2011 Annual Science Report

Astrobiology Roadmap Objective 2.2 Reports Reporting  |  SEP 2010 – AUG 2011

Project Reports

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

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

    ROADMAP OBJECTIVES: 1.1 1.2 2.2 3.1
  • Astronomical Observations of Planetary Atmospheres and Exoplanets

    This task encompasses remote-sensing observations of Solar System and extrasolar planets made by the VPL team. These observations, while providing scientific exploration in its own right, also allow us to test our planetary models and help advance techniques to retrieve information from the astronomical data that we obtain. This can include improving our understanding of the accuracy of inputs into our models, such as spectral databases. This year we made and/or analyzed observations of Mars, Venus and Earth taken by ground-based and spaceborne observatories, to better understand how well we can determine planetary properties like surface temperature and atmospheric composition, when a terrestrial planet is observed only as a distant point of light.

    ROADMAP OBJECTIVES: 1.2 2.2 7.2
  • Detectability of Life

    Detectability of Life investigates the detectability of chemical and biological signatures on the surface of icy worlds, with a focus on spectroscopic techniques, and on spectral bands that are not in some way connected to photosynthesis.Detectability of life investigation has three major objectives: Detection of Life in the Laboratory, Detection of Life in the Field, and Detection of Life from Orbit.

    ROADMAP OBJECTIVES: 1.2 2.1 2.2 4.1 5.3 6.1 6.2 7.1 7.2
  • AIRFrame Technical Infrastructure and Visualization Software Evaluation

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

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Cosmic Distribution of Chemical Complexity

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

    ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 3.2 3.4 4.3 7.1 7.2
  • Task 1.1.1 Models of the Internal Dynamics: Formation of Liquids in the Subsurface and Relationships With Cryovolcanism

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • Advancing Techniques for in Situ Analysis of Complex Organics

    Our research in laser mass spectrometry is part of the overall program of the Goddard Center for Astrobiology to investigate the origin and evolution of organics in planetary systems. Laser mass spectrometry is a technique that is used to determine the chemical composition of sample materials such as rocks, dust, ice, meteorites in the lab. It also may be miniaturized so it could fit on a robotic spacecraft to an asteroid, a comet, or even Mars. On such a mission it could be used to discover any organic compounds preserved there, which in turn would give us insight into how Earth got its starting inventory of organic compounds that were necessary for life. The technique uses a high-intensity laser to “zap” atoms and molecules directly off the surface of the sample. The mass spectrometer instantly captures these particles and provides data that allow us to determine their molecular weights, and therefore their chemical composition. Our recent work has been to understand the different kinds of spectra one obtains when analyzing complex samples that are analogs of Mars and other planetary bodies, such as desert-varnished basalts and extracts of the Murchison meteorite. We also have been improving the instrument to better detect certain kinds of organic compounds in such complex rocks, such as to selectively ionize certain hydrocarbons and simplify data analysis, and to maintain high vacuum integrity while changing out samples. Finally, our work on improving operational protocols for laser analysis of samples had helped the design of the mass spectrometer on the 2018 ExoMars rover mission, which includes a pulsed laser mode.

    ROADMAP OBJECTIVES: 2.1 2.2 7.1
  • Project 2: Origin and Evolution of Organic Matter in the Solar System

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

    ROADMAP OBJECTIVES: 2.2 3.1 7.1
  • Task 1.1.2 Models of the Reaction Between Hydrocarbons and Water Ice

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3
  • 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
  • Path to Flight

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

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 7.1 7.2
  • Task 1.2 Interaction of Methane/ethane With Water Ice

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Biosignatures in Extraterrestrial Settings

    The focus of this project is to explore indicators of life outside of Earth, both within the Solar System and on extrasolar planets. The work includes studies of the chemistry and composition of the Solar System, and the past history of conceivable sites for life in the Solar System. We also look for habitable planets outside the Solar System; work on developing new techniques to find and observe potentially habitable planets; and model the dynamics, evolution and current status of a variety of extrasolar planets.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 4.1 4.3 6.2 7.1 7.2
  • Task 2.1.1 Master Atmospheric Chemistry Simulation

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Survivability of Icy Worlds

    Investigation 2 focuses on survivability. As part of our Survivability investigation, we examine the similarities and differences between the abiotic chemistry of planetary ices irradiated with ultraviolet photons (UV), electrons, and ions, and the chemistry of biomolecules exposed to similar conditions. Can the chemical products resulting from these two scenarios be distinguished? Can viable microbes persist after exposure to such conditions? These are motivating questions for our investigation.

    ROADMAP OBJECTIVES: 2.2 3.2 5.1 5.3 7.1 7.2
  • Composition of Parent Volatiles in Comets

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

    ROADMAP OBJECTIVES: 2.2 3.1 4.1
  • Task Atmospheric State and Dynamics

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Comet Activity and Composition

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

  • Cosmochemical Search for the Origin of Water in Planetary Bodies

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

    ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 3.2
  • Task Atmospheric Observations

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Task 2.2.1 Characterization of Aerosol Nucleation and Growth

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Habitability of Water-Rich Environments, Task 1: Improve and Test Codes to Model Water-Rock Interactions

    The goal of this task is to develop computer codes to model the chemistry and mineralogy of water-rock interactions on present and early Earth, and on extraterrestrial bodies with liquid water (ancient Mars, icy moons, early asteroids, and extrasolar planets). This year we developed and tested codes to model temporal changes in aqueous chemistry and mineralogy during vertical percolation of fluids through layered rocky materials. In particular, we were able to model neutralization of acidic fluids along with percolation together with changes in mineralogy of altered basalts. The model results closely match many observations.

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

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

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

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Exploring the Atmosphere of Mars at Infrared Wavelengths and the Organic Volatile Composition of Comet 2P/Encke

    Yana L. Radeva is a Research Associate at The Catholic University of America, conducting her postdoctoral research at NASA’s Goddard Space Flight Center. During the time period September 1, 2010 – August 30, 2011, she analyzed high-resolution infrared spectra of the Martian atmosphere, searching for biomarker gases (such as methane), and studying the spatial distribution, diurnal and seasonal evolution of trace species. Dr. Radeva analyzed data-sets acquired with the NIRSPEC instrument on the Keck II telescope during the 2009-2010 observing campaign, covering a range of Ls = 8 – 83° (early through late spring in the Martian Northern hemisphere). Dr. Radeva also analyzed data acquired with the ultra-high resolution infrared spectrometer CRIRES at ESO’s VLT, and retrieved abundances and rotational temperatures from the spectral lines of O2 (a1Δg), used as a tracer for ozone. She presented spatial maps of ozone on Mars, and a comparison with models of the ozone distribution, at the annual American Geophysical Union meeting (December 2010). Dr. Radeva published a paper on results of her dissertation work, entitled “A Newly Developed Fluorescence Model for C2H6 ν5 and Application to Cometary Spectra Acquired with NIRSPEC at Keck II” (ApJ, 729, 2, 135). She also presented results of her analysis of the organic composition of comet 2P/Encke at the annual AAS Division for Planetary Sciences conference (October 2010).

    ROADMAP OBJECTIVES: 2.1 2.2 7.1
  • Habitability of Water-Rich Environments, Task 2: Model the Dynamics of Icy Mantles

    Jupiter’s moon Europa provides a combination of physical and chemical conditions that may be among the most suitable in the solar system for sustaining life. Europa almost certainly has a liquid ocean. This ocean may have the ingredients necessary for life, but it is shielded from observation by a thick overlying ice layer. Under certain conditions this ice layer may undergo convection that can transport chemical species from the ocean to the surface, where they may be detected. Our computer modeling of convection in this ice layer aims to quantify how much ocean material may be brought to the surface. This work provides guidance for future missions to Europa.

  • Task 3.1.2 Chemistry Active in Titan Dunes

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

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

    Europa is of keen interest to astrobiologists and planetary geologists because of indications that it may possess a sub-surface ocean. In this task we seek to understand the global distribution and timing of Europan geologic units, to identify regions of recent activity. We also seek to map chemical signatures on its surface. Simultaneously we are numerically modeling the convection in the icy shell overlying the subsurface ocean, with a particular aim of determining whether chemical species from the ocean can be brought to the surface. Through this combined approach we seek to understand Europa’s ocean’s pH and composition, and evaluate the habitability of this icy moon.

  • Ice Chemistry of the Solar System

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3 6.2 7.1
  • Task 3.3.1 Solubility of Gases and Organics in Liquid Methane and Ethane

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • The Subglacial Biosphere – Insights Into Life-Sustaining Strategies in an Extraterrestrial Analog Environment

    Sub-ice environments are prevalant on Earth today and are likely to have been more prevalent the Earth’s past during episodes of significant glacial advances (e.g., snow-ball Earth). Numerous metabolic strategies have been hypothesized to sustain life in sub-ice environments. Common among these hypotheses is that they are all independent of photosynthesis, and instead rely on chemical energy. Recently, we demonstrated the presence of an active assemblage of methanogens in the subglacial environment of an Alpine glacier (Boyd et al., 2010). The distribution of methanogens is narrowly constrained, due in part to the energetics of the reactions which support this functional class of organism (namely carbon dioxide reduction with hydrogen and acetate fermentation). Methanogens utilize a number of metalloenzymes that have active site clusters comprised of a unique array of metals. During the course of this study, we identified other features that were suggestive of other active and potentially relevant metabolic strategies in the subglacial environment, such as nitrogen cycling. The goals of this project are 1) identifying a suite of biomarkers indicative of biological CH4 production 2). quantifying the flux of CH4 from sub-ice systems and 3). developing an understanding how life thrives at the thermodynamic limits of life. This project represents a unique extension of the ABRC and bridges the research goals of several nodes, namely the JPL-Icy Worlds team and the ASU-Follow the Elements team.

    ROADMAP OBJECTIVES: 2.1 2.2 5.1 5.2 5.3 6.1 6.2 7.1 7.2
  • Task 3.3.2 Precipitation of Organics in Titan Lakes

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Habitability of Water-Rich Environments, Task 5: Evaluate the Habitability of Small Icy Satellites and Minor Planets

    We are investigating whether liquid can exist beneath the surface ice of small icy satellites and Kuiper belt objects (KBOs). We are also trying to predict whether this liquid can be brought to the surface in a “cryovolcanic” flow, or if there are other observational signatures of subsurface liquid. Numerical modeling has been performed to understand physical and chemical processes, fluid chemistry and mineralogy of low- and high-temperature aqueous processes on icy bodies in the outer solar system.

  • Task 3.3.3 Solubility in Lakes

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Main Belt Comets

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Task 3.4.1 Tholin Chemical Analysis Using Nuclear Magnetic Resonance

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Task 3.4.2 Tholin Analysis Based on Selective Detection of Functional Groups

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

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

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

    ROADMAP OBJECTIVES: 2.2 3.1 3.2 7.1
  • Remote Sensing of Organic Volatiles in Planetary and Cometary Atmospheres

    We developed state-of-the-art spectroscopic methods to analyze our extensive infrared database of Mars and cometary spectra. In the last two years, we acquired the deepest and most comprehensive search for biomarkers on Mars using powerful infrared high-resolution spectrometers (CRIRES, NIRSPEC, CSHELL) at high-altitude observatories (VLT, Keck-II, NASA-IRTF respectively). In order to analyze this unprecedented wealth of data, we developed highly automated and advanced processing techniques that correct for bad-pixels/cosmic-rays and perform spatial and spectral straightening of anarmophic optics data with milli-pixel precision. We also constructed line-by-line models of the ν7 band of ethane (C2H6), the ν3 and ν2 bands of methanol (CH3OH), we compiled spectral information for H2O and HDO using 5 databases (BT2, VTT, HITEMP, HITRAN and GEISA), and compiled spectral information NH3 using 4 databases (BYT2, TROVE, HITRAN and GEISA). These great advancements have allowed us to understand the infrared spectrum of planetary bodies with unprecedented precision.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 4.1 7.1 7.2
  • Task 3.5.2 Energetics of Titan Life

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Small Body Missions

    The team has been active in coordinating and executing Earth-based observations in support of two extended Discovery missions to comets: EPOXI and StardustNExT. These missions re-used the spacecraft from two previously successful missions to fly past new targets. The Earth-based observations were used for mission planning and development, and to give us a time baseline of observations with instruments and at wavelengths not possible during a fast flyby with limited instrumentation. The ground-based and Earth-orbital data plays a critical role in the interpretation and understanding of the in-situ data obtained by the spacecraft. The EPOXI flyby of comet 103P/Hartley 2 on 4 November 2010 revealed a small, highly active comet with CO2-driven jets and a swarm of icy chunks surrounding the nucleus, and the StardustNExT flyby of comet 9P/Tempel 1 on 14 February 2011 allowed us to visit a comet nucleus for the second time to look for changes on the surface after it had made one orbit around the sun.

  • Research Activities in Planetary Environments Lab

    A new instrument called VAPoR (Volatile Analysis by Pyrolysis of Regolith) was developed to demonstrate an end-to-end pyrolysis time of flight mass spectrometer system with sufficient mass resolution, mass range, sensitivity, precision, and dynamic range to be applied to astrobiology missions. The mass spectrometer derived from this development can be used as an in situ detector of water, noble gases, oxygen, and other potential biomarkers such as organic molecules that are signatures of extinct or extant life and isotopic composition of elements such as C, H, and S that are fractionated by biological processes. A small lightweight mass spectrometer such as VAPoR will conserve precious mass, power, and volume resources in future missions to polar regions of the Moon, asteroids, comets, Mars, Europa, Enceladus, or Titan. The VAPoR instrument was tested most recently during the 2011vDesert Research and Technology Studies (DRATS) field campaign where detailed in situ bulk chemical characterization of volatiles released from regolith samples was carried out.

    ROADMAP OBJECTIVES: 2.1 2.2 7.1
  • Solar System Icy Body Thermal Modeling and Evolutionary Pathways

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

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

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

    ROADMAP OBJECTIVES: 1.1 2.2 3.1 4.3
  • X-Ray Emission From an Erupting Young Star and Diffuse Nebula in the Carina Star Forming Region

    High-energy photons in the young stellar environment are known to be important in stimulating chemical reactions of molecules and producing pre-biotic materials. In this reporting period, we approached this problem from two directions: X-ray emission mechanism of a young star that experienced an episodic outburst and spectral characteristics of the diffuse X-ray emission from the Carina massive star-forming region. Notable results are that X-ray variation of V1647 Ori during its mass accretion outbursts in 2003-2005 and from 2008 clearly followed the optical/IR variations that trace the mass accretion activity. However, we also found a possible discrepancy between these bands in the latest data in 2010, and therefore plan to keep monitoring the star in X-rays.

  • Surfaces of Trojan Asteroids

    With a total mass similar to the main asteroid belt, the Trojan asteroids are a major feature in the solar system. Thermal infrared (TIR) emission spectra of Trojan asteroids obtained with the Spitzer space telescope exhibit a 10-µm emissivity plateau that closely resembles the emission feature of active comets. This result is very puzzling because the light scattering properties of a regolith aster-oid surface is significantly different from a diffuse dust cloud of comet. It has been suggested that the Trojan surfaces may consist of fine-grained silicates suspended in a transparent matrix.