred nm) films by sublimation on MgF2 windows inside the sample cell. Dark samples are shielded from the UV photons and enable us to discriminate between the effects of exposure to photons and cosmic rays. The corresponding time-dependent ground-control for the Organic experiment measured over ~19 months is presented and preliminary data of returned flight samples are shown.

  • Project 9: Microenvironmental Influences on Prebiotic Synthesis

    Before biotic, i.e., “biologically-derived” pathways for the formation of essential biological molecules such as RNA, DNA and proteins could commence, prebiotic pathways were needed to form the molecules that were the basis for the earliest life. Much research has been done on possible non-biological routes to synthesis of RNA, thought by many to be the best candidate or model for the emergence of life. Our work focuses on possible physicochemical microenvironments on early earth that could have influenced and even directed or templated the formation of RNA or its predecessors.

  • Task 3.1.2 Chemistry Active in Titan Dunes

    Triboelectric reactions of complex organics and water ice are a potential chemical mechanism active in the dunes of Titan. Laboratory experiments have been conducted to simulate and assess how important this possibility can be in the Titan context.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • The ABRC Philosophy of Astrobiology and the Origin of Life Discussion Group

    A unique feature of Montana State’s ARBC is our Philosophy of Astrobiology Focus Group. Our group consists of faculty, undergraduate, and graduate students from philosophy, history, chemistry and bio-chemistry who are interested in examining the philosophical questions that intersect with astrobiology research.

    Specifically: • What are the defining characteristics of life? • What would we look for in searching for “alternative” life forms? • What is “intelligence” and how would we know when we had found it? • How do we choose between competing theories of the origins of life? • How are emerging sciences, such as astrobiology, different from mature sciences? • What are the social implications of discovering life on another planet or, alternatively, for failing to find life? • What are the ethical obligations of scientists in conducting research on other planets? • How should we assess potential environmental and health risks associated with astrobiological research?

  • Ice Chemistry Beyond the Solar System

    The molecular inventory available on the prebiotic Earth was likely derived from both terrestrial and extraterrestrial sources. Many molecules of biological importance have their origins via chemical processing in the interstel-lar medium, the material between the stars. Polycyclic aromatic hydrocarbons (PAHs) and related species have been suggested to play a key role in the astrochemical evolution of the interstellar medium, but the formation mechanism of even their simplest building block, the aromatic ben¬zene molecule, has remained elusive for decades. Formamide represents the simplest molecule contain-ing the peptide bond. Conse¬quently, the formamide molecule is of high interest as it is considered as an important precursor in the abiotic synthesis of amino acids, and thus significant to further prebiotic chemistry, in more suitable environments. Ultra-high vacuum low-temperature ice chem-istry experiments have been conducted to understand the formation pathways in the ISM for many astrobiologcally important molecules.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1 3.2 3.3 6.2 7.1
  • Ice Chemistry of the Solar System

    The overall goals of this project are to understand the chemical evolution of the Solar System, in particular leading to the development of astrobiologically important molecules. This is being achieved by investigation the formation of key organic carbon-, hydrogen-, oxygen-, and nitrogen-bearing (CHON) molecules in ices of Kuiper belt objects by reproducing the space environment experimentally in a unique ultra-high vacuum surface scattering machine. During this reporting period, our team worked on six projects towards our research goal to better understand the ice-based astrochemistry of chemical synthesis for carbon-containing compounds within the solar system. The Keck Astrochemistry Laboratory was also completed during this reporting period.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3 6.2 7.1
  • High-Resolution Spectroscopy of Comets at Infrared Wavelengths

    Dr. Lucas Paganini has initiated a robust means for quantitative detections of sulfur compounds at submillimeter and infrared (IR). He was awarded 20 hours observing time with the ESO’s sub-millimeter and far-IR Herschel Space Observatory for a proposed investigation on the analysis of OPR and D/H of hydrogen sulfide in comets. And he collaborated extensively on astronomical observations and scientific interpretation of comets 103P/Hartley 2, C/2003 K4 (LINEAR), and 10P/Tempel 2.

    ROADMAP OBJECTIVES: 1.1 3.1 3.2
  • Task 3.3.1 Solubility of Gases and Organics in Liquid Methane and Ethane

    The solubilities of gases and organics in liquid ethane and methane have been measured.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • NIR Spectroscopic Observations of Circumstellar Disks Around Young Stars

    As a research scientist in the Planetary Systems Laboratory at NASA GSFC, A. Mandell studies the formation and evolution of planetary systems and the structure and composition of the atmospheres of extra-solar planets utilizing near-infrared spectroscopy. Mandell’s current observing campaigns focus primarily on high-resolution ground-based spectroscopy of circumstellar disks and extrasolar planetary transits and secondary eclipses using instruments on the Keck II telescope and the Very Large Telescope. Additionally, Mandell assists as a co-investigator on computational studies of terrestrial planet formation and evolution using N-body simulations of planetary accretion.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1
  • Super-Earth Atmospheres

    In this task we use computer models to study aspects of the atmospheres of extrasolar super-Earths, planets that orbit other stars that are 2-10 times more massive than the Earth. Significant progress was made this year on two models, one that calculates how the atmosphere of the super-Earth is affected by radiative and particles coming from its parent star and one that calculates the surface temperature and change in atmospheric temperature with altitude for superEarth atmospheres.

    ROADMAP OBJECTIVES: 1.1 2.1 3.1
  • Task 3.3.2 Precipitation of Organics in Titan Lakes

    Preliminary evaporation-precipitation experiments have been conducted on benzene and acetylene in liquid ethane within the cryostat to simulate processes on Titan lake shores.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Task 3.3.3 Solubility in Lakes

    Atomistic simulations are being used to study the chemical environment of Titan’s hydrocarbon lakes.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Main Belt Comets

    The distribution of volatiles, and in particular water, in our solar system is a primary determinant of solar system habitability, and understanding how volatiles were distributed throughout the solar system during the era of planetary formation. In particular, the origin of terrestrial water is a fundamental unresolved planetary science issue. There are three leading scenarios for its origin: direct capture from nebular gas, delivery from icy planetesimals, and chemical reactions between oxides in a magma ocean and a tenuous hydrogen atmosphere. Comets provide one of the mechanisms for large-scale transport and delivery of water within our solar system, and asteroids provide another source of volatiles. However, neither comets nor asteroids can explain both Earth’s water and its noble gas inventory. A recently discovered new class of icy bodies in the outer asteroid belt, the Main Belt Comets (MBCs), are comets in near-circular orbits within the asteroid belt that are dynamically decoupled from Jupiter. Dynamics suggest they formed in-situ, beyond the primordial snow line, and as such represent a class of icy bodies that formed at a distance from the Sun that has not yet been studied in detail and which could potentially hold the key to understanding the origin of water on terrestrial habitable worlds. The UH NAI team has been very active in searching for additional MBCs, and characterizing those that are known.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Observations of the Water and Organic Content of Protoplanetary Disks and Comets

    The Blake group has been carrying out joint observational and laboratory program with NAI node scientists on the water and simple organic chemistry in the protoplanetary disk analogs of the solar nebula and in comets. It has been a highly productive year. The major overview papers outlining the results from our extensive (>100 disks) Spitzer IRS survey of the molecular emission from the terrestrial planet forming region are now published, and the initial follow-up work with GSFC scientists on the high spectral resolution ground based observations of such emission has just been submitted for publication. We have probed the outer disk’s water emission with the Herschel HIFI instrument, and also measured the D/H ratio in a Jupiter Family Comet for the first time with Herschel – finding a value consistent with that in the Earth’s oceans. Now that ALMA is ramping up toward operations, we look forward to high angular resolution observations of simple organics in the outer regions of disks and comets over the coming years. The full suite of results will permit the first detailed examination of the radial water and gas phase organic chemistry in planet-forming environments.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1
  • Organic Chemistry in a Dynamic Solar Nebula: Lab Studies and Flight Mission Implementation

    Over the past year we have concentrated on four major activities. The first is laboratory research on the generation of organics and the trapping of noble gases via Fischer-Tropsch type (FTT) reactions. The second is an attempt to understand and model the interrelated carbon and oxygen chemical cycles in a dynamic, turbulent nebula. The third is preparation for the design phase of the OSIRIS-REx mission, especially the characterization of regolith properties of the Type B asteroid that we are targeting. The final is proposal activity leading to the (possible) selection of a Discovery-class comet exploration mission (Comet Hopper or CHopper). In both of the mission activities, my goal has been to ensure that the missions can extract the maximum knowledge of the chemical and physical processes that occurred in the early solar system from the bodies that will be visited.

    ROADMAP OBJECTIVES: 3.1 3.2 7.1
  • Task 3.4.1 Tholin Chemical Analysis Using Nuclear Magnetic Resonance

    The definition and assessment of future flight capable analytical methods for complex organic analysis was pursued, in particular evaluating the potential of nuclear magnetic resonance (NMR).

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Measurements of Primitive Water

    Our research goal is to collect and analyze water that may sample the primordial water accreted by the Earth. This primordial water may reside at the bottom of the Earths mantle and may be sampled from “hotspot” volcanism such at that occurring in Iceland and Hawaii. Glass melt inclusions inside olivine crystals that formed at depth before the lava interacted with surface waters give us the best chance to find this primordial water.

  • Task 3.4.2 Tholin Analysis Based on Selective Detection of Functional Groups

    Titan organics comprise a very complex mixture of compounds. Several approaches are being developed that provide targeted detection of specific functional groups, such as nitriles, imines, primary amines, and carbon-carbon multiple bonds.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Radio Observations of Simple Organics: Tracing the Origins and Preservation of Solar System Materials

    We have continued observational programs designed to explore the chemical composition of comets and establishing their potential for delivering pre-biotic organic materials and water to the young Earth and other planets. State of the art, international facilities are being employed to conduct multiwavelength, simultaneous, studies of comets in order to gain more accurate abundances, distributions, temperatures, and other physical parameters of various cometary species. Additionally, observational programs designed to test current theories of the origins of isotopically fractionated meteorite (and cometary) materials are currently underway. Recent chemical models have suggested that in the cold dense cores of star forming regions, significant isotope enrichment can occur for nitrogen and possibly vary between molecular species and trace an object’s chemical evolution. Observations are being conducted at millimeter and submillimeter wavelengths of HCN and HNC isotopologues for comparison to other nitrogen-bearing species to measure fractionation in cold star forming regions.

    ROADMAP OBJECTIVES: 2.2 3.1 3.2 7.1
  • Task 3.5.1 Titan Genetics

    An open question is: “What chemical structures might support the genetic component of Darwinian evolution in Titan environments?” This is being approached theoretically and experimentally.

    ROADMAP OBJECTIVES: 1.1 3.1 3.2
  • Task 3.5.2 Energetics of Titan Life

    Thermochemical and dynamic modeling is being used to provide improved constraints on the available chemical energy and trace element fluxes to facilitate potential life on the surface of Titan.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Research Activities in the Astrobiology Analytical Laboratory

    The Astrobiology Analytical Laboratory is a laboratory dedicated to the study of organic compounds derived from Stardust and future sample return missions, meteorites, lab simulations of Mars, interstellar, proto-planetary, and cometary ices and grains, and instrument development. This year, we conclusively demonstrated the presence of indigenous nucleobases and purines in carbonaceous chondrites, resolving a 50-year-old debate. We continued analyses of meteoritic amino acids, which led to both the first detection of these compounds in thermally altered meteorites and a more detailed understanding of their presence in aqueously altered meteorites. We collaborated with researchers at various institutions to bring our analytical expertise to the study of precious and unique samples. We look forward to our increased participation in the OSIRIS-REx asteroid sample return mission.

    ROADMAP OBJECTIVES: 2.1 3.1 7.1
  • Solar System Icy Body Thermal Modeling and Evolutionary Pathways

    Thermal processing on small icy bodies in the solar system (comets, asteroids, Kuiper belt objects) will cause the volatile composition and interior structure to change over time. We seek to understand the evolutionary processes in these bodies so we can understand the observations made in the present epoch and to what extent we can infer the earliest stages of the solar system from these objects.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • The Dynamical Origin and Evolution of COmetary Reservoirs

    Comet taxonomy can only achieve its full significance if the chemical composition of a particular object is linked to its formation location in the solar nebula. This can only be accomplished through a comprehensive, end-to-end dynamical model of the origin and evolution of the comet reservoirs. Such is the goal of this program. Toward these ends, we have recently shown that most of the Oort cloud was probably captured from the proto-planetary disks of other stars when the Sun was in its birth star cluster.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 4.3
  • Water in Planetary Interiors

    We have synthesized samples of high pressure mineral phases that are likely hosts for H, and thus water, in planetary interiors, and measured physical properties including crystal structure, density, elasticity, and electrical conductivity to see if there is evidence of deep hydration in the Earth.

    ROADMAP OBJECTIVES: 1.1 2.1 3.1 3.2