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2010 Annual Science Report

Astrobiology Roadmap Objective 1.1 Reports Reporting  |  SEP 2009 – AUG 2010

Project Reports

  • Biosignatures in Ancient Rocks

    This team of geologists, geochemists, paleontologists and biologists seeks signs of early life in ancient rocks from Earth. Working mostly on that part of Earth history before the advent of skeletons and other preservable hard parts in organisms, our group focuses on geochemical traces of life and their activities. We also investigate how life has influenced, and has been influenced by changes in the surface environment, including the establishment of an oxygen-rich environment and the initiation of extreme climate states including global glaciations. For this we use a combination of observations from modern analogous environments, studies of ancient rocks, and numerical modeling.

    ROADMAP OBJECTIVES: 1.1 3.2 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • AbGradCon 2010

    The Astrobiology Graduate Student conference is a conference organized by astrobiology graduate students for astrobiology grad students. It provides a comfortable peer forum in which to communicate and discuss research progress and ideas.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Project 1: Looking Outward: Studies of the Physical and Chemical Evolution of Planetary Systems

    We study the origin of life through a wide variety of approaches, beginning here with theoretical investigations of protoplanetary disks, the environments in which simple organic molecules first appeared and were concentrated in planetary bodies. We also study the survival of this organic matter during subsequent evolution through observations of circumstellar disks around both young and mature stars, extrasolar planetary systems, and small bodies in our Solar System, and through detailed models of planetary system formation.

    ROADMAP OBJECTIVES: 1.1 1.2 2.2 3.1
  • NAI Focus Group: Icy Satellites Environments Focus Group (ISEFoG)

    This focus group provides a forum for cross-team multidisciplinary discussions related to icy outer solar system satellite processes.

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

    This project is aimed to improve our understanding of the connection between chemistry in space and the origin of life on Earth, and its possibility on other worlds. Our approach is to trace the formation and development of chemical complexity in space, with particular emphasis on understanding the evolution from simple to complex species. The work focuses upon molecular species that are interesting from a biogenic perspective and also upon understanding their possible roles in the origin of life on habitable worlds. We do this by first measuring the spectra and chemistry of materials under simulated space conditions in the laboratory. We then use these results to interpret astronomical observations made with ground-based and orbiting telescopes. We also carry out experiments on simulated extraterrestrial materials to analyze extraterrestrial samples returned by NASA missions or that fall to Earth in meteorites.

    ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 3.2 3.4 4.3 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 aims to characterize the composition and structure of these materials and the chemical pathways by which they form and evolve. The long-term goal is to determine the inventories of proto-planetary disks around young sun-like stars, leading to a clear understanding of the processes that led to our own origins and insight into the probability of life-supporting environments emerging around other stars.

  • Astrobiological Exploration of Mars

    Astrobiological research informs many NASA missions and especially those concerned with exploring our near neighbor Mars. MIT team members have been making notable contributions to the Mars Exploration Rovers and Mars Science Laboratory missions.

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

    The evolution of habitable planets may be affected by the injection of short-lived radionuclides, produced by supernova explosions, early in solar system history. In this task we are finding evidence of such injection in some of the earliest Solar System materials (calcium-aluminum-rich inclusions) and constraining the timing of early Solar System events.

  • AIRFrame Technical Infrastructure and Visualization Software Evaluation

    The Astrobiology Integrative Research Framework (AIRFrame) analyzes published and unpublished documents to identify and visualize implicit relationships between astrobiology’s diverse constituent fields. The main goal of the AIRFrame project is to allow researchers and the public to discover and navigate across related information from different disciplines.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Task 1.1.2 Models of the Internal Dynamics: Formation of Liquids in the Subsurface and Relationships With Cryovolcanism

    The rate of the heat flow through the Titan ice crust sets a limit on how long water can exist in liquid form on the surface of Titan

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Disks and the Origins of Planetary Systems

    This task is concerned with understanding the evolution of complexity as primitive planetary bodies form in habitable zones. The planet formation process begins with fragmentation of large molecular clouds into flattened protoplanetary 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 envelope 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 2.1 4.3
  • Habitability of Icy Worlds

    Habitability of Icy Worlds investigates the habitability of liquid water environments in icy worlds, with a focus on what processes may give rise to life, what processes may sustain life, and what processes may deliver that life to the surface. Habitability of Icy Worlds investigation has three major objectives. Objective 1, Seafloor Processes, explores conditions that might be conducive to originating and supporting life in icy world interiors. Objective 2, Ocean Processes, investigates the formation of prebiotic cell membranes under simulated deep-ocean conditions, and Objective 3, Ice Shell Processes, investigates astrobiological aspects of ice shell evolution.

    ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 3.2 3.3 3.4 4.1 5.1 5.3 6.1 6.2 7.1 7.2
  • Biosignatures in Extraterrestrial Settings

    The team will investigate the abundance of sulfur gases and elucidate how these gases can be expected to evolve with time on young terrestrial planets. They will continue studies of planet formation in the presence of migration and model radial transport of volatiles in young planetary systems, and will be involved with searches for M star planetary companions and planets around K-giant stars.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 4.1 4.3 6.2 7.1
  • Astrophysical Controls on the Elements of Life, Task 2: Model the Chemical and Dynamical Evolution of Massive Stars

    Massive stars are the primary source for the elements heavier than hydrogen and helium on the periodic table. We are simulating the evolution of these stars and their eventual deaths in supernova explosions with state of the art physics in order to generate the most accurate estimates possible of the yields of chemical elements from both individual stars and stellar populations. We are also observing the variations of elemental abundances in nearby planet host candidates in order to determine the range of variation in bioessential elements and the effects of non-sunlike compositions on the evolution of the host stars.

  • 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 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
  • Amino Acid Alphabet Evolution

    A standard “alphabet” of just 20 amino acids builds the proteins that interact to form metabolism of all life on Earth (rather like the English of 26 letters can be linked into words that interact in sentences and paragraphs to produce meaningful writing). However, considerable research from many scientific disciplines points to the idea that many other amino acids are made by non-biological processes throughout the universe. A natural question is why did life on our planet “choose” the members of its standard alphabet?

    Our project seeks to gather and organize the diverse information that describes these non-biological amino acids, to understand their properties and potential for making proteins and thus to understand better whether the biology that we know is a clever, predictable solution to making biology – or just one of countless possible solutions that may exist elsewhere.

    ROADMAP OBJECTIVES: 1.1 3.1 3.2 3.4 4.1 4.3 6.2 7.1 7.2
  • Project 3: The Origin, Evolution, and Volatile Inventories of Terrestrial Planets

    The origin and Sustenance of life on Earth strongly depends on the fact that volatile elements H-C-O-N where retained in sufficient abundance to sustain an ocean-atmosphere. The research in this project involves studies of how terrestrial planets form, why differences exist among the terrestrial planets, how volatiles behave deep within the Earth, and how volatiles and life influence the large and small scale composition of the near surface Earth.

    ROADMAP OBJECTIVES: 1.1 3.1 4.1
  • Path to Flight

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

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 7.1 7.2
  • Project 3: Pathways for Exogenous Organic Matter to the Early Earth and Mars

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

  • Task 1.2 Interaction of Methane/ethane With Water Ice

    The extent to which hydrocarbon liquids interact with the bedrock water ice sets the stage for reactions leading to the formation of prebiotic oxygen-containing organic compounds on the Titan surface.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • 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 determine how much supernova material can make its way into a forming solar system during its initial stages, when the gas that will form the star and the planets are collapsing from a molecular cloud. This supernova material may contain radioactive isotopes like 26Al, which is the primary mechanism by which asteroids melted and which may control delivery of water and other elements to terrestrial planets. This supernova material may also change the abundance ratios of bioessential elements.

  • Delivery of Volatiles to Terrestrial Planets

    Habitable planets are too small to trap gases from the planet-forming disk. Their oceans and atmospheres must originate in the planetesimals from which the planet is built. In this task, we explore how, when, and from where Earth, Mars and habitable worlds around other stars can accumulate water and organic carbon. The main challenge is that water and organic carbon are relatively volatile elements (compared to rock and metal). Therefore, during the period of time in which solids condensed at the current position of Earth, water and carbon would have been mainly in the gas phase. Getting these materials to the habitable zone requires that material from further out in the disk would be transported inward. Another challenge is that upon reaching the Earth, both large and small suffer severe heating during atmospheric entry. We also have investigated the fate of these compounds upon release into the atmosphere.

    ROADMAP OBJECTIVES: 1.1 3.1 4.1 4.3
  • Task 2.1.1 Master Atmospheric Chemistry Simulation

    The master atmospheric chemistry model will contribute to the understanding of the extent to which organic chemistry in atmospheric processes produces complex compounds.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Bioastronomy 2007 Meeting Proceedings

    This is the published volume of material from an astrobiology meeting hosted by our lead team in 2007 in San Juan Puerto Riceo. The book includes 60 papers covering the breadth of astrobiology, and developed a new on-line astrobiology glossary.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Detectability of Biosignatures

    In this project VPL team members explore the nature and detectability of biosignatures, global signs of life in the atmosphere or on the surface of a planet. Work this year focused on the build up and detectability of sulfur-based biosignatures in early Earth-like atmospheres, especially for planets orbiting stars cooler than our Sun. We also explored the potential non-biological generation of oxygen and ozone in early Earth-like atmospheres, which could result in a “false positives” for photosynthetic life. In parallel, we worked on acquiring and getting running two simulators for telescopes that will one day be able to observe and determine the properties of extrasolar terrestrial planets.

    ROADMAP OBJECTIVES: 1.1 1.2 4.1 6.2
  • Astrophysical Controls on the Elements of Life, Task 4: Model the Injection of Supernova Material Into Protoplanetary Disks

    The goal of this task is to determine how much supernova material can make its way into a forming solar system, after the star has formed and is surrounded by a protoplanetary disk. This supernova material may contain radioactive isotopes like 26Al, which is the primary mechanism by which asteroids melted and which may control delivery of water and other elements to terrestrial planets. This supernova material may also change the abundance ratios of bioessential elements.

  • Project 5: 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 these minerals play in the development of potential life forms. One hydrous mineral found on Earth and inferred from in situ measurements on Mars, is the mineral Jarosite, KFe3(SO4)2(OH)6. We are investigating whether radiometric ages, specifically 40Ar/39Ar ages on jarosite can be interpreted to accurately record climate change events on Mars. This project not only requires understanding the conditions required for jarosite formation and preservation on planetary surfaces, but also assessing under what conditions its “radiometric clock” can be reset (e.g., during changes in environmental conditions such as temperature). By studying jarosites formed by a variety of processes on Earth, we will be prepared to analyze and properly interpret ages measured from jarosite obtained from future Mars sample return missions.

    ROADMAP OBJECTIVES: 1.1 2.1 7.1
  • Astrophysical Controls on the Elements of Life, Task 5: Model the Variability of Elemental Ratios Within Clusters

    This involves a comprehensive chemodynamic study of the self-enrichment of star forming regions and its astrobiological implications. Our approach will start from the point of star formation and diligently model the subsequent production, dissemination, and accretion of 92 chemical elements, with a special focus on bioessential elements and short-lived radionucides. Our goal is to capture the full evolution over which a molecular cloud, the primary units of star-forming gas, is converted into an open cluster, the primary units of formed stars — determining the probability distribution of all elements that are important in the formation of terrestrial planets and life.

  • Comparative Icy Bodies Studies Data Access Framework

    We are developing a new database architecture and software to efficiently
    access and archive terabyte-sized sets of small body (comet and asteroid) data
    for long term studies relevant to thermal modeling, secular changes in activity,
    composition and evolution. Ultimately this will will be instrumental when connected
    with other large scale small body projects in the solar system (comet taxonomies,
    dynamical studies) to understand the formation and evolution of the solar system.

  • Task Atmospheric State and Dynamics

    The physical conditions in the Titan atmosphere set the context for the formation of organic compounds in the atmosphere.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Dynamical Effects on Planetary Habitability

    VPL explored numerous features of orbits. We showed that comets are unlikely to have produced more than 1 mass extinction event in the past 500 million years. We catalogued the fractions of habitable zones of nearby stars that are capable of supporting a habitable planet. We also participated in the discovery of two planets whose orbital planes are offset by 30 degrees.

    ROADMAP OBJECTIVES: 1.1 1.2 4.3
  • Current Status and Future Bioastronomy

    Irvine and colleagues at the University of Massachusetts have been using a unique new broadband radio receiver to measure the spectra of external galaxies in the 3mm wavelength region, and hence to study the chemistry of their interstellar gas.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Computational Astrobiology Summer School

    The Computational Astrobiology Summer School (CASS) is an excellent opportunity for graduate students in computer science and related areas to learn about astrobiology, and to carry out substantial projects related to the field.

    The two-week on-site part of the program is an intensive introduction to the field of astrobiology. NASA Astrobiology Institute scientists present their work, and the group discusses ways in which computational tools (e.g. models, simulations, data processing applications, sensor networks, etc.) could improve astrobiology research. Also during this time, participants define their projects, with the help of the participating NAI researchers. On returning to their home institutions, participants work on their projects, under the supervision of a mentor, with the goal of presenting their completed projects at an astrobiology-related conference the following year.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Project 6: The Environment of the Early Earth

    This project involves the development of capabilities that will allow scientists to obtain information about the conditions on early Earth (3.0 to 4.5 billion years ago) by performing chemical analyzes of crystals (minerals) that have survived since that time. When they grow, minerals incorporate trace concentrations of ions and gaseous molecules from the local environment. We are conducting experiments to calibrate the uptake of these “impurities” that we expect to serve as indicators of temperature, moisture, oxidation state and atmosphere composition. To date, our focus has been mainly on zircon (ZrSiO4), but we have recently turned our attention to quartz as well.

    ROADMAP OBJECTIVES: 1.1 4.1 4.3
  • PHL 278: A Gateway Course for a Minor in Astrobiology

    We have recently developed obtained Montana Board of Regents for an undergraduate minor in Astrobiology at Montana State University. The Minor includes courses in Earth Sciences, Physics, Astronomy, Microbiology, Ecology, Chemistry, and Philosophy. Two new courses have been developed as part of the minor, one of which is a gateway or introductory course examines the defining characteristics of life on earth as well as the challenges of a science that studies life and its origin. The other course which will be offered fall 2011 is the capstone course for the minor which will delved into the science of Astrobiology in more detail and targeted for Juniors and Seniors that have fulfilled the majority of the requisite course requirements for the curriculum.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Astrophysical Controls on the Elements of Life, Task 6: Determine Which Elemental or Isotopic Ratios Correlate With Key Elements

    Many of the elements important to life or to the development of potentially habitable solar systems are difficult or impossible to observe directly. We are working to understand where these elements are produced in stars and whether they correlate with elements that are more easily observed. This effort requires modeling of the dynamics and nuclear burning in supernova explosions to determine what elements are produced together and, equally important, how the ejected material is incorporated into the gas that forms stars and planets. We are also observing a region of star formation to detect the signature of enrichment of newly formed sunlike stars by the explosion of their nearby, more massive cousins.

  • Task Atmospheric Observations

    The observed organic haze in the Titan atmosphere is a result of abiotic atmospheric synthesis chemical processes.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Evolution of Protoplanetary Disks

    Drs. Aki Roberge and Carol Grady are pursuing studies related to Theme 2 of the NASA GSFC Astrobiology Node, “From Molecular Cores to Planets: Our Interstellar Heritage.” Over the last year, they have begun work on two Open Time Key Projects for the Herschel Space Observatory, an ESA mission launched in May 2009. Herschel is expected to spearhead the next big advances in our knowledge of planet formation, protoplanetary disk evolution, and debris disks. One project (GASPS) will illuminate the evolution of gas abundances and chemistry in protoplanetary disks over the planet-forming phase. The other (DUNES) will sensitively probe the Sun’s nearest neighbors for signs of cold debris disks associated with extrasolar Kuiper Belts. Both projects have begun to produce exciting results, including discovery of a possible new class of ultra-cold debris disks that challenge theories of debris disk evolution and planet formation.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1 3.2
  • Astrophysical Controls on the Elements of Life, Task 7: Update Catalog of Elemental Ratios in Nearby Stars

    We are creating the first 3D maps of the elements for stars within 1000 light-years of the Sun, building upon the Habitable Star Catalog produced by Maggie Turnbull and Jill Tarter in 2003. We currently have abundance levels of bioessential elements for about 800 of the 17,000 stars listed in the Habitable Star Catalog. This project employs 2 graduate students (resulting in 1 PhD and 1 masters degree) and 1 undergraduate student. When this project is completed, our publicly available 3D maps will enable discovery of directions, or regions, in space where stars have abundance patterns more favorable to producing habitable worlds.

  • Contribution of Planetesimals to the Composition of Gas-Giant Planets

    We have studied the interaction of planetesimals with the gaseous envelope of a giant planet at the late stage of planet formation while the envelope is contracting. We have shown that because of gas drag, material from planetesimals is deposited in the gas which enhances its metallicity over that of the Sun.

  • Task 2.2.1 Characterization of Aerosol Nucleation and Growth

    Laboratory experiments of aerosol formation in the Titan atmosphere provide input to model simulations of atmospheric processes that can lead to the formation of large organic compounds.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Formation of Terrestrial Planets

    This past year VPL has continued to explore key unknowns in our understanding of terrestrial planet formation. We have performed supercomputer simulations of the early formation of the Earth, and found that it can proceed more quickly than previously appreciated and suggests terrestrial exoplanets may be common. We also showed how the shape of belts of asteroids in the outer reaches of planetary systems, which can be directly observable, provide clues to the layout of the interior planets, which are often not observable.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1 4.3
  • Task Ultraviolet/infrared Spectroscopy of Ice Films

    These experiments explore to what extent long wavelength photons, the main solar radiation penetrating deep into the Titan atmosphere, can initiate chemical reactions in Titan atmospheric ices.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Modelling Planetary Albedo & Biomarkers in Rocky Planets’/moons Spectra

    The recent discovery of several potentially habitable Super-Earths (planets up to about 10x the mass of our own Earth that could be rocky) and the first nearby super-Earth planets around the habitable Zone of Gl581, has proven that we can already detect potentially habitable planets and makes this research extremely relevant. We model atmospheric spectral signatures, including biosignatures, of known and hypothetical exoplanets that are potentially habitable.
    The atmospheric characterization of such Super-Earths and potentially habitable Moons, will allow us to explore the condition on the first detectable rocky exoplanets and potentially characterize the first detectable Habitable Exoplanet.

    ROADMAP OBJECTIVES: 1.1 1.2 4.1 4.2 6.2 7.2
  • Fingerprinting Late Additions to the Earth and Moon via the Study of Highly Siderophile Elements in Lunar Impact Melt Rocks

    Two new lunar Apollo 17 poikilitic breccias have been examined for highly siderophile element (HSE) abundances and Os isotopic compositions. Both samples overlap chemically and isotopically with prior analyses of poikilitic breccias, indicating a consistent “fingerprint” for this Serenitatis lithology. New techniques have been developed to provide in situ analysis of breccia sub samples prior to HSE analysis. Pure lunar crust has very low concentrations of all HSE measured, including for the first time, Pd and Pt.

  • Planetary Surface and Interior Models and SuperEarths

    We use computer models to simulate the evolution of the interior and the surface of real and hypothetical planets around other stars. Our goal is to work out what sorts of initial characteristics are most likely to contribute to making a planet habitable in the long run. Observations in our own Solar System show us that water and other essential materials are continuously consumed via weathering (and other processes) and must be replenished from the planet’s interior via volcanic activity to maintain a biosphere. The surface models we are developing will be used to predict how gases and other materials will be trapped through weathering over time. Our interior models are designed to predict how much and what sort of materials will come to a planet’s surface through volcanic activity throughout its history.

    ROADMAP OBJECTIVES: 1.1 1.2 4.1 5.2 6.1
  • Task Aerosol Photoprocessing and Analysis

    A laboratory device is being constructed to simulate the condensation of aerosols in Titan’s atmosphere for exploring the possible effects of exposure of these aerosols to solar radiation.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Habitability of Water-Rich Environments, Task 2: Model the Dynamics of Icy Mantles

    Europa, one of Jupiter’s moons, is one of the few places in our solar system hypothesized
    to be habitable. Beneath a frozen, icy surface lies a liquid water ocean that could contain the chemical constituents required by life. Future missions to Europa will study its surface in detail in an effort to extrapolate the conditions below. So it is important to understand how mass can be transported from the deep ocean, through the ice, and to the surface of the moon. To understand this process, we are performing numerical fluid-dynamical calculations of 2-phase, thermochemical convection to investigate how chemistry from the deep ocean is transported to Europa’s surface. Furthermore, we are investigating how this material transport is expected to deform Europa’s surface, such that future missions will be able to infer deep, convective processes of the moon’s interior from surface observations.

  • Postdoctoral Fellow Report: Mark Claire

    I am interested in how biological gases affect the atmosphere of Earth (and possibly other planets.) Specifically, I use computer models to investigate how biogenic sulfur gases might build up in a planetary atmosphere, and if this would lead to observable traces in Earth’s rock record or in the atmospheres of planets around other stars. I’ve also worked on how perchlorate formed in Earth’s Atacama desert as an attempt to explain how perchlorate formed on Mars

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1 7.2
  • Task 3.1.1 Reactions of Organics With Ices and Mineral Grains

    Chemistry catalyzed by mineral grains on the Titan surface, for example a result of meteoritic infall, might lead to the formation of prebiotic compounds resulting from the insertion of oxygen into organic compounds of atmospheric origin.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Habitability of Water-Rich Environments, Task 3: Evaluate the Habitability of Europa’s Subsurface Ocean

    We completed several reviews that summarize current knowledge about the geological and chemical evolution of Europa’s icy shell and its putative ocean.

  • D/H Measurements in Samples From Mantle Hotspots

    The origin of Earth’s water is an open question. We are trying to constrain the origin of Earth’s water by measuring the D/H ratios of glass inclusions inside olivine grains from lavas erupted at the Hawaiian and Icelandic hot spots. The hope is that these glass inclusions retain hydrogen from the deep mantle of the Earth, hydrogen that may preserve the original hydrogen isotopic composition of the Earth.

  • Formation and Prospect of the Detection of Habitable Super-Earths Around Low-Mass Stars: Reconciling Theory With Observation

    We have studied the formation of terrestrial planets around M stars with a migrating giant planet. Results indicate that terrestrial planet formation is possible at somewhat large distances where the giant planet captures the terrestrial body in resonance, and the two objects migrate to close-in orbits.

  • NIR Spectroscopic Observations of Circumstellar Disks Around Young Stars

    Using the NIRSPEC instrument on the Keck telescope in collaboration with Dr. Michael Mumma of NASA GSFC and Dr. Geoffrey Blake of CalTech, we made the first discovery of OH ro-vibrational emission in the L band (3 – 4 μm) in the planet-forming (1-10 AU) region of disks around Herbig Ae stars (Mandell et al. 2008). OH is a sensitive tracer of the UV and IR radiation field and the dissociation and recombination of H2 and H2O, and combined with a strong upper limit for H2O emission these observations provide a sensitive constraint on the formation and destruction rate of water and the vertical height of the dust absorbing layer. Line strengths are characteristic of temperatures of ~600K, and the location is constrained to beyond ~1 AU by the spectral line widths, suggesting we are observing the warm molecular layer beyond the inner dust rim.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1 7.2
  • Task 3.1.2 Heterogeneous Chemistry

    There are a variety of heterogenous surface chemical processes possible in the Titan environment that can be simulated in laboratory experiments to determine how effective each may be in leading to the synthesis of prebiotic chemistry.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Stellar Effects on Planetary Habitability

    Habitable environments are most likely to exist in close proximity to a star, and hence a detailed and comprehensive understanding of the effect of the star on planetary habitability is crucial in the pursuit of an inhabited world. We looked at how the Sun’s brightness would have changed with time. We also model how stars with different masses, temperatures and flare activity affect the habitability of planets, including looking at the effect of a very big flare on a planet’s atmosphere and surface. We find that a planet with an atmosphere like Earth orbiting around a cool red star is fairly well protected from UV radiation, but particles associated with the flare can produce damaging chemistry in the planetary atmosphere that severely depletes the planet’s ozone layer.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1 4.3 5.3 6.1 7.2
  • Hydrogen in Nominally Anhydrous Minerals

    The amount of water in the Earth’s interior is not known. Experiments have shown that at high pressure, the high-pressure forms of the minerals that make up the Earth’s mantle can contain significant hydrogen substituting for magnesium. We are carrying out a series of experiments to determine how much hydrogen (=water) can be contained in these high-pressure minerals. Mineral samples produced at mantle pressures in the presence of water are being measured using the Cameca ims 1280 ion microprobe at the Unversity of Hawaii to determine the maximum amount of water that each mineral can hold at high pressure, providing a constraint on the possible water content of the mantle.

  • Task 3.3.1 Solubility of Organics in Methane

    The first step in understanding what chemistry might occur in the Titan lakes requires understanding the degree to which organics can actually dissolve in liquid hydrocarbons.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Habitability of Water Rich Environments – Task 6 – Waterworld Habitability

    We explored effects of initial compositions, 26Al content and major collisions on the composition and abundance of C-H-O-N volatiles during the formation of solid extrasolar planets.

  • Project 3E: In Situ Sulfur Isotope Studies in in Archean-Proterozoic Sulfides

    Sulfur is an essential element for life on Earth, and it participates in a diverse array of chemical reactions as it moves through the lithosphere, atmosphere, hydrosphere and biosphere. The sulfur isotopic composition of sulfide minerals integrates these processes and thus provides useful information about changing Earth systems. Sulfur isotope studies are vital components of current knowledge about the evolution of habitable environments on early Earth, the antiquity of microbial metabolisms, the evolution of photosynthesis, the oxygenation of the atmosphere, and the mass extinctions of the Phanerozoic, and they are likely to play just as critical a role in the discovery and detection of biosignatures in extraterrestrial materials. Recent developments have made it possible to measure sulfur isotope ratios in situ with analytical precision and accuracy approaching that of “conventional” bulk techniques which are more destructive, remove samples from their petrologic context, and mask variability on small spatial scales. Using the CAMECA ims-1280 at the WiscSIMS laboratory, we have explored the limiting factors for precision and accuracy of SIMS sulfur isotope measurements in various sulfide minerals, used the findings to develop techniques that optimize precision and accuracy, and applied these techniques in several contexts relevant to astrobiology. In the near future, these developments will support paired, in situ sulfur, carbon and iron isotope analyses on the same samples in an effort to understand the co-evolution of microbial communities and biogeochemical cycles in early Earth environments.

    ROADMAP OBJECTIVES: 1.1 4.1 4.2 7.1
  • Task 3.3.2 Solubility in Lakes

    The solubility of organics in hydrocarbon lakes is a key limiting factor to the extent of chemistry that can occur in Titan lakes.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Super-Earth Atmospheres

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

    ROADMAP OBJECTIVES: 1.1 2.1 3.1
  • Task 3.4 Tholin Chemical Analysis

    New techniques need to be developed to characterize the chemical composition of tholins at the molecular structural level.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Icy Blue Trans-Neptunian Objects

    Trans-Neptunian Objects (TNOs) contain some of the most pristine material in the solar system and therefore offer a unique opportunity to study chemical and physical properties of the early solar system. This project undertakes to search for rotational color variation on TNOS to look for chemical heterogeneity and infer the presence of exposed ice.

  • Task 3.5 Titan Genetics

    This project addresses the question of how complex molecules might be formed in liquid hydrocarbons, rather than liquid water.

    ROADMAP OBJECTIVES: 1.1 3.1 3.2 3.3
  • The Commonality of Life in the Universe

    This research considers under what conditions and where in the Universe Titan might be habitable.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Understanding Past Earth Environments

    We study the chemical and climate evolution of the Earth as the best available proxy for what other inhabited planets might be like. A particular focus is on the “Early Earth” (formation through to the 1.6 billion years ago) which is poorly represented in the geological record but comprises half of Earth’s history. We have studied the total pressure of the Archean atmosphere (prior to 2.5 billion years ago), developed constraints on CO2 concentration, studied the oxygen and nitrogen cycles, the fractionation of sulfur isotopes and explored the effect of hazes on early Earth climate.

    ROADMAP OBJECTIVES: 1.1 1.2 4.1 4.2 5.1 5.2 6.1
  • Lunar Water, Volatiles, and Differentiation

    Recent discoveries of water in the Moon have important implications for how and when water was delivered to Earth. One way of investigating this is to determine how much water the Moon had when it formed. We do this by searching for water in rocks rich in trace elements that behave somewhat like water does in magmas. It turns out that this problem cannot be separated from study of lunar differentiation, so we also try to figure out how the major types of lunar rocks formed.

  • Understanding the Early Mars Environment

    In 2009-2010, VPL’s investigations into Mars were carried out in two major themes: investigation of the how the climate and chemistry of early Mars might (or might not) allow liquid water at the surface, and follow up science to the surprising discovery of perchlorate by NASA’s 2008 Phoenix Lander. VPL determined that, contrary to previous thought, SO2 could not keep early Mars warm, due to the inevitable formation of sulfate aerosols which counteract any warming due to SO2. Investigations into the formation of perchlorate in Earth’s deserts provide clues towards potential formation of Martian perchlorate, and specific predictions were made to all for future rovers to discriminate between evaporated versus frozen perchlorate minerals.

  • Main Belt Comet Characterization

    We are undertaking a comprehensive characterization of known main belt comets, an
    important new class of volatile rich objects in the asteroid belt. These objects may retain
    water from the early era of the solar system, and as such represent a reservoir of water that we have not yet sampled, and thus they may play an important role in understanding how volatiles got distributed to habitable worlds.

  • Mars Bulk Composition and Aqueous Alteration

    The bulk composition of Mars, including its total inventory of water, is central to understanding how Mars and the other inner planets formed. Comparison between the abundances of water and volatile elements in Mars, Earth, and Moon are particularly important to understand the source of water to the Earth. Martian bulk composition is also crucial to elucidating the processes involved in the initial differentiation into core, mantle and crust, and to the subsequent geologic evolution of the crust. Unraveling and quantifying the details of aqueous alteration on Mars is central to assessing the planet’s habitability and much of its geologic evolution. It also bears on determining Martian bulk composition and the source of planetesimals that accreted to form Mars.

  • VPL Databases, Model Interfaces and the Community Tool

    The Virtual Planetary Laboratory develops modeling tools and provides a collaborative framework for scientists from many disciplines to coordinate research on the environments of extrasolar planets. As part of this framework, the VPL acts as a central repository for planetary models and the inputs required to generate those results. Developing a comprehensive storehouse of input data for computer simulations is key to successful collaboration and comparison of the models. As part of the on-going VPL Community Tools, we are developing a comprehensive database of molecular, stellar, pigment, and mineral spectra useful in developing extrasolar planet climate models and interpreting the results of NASAs current and future planet-finding missions. The result, called the Virtual Planetary Spectral Library, provides a common source of input data for modelers and a single source of comparison data for observers.

  • PanSTARRS MBC Stamp Server and Searching for Main Belt Comets

    We have been developing the architecture to search for activity in moving objects
    discovered with the new Pan-STARRS1 all sky survey, and in particular to look
    for volatile-driven activity in the new class of objects, called Main Belt Comets.
    The survey facility is now operational and we are starting to do the first big processing
    of the datasets.

  • Planetesimal Accretion in Binary Star Systems

    We have studied the collisional growth of planetesimals in a circumstellar disk in a binary star system. Our simulations shows in an eccentric disk, the precession of the gaseous component causes large planetesimals in the outer part of the disk to collide and accrete to larger objects.

  • Stoichiometry of Life, Task 4: Biogeochemical Impacts on Planetary Atmospheres

    Oxygenation of Earth’s early atmosphere must have involved an efficient mode of carbon burial. In the modern ocean, carbon export of primary production is dominated by fecal pellets and aggregates produced by the animal grazer community. But during most of Earth history the oceans were dominated by unicellular, bacteria-like organisms (prokaryotes) causing a substantially altered biogeochemistry. The NASA Ocean Biogechemical Model (NOBM) is applied using cyanobacteria (blue-green algae) as the only photosynthetic group in the oceans. The analyses showed that the early Earth ocean had 19% less primary production and 35% more nitrate due to slower growth by the cyanobacteria, and reduced nutrient uptake efficiency relative to modern phytoplankton Additionally there was 8% more total carbon in the oceans as a result of higher atmospheric pCO2. We plan to optimize this early Proterozoic ocean model in combination with a 1 D model to account for changes in aggregate formation and sinking speed in response to varying nutrients.

    ROADMAP OBJECTIVES: 1.1 4.1 4.2 5.2 6.1 7.2
  • Quantification of the Disciplinary Roots of Astrobiology

    While astrobiology is clearly an interdisciplinary science, this project seeks to address the question of how interdisciplinary it is. We are reviewing published works across a broad range of scholarly databases, comparing disciplinary indicators such as subject terms, journal titles and author affiliations, and creating a computational model to identify and compare the makeup of astrobiological research literature in terms of the proportion of work that come from constituent fields.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Reconciling Giant Planet Formation With the Origin and Impact History of the Parent Bodies of Differentiated Meteorites

    We have studied the interactions of protoplanets with planetsimals in the terrestrial region of the solar system during the formation of giant planets. We have shown that when Jupiter grows to 50 Earth-masses, it will affect the dynamics of planetesimals and their scattering to the inner asteroid belt.

  • Solar System Icy Body Thermal Modeling and Evolutionary Pathways

    Thermal evolution models have been developed and applied to various classes of small, icy
    solar system bodies in order to understand the longevity and composition of volatiles materials
    they contain, and to explore the evolution of these bodies. The models use a quasi-3D
    thermal evolution code, which is combined with astronomical observations, and dust-
    dynamical modeling. We have completed a parameter study of ice in the new class of objects
    called the main belt comets, and have found that unexpectedly, water ice can survive over
    the age of the solar system under certain conditions. This provides exciting prospects for
    potentially exploring a previously unexplored reservoir of early solar system volatiles. We are
    extending these models to comets which spend less time in the inner solar system and have
    found that for comet Kopff, there is a volatile other than water driving some of the activity. This
    modeling is being extended to Centaur objects which are evolving dynamically into the inner solar system from the Kuiper belt region.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1