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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

• Project 1: Looking Outward: Studies of the Physical and Chemical Evolution of Planetary Systems

  This project integrates the work of Carnegie Institution Astronomers in the 1) the search for extrasolar planets, 2) understanding the flow of matter in protoplanetary disks around young stars, 3) understanding the origin of Near Earth Objects, in particular, their relationship with objects in the asteroid belt, and 4) understanding the composition of disks around young stars and the potential delivery of volatiles to terrestrial planets in other solar systems.

  ROADMAP OBJECTIVES: 1.1 1.2 2.2 3.1

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

  The initial Solar System abundances of the short-lived radionuclides (SLRs) ²⁶Al (half life ~0.73 Ma) and ⁶⁰Fe (half life ~2.6 Ma) are important to constrain since, if present in sufficient abundance, these SLRs served as heat sources for dehydration and differentiation processes on planetary bodies. The implications for this work include the astrophysical environment in which the Sun formed, and the abundance of water on the terrestrial planets.

  ROADMAP OBJECTIVES: 1.1 3.1

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

  The effort focused on establishing the geologically-determined conditions for organic evolution in the surface and interior. Using the standard prescription for modeling of satellite interiors, novel equations of state and thermal parameters were included that more realistically simulate Titan’s interior. The new value of the tidal love number for Titan was considered, along with inclusion of crustal clathrate. The likelihood of direct contact between an interior ocean and rock, as well as the cycling of hot water from rock to ocean, was demonstrated. The result raises the interest of Titan as an astrobiologically significant object in the solar system.

  ROADMAP OBJECTIVES: 2.2 3.1

• 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

• 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 seeks 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.

  ROADMAP OBJECTIVES: 1.1 3.1

• 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

• Project 2: Origin and Evolution of Organic Matter in the Solar System

  Extraterrestrial organic matter as is found in comets and certain meteorites has the potential to tell us much about the origin of the solar system, the origin of planetary volatiles, and possible the origins of life. In this project, we bring a powerful array of analytical methods to bare on understanding extraterrestrial organic matter at the molecular level. Our work links astronomy, chemistry, physics, and planetary science.

  ROADMAP OBJECTIVES: 2.2 3.1 7.1

• Biosignatures in Extraterrestrial Settings

  Exploring the prospects for biosignatures in extraterrestrial settings is a multi

  ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 4.1 4.3 6.2 7.1 7.2

• 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

• Delivery of Volatiles to Terrestrial Planets

  We are investigating the mechanisms by which terrestrial planets obtain water and organic compounds. By understanding how these crucial constituents for life came to Earth, we can determine whether these mechanisms also operate in exoplanetary systems. When an earth-like planet is finally discovered in an exoplanetary system, it will be difficult to directly measure the composition of that planet. However, VPL scientists will use the observable properties of the system to determine whether that planet has a history that allowed water and organics to have been transported to it. One of the important questions is the initial state of the organic compounds, which sets stringent limits on the ability of the earth-like planets to acquire carbon.

  ROADMAP OBJECTIVES: 1.1 1.2 3.1 4.1 4.3

• Aqueous Alteration of CR Chondrites

  Petrologic studies of chondrites have shown that many samples contain hydrated minerals that are formed by aqueous alteration of primitive components. Through this discovery, it has become clear that the action of water played a key role in geologic processes of the early Solar System. CR chondrites – a subclass of carbonaceous chondrites – display a range of mineralogy from practically anhydrous (type 3) to completely hydrated (type 1). In addition, CRs show minimal evidence for thermal metamorphism that overprints or obscures aqueous alteration signatures. Knowledge of the aqueous alteration in CR chondrites will yield important interpretations on how, and to what extent, water affected the geologic evolution of primary nebular components, with implications that extend to how and where life began to evolve in the Solar System. A particularly important issue is how aqueous alteration affected the initial set of organic compounds present in carbonaceous chondrites. Amino acids (the building blocks of life) are a class of organic molecule present in meteorites. Understanding how or if organic molecules form on meteorites and their interactions with the water in meteorites has important implications for the chemical inventory of the meteorites, the process by which life formed on our planet, and the possibility that life can form on other planets in our Solar System. We are using a suite of micro analytical tools to understand the early solar system aqueous environment and production or organic material.

  ROADMAP OBJECTIVES: 1.1 3.1

• Task 1.1.2.1 Models of the Reaction Between Hydrocarbons and Water Ice (Part 1)

  Studying the morphology and composition of Titan’s northern lakes and seas allow refining the values of the carbon contained in different reservoirs (atmosphere, lakes, dune fields). From this a carbon cycle can be constructed that takes into account the interactions between the interior, surface, and atmosphere.

  ROADMAP OBJECTIVES: 2.2 3.1

• Astrophysical Controls on the Elements of Life, Task 2: Model the Chemical and Dynamical Evolution of Massive Stars

  Stars create the chemical elements heavier than hydrogen and helium, with the majority arising from the lives and violent deaths of massive stars in supernova explosions. The starting chemical composition of stars also affects their evolution and that of their associated planets. We have performed computational simulations for a large range of stellar masses to provide predictions for important stellar characteristics (i. e. brightness, temperature, stellar winds, composition) over the stars’ lifetimes and made the data available to the public. We have also simulated the explosions of massive stars to predict the chemical abundances of material ejected from the dying stars and how that material is distributed in the surrounding universe. As a complement, we are finding the chemical abundances of hundreds of nearby, potentially habitable stars and modeling how the habitable zones and planets of stars with different abundances evolve.

  ROADMAP OBJECTIVES: 1.1 3.1

• Astrobiology/Bioastronomy Through the International Astronomical Union, the 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, and are planning observations of organic molecules in comets.

  ROADMAP OBJECTIVES: 3.1

• Astrophysical Controls on the Elements of Life, Task 3: Model the Injection of Supernova Material Into Star-Forming Molecular Clouds

  The goal of this task is to see if material ejected from a star that has exploded as a supernova can make its way into the gas as it is forming new solar systems. It has been expected that this material, because it is moving so fast (> 2000 km/s) when it hits the cold, dense molecular cloud in which stars are forming, would shock, heat up, and then “bounce” off of the cloud boundary. Our numerical modeling using state-of-the-art numerical codes and thousands of computers at the Arizona Center for Advanced Computing, shows that the gas can in fact cool quickly enough to penetrate into the molecular cloud. Stars can be contaminated with supernova material just as they are forming, at contamination levels consistent with isotopic and chemical evidence from meteorites.

  ROADMAP OBJECTIVES: 1.1 3.1

• Task 1.1.2.2 Models of the Reaction Between Hydrocarbons and Water Ice (Part 2)

  In the clathrate phase, there can be an exchange between primordial methane clathrates, which are believed to make at least part of Titan’s upper crust, and ethane, which is the primary product of Titan’s atmospheric chemistry and is one of the major constituents of the lakes. Including these exchanges in a geophysical model of Titan allows explaining Titan’s shape as measured by the Cassini mission. These exchanges also may have an influence on Titan’s hydrocarbon cycle.

  ROADMAP OBJECTIVES: 2.2 3.1

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

  Project 3 focuses on understanding the nature of volatiles (principally water and gase like carbon dioxide and methane) in planetary interiors. The origin of Earth’s oceans and the initiation of plate tectonics may have related through the retention of water deep in Earth’s mantle. In this project scientists study how volatiles behave in silicate melts and Earth’s deep interior. They also study other rock planets, e.g. Mars and Mercury to understand how the presence or absence of volatiles may have lead to such disparate outcomes relative to Earth.

  ROADMAP OBJECTIVES: 1.1 3.1 4.1

• 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

• 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

• Project 4: 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 collaborative interaction among NAI investigators.

  ROADMAP OBJECTIVES: 1.1 3.1 4.1 4.3

• 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

• 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 it 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 modeling of habitable planets around brown dwarfs, the first comprehensive analysis of exomoon habitability, the role of distant stellar companions on planetary system architecture, and an improved understanding of the origins of terrestrial planet composition.

  ROADMAP OBJECTIVES: 1.1 1.2 3.1 4.3

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

  The goal of this project is to determine whether supernova material could be injected into a protoplanetary disk, the disk of gas and dust from which planets form. A secondary issue is whether these materials would be mixed within the disk efficiently, and whether such an injection into our own protoplanetary disk can explain the isotopic evidence from meteorites that the solar system contained short-lived radionuclides like ²⁶Al.

  ROADMAP OBJECTIVES: 1.1 3.1

• 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

• 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

• 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

• Task 1.2 Interaction of Methane/ethane With Water Ice

  A Titan lake simulation system is under construction to provide a testbed for testing small instruments and components at Titan lake conditions in preparation for future in-situ missions.

  ROADMAP OBJECTIVES: 2.2 3.1

• 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

• Task 2.1.1.1 Master Atmospheric Chemistry Simulation

  A new approach to the condensation of molecules onto grains and sublimation back to the gas has been implemented to account for these processes in an approach that is numerically stable and relies on the extensive database of laboratory data on the saturation vapor pressures of molecules. This, combined with the new description of grain size distribution (implemented last year), will provide a great improvement in the description of the organic chemistry in Titan’s atmosphere.

  ROADMAP OBJECTIVES: 2.2 3.1

• Astrophysical Controls on the Elements of Life, Task 5: Model the Variability of Elemental Ratios Within Clusters

  This project aims to better understand the self-enrichment that goes on in star-forming molecular clouds as stars near the end of their lives and deposit heavy elements into the surrounding medium, where other stars are still in the midst of forming. Through detailed hydrodynamic simulations we are studying the mixing of heavy elements and its relation to variable abundance ratios in present-day clusters, as well as the transition from pristine to enriched star formation in the early universe.

  ROADMAP OBJECTIVES: 1.1 3.1

• Project 1E: 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). The Organics experiment on EXPOSE-R exposed 11 polycyclic aromatic hydrocarbons (PAHs) and 3 fullerene molecules in the form of ultra-thin films to solar UV under vacuum or controlled atmosphere. Ground control experiments of EXPOSE-R were performed at the DLR MUSC Center. A large fraction of the 210 samples (flight, flight dark, ground dark control, and the simulated ground control) have been measured by UV and IR spectroscopy in the last view months. Preliminary data of returned flight samples are shown.

  ROADMAP OBJECTIVES: 3.1

• Composition of Parent Volatiles in Comets

  During the period covered by this progress report we observed the Oort cloud comets C/2009 (Garradd) and C/2010 G2 (Hill). We completed our comprehensive study of prebiotic molecules in comet C/2007 N3 (Lulin). We continued our multi-comet surveys of spin temperatures and searches for deuterated species. We conducted spatially-resolved measurements of water rotational temperature, column abundance, and ortho-para ratio in the inner coma of comet 103P/Hartley 2 – the target of NASA the EPOXI fly-by mission. We studied the volatile composition of another Jupiter-family comets – 21P/Giacobini-Zinner. We studied the activity of comet Christensen beyond 3 AU from the Sun.

  ROADMAP OBJECTIVES: 2.2 3.1

• 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

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

  Abundances of both common and trace elements can have substantial effects on the habitability of stellar systems. We study the formation and composition of structures in supernova explosions that deliver bioessential elements to material that will form new stars and planets. We use the abundance of the element europium to estimate the abundances of uranium and thorium in nearby stellar systems and their effects on the thermal evolution of extrasolar planets. The relative abundances of common elements vary substantially among nearby stars, and we find that the impact of this on a star’s evolution can change the amount of time its planets are habitable by billions of years.

  ROADMAP OBJECTIVES: 1.1 3.1

• Task 2.1.1.2 Titan Aerosol Chemistry

  The observed vertical profiles of Titan organic aerosols have been analyzed and the possible chemistry forming these aerosols studied. The elementary reaction of the ethynyl radical with diacetylene represents an efficient pathway to produce triacetylene in Titan’s atmosphere in those regions where density profiles of photolytically-generated ethynyl radicals and diacetylene overlap. The model of Titan’s atmosphere indicates that successive reactions of the triacetylene molecule can yield even more complex polyynes. These polyynes are thought to be the basis out of which the organic aerosols are formed.

  ROADMAP OBJECTIVES: 2.2 3.1

• 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

• 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

• Task 2.1.2.1 Atmospheric State and Dynamics

  To support the master atmospheric model, realistic Titan atmospheric profiles [winds, temperatures and densities] from the surface to ~1200km, for a variety of seasons and solar cycles, is needed.

  ROADMAP OBJECTIVES: 2.2 3.1

• Task 2.1.2.2 Atmospheric Observations

  Airglow emission from the atmosphere was discovered while Titan was deep in Saturn’s shadow. This suggests an important role for charged particles in producing this airglow.

  ROADMAP OBJECTIVES: 2.2 3.1

• 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 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

• Task 2.2.1 Characterization of Aerosol Nucleation and Growth

  One goal has been to elucidate the mechanisms and develop a quantitative understanding of particle formation and growth in the Titan atmosphere. Work has focused on elucidating the role of molecular interactions in growth of Titan aerosol particles using numerical simulations.

  ROADMAP OBJECTIVES: 2.2 3.1

• Herschel Lunar Impact Study

  The Herschel Space Telescope, parked in a Lagrangian point beyond the Moon, will be retired in 2013. A controlled, high velocity impact by the Herschel spacecraft into the lunar surface would provide new data about the Moon and elucidate the nature of lunar volatiles, including water ice. The impact site should be at a cold, shadowed location, but the impact plume needs to be sunlit and observable from Earth, which places significant constraints on possible impact locations. We have carried out calculations of shadow heights to identify potential impact sites that simultaneously satisfy all necessary constraints.

  ROADMAP OBJECTIVES: 1.1 3.1

• Task 2.2.2 Ultraviolet/infrared Spectroscopy and Photoprocessing of Ice Films

  Investigations of the condensed phase chemistry of Titan’s atmospheric aerosols has continued. The focus this year has been on the photochemistry of acetylene imbedded in C₄N₂ ice—to simulate atmospheric aerosol photochemistry involving most abundant unsaturated molecule (acetylene) in Titan’s atmosphere.

  ROADMAP OBJECTIVES: 2.2 3.1

• 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

• Task 3.1.1.1 Reactions of Organic Ices With Electrons (Part 1)

  Ices exposed to low-energy electrons can be the cradle to further chemical reactions.

  ROADMAP OBJECTIVES: 2.2 3.1

• Progress Report for the Cosmic Ice Laboratory

  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 one manuscript published and another in preparation. A project on the formation of sulfuric-acid hydrates was completed, and a new project involving thermal chemistry at Europa was started. Studies of frozen acetylene were performed and measurements of the infrared optical constants of frozen hydrocarbon molecules 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.

  ROADMAP OBJECTIVES: 3.1

• Task 3.1.1.2 Reactions of Organic Ices With Electrons (Part 2)

  Secondary electrons can stimulate the polymerization of HCN. These electrons are present at low altitudes and in the near surface regions of Titan and not only lead to polymerization, but also negative charging of the haze particles.

  ROADMAP OBJECTIVES: 2.2 3.1

• Progress Report From G. Blake – CIT

  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. Scientific results continue to flow at a rapid clip. We have followed up our major overview papers outlining the results from our extensive (>100 disks) Spitzer IRS survey of the molecular emission from the terrestrial planet forming region with follow-up work with GSFC scientists on the high spectral resolution ground-based observations of such emission and that from cometary comae (and possible non-transiting exoplanets) using the Keck telescope and the VLT. We have measured the angular scale of the disk emission, and discovered a new transitional disk class characterized by a wide angle molecular wind. We have probed the outer disk’s water emission with the Herschel HIFI instrument, and also measured the (D/H)water ratio in a Jupiter Family Comet for the first time with Herschel – finding a value consistent with that in the Earth’s oceans. Our first Cycle 0 ALMA data are now in hand, and beautifully demonstrate the high angular resolution observations of simple organics in the outer regions of disks and comets that will become possible 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 7.2

• Task 3.1.1.3 Reactions of Organics With Ices and Mineral Grains

  One focus is on understanding reactions occurring on Titan’s surface with an emphasis on determining whether mineral deposits from meteoritic infall can catalyze the formation of more complex molecules of prebiotic relevance such as amines, polyamines or simple amino acids.

  ROADMAP OBJECTIVES: 2.2 3.1

• 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

• 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

• Task 3.1.2 Chemistry Active in Titan Dunes

  The goal of this project is to demonstrate that chemical reactions can occur between atmospheric organics and water ice, even at the low temperature (ca. 100 K) of Titan’s surface, leading to the incorporation of oxygen to form molecules of astrobiological significance. Studies using a low temperature fluidized bed reactor demonstrate that amino acids, glycine specifically, are produced by tribochemical reactions driven by Aeolian processes in Titan’s dunes.

  ROADMAP OBJECTIVES: 2.2 3.1

• The Chemical Composition of Comets

  Understanding the origin and the distribution of organic matter and volatile material in the early Solar System is of central importance to astrobiology. Comets, which have escaped the high-temperature melting and differentiation that asteroids experience, are “astrobiological time cap-sules” that have preserved a valuable record of the complex chemical and physical environment in the early solar nebula. Studying the primordial chemistry and evolution of cometary nuclei will pro-vide important clues about the birthplace of comets and in turn place strong constraints on the cur-rent Solar System formation models. In late 2011 and 2012, two bright comets, C/2011 L4 (Pan-STARRS) and C/2009 P1 (Garradd), visited the inner Solar System for the first time. In March 2012, C/2011 L4 (PanSTARRS) is expected to appear even brighter than the comet Hale-Bopp, the bright-est since 1996. We have recently studied C/2011 L4 and C/2009 P1 in the sub-millimeter and infra-red wavelength regimes using the James Clerk Maxwell Telescope (JCMT), Caltech Submillimeter Observatory (CSO), Gemini-North and the Keck Telescopes on Mauna Kea, Hawaii. We investigated the chemical compositions of these comets and compared them with those of other comets. Our unique observations of these two bright comets over a wide range of heliocentric distances allow monitoring of the abundances of several native molecules that are key to understanding comet formation.

  We are also conducting a systematic survey of comet brightness around their orbits in order to model their volatile composition. Using space-based data from the Akari Satellite, the WISE Satel-lite, and the EPOXI mission we are showing that these models can provide information on gas spe-cies normally not detectable through Earth’s atmosphere. This gives us the opportunity to investi-gate the wide spread distribution of key cometary volatiles (water, carbon monoxide and carbon dioxide) and their relation to protoplanetary disk chemistry.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• 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

• Task 3.2 Cosmic-Ray Induced Surface Ice Chemistry

  Oxygenation chemistry involving the condensed Titan’s organic aerosols with water-ice on Titan’s surface may be induced by high energy photons simulating the cosmic ray induced chemistry on Titan’s surface.

  ROADMAP OBJECTIVES: 2.2 3.1

• Task 3.3.1 Solubility of Gases and Organics in Liquid Methane and Ethane

  A goal is to measure the solubilities of Titan surface and atmospheric species in cryogenic liquid hydrocarbons, in order to constrain the composition of the hydrocarbon lakes, and provide an understanding into the nature of erosion and sedimentation on Titan.

  ROADMAP OBJECTIVES: 2.2 3.1

• Rings in Debris Disks: A Signature of Planets or of Volatiles?

  Marc Kuchner and his collaborator Wladimir Lyra at JPL have developed a new explanation for the origin of eccentric rings in debris disks—like the rings around Fomalhaut and HR 4796. A popular explanation for these rings is that they represent dust shepherded by extrasolar planets, which are often too faint to see. Instead of hidden planets, Kuchner and Lyra’s models invoke a hidden component of gas in these disks, which supports a thermal instability that causes the dust to clump together in narrow eccentric rings. The presence of this instability makes inferring the presence of exoplanets more difficult, but it may aid in planet formation and provide important clues to the history of volatiles in the solar system.

  ROADMAP OBJECTIVES: 1.1 1.2 3.1

• 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 3.3.2 Precipitation of Organics in Titan Lakes

  Laboratory experiments simulating processes on the beaches of Titan lakes have been pursued. Work to date suggests that, at 94 K and 1 bar pressure, the precipitation of dissolved acetylene and benzene results in the formation of both solids on the beaches.

  ROADMAP OBJECTIVES: 2.2 3.1

• Task 3.4.1 Tholin Chemical Analysis Using Nuclear Magnetic Resonance

  One effort is to develop techniques for analyzing the structural features of Titan organic aerosol analogues (tholins) and HCN polymers.

  ROADMAP OBJECTIVES: 2.2 3.1

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

  The goal of this project has been to develop methods to identify and determine the structure of complex organic compounds formed in the Titan environment. These methods also may be useful for in situ chemical analyses in future robotic explorations of Titan’s complex atmospheric and surface chemical environment.

  ROADMAP OBJECTIVES: 2.2 3.1

• Task 3.5.2 Energetics of Titan Life

  Infall to the Titan system of both interplanetary and circum-Saturnian dust and ice particles can provide exogenic fluxes of several elements, such as germanium and oxygen, which may be important in facilitating potential Titan metabolisms.

  ROADMAP OBJECTIVES: 2.2 3.1