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Project Reports

• 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 study of various proposed formation mechanisms for different features types such as ridges, bands, and chaotic terrain. The second, a search for current geological activity by comparing Galileo images taken on different orbits, is also in progress. We have performed a first-stage search of the Galileo Europa images to find overlapping images, and are currently working on an automated search method to make sure that we find all possible comparison images. We are also working on automated processing techniques.

  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 7.2

• Subsurface Biospheres

  Members of our team at UNC Chapel Hill focus on molecular studies of deep subsurface communities

  ROADMAP OBJECTIVES: 2.1 2.2 4.1 4.3 5.2 5.3 6.1 7.1 7.2

• Genome Evolution and Innovation

  ROADMAP OBJECTIVES: 3.2 3.3 3.4 4.1 4.2 5.1 5.2 5.3 6.1 6.2 7.2

• Biosignatures in Chemosynthetic and Photosynthetic Systems

  ROADMAP OBJECTIVES: 2.1 4.1 5.1 5.2 6.1 7.1 7.2

• Iron Oxidation – Shaping the Past and Present Environments

  The biology of Iron Oxidation

  ROADMAP OBJECTIVES: 4.1 5.1 5.3 6.1

• The History of Evolution of the Martian Surface and Water on Mars

  ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1

• Molecular Survey of Microbial Diversity in Hypersaline Ecosystems

  ROADMAP OBJECTIVES: 3.2 3.4 4.1 4.2 5.1 5.2 5.3 6.1 6.2 7.2

• Project 3. Prebiotic Chemical and Isotopic Evolution on Earth

  The first focus of this project has been on the Archean sulfur cycle and understanding the significance of mass-independent sulfur isotope signals.

  ROADMAP OBJECTIVES: 3.1 4.1 7.1

• Genomic Record of the Earth’s Early Biosphere

  ROADMAP OBJECTIVES: 4.1 4.2

• Microbial Communities and Activities in the Deep Marine Subsurface

  ROADMAP OBJECTIVES: 4.1 5.1 5.3 6.1 6.2

• Project 4. Prebiotic Molecular Selection and Organization

  Studies in molecular self-organization focused on two types of amphiphilic molecules, which are molecules that possess both hydrophobic and hydrophilic regions. These molecules tend to self-organize spontaneously in an aqueous environment.

  ROADMAP OBJECTIVES: 3.1 3.2 3.4 4.1 7.1

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

  ROADMAP OBJECTIVES: 1.1 3.1 4.1 4.2 5.2 5.3 6.1 7.1

• Experimental and Theoretical Analysis of Mass-Independent Sulfur Isotope Effects-Part of the Geobiology and Geochemistry of Early Earth Project

  ROADMAP OBJECTIVES: 4.1

• Mass Extinction Events, the Longest Snowball Earth Event, the Evolution of Oxygenic Photosynthesis, and TPW Induced Perturbations of the Carbon Cycle.

  ROADMAP OBJECTIVES: 3.1 3.3 4.1 4.3 6.1

• Modeling Early Atmospheric Composition and Climate

  ROADMAP OBJECTIVES: 1.1 4.1

• Origins and Signatures of Biogenic and Abiogenic Hydrocarbons.

  Completed experimental results showed δ²H of H₂ can only be used as an indicator of in-situ water radiolysis for groundwater with relatively young ages and low temperatures.

  ROADMAP OBJECTIVES: 2.1 4.1 4.2 7.1 7.2

• Radiolysis as a Source of Chemical Energy for Microbial Metabolism in the Deep Subsurface

  Radiolysis of water can accelerate water/rock interaction through production of radicals (e.g., hydrogen, hydroperoxyl, hydroxyl), ions (e.g., superoxide, protons, hydroxide), and reactive molecules (e.g., hydrogen, hydrogen peroxide, oxygen)

  ROADMAP OBJECTIVES: 3.3 4.1 4.2 5.1 5.2 5.3 6.1 7.2

• Evolution of a Habitable Planet (Capo)

  ROADMAP OBJECTIVES: 1.1 4.1 6.1

• Habitable Planets

  ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1 4.3

• Project 6. Molecular and Isotopic Biosignatures

  Steele and Postdoctoral Fellow Marc Fries used the new WiTec Raman imaging system to begin the examination of in situ carbon formation in a variety of samples, including Precambrian rocks and samples from a Mars analog site in Svalbard

  ROADMAP OBJECTIVES: 3.1 4.1 4.2 6.1 6.2 7.1 7.2

• Evolution of a Habitable Planet (Stewart)

  ROADMAP OBJECTIVES: 1.1 4.1 6.1

• Darwinian Chemistry

  ROADMAP OBJECTIVES: 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.2 5.3 6.1 6.2 7.1

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

  ROADMAP OBJECTIVES: 1.1 1.2 3.1 4.1 7.2

• Ecosystem to Biosphere Modeling

  ROADMAP OBJECTIVES: 4.1 5.3 6.1 7.2

• The Evolution and Diversity of Ancient CO2-fixation Pathways in Anaerobic and Extremophilic Microorganisms: Clues to the Early Evolution of Life on Earth

  ROADMAP OBJECTIVES: 4.1 5.1 5.3

• Microbial Mat Communities

  Our primary research objective is to better understand the origins and adaptive radiation of an ancient and biogeochemically significant assemblage of microorganisms, the sulfate-reducing prokaryotes (SRP).

  ROADMAP OBJECTIVES: 4.1 4.2 5.1 5.2 5.3 6.1

• Isotope Effects in Atmospheric Sulfur Chemistry (Castleman)

  ROADMAP OBJECTIVES: 3.1 4.1

• Geochemical Processes and Biosignatures (House)

  ROADMAP OBJECTIVES: 4.1 5.1 5.2 5.3 6.1

• Evolution of Atmospheric O2, Climate, and Biosphere – Ohmoto

  Evolution of the Atmosphere, Oceans, and Biosphere on Early Earth:
  Geological, Geochemical, and Biological Approaches

  ROADMAP OBJECTIVES: 4.1 6.1

• The Impact of Atmospheric Particles on Life

  ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 4.1 4.3 7.1

• Lee Kump

  This year we published a paper in Geology which proposed that episodic release of hydrogen sulfide (H₂S ) from the ocean caused the end-Permian mass extinction. Moreover, we suggested that the underlying environmental driver, euxinic deep waters (enriched in H₂S), may have been the norm during a billion years of Earth history (from 1.8 Ga to 0.8 Ga), and that H₂S eruptions may have delayed colonization of the land surface

  ROADMAP OBJECTIVES: 1.1 4.1 4.3 5.2 6.1

• The Virtual Planetary Laboratory – The Life Modules

  Coupled model of the anaerobic, early Archean biosphere, prior to the origin of oxygenic photosynthesis (Kharecha, Kasting, and Siefert). This model includes organisms that metabolize using H₂, H₂S, and Fe⁺⁺ as reductants. A primary goal was to estimate the production rate of methane.

  ROADMAP OBJECTIVES: 3.2 3.3 4.1 4.2 5.3 6.1 6.2 7.1 7.2

• Causes of Mass Extinctions: Testing Impact Models_Kring

  ROADMAP OBJECTIVES: 1.1 4.1 4.3

• Evolution of a Habitable Planet (Arthur)

  ROADMAP OBJECTIVES: 4.1 5.3 6.1

• Earth’s Early Environment and Life

  ROADMAP OBJECTIVES: 4.1 4.3

• The Organic Volatile Composition of Comets: A Window on the Early Solar System

  Our long-range objective is to establish a taxonomy for comets based on chemistry, rather than orbital dynamics. The formation temperature of a given comet can be constrained by measures of the ortho-para ratios in H₂O and by the isotopic enhancements (e.g., in deuterium) in selected volatile species.

  ROADMAP OBJECTIVES: 1.1 2.1 3.1 4.1 4.3