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Project Reports

• Cosmic Distribution of Chemical Complexity

  The three tasks of this project explore the connections between chemistry in space and the origin of life. We start by tracking the formation and evolution of chemical complexity in space, from simple carbon-rich molecules such as formaldehyde and acetylene to complex species including amino acids, nucleic acids and polycyclic aromatic hydrocarbons. The work focuses on carbon-rich 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 with 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

• An Atomic Level Description of the Specific Interactions Between Nascent Peptide and Ribosome Exit Tunnel

  The ribosome exit tunnel is an ancient path that must be traveled by all peptides/proteins synthesized by the ribosome. We have synthesized peptolides and demonstrated their potential as probes to decipher the interaction between the nascent peptide and the exit tunnel. This study has furnished vital information about the path of travel of peptides attached to the flag-pole moiety of a ketolide. In continuation of our study, we have designed and commenced the synthesis of a series of oxazolidinone-peptide conjugates (Zyvotides) that places nascent peptide at a different window to the exit tunnel. We will characterize the interaction of these zyvotides with the ribosome exit tunnel using the tools we have developed during our investigation of the peptolides.

  ROADMAP OBJECTIVES: 3.2

• Amino Acid Alphabet Evolution

  A genetically encoded alphabet of just 20 amino acids has produced the universe of protein structures and functions found throughout Earth’s biosphere. Relationships within this amino acid alphabet are responsible for fundamental biological phenomena, such as protein folding and patterns of molecular evolution. In attempting to unravel these relationships, considerable scientific ingenuity has been spent developing systems to simplify the genetically encoded alphabet of 20 amino acids while minimizing the associated loss of chemical diversity. These efforts present an opportunity to generate a composite picture of the properties that link the amino acids as a set. We are therefore investigating whether different simplification schemes (“simplified amino acid alphabets”), including those derived from very different approaches, can be combined to create a coherent description of amino acid similarity. By understanding the organization and relationships between amino acids on Earth, we hope to shed light on the chemical logic to be expected as a product of evolution in extraterrestrial environments.

  An extensive scientific literature has converged on surprisingly clear agreement that a subset of only around half of the 20 genetically encoded amino acids was likely present from the inception of genetic coding (the “early” amino acids), and an equal sized subset was incorporated through subsequent evolution (the “late” amino acids). A further widespread assumption is that, as the set expanded, natural selection favored the addition of amino acids that extended the range of protein structures and functions. We initiated a quantitative investigation for consilience between these two important ideas.

  ROADMAP OBJECTIVES: 3.2 4.1 4.2 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 6.1 6.2 7.1 7.2

• Biosignatures in Ancient Rocks

  The Biosignatures in Ancient Rocks group investigates the co-evolution of life and environment on early Earth using a combination of geological field work, geochemical analysis, genomics, and numerical simulation.

  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

• BioInspired Mimetic Cluster Synthesis: Bridging the Structure and Reactivity of Biotic and Abiotic Iron-Sulfur Motifs

  Bioinspired synthetic techniques are bridging the gap between iron sulfur (FeS) mineral surfaces that demonstrate chemical reactivity and the highly evolved FeS cluster centers observed in biological metalloenzymes. An emerging paradigm in biology relating to the synthesis of certain complex iron sulfur clusters involves the modification of standard FeS clusters through radical chemistry catalyzed by radical S-adenosylmethionine (SAM) enzymes. In our attempts to examine potential sources for prebiotic and/or early biotic catalysts, we have initiated a new experimental line that probes the ability of short conserved FeS amino acid motifs that are present in modern day enzymes for their ability to coordinate FeS clusters capable of initiating small molecule radical reactions.

  ROADMAP OBJECTIVES: 3.1 3.2 3.3 3.4 7.1 7.2

• Ecology of Extreme Environments: Characterization of Energy Flow, Bioenergetics, and Biodiversity in Early Earth Analog Ecosystems

  The distribution of organisms and their metabolic functions on Earth is rooted, at least in part, to the numerous adaptive radiations that have resulted in the ability to occupy new ecological niches through evolutionary time. Such responses are recorded in extant organismal geographic distribution patterns (e.g., habitat range), as well as in the genetic record of organisms. The extreme variation in the geochemical composition of present day hydrothermal environments is likely to encompass many of those that were present on early Earth, when key metabolic processes are thought to have evolved. Environments such Yellowstone National Park (YNP), Wyoming harbor >12,000 geothermal features that vary widely in temperature and geochemical composition. Such environments provide a field laboratory for examining the tendency for guilds of organisms to inhabit particular ecological niches and to define the range of geochemical conditions tolerated by that functional guild (i.e., habitat range or zone of habitability). In this aim, we are examining the distribution and diversity of genes that encode for target metalloproteins in YNP environments that harbor geochemical properties that are thought to be similar to those that characterize early Earth. Using a number of newly developed computational approaches, we have been able to deduce the primary environmental parameters that constrain the distribution of a number of functional processes and which underpin their diversity. Such information is central to constraining the parameter space of environment types that are likely to have facilitated the emergence of these metal-based biocatalysts.

  ROADMAP OBJECTIVES: 3.2 3.3 3.4 4.1 4.2 5.1 5.2 5.3

• Survivability of Icy Worlds

  Survivability of Icy worlds (Investigation 2) focuses on survivability. As part of our Survivability 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

• Deconstruction of the Ribosome

  In the ribosome, RNA and protein are fully interdependent, part of the highly complex system of translation. We demonstrate here that isolated Domain III of 23S rRNA from Thermus thermophilus retains function after being split essentially in half. Chemical footprinting shows that a core of Domain III (DIII^core), obtained replacement of helices 54-59 with a simple stem-loop, folds to a near-native state in the presence of Mg²⁺ ions. Both DIII and DIII^core form specific complexes with ribosomal protein L23 in vivo, as indicated with a yeast three-hybrid experiment. L23 has a globular domain on the LSU surface and an extension (L23peptide) that penetrates into the ribosomal large subunit. In the assembled LSU, L23peptide (amino acids 58-79) traverses the surface of DIII^core. In solution, DIII^core forms a stable 1:1 complex with L23peptide, as observed with spectroscopic assay. The experiments described here are intended to recapitulate steps in early ribosomal evolution. We have previously proposed that some of the extensions of ribosomal proteins are molecular fossils that predate the globular protein domains in evolution. In our favored model of ribosomal origins, small independently-folding RNA elements associated with short peptides. Such complexes assembled to form a primitive peptidyl transferase center. The PTC evolved into the modern LSU, in a series of cooptions that left unaltered the basic structure and function of the PTC. This model predicts a continuous size distribution of folding and assembly elements within the LSU. We anticipate autonomy and specificity of folding and interaction of small, mid-sized and large rRNA and protein components.

  ROADMAP OBJECTIVES: 3.2 4.1 4.2

• 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

• Charting the Universe of Amino Acid Structures

  More than 3.5 billion years ago, life on our planet evolved a precise alphabet of 20 amino acids to function as building blocks which cells use to construct proteins according to genetic instructions. However, the twenty genetically encoded amino acids are but a tiny fraction of the chemical structures that could plausibly play such a role. Any science of the origins, distribution and future of life in the universe must take into account this larger context of chemical structures. But while astrochemistry, prebiotic chemistry, and bioengineering all hint at the chemical structures it contains, until now this amino acid universe has remained largely unexplored. Efforts to describe the structures it contains, or even estimate their number, have been hampered by the complexity inherent to the combinatorial properties of organic molecules. We have formed a new collaboration to combine European (DLR) advances in computational chemistry with NAI expertise in organic chemistry and amino acid biology to address this gap in current scientific understanding. Our early results have provided the first ever sketch of the amino acid structure universe, showing it to be far larger and more complex than previously supposed. This forms an important milestone in defining and exploring the principles of “universal biology”

  ROADMAP OBJECTIVES: 3.1 3.2 6.2 7.1 7.2

• Molecular Evolution: A Top Down Approach to Examine the Origin of Key Biochemical Processes

  The emergence of metalloenzymes capable of activating substrates such as CO, N2, and H2, were significant advancements in biochemical reactivity and in the evolution of complex life. Examples of such enzymes include [FeFe]- and [NiFe]-hydrogenase that function in H2 metabolism, Mo-, V-, and Fe-nitrogenases that function in N2 reduction, and CO dehydrogenases that function in the oxidation of CO. Many of these metalloenzymes have closely related paralogs that catalyze distinctly different chemistries, an example being nitrogenase and its closely related paralog protochlorophyllide reductase that functions in the biosynthesis of bacteriochlorophyll (photosynthesis). By specifically focusing on the origin and subsequent evolution of these metallocluster biosynthesis proteins in relation to paralogous proteins that have left clear evidence in the geological record (photosynthesis and the rise of O2), we have been able to obtain significant insight into the origin and evolution of these functional processes, and to place these events in evolutionary time.

  The genomes of extant organisms provide detailed histories of key events in the evolution of complex biological processes such as CO, N2, and H2 metabolism. Advances in sequencing technology continue to increase the pace by which unique (meta)genomic data is being generated. This now makes it possible to seamlessly integrate genomic information into an evolutionary context and evaluate key events in the evolution of biological processes (e.g., gene duplications, fusions, and recruitments) within an Earth history framework. Here we describe progress in using such approaches in examining the evolution of CO, N2, and H2 metabolism.

  ROADMAP OBJECTIVES: 3.2 4.1 5.1

• Project 1C: Absorption of Amino Acids on Minerals

  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. It has also been suggested in the literature that amino acids may have been delivered to early Earth by meteorite impacts. We focused here on amino-acid adsorption and conformation on model mineral, γ-Al₂O₃.

  We measured adsorption of the acidic amino-acids, glutamate and aspartate, on model nanparticulate oxide mineral, γ-Al₂O₃. Our results should help provide an estimate of the amount of amino-acids delivered. Using bulk adsorption isotherms our results showed similar amounts of adsorption of both amino-acids and FTIR spectroscopy revealed similar bonding configurations for the adsorbed species, over a range of pHs and concentrations.

  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

• Astrochemistry Theory and Observation Group NAI Report

  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

• Extremophile Ribosomes

  Diapausing embryos (resting eggs) from brachionid rotifers are able to withstand desiccation and thermal stress. Resting eggs can remain viable for decades, and develop normally once placed in a permissive environment that allows for hatching, growth and development. The exact mechanisms of resistance are not known, although several molecules have been suggested to confer protection during desiccation and thermal stress. In this study, we have identified by mass spectrometry two thermostable proteins, LEA (late embryogenesis abundant) and VTG (vitellogenin-like), found exclusively in the resting eggs of Brachionus manjavacas. This is the first observation that LEA proteins may play a role in thermostability and the first report of a VTG-like protein in the phylum Rotifera. These proteins exhibited increased expression in rotifer resting eggs when compared to amictic females. Our data suggest the existence of alternate pathways of desiccation and thermal resistance in brachionid rotifers.

  ROADMAP OBJECTIVES: 3.2 4.2 5.3

• 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

• Project 4: Geochemical Steps Leading to the Origins of Life

  The origins of life on Earth remains one of the outstanding problems in science. This project seeks to go to the root of the problem and focus on what were likely critical first steps. The research focuses on the natural synthesis of small organic molecules and subsequent interaction with potentially catalytic mineral phases opening up the system to greater chemical complexity. Organic mineral interactions are complex and difficult to analyze. Using a variety of powerful spectroscopic and mass spectrometric tools we are able to perform experiments that yield data that aid our understanding of such interactions.

  ROADMAP OBJECTIVES: 3.1 3.2

• Path to Flight

  The (Field Instrumentation and) Path to Flight investigation’s purpose is to enable in-situ measurements of organics and biological material with field instrumentation that have high potential for future flight instrumentation. The preceding three Investigations (Habitability, Survivability and Detectability) provide a variety of measurable goals that are used to modify or “tune” instrumentation that can be placed in the field. In addition the members involved with Investigation provide new measurement capabilities that have been developed with the specific goal of life-detection and organic detection using both non-contact/non-destructive means and ingestion based methods. The developments under this investigation (Inv 4) incorporate state-of-the-art laboratory instruments and next generation in-situ instrumentation that have been developed under programs that include NASA as well as NSF and DOD. These include mass-spectrometers, gas analyzers, and fluorescence/Raman spectrometry instruments.

  ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 7.1 7.2

• Origins of Functional Proteins and the Early Evolution of Metabolism

  The main goal of this project is to identify critical requirements for the emergence of biological complexity in early habitable environments by examining key steps in the origins and early evolution of functional proteins and metabolic reaction networks. In particular, we investigate whether protein functionality can arise from an inventory of polypeptides that might have naturally existed in habitable environments. We attempt the first demonstration of multiple origins of a single enzymatic function. We investigate experimentally how primordial proteins could evolve through the diversification of their structure and function and thus demonstrate key steps in the earliest evolution of protein functions.

  ROADMAP OBJECTIVES: 3.2 3.4

• Radical SAM Chemistry and Biological Ligand Accelerated Catalysis

  Iron sulfur (FeS) clusters are thought to be among the most ancient cofactors in living systems. The FeS enzyme thrust is focused on examining the structure, mechanism, and biosynthesis of the complex FeS enzymes nitrogenase and hydrogenase. Exciting recent results have identified important links between the biosynthesis of the H-cluster and FeMo-co and have outlined a new paradigm for the biosynthesis of complex FeS clusters. The observations made have provided direct links to the evolution of FeS biocatalysts from their mineral-based precursors.

  ROADMAP OBJECTIVES: 3.1 3.2 3.3 7.1 7.2

• 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. For the past several years, Co-I DiSanti’s research has emphasized 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. More recently, we have extended our thinking by suggesting oxidation reactions on grains as a means of interpreting results from our recent observational campaign on long-period comet C/2009 P1 (Garradd), in the fall/winter 2011/2012. We have also made major strides in the development and application of fluorescence models for interpretation of observed line intensities in comets, including an empirical treatment of the n2 band of CH₃OH, led by Co-I DiSanti.

  ROADMAP OBJECTIVES: 3.1 3.2

• Resurrection of an Ancestral Peptidyl Transferase

  Ancient components of the ribosome, inferred from a consensus of previous work, were constructed in silico, in vitro, and in vivo. The resulting model of the ancestral ribosome presented here incorporates about 20% of the extant 23S rRNA and fragments of four ribosomal proteins. We test hypotheses that ancestral rRNA can: (i) assume canonical 23S rRNA-like secondary structure, (ii) assume canonical tertiary structure, and (iii) form native complexes with ribosomal protein fragments. Footprinting experiments support formation of predicted secondary and tertiary structure. Gel shift, spectroscopic and yeast three-hybrid assays show specific interactions between ancestral rRNA and ribosomal protein fragments, independent of other, more recent, components of the ribosome. This robustness suggests that the catalytic core of the ribosome is an ancient construct that has survived billions of years of evolution without major changes in structure. Collectively, the data here support a model in which ancestors of the large and small subunits originated and evolved independently of each other, with autonomous functionalities.

  ROADMAP OBJECTIVES: 3.2 4.2

• Postdoctoral Fellow Report: Steven Mielke

  S. P. Mielke completed an NAI NASA Postdoctoral Program (NPP) fellowship during September 1, 2011 to February 29, 2012. His postdoctoral research has provided the basis for the project: “The Long-Wavelength Limit for Oxygenic Photosynthesis.” He continues this research as a Research Associate at Rockefeller University.

  ROADMAP OBJECTIVES: 3.2 4.2 5.1 5.3 6.2 7.2

• 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 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.

  ROADMAP OBJECTIVES: 3.1 3.2

• RiboVision: Visualization and Analysis of Ribosomes

  Ribosomes present special problems and opportunities related to visualization and analysis because they are exceeding complex and information-rich. Many structures have determined at near-atomic resolution, a large number of rRNAs have been sequenced, and each is a large macromolecular assembly with many components and highly complex function. We are devising visualization and analysis methods in analogy with Google Maps, but applied to the ribosome.

  ROADMAP OBJECTIVES: 3.2 4.2

• The ABRC Philosophy of Astrobiology and the Origin of Life Discussion Group

  The focus group continues to meet every other week. This year, 3 faculty members (Sara Waller, Prasanta Bandyopadhyay, and Visiting Assistant Professor Jeffrey Stephenson) and one graduate student (Stephen Keable) form the core of the group. We have discussed exo-environmental ethics, time travel, and the latest research on arsenic-based life forms. Dr. Bandyopadhyay is finishing a paper for publication that develops a Baysian analysis of the probability of the existence of extra-terrestrial life. Dr. Stephenson is working on an article in exo-environmental ethics. Dr. Waller continues to work with students who record communicative vocalizations of non-human animals on Earth to develop an empirical basis for analyzing potential extra-terrestrial communications. The group recently submitted a grant proposal to the NAIDDF to support further research and discussion on pressing questions of policy regarding exo-environmental ethics.

  ROADMAP OBJECTIVES: 3.1 3.2

• Project 8: 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, abiotic 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 and processes on early earth that could have influenced and even directed or templated the formation of RNA or its predecessors.

  ROADMAP OBJECTIVES: 3.1 3.2

• The Long Wavelength Limit for Oxygenic Photosynthesis

  Photosynthesis produces signs of life (biosignatures) on a planetary scale: atmospheric oxygen and the reflectance signature of photosynthetic pigments. Oxygenic photosynthesis is therefore a primary target in NASA’s search for life on habitable planets in other solar systems. An unanswered question is what the upper limit is to the photon wavelength at which oxygenic photosynthesis can remain viable. On other planets that have a parent star very different spectrally from our Sun, can we expect oxygen from plants of different colors from those on Earth?

  The cyanobacterium, Acaryochloris marina serves as a model organism for oxygenic photosynthesis adapted to low light and red-shifted light environments similar to what may be found on habitable planets orbiting M stars. Until A. marina was discovered in 1996, all known oxygenic photosynthesis relied on the pigment chlorophyll a (Chl a). A. marina instead uses chlorophyll d, which can absorb the far-red and near-infrared light in A. marina’s habitat. We use photoacoustics in the lab to measure the energy storage efficiency of A. marina with lasers, and molecular electrostatics modeling to surmise how replacement of Chl a by Chl d in A. marina affects arrangements within the photosystem molecules. We are finding that A. marina can perform oxygenic photosynthesis quite efficiently in its unique light niche.

  ROADMAP OBJECTIVES: 3.2 4.2 5.1 5.3 6.2 7.2

• Ice Chemistry of the Solar System

  We are currently in the process of establishing a research program at the University of Hawai’i at Manoa to investigate the evolution of Solar System and interstellar ices; these grains are chemically processed continuously by radiation from either our Sun, or galactic cosmic radiation (GCR). The nature of the chemistry that occurs here is an important component of understanding the origin of complex biomolecules that could have seeded the primordial Earth, helping to kick-start the origin of life. We have constructed one of the leading laboratory facilities in the world capable of carrying out this research, and we focus on establishing the underlying chemical pathways.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3 4.1 7.1 7.2

• Measuring Interdisciplinarity Within Astrobiology Research

  To integrate the work of the diverse scientists working on astrobiology, we have harvested and analyzed thousands of astrobiology documents to reveal areas of potential connection. This framework allows us to identify crossover documents that guide scientists quickly across vast interdisciplinary libraries, suggest productive interdisciplinary collaborations, and provide a metric of interdisciplinary science.

  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

• Reconstruction of Ancient Proteins

  The genetic code is one of the most ancient and universal aspects of biology on Earth, and determines how specific DNA sequences get interpreted as peptide sequences, which then fold into all the proteins necessary for the growth and function of living cells. To a large extent, this code is determined by a class of proteins that specify which RNA adaptor molecules (tRNA) become attached to which amino acids, aminoacyl-tRNA synthetases. Therefore, reconstructing the amino acid sequences of the ancestors of these synthetases, existing ~4 billion years ago, can tell us the mechanisms by which the genetic code arose, and how it evolved to the modern form inherited by all known living organisms.

  ROADMAP OBJECTIVES: 3.2 3.4 4.1 4.2

• VPL Databases, Model Interfaces and the Community Tool

  The Virtual Planetary Laboratory (VPL) develops computer models of planetary environments, including planets orbiting other stars (exoplanets) and provides a collaborative framework for scientists from many disciplines to coordinate their research. As part of this framework, VPL develops easier to use interfaces to its models, and provides model output datasets, so that they can be used by more researchers. We also collect and serve to the community the scientific data required as input to the models. These input data include spectra of stars, data files that tell us how atmospheric gases interact with incoming stellar radiation, and plant photosynthetic pigments. We also develop tools that allow users to search and manipulate the scientific input data. This year we provided Earth model datasets, new tools for searching the molecular spectroscopic database, and a new database of biological pigments. All of these products and others are published on the VPL Team Website at: http://depts.washington.edu/naivpl/content/models-spectra.

  ROADMAP OBJECTIVES: 1.1 1.2 3.2 4.1 6.1 7.1 7.2

• Remote Sensing of Organic Volatiles in Planetary and Cometary Atmospheres

  In the last year, we have greatly advanced our capabilities to model spectra of cometary and planetary atmospheres (Villanueva et al. 2012a, 2012b). Using these newly developed analytical methods, we derived the most comprehensive search for biomarkers on Mars (Villanueva et al. 2012, submitted) from our extensive database of high-quality Mars spectra. Furthermore, we retrieved molecular abundances of several comets (Villanueva et al. 2012c, Gibb et al. 2012, Paganini et al. 2012a/b), and of several young circumstellar disks (Mandell et al. 2012). These great advancements have allowed us to understand the infrared spectrum of planetary bodies and their composition with unprecedented precision.

  ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 7.1 7.2

• Research Activities in the Astrobiology Analytical Laboratory

  We are a laboratory dedicated to the study of organic compounds derived from past and future sample return missions, meteorites, lab simulations of Mars, interstellar, proto-planetary, and cometary ices and grains, and instrument development. This year, we continued our analyses of amino acids in carbonaceous chondrites, identifying large L-enantiomeric excesses in the Tagish Lake meteorite that may point towards abiotic processes that could lead to homochirality. We made the first detection of amino acids in CH and CB chondrites, and used compound-specific isotopic analysis to understand formation mechanisms for amino acids in CM and CR chondrites. We hosted two graduate students, welcomed a new NAI NPP postdoctoral researcher to our laboratory, and participated in numerous public outreach and education events, including providing a lecturer to the annual NAI Santander Summer School. We continued our participation in the OSIRIS-REx asteroid sample return mission and provided support for the Sample Analysis at Mars instrument of NASA’s Mars rover Curiosity.

  ROADMAP OBJECTIVES: 3.1 3.2 7.1

• Summary of Research Accomplishments for L. Paganini

  Dr. Lucas Paganini has performed astronomical observations of six comets that led to four publications in peer-reviewed journals (namely, two papers as first author and two as co-author). In July 2011 he (and colleagues) discovered that comet C/2009 P1 (Garradd) is CO-rich. And in 2012 he (and colleagues) detected carbon monoxide in a comet beyond Jupiter (at 6.26 AU from the Sun), thus setting a new record for detections by infrared (IR) spectroscopy of parent volatiles in comets at relatively large heliocentric distances. Until now considered to be a somewhat impossible task with IR ground-based facilities, these discoveries open up new opportunities for targeting multiple volatile species at low rotational temperatures, as well as the unique possibility to characterize hypervolatiles in distant comets.

  ROADMAP OBJECTIVES: 1.1 3.1 3.2

• Task 3.5.1 Titan Genetics

  This project seeks to determine what chemical structures might support the genetic component of Darwinian evolution in Titan environments.

  ROADMAP OBJECTIVES: 2.2 3.2 4.2 6.2