2014 Annual Science Report

Astrobiology Roadmap Objective 3.1 Reports Reporting  |  SEP 2013 – DEC 2014

Project Reports

  • Life Underground

    Our multi-disciplinary team from USC, Caltech, JPL, DRI, RPI, and now also Northwestern is developing and employing field, laboratory, and modeling approaches aimed at detecting and characterizing microbial life in the subsurface—the intraterrestrials. We posit that if life exists, or ever existed, on Mars or other planetary body in our solar system, evidence thereof would most likely be found in the subsurface. This study takes advantage of unique opportunities to explore the subsurface ecosystems on Earth through boreholes, mine shafts, sediment coring, marine vents and seeps, and deeply-sourced springs. Access to the subsurface—both continental and marine—and broad characterization of the rocks, fluids, and microbial inhabitants is central to this study. Our focused research themes require subsurface samples for laboratory and in situ experiments. Specifically, we are carrying out in situ life detection, culturing and isolation of heretofore unknown intraterrestrial archaea and bacteria using numerous novel and traditional techniques, and incorporating new and existing data into regional and global metabolic energy models.

    ROADMAP OBJECTIVES: 2.1 2.2 3.1 3.3 4.1 5.1 5.2 5.3 6.1 6.2 7.2
  • Co-Crystals on the Surface of Titan

    We have discovered that benzene and ethane form a co-crystalline inclusion compound at Titan surface temperatures and pressures. Co-crystals of other organic compounds could be common on Titan’s surface. These results can help explain the release of ethane observed at the Huygens landing site, and point to a new type of surface material that may have significant impact on Titan surface chemistry and geology.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2
  • Cosmic Distribution of Chemical Complexity

    This project explores the connections between chemistry in space and the origin of life. It is comprised of three tightly interwoven tasks. We track the formation and evolution of chemical complexity in space starting with simple carbon-rich molecules such as formaldehyde and acetylene. We then move on to more 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: 2.2 3.1 3.2
  • 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.

  • Astrobiology of Icy Worlds

    Our goal in the Astrobiology of the Icy Worlds Investigation is to advance our understanding of the role of ice in the broad context of astrobiology through a combined laboratory, numerical, analytical, and field investigations. Icy Worlds team pursues this goal through four major investigations namely, the habitability, survivability, and detectability of life of icy worlds coupled with “Path to Flight” Technology demonstrations. A search for life linked to the search for water should naturally “follow the ice”. Can life emerge and thrive in a cold, lightless world beneath hundreds of kilometers of ice? And if so, do the icy shells hold clues to life in the subsurface? These questions are the primary motivation of our science investigations

    ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 3.2 4.1 5.1 5.2 5.3 6.2 7.1
  • Astrophysical Controls on the Elements of Life – Task 4 – Model the Injection of Supernova Material Into Protoplanetary Disks

    The goal of this project has been 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.

  • Project 2: Cells as Engines and the Serpentinization Hypothesis for the Origin of Life

    All life is, and must be, “powered” since all of its most essential and distinguishing processes have to be driven “up-hill” against their natural thermodynamic direction. By the 2nd law of thermodynamics, however, a process can only be made to proceed up-hill by being mechanistically linked, via a molecular device functioning as an engine, to another, more powerful, process that is moving in its natural, down-hill direction. On fundamental principles, we argue, such engine-mediated conversion activities must also have been operating at, and indeed have been the cause of, life’s emergence. But what then were life’s birthing engines, what sources of power drove them, what did they need to produce, and how did they arise in an entirely lifeless world? Promising potential answers to these and other questions related to the emergence of life are provided by the Alkaline Hydrothermal Vent/serpentinization (“AHV”) hypothesis, whose original propounder and lead proponent, Dr. Michael Russell of JPL, is a co-investigator on this project. The goal of the project is specifically to clarify the essential mechanistic modus operandi of all molecular engines that power life, and to see how the most fundamental and prerequisite of these could have arisen, and operated, in the structures and flows produced by the serpentinization process. Importantly, candidate answers to these questions can be put to definitive laboratory tests.

    ROADMAP OBJECTIVES: 1.1 2.1 3.1 3.2 3.3 3.4
  • Project 1B: Photostability of Pigments and Amino Acids in Space Environment on the International Space Station

    Radiation plays a fundamental role in space environments, planetary systems and on the young Earth where life has emerged ~ 3.6 billion years ago. In order to measure the photostability and photochemical alteration of organic compounds in actual space environments, experiments in Low Earth Orbit (LEO) are crucial to our understanding of potentially destructive effects, particularly from the VUV (vacuum ultraviolet) spectral region. Space-based experiments are conducted in part due to the difficulty of accurately simulating the entire space environment in the laboratory (such as UV radiation, galactic cosmic ray irradiation, microgravity, temperature etc.). In preparation for the EXPOSE-R2 space exposure facility on the International Space Station (ISS) we prepared and investigated thin films of key pigments as well as mineral-associated amino acids for the experiments BIOMEX and Photochemistry on the Space Station that investigate a range of chemical compounds relevant for astrochemistry and astrobiology. The EXPOSE-R2 facility was launched on July 24th, 2014 to the ISS and was activated in November 2014. EXPOSE-R2 will remain in Low Earth Orbit (LEO) for 12-18 months. After retrieval non-destructive as well as destructive analyses will be performed in Earth laboratories to understand the effects of space exposure. We report on the flight preparation of samples and discuss the characteristics of the biomolecule thin-films measured by spectroscopy.

  • Development of Direct Sampling Methodology for Analysis of Complex Organic Mixtures on Titan’s Surface

    Photochemistry in Titan’s dense atmosphere generates a complex mixture of organic molecules that have been deposited on Titan’s surface over time. Requiring no sample pretreatment or handling, the technique of direct analysis in real time (DART), combined with an ion trap mass spectrometer having MS/MS capability, is shown to be an enabling experimental methodology to vaporize, ionize, and structurally characterize organic components of this mixture. A key important development is the use of temperature programmed desorption, accomplished by heating of the probe gas, to examine complex mixtures of organics with a wide range of volatility (polypropylene glycol and tar samples from a petroleum seep). Of particular relevance to astrobiology, this methodology is employed to compare Titan simulants produced in a pulsed discharge from gas mixtures designed to probe mechanistic pathways leading to high molecular weight products.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2
  • 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
  • Analysis of Prebiotic Organic Compounds in Astrobiologically Relevant Samples

    The Astrobiology Analytical Laboratory (AAL) of the GCA is dedicated to the study of organic compounds derived from past and future sample return missions, meteorites, lab simulations of Mars, interstellar, protoplanetary, and cometary ices and grains, and instrument development. This year, we continued our work analyzing the organic content of carbonaceous chondrites, expanding beyond our previous amino acid and nucleobase analyses to determine distribution and abundances of pyridine carboxylic acids and aliphatic amines. We investigated the effects of cosmic ray irradiation on amino acids. We supported development of a liquid chromatographmass spectrometer aimed at in situ analyses of amino acids and chirality on airless bodies including asteroids and the outer planet’s icy moons Enceladus and Europa. We hosted an undergraduate and participated in numerous public outreach and education events. We continued our participation in the OSIRISREx asteroid sample return mission and provided support for the Sample Analysis at Mars instrument of NASA’s Mars rover Curiosity.

  • Disks and the Origins of Planetary Systems

    This task is concerned with the evolution of complex habitable environments. The planet formation process begins with fragmentation of large molecular clouds into flattened disks. This disk is in many ways an astrochemical “primeval soup” in which cosmically abundant elements are assembled into increasingly complex hydrocarbons and mixed in the dust and gas within the disk. Gravitational attraction among the myriad small bodies leads to planet formation. If the newly formed planet is a suitable distance from its star to support liquid water at the surface, it is in the so-called “habitable zone.” The formation process and identification of such life-supporting bodies is the goal of this project.

    ROADMAP OBJECTIVES: 1.1 1.2 2.2 3.1 4.1 4.3
  • Circumstellar Debris and Planetesimals in Exoplanetary Systems

    This year, GCA astronomer Marc Kuchner invited the public to help him discover new planetary systems through a new website, DiskDetective.org. At DiskDetective.org, volunteers view data from NASA’s Wide-field Infrared Survey Explorer (WISE) mission and three other surveys. WISE measured more than 745 million objects, representing the most comprehensive survey of the sky at mid-infrared wavelengths ever taken.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1
  • Astrophysical Controls on the Elements of Life – Task 5 – Model the Variability of Elemental Ratios Within Clusters

    We carried out studies of self-enrichment of the earliest star clusters. Building on the turbulence simulations in Pan & Scannapieco (2010) and Pan et al. (2011), we examined the mixing of heavy elements generated by stars into the surrounding cluster environments.

  • Investigation of Electron-Molecule Chemistry and Micrometeorite Induced Reactions on Titan’s Surface

    Low-energy electron-beam irradiation and dissociative electron attachment (DEA) experiments were performed on nitrogen-containing organic condensates as a model for cosmic-ray induced polymerization processes and charging events that can occur within Titan’s atmosphere and on Titan’s organic-rich surface. In addition, detailed analysis of meteorite surfaces were analyzed with an emphasis of understanding the corrosion of schreibersite and the role this may play in the formation of phosphorylated pre-biotic molecules.

    ROADMAP OBJECTIVES: 3.1 3.2 7.1
  • Project 4: Vistas of Early Mars: In Preparation for Sample Return

    To understand the history of life in the solar system requires knowledge of how hydrous minerals form on planetary surfaces, and the role minerals may play in the development of potential life forms. The minerals hematite and jarosite have been identified on Mars and presented as in situ evidence for aqueous activity. This project seeks to understand (i) the conditions required for jarosite and hematite formation and preservation on planetary surfaces, and (ii) the conditions under which their “radiometric clocks” can be reset (e.g., during changes in environmental conditions such as temperature). By investigating the kinetics of noble gases in minerals, known to occur on Mars and Earth, we will be prepared to analyze and properly interpret ages measured on samples from future Mars sample return missions.

    ROADMAP OBJECTIVES: 2.1 3.1 7.1
  • Biosignatures in Extraterrestrial Settings

    The Biosignatures in Extraterrestrial Environments group works on finding and characterizing exoplanets, in particular through very high resolution spectroscopy; and developing new techniques for finding exoplanets and characterizing their properties. It also works on understanding the evolution and dynamics of planetary systems, including the solar system, and the role of astrophysical processes in establishing and sustaining life in extraterrestrial environments.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 4.1 4.3 6.2 7.1 7.2
  • Astrophysical Controls – 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 isotopes that influence habitability to material that will form new stars and planets. We examine ratios of elements that have substantial effects of the mineralogy and interiors of 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 large factors.

  • Longer Wavelength Photochemistry of Condensates and Aerosols in Titan’s Lower Atmosphere and on the Surface

    This study focuses on the condensed phase photochemistry on Titan. In particular, we focus on understanding longer wavelength photochemistry of solid hydrocarbons so simulate photochemistry that could occur based on the UV penetration through the atmosphere and on the evolution of complex organic species in astrobiologically significant regions on Titan’s surface. Here we investigate the oxygenation chemistry involving the condensed Titan’s organic aerosols with water-ice on Titan’s surface – induced by high energy photons simulating the cosmic ray induced chemistry on Titan’s surface.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • NAI Titan Education and Public Outreach

    Planetariums have a long history of experimentation with audio and visuals to create new multimedia experiences. We report on a series of innovative experiences that began in the Gates Planetarium at the Denver Museum of Nature & Science, combining live performances of music and navigation through scientific visualizations. The Life Out There productions featured a story showcasing astrobiology concepts at scales ranging from galactic to molecular, and told using VJ-ing of immersive visualizations and musical performances from the House Band of the Universe. These hour-long shows were broken into four separate themed musical movements, with an improvisatory mix of music, dome visuals, and spoken science narrative which resulted in no two performances being exactly alike. Post-performance dissemination is continuing via a recorded version of the performance available as a DVD and online streaming video. Written evaluations from visitors who were present at the live shows reveal high satisfaction and subsequent interest in astrobiology topics. Life Out There concerts have been used to inaugurate a new evening program to draw in a younger audience demographic to DMNS, and have been taken on the road to other venues in other cities.

    We continued the development and public presentation of this live digital planetarium show about Titan and Astrobiology. This live lecture planetarium show, entitled “Life Out There” makes use of the digital imaging capabilities of the dome, through the innovative Uniview software, a “real time” virtual simulation of the known universe based on accurate astronomical databases and modeling. The inclusion of live musicians, who serve to introduce each section of the show, helps to attract an audience beyond those who reliably come to space science events at the planetarium, and help to create a relaxing and evocative atmosphere conducive to wonder and learning. With Uniview, we can utilize the SPICE Kernels that spacecraft teams use to describe mission trajectories, and create virtual versions that can be followed along through the simulation. Using 3-D spacecraft models, the public can follow spacecraft missions shown with breathtaking realism within the immersive display. We have a detailed model of the Cassini spacecraft, and we are using the most recently updated SPICE kernels of Cassini, including the many Titan flybys, to show the public the fantastic journey of Cassini and Huygens in exploring Titan. In addition to the live lecturer, a second operator controls the Uniview software, allowing these flybys to be seen from any perspective deemed instructive and/or entertaining. Various Cassini and Huygens image data sets, including camera data, infrared spectrometer data and radar data, are being texture mapped and rendered on the moon’s surface. The atmosphere is visually peeled away, and various visuals are used together with an original script and musical score, both written by E/PO lead David Grinspoon, to explore themes of Titan and Astrobiology for the public. The visual content was directed by Dr. KaChun Yu, Curator of Space Sciences at DMNS, in collaboration with Dr. Grinspoon.

    We developed, tested, evaluated and disseminated a 20-minute stage show for informal science centers to excite and inform visitors about the science and exploration of Titan. The show utilizes a participatory exercise in scientific illustration to engage visitors in the material. Each participant is given a clipboard and pencils, and the facilitator, using a series of Cassini and Huygens images and videos of Titan, leads them through an exercise in which each draws a sketch of a Titan landscape, learning along the way about many aspects of the Titan environment as revealed by modern exploration. The show has now been seen by many thousands of visitors to the Denver Museum of Nature and Science.

    During this last year we focused on disseminating the presentation materials and supporting media, and training materials, including a training DVD for presenters for use at other informal science centers.

    We continued the development and public presentation of a live digital planetarium show about Titan and Astrobiology. This live lecture planetarium show, entitled “Life Out There” makes use of the digital imaging capabilities of the dome, through the innovative Uniview software, a “real time” virtual simulation of the known universe based on accurate astronomical databases and modeling. The inclusion of live musicians, who serve to introduce each section of the show, helps to attract an audience beyond those who reliably come to space science events at the planetarium, and help to create a relaxing and evocative atmosphere conducive to wonder and learning. With Uniview, we can utilize the SPICE Kernels that spacecraft teams use to describe mission trajectories, and create virtual versions that can be followed along through the simulation. Using 3-D spacecraft models, the public can follow spacecraft missions shown with breathtaking realism within the immersive display. We have a detailed model of the Cassini spacecraft, and we are using the most recently updated SPICE kernels of Cassini, including the many Titan flybys, to show the public the fantastic journey of Cassini and Huygens in exploring Titan. In addition to the live lecturer, a second operator controls the Uniview software, allowing these flybys to be seen from any perspective deemed instructive and/or entertaining. Various Cassini and Huygens image data sets, including camera data, infrared spectrometer data and radar data, are being texture mapped and rendered on the moon’s surface. The atmosphere is visually peeled away, and various visuals are used together with an original script and musical score, both written by E/PO lead David Grinspoon, to explore themes of Titan and Astrobiology for the public. The visual content was directed by Dr. KaChun Yu, Curator of Space Sciences at DMNS, in collaboration with Dr. Grinspoon.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2
  • Evolution of Protoplanetary Disks and Preparations for Future Observations of Habitable Worlds

    The evolution of protoplanetary disks tells the story of the birth of planets and the formation of habitable environments. Microscopic interstellar materials are built up into larger and larger bodies, eventually forming planetesimals that are the building blocks of terrestrial planets and their atmospheres. With the advent of ALMA, we are poised to break open the study of young exoplanetesimals, probing their organic content with detailed observations comparable to those obtained for Solar System bodies. Furthermore, studies of planetesimal debris around nearby mature stars are paving the way for future NASA missions to directly observe potentially habitable exoplanets.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1 4.3 7.2
  • Project 6: 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.

  • Astrophysical Controls on the Elements of Life, Task 1: High-Precision Isotopic Studies of Meteorites
  • Habitable Planet Formation and Orbital Dynamical Effects on Planetary Habitability

    This task explores how habitable planets form and how their orbits evolve with time. Terrestrial planet formation involves colliding rocks in a thin gaseous disk surrounding a newborn star and VPL’s modeling efforts simulate the orbital and collisional evolution of a few to millions of small bodies to determine the composition, mass and orbital parameters of planets that ultimately reach the habitable zone. After formation, gravitational interactions with the star and planet can induce short- and long-term changes in orbital properties that can change available energy to drive climate and illuminate the planetary surface. The VPL simulates these effects in known and hypothetical planetary systems in order to determine the range of variations that permit planetary habitability.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1 4.3
  • Project 6. Mining Archaeal Genomes for Signatures of Early Life: Comparison of Metabolic Genes in Methanogens

    Methanogenic archaea derive energy from simple starting materials, producing methane and carbon dioxide in the process. The chemical simplicity of the growth substrates and versatility of the organisms in extreme environments provide for a possibility that they could exist on other planets. By characterizing the evolution of methanogens from the most simple to most complex organism as well as their growth characteristics under controlled environments, we hope to address the question as to whether they could exist on planets such as Mars, where bursts of methane have been seen, yet no source has yet been identified.

    ROADMAP OBJECTIVES: 1.1 2.1 3.1 3.2 3.3 3.4 4.1 4.2 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Structural Investigation of Titan Tholin

    Using analytical methods including nuclear magnetic resonance spectroscopy, mass spectrometry and non-aqueous microchip gel electrophoresis, we investigate the properties and structure of the major components of laboratory analogues of Titan tholins.

  • Project 7: 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 3.3 3.4
  • Titan as a Prebiotic Chemical System – Benner

    In 2007, NASA sponsored a committed of the National Academies of Science to explore whether life might exist in environments outside of the traditional habitable zone, defined as positions in a solar system where liquid surface water might be found. Alternative solvents which have analogous “habitable zones” farther away from their star include hydrocarbons, ammonia, and dinitrogen. The core question asked whether life having genetic biopolymers might exist in these solvents, which are in many cases (including methane) characterized by the need for “cold” (temperatures < 100K in the case of methane).

    These “weird” solvents would require “weird” genetic molecules, “weird” metabolic processes, and “weird” bio-structures. In pursuit of this “big picture” question, we turned to Titan, which has exotic solvents both on its surface (methane-hydrocarbon) and sub-surface (perhaps super-cooled ammonia-rich water). This work sought genetic molecules that might support Darwinian evolution in both environments, including non-ionic polyether molecules in the first and biopolymers linked by exotic oxyanions (such as phosphite, arsenate, arsenite, germanate) in the second.

    In the current year, we completed our studies that identified biopolymers that might work in hydrocarbon solvents. These studies have essentially ruled out biological processes in true cryosolvents. However, a series of hydrocarbons containing different numbers of carbon atoms (one, two, three, and four, for example, in methane, ethane, propane, and butane) cease to be cryosolvents as their chain lengths increase. These might be found on “warm Titans”. Further, they might exist deep in Titan’s hydrocarbon oceans, where heating from below would lead to warm hydrocarbon oceans.

    These studies showed that polyethers are insufficiently soluble in hydrocarbons at very low temperatures, such as the 90-100 K found on Titan’s surface where methane is a liquid at ambient pressures. However, we did show that “warm Titans” could exploit propane (and, of course, higher hydrocarbons) as a biosolvent for certain of these “weird” alternative genetic biopolymers; propane has a huge liquid range (far larger than water). Further, we integrated this work with mineralogy-based work that allows reduced molecules to appear as precursors for less “weird” genetic biomolecules, especially through interaction with various mineral species, including borates, molybdates, and sulfates.

    ROADMAP OBJECTIVES: 1.1 1.2 2.2 3.1 3.2 3.4 4.1 5.3 6.2 7.1 7.2
  • Developing New Biosignatures

    This project works to develop new biosignatures based on element, molecules, or isotopes. For example, we are working with the method secondary ion mass spectrometry (SIMS) to analyze microorganisms or microfossils. We are also looking at the Isolation and analysis of F430, archaeol, and IPL-archaeol from the Cascadia Margin. We are also interested in DNA as a biosignature. For that work, we are extracting DNA from deep sea sediment and other difficult environments. Finally, we are also investigating prebiotic molecules in order to known which carbon-containing biomolecules can not be reasonable biosignatures.

    ROADMAP OBJECTIVES: 3.1 7.1 7.2
  • Titan as a Prebiotic Chemical System – Willacy

    To develop a comprehensive model of the chemistry in Titan’s atmosphere including condensation of molecules onto grains and sublimation back to the gas, and exchange between the atmosphere and surface.

  • Fischer-Tropsch-Type Reactions in the Solar Nebula

    Fischer-Tropsch-Type (FTT) reactions can form complex hydrocarbons via surface-mediated reactions using simple gases (CO, N2, and H2) on almost any grain surface and are currently being studied in relation to the early Solar Nebula. Several theories exist as to how hydrocarbons are formed in the early Solar System but the compelling nature of this type of reaction is that it is passive and generates a wide variety of complex hydrocarbons using commonly available components (gases/grains) without invoking a complex set of conditions for formation.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2
  • Titan as a Prebiotic System Activity Report

    We are calculating how much material, over time, is ejected from geysers on the moon Enceladus and ends up on the moon Titan, and how this material may be important for pre-biological chemistry on Titan.

    ROADMAP OBJECTIVES: 2.2 3.1 3.2 3.3
  • Fundamental Properties Revealed by Parent Volatiles in Comets

    We studied water and other prebiotic molecules in the atmospheres of comets C/2012 S1 (ISON) and C/2013 R1 (Lovejoy). These projects aim at improved understanding of cometary chemistry – a test bed for the contribution of comets to the delivery of exogenous prebiotic organics and water to early Earth, hypothesized as a precursor event to the emergence of the biosphere.

    ROADMAP OBJECTIVES: 2.2 3.1 4.3
  • Laboratory Investigations Into Chemical Evolution in Icy Solids From the Interstellar Medium to the Outer Solar System to Meteorites

    NAI-GCA support in 2014 helped us continue our work on amino-acid stability. In 2014, we performed radiation experiments to measure the destruction rate of glycine in CO2 ice. In particular, we found that this rate depends on concentration and temperature, and is 20-40 times greater than for glycine in H2O-ice.

    ROADMAP OBJECTIVES: 2.1 2.2 3.1 7.1 7.2
  • Long-Term Variation of High Energy Activity of Young Stars in Mass Accretion Outburst and Quiescence

    High-energy photons in the young stellar environment are known to stimulate chemical reactions of molecules, producing prebiotic materials that might later be incorporated into comets and through them into young planets. Observational tests are sorely needed to assess the significance of such processing for Astrobiology, and to guide development of theoretical models for chemical evolution in protoplanetary environments.

  • NNX09AH63A Origin and Evolution of Organics in Planetary Systems

    The Blake group has been carrying out joint observational and laboratory programs with NAI node scientists on the water and simple organic chemistry in the protoplanetary disk analogs of the solar nebula and in comets. Observationally, we continue to build on our extensive (>100 disks) Spitzer IRS survey of the infrared molecular emission from the terrestrial planet forming region of disks with follow-up work using the high spectral resolution ground-based observations of such emission (via the Keck and the Very Large Telescopes, the Herschel Space Observatory, SOFIA, and ALMA) along with that from comets. This year, we emphasized disk studies with the rapidly maturing capabilities of the ALMA observatory, that promises to revolutionize our understanding of the formation and migration of protoplanets, and with infrared studies of the molecular volatiles detectable in both comets and exoplanetary atmospheres. In the lab, we have continued to exploit our novel approach to broad-band chirped pulse microwave spectroscopy that promises to drop the size, mass and cost of such instruments by one to two orders of magnitude, and have developed a decade-spanning THz frequency comb with unprecedented precision. We are using these new instruments to measure the rotational spectra of prebiotic compounds, along with a detailed characterization of their large amplitude vibrations. Looking forward, these techniques have the potential to make site-specific stable isotope measurements, a capability we will continue to explore with GSFC Node scientists.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1
  • Remote Sensing of Organic Volatiles on Mars and Modeling of Cometary Atmospheres

    During this period, Dr. Villanueva mainly worked on processing high-resolution (spectral and spatial) data of Mars acquired in January/2014 and in the observational campaigns of 2008, 2009 and 2010, using the recently developed new analytical and modeling capabilities. Unprecedented maps of the D/H ratio in water were extracted from these data, and a paper was recently accepted by Science (see below). In addition, he participated in several international conferences and collaborated on several Titan and cometary projects.

    ROADMAP OBJECTIVES: 1.1 2.1 3.1 3.2 4.1 7.1
  • The Evolution of Organics in Space

    The molecular heritage of our Solar System stretches back to the interstellar cloud from which it formed. Knowledge of the chemistry of this cloud is crucial to understanding the process of star and planet formation; this is part of the field of astrochemistry. Since much of astrochemistry deals with the organic molecules found in space and in solar system environments, astrochemistry itself may be considered part of the larger field of astrobiology. The present project includes both observations of these organic molecules and participating in the preparation of an Encyclopedia of Astrobiology.

  • The Variability of Carbon Monoxide Abundances Among Oort Cloud Comets

    Direct observations of neutral CO in multiple wavelength regimes (radio, infrared and ultraviolet) have established a wide range for measured CO abundances (relative to water), ranging from a few tenths of a percent to ~30%. But the largest complexity when interpreting measurements of CO stems from its competing roles as a primary (parent) vs product species. For instance, CO is a principal product of CO2 dissociation, so comets rich in CO2 should also reveal a significant production rate for CO — this product CO is extended and its detection is strongly dependent on the instrumental field-of-view (FOV). Prior to 2013, only six comets within 2.5 AU of the Sun (where both H2O and CO are active primary volatiles) were identified as being enriched in native CO. During late 2013, we confirmed a relatively high abundance of CO in C/2013 R1 (Lovejoy; hereafter C/2013 R1), supporting the existence of a so-far sparse (yet growing) fraction of CO-rich comets.

    ROADMAP OBJECTIVES: 1.1 3.1 3.2 7.1
  • Undergraduate Research Associates in Astrobiology (URAA)

    In 2014, the Goddard Center for Astrobiology (GCA) hosted the tenth session of our summer program for talented science students (Undergraduate Research Associates in Astrobiology), a ten-week residential research program tenured at Goddard Space Flight Center and the University of Maryland, College Park (http://astrobiology.gsfc.nasa.gov/education.html). Competition was very keen, with an oversubscription ratio of 3.0. Students applied from over 15 Colleges and Universities in the United States, and 2 Interns from 2 institutions were selected. Each Intern carried out a defined research project working directly with a GCA scientist at Goddard Space Flight Center or the University of Maryland. As a group, the Associates met with a different GCA scientist each week, learning about his/her respective area of research, visiting diverse laboratories and gaining a broader view of astrobiology as a whole. At summer’s end, each Associate reported his/her research in a power point presentation projected nation-wide to member Teams in NASA’s Astrobiology Institute, as part of the NAI Forum for Astrobiology Research (FAR) Series.

    ROADMAP OBJECTIVES: 1.1 3.1 6.2
  • Volatile Composition of Comets: Emphasis on Oxidized Carbon

    DiSanti’s research emphasizes the chemistry of volatile oxidized carbon in comets, in particular the efficiency of converting CO to H2CO and CH3OH through reduction reactions on the surfaces of icy grains prior to their incorporation into the cometary nucleus. Additionally, oxidation reactions on grains can play a significant role, particularly for CO-enriched, C2H2-depleted comets such as C/2009 P1 (Garradd; see item 1 under Section 3 below). Such processes produce precursor molecules that (if delivered to Earth through impact of comet nuclei) could have enabled the emergence of life, and so are highly relevant to Astrobiology.