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Project Reports

• Disks and Dips

  ROADMAP OBJECTIVES: 1.1 1.2

• Likelihood of a Supernova Impact on the Young Solar System

  ROADMAP OBJECTIVES: 1.1

• Planetary Biology, Evolution, and Intelligence

  Chris Chyba, Cynthia Phillips, Kevin Hand- The project has two components. The first, an overview of the astrobiological potential of various geological features on Europa, is proceeding well — we are continuing the study of various proposed formation mechanisms for different feature types such as ridges, bands, and chaotic terrain.

  ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 3.2 4.1 4.2 5.1 5.2 5.3 6.1 6.2 7.1

• The Impact of Atmospheric Particles on Life

  ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 4.3

• Project 1. From Molecular Clouds to Habitable Planetary Systems

  The work this year of Co-Investigator Chambers involved the development of a model for the oligarchic growth stage of planet formation, a key stage that determines many of the final characteristics of a planetary system

  ROADMAP OBJECTIVES: 1.1 1.2 2.1 3.1 7.2

• Climate, Habitability, and the Atmosphere on Early Mars

  ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1 7.1

• A 1-D Climate Model for Extrasolar Terrestrial Planets

  ROADMAP OBJECTIVES: 1.1 1.2 7.2

• Interaction Between the Atmosphere and Water on Mars

  ROADMAP OBJECTIVES: 1.1

• Module 3: Nature of Planetary Systems

  Direct detection for extrasolar planets is fast becoming a reality, and LAPLACE is well-poised to be the forefront of this new area of research. Using multiple techniques we are now in the process of carrying out surveys for young planets as well as developing new techniques which will push our sensitivity to older planets around more nearby stars.

  ROADMAP OBJECTIVES: 1.1 1.2

• Project 2. Extraterrestrial Materials: Origin and Evolution of Organic Matter and Water in the Solar System

  The abundant organic compounds in primitive meteorites and interplanetary dust particles (IDPs) are thought to originate largely in the interstellar medium. However, this material may have been modified in the protoplanetary disk and has been modified to varying extents in the asteroidal parent bodies.

  ROADMAP OBJECTIVES: 1.1 2.1 3.1

• Evolution of a Habitable Planet (Brantley)

  ROADMAP OBJECTIVES: 1.1

• RNA Activities Relevant to Ribocytes

  ROADMAP OBJECTIVES: 1.1 3.1 3.2 3.4 6.2

• The Generalized Terrestrial Planet Photochemical Model

  ROADMAP OBJECTIVES: 1.1 7.2

• Module 2: Formation and Evolution of Habitable Worlds

  This module uses observations of the gas and dust in (a) planet-forming accretion disks surrounding young stars and (b) debris disks surrounding more mature stars to understand key steps and timescales in the formation of planetary systems and their evolution, and to constrain outcome planetary system architectures

  ROADMAP OBJECTIVES: 1.1

• The Abiotic Planetary Model: The Upper and Lower Boundary Condition on the Atmosphere

  ROADMAP OBJECTIVES: 1.1 4.1 7.2

• Extrasolar Planetary Systems and the Potential for Terrestrial Planets

  ROADMAP OBJECTIVES: 1.1

• Dynamics of Comets, Asteroids, and Planets

  In collaboration with Mayer, Quinn is exploring the viability of the gravitational instability model for the formation of gas giant planets.

  ROADMAP OBJECTIVES: 1.1 4.3

• Origins and Signatures of Biogenic Hydrocarbons – Controls on the Transition From Abiogenic Geochemistry to Biotic Systems in the Deep Subsurface and Identification of Signature for Life

  Studies of deep subsurface, ecosystems hosted by ancient groundwater are directly relevant to the exploration for extant life in the subsurface of Mars. Laboratory investigations focus on determining the types of prebiotic compounds that form in the subsurface and assessing whether life itself could have been spawned beneath a planet’s surface. Field investigations focus on deep subsurface groundwater sampled at commercial mines in South African and Canadian Archaean rocks.

  ROADMAP OBJECTIVES: 1.1 2.1 3.1 4.1 4.2 6.1 7.1 7.2

• Prebiotic Organics From Space

  ROADMAP OBJECTIVES: 1.1 3.1 3.4 4.3 7.1 7.2

• Recognition of Theoretical Environments on Mars

  Our focus over the past year was a) to investigate the use of visible-near infrared spectroscopy of Rio Tinto to develop tools for recognizing habitable environments and b) investigating Mars data sets for habitable environment

  ROADMAP OBJECTIVES: 1.1 2.1

• The History of Evolution of Surface Water on Mars

  Our original premise was that the channels on Mars identified as formed by seepage would be excellent sites to explore for signs of life because of the combined effects of sustained water (to cause erosion) and the subsurface nature of the flow (away from harmful UV radiation).

  ROADMAP OBJECTIVES: 1.1 2.1

• Database of Molecular Spectroscopy to Support Extrasolar Planet Modeling

  The VPL database of molecular spectroscopic parameters contains a compilation of calculated and experimental linelists (including line positions, line intensities, lower state transition energies and broadening coefficients) combined with a collection of empirical absorption cross-sections for specific molecules of interest to planetary environmental and spectrum generating models. These data reside on the VPL’s supercomputer for use with the VPL atmospheric and spectral generation models.

  ROADMAP OBJECTIVES: 1.1 7.2

• Delivery of Organic Materials to Planets

  ROADMAP OBJECTIVES: 1.1 3.1

• Habitable Planets

  ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1 4.3

• Relationship Between Hydrogeology and Microbiology at Active Springs

  We are currently investigating a sulfur spring system in a zone of high deformation in the central coast range of California. This system presents opportunities to study multiple, sustained groundwater discharge sites with environmental gradients affecting extant microbial communities.

  ROADMAP OBJECTIVES: 1.1 2.1 4.2 5.2 7.1

• Planet Formation in OB Associations

  ROADMAP OBJECTIVES: 1.1

• Early Oceans on Mars

  The idea that standing bodies of water might once have existed on Mars’ surface is supported by several lines of evidence, including geologic and topographic features near the margins of the northern lowlands that have been interpreted as shorelines formed by ancient oceans

  ROADMAP OBJECTIVES: 1.1 4.1 7.1 7.2

• Model Synthesis and Architecture

  The VPL integrated model to develop self-consistent planetary environments has acquired several separate components into its model suite over the past year, including weathering, land model, and tectonic/solid earth components. These are now housed in a version controlled online database of all VPL software components, including the coupled online model as well as other model components under development.

  ROADMAP OBJECTIVES: 1.1 1.2 4.1 4.3 7.2

• Re-Tracing Steps Towards a Habitable World: The Biogeochemical Evolution of Sulfur on the Early Earth.

  ROADMAP OBJECTIVES: 1.1 4.1 4.2 5.3 7.1

• Numerical Simulations of Planetary Dynamics

  Dr. Lufkin, in collaboration with Drs. Richardson and Mundy, has investigated the effect of giant planet migration on disks of planetesimals, to estimate the feasibility of finding terrestrial planets exterior to known Hot Jupiter systems. Theories of planet formation suggest that giant planets should be forming and migrating at the same time as terrestrial planets are forming in and around the habitable zone. The giant planet can strongly affect the orbits of planetesimals that might otherwise be forming Earth-like planets (Figure 1).

  ROADMAP OBJECTIVES: 1.1

• Extraterrestrial Organics

  ROADMAP OBJECTIVES: 1.1 2.2 3.1 4.1 4.3

• Evolution of the Interior and Its Consequences for Water on Mars

  This large-scale volcanism early in martian history is estimated to have released enough water to produce a 120-m-thick global layer and enough CO₂ to produce a 1.5 bar atmosphere (Phillips et al., 2001). The release of volatiles would have had a major effect on climate and habitability. (Objective 1.1 in the Roadmap)

  ROADMAP OBJECTIVES: 1.1

• Isotopic Fingerprints of Past Life and Surface Conditions on Mars

  We have advanced the research on five fronts. (1) Our work in collaboration with the Dietrich group reached fruition as high-quality He-3 exposure ages were determined for the Box Canyon basalts of south central Idaho.

  ROADMAP OBJECTIVES: 1.1 2.1 7.1

• Keck Cosmochemistry Laboratory

  The W. M. Keck Cosmochemistry laboratory will soon begin analysis of extraterrestrial samples, including sample of interest to astrobiology. At its heart is a Cameca ims 1280 ion microprobe. This state-of-the-art instrument uses a focused ion beam to sputter and ionize atoms from sample surfaces. The sputtered ions are then extracted into a mass spectrometer and measured. The 1280 can measure isotopic compositions of most elements, with better precision and accuracy than previous ion probes.

  ROADMAP OBJECTIVES: 1.1 2.1 3.1 3.2

• Modeling Terrestrial Planet Formation and Composition

  We have run the most realistic simulations of the final stages in the formation of Earth-like planets to date (Raymond), including 10 times as many particles as previous simulations.

  ROADMAP OBJECTIVES: 1.1 1.2 3.1

• Evolution of Atmospheric O2, Climate, and Biosphere (Ohmoto)

  ROADMAP OBJECTIVES: 1.1 2.1 4.1 4.3 5.1 5.2 6.1 7.1

• Evaluation of Habitable Environments on Mars

  ROADMAP OBJECTIVES: 1.1 2.1

• Planetary Habitability and Life Detection (Sigurdsson)

  ROADMAP OBJECTIVES: 1.1 1.2

• Causes of Mass Extinctions: Testing Impact Models

  ROADMAP OBJECTIVES: 1.1 4.3

• Isotopic Studies of the Precambrian Earth and Element Cycling Processes (Pitt)

  ROADMAP OBJECTIVES: 1.1 4.1 6.1

• Origin and Evolution of Organics in Planetary Systems

  This progress report summarizes astrobiology research done at Washington University in St. Louis under the direction of Professor Bruce Fegley, Jr. This research is part of the NASA Goddard Astrobiology Node.

  ROADMAP OBJECTIVES: 1.1 3.1

• Evolution of a Habitable Planet (Kump)

  ROADMAP OBJECTIVES: 1.1 4.1 4.2 4.3 5.2 6.1

• Characterization of Terrestrial Planets From Disk-Averaged Spectra: Earths Around Other Stars

  The results of our coupled climate-chemical modeling of Earth-like planet atmospheres around M stars was published (Segura et al., 2005).

  ROADMAP OBJECTIVES: 1.1 4.3 7.2

• Chemical Models of Nebular Processes

  ROADMAP OBJECTIVES: 1.1

• Summary of Activities in the Astrobiology Analytical Laboratory

  Dworkin has been active in the lab section of the GCA Astrobiology Team by operating the Astrobiology Analytical Laboratory and collaborating with numerous other laboratories. This involves the creation and maintenance of a world-class organic analytical laboratory. In the last year he developed the methodology for the detection of chiral amino acids at the femtomole level in a variety of laboratory and natural samples.

  ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 7.1

• Understanding the Earth’s Early Environment

  ROADMAP OBJECTIVES: 1.1 4.1 7.2

• Origin and Evolution of Organics in Planetary Systems

  As part of the overall Astrobiology Node at the NASA Goddard Space Flight Center, whose goal is an understanding of the Origin and Evolution of Organics in Planetary Systems (Mike Mumma, P.I.), Co-Investigator Blake is directing both laboratory and astronomical spectroscopy programs.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• Habitability and Water Delivery in Binary-Planetary Systems

  In the last year, a systematic study was completed of the formation and stability of planets, both giant and terrestrial, in multiple planets systems, as well as binary star systems. The motivation behind this study comes from the fact that among more than 180 extrasolar planets discovered to-date, 18 are in multiple planets systems, and approximately 20% are within binary star systems. Among these binary-planetary systems, γ Cephei has been the focus of my research.

  ROADMAP OBJECTIVES: 1.1

• Early Accretion of Asteroids and Protoplanets

  ROADMAP OBJECTIVES: 1.1

• Formation of Planetesimals in a Dynamically Evolving Nebula

  ROADMAP OBJECTIVES: 1.1

• Variable Young Stellar Objects Survey

  ROADMAP OBJECTIVES: 1.1

• TES and THEMIS Study of Proposed Paleolake Basins Within the Aeolis Quadrangle of Mars

  ROADMAP OBJECTIVES: 1.1 2.1

• Terrestrial Analog Study: Sierra Madera Impact Structure, Texas

  Sierra Madera impact crater is 12 km in diameter (Fig. 1) and is a well-exposed remnant of a complex impact crater, which contains impact-generated breccias (disrupted rock with sharp-angled fragments cemented in a fine matrix) and shatter cones (a cone-shaped fracture pattern found in rocks that have been exposed to a sudden release of energy, such as an impact) (Wilshire et al., 1972; Huson, 2006).

  ROADMAP OBJECTIVES: 1.1 4.3

• TES/THEMIS Study of Valles Marineris, Mars

  Weitz et al. (2003) identified dunes, landslide materials and a blocky deposit in the floor (Fig. 1) of the Melas Chasma within Valles Marineris, as well as a large number of valleys along the southern wallrock of the chasma.

  ROADMAP OBJECTIVES: 1.1 2.1

• D/H Studies – Origin of Earth’s Water

  We have begun a project to look at the evidence that the Earth’s water was partially brought in by cometary sources.

  ROADMAP OBJECTIVES: 1.1