2006 Annual Science Report
Astrobiology Roadmap Objective 4.1 Reports Reporting | JUL 2005 – JUN 2006
Roadmap Objective 4.1—Earth's early biosphere
Project Reports
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Iron and Sulfur-Based Biospheres and Their Biosignatures
A core focus for the research within the BioMars project has centered on the topic of microbial communities sustained by iron and sulfur cycling, as these elements are abundant at the Mars surface and exist in multiple redox states, as would be required if they play a metabolic role. Our team has investigated a number of potential Earth analog systems, with a view to understanding their geochemistry, microbiology, and potential biosignatures.
ROADMAP OBJECTIVES: 4.1 7.1 7.2 -
Project 6. Molecular and Isotopic Biosignatures
Co-Investigator 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: 2.1 3.1 4.1 4.2 5.3 6.1 6.2 7.1 7.2 -
Bacterial Tubulin and the Evolution of the Eukaryotic Cell; Sea Ice Bacteria
ROADMAP OBJECTIVES: 4.1 4.2 5.3 -
Understanding Mars Subsurface Methane Hydrates and Brines and Potentials for Microbial Habitats
The sub-permafrost zone of Mars is acknowledged as having the greatest potential for habitability because water is readily available. CH4 leakage from the sub-permafrost zone would occur wherever the permafrost zone has been breached by recent fracturing due to impacts or by geothermal heating.
ROADMAP OBJECTIVES: 4.1 4.3 5.3 6.1 6.2 -
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 -
Design and Assembly of a Cavity-Ring Down Spectrometer for Determination of Concentration and Isotopic Composition of Methane in Gases
ROADMAP OBJECTIVES: 2.1 3.2 3.3 4.1 5.2 5.3 6.2 7.1 7.2 -
Building a Habitable Planet: The Geological Record
Research continued in the following 6 areas: late Archean — early Paleoproterozoic hydrocarbon biomarker molecules, Archean sulfur isotopes and sulfur cycling, metamorphism of early Archean biosignatures, nutrient availability (N, P) in Precambrian oceans, paleobarometry of the Archean atmosphere and diamond drilling of astrobiologically significant Archean and early Proterozoic sedimentary horizons in the Pilbara Craton of Australia. Field-work was conducted on early Archean supracrustal rocks of the Fortescue, Warrawoona and Coonterunah Groups in the Pilbara Craton, Australia and the Isua Supracrustal Belt, Greenland.
ROADMAP OBJECTIVES: 4.1 4.2 7.1 -
Climate, Habitability, and the Atmosphere on Early Mars
ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1 7.1 -
Iron Oxidation – Shaping the Past and Present Environments
ROADMAP OBJECTIVES: 4.1 5.1 6.1 7.2 -
Biosignatures in Chemosynthetic and Photosynthetic Systems
During the past year, our team has made strong contributions in research, mission involvement, synergistic community activities, and education & public outreach.
ROADMAP OBJECTIVES: 2.1 4.1 5.1 5.2 6.1 7.1 7.2 -
Metamorphism, Organic Synthesis and the Emergence of Life on Earth
ROADMAP OBJECTIVES: 3.1 4.1 -
Evolution of a Habitable Planet (Arthur)
ROADMAP OBJECTIVES: 4.1 5.3 6.1 -
Subseafloor Basement (Basalt) Biosphere Studies
Using UHNAI funds in 2004-2005, we began to acquire laboratory equipment and initiate the first environmental electrochemistry research effort at UH, making use of solid-state voltammetric sensors.
ROADMAP OBJECTIVES: 4.1 5.1 5.2 5.3 6.1 -
Sulfur Isotopes in the Early Earth Atmosphere
ROADMAP OBJECTIVES: 4.1 -
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 5.3 6.1 7.1 -
Ecosystem to Biosphere Modeling
The newly completed methanogenesis component of the model MBGC (MicrobialBioGeoChemistry) was used to examine the effects of competition between methanogens and sulfate-reducing bacteria on metabolism and gas flux in the microbial mat.
ROADMAP OBJECTIVES: 4.1 5.3 6.1 7.2 -
The Abiotic Planetary Model: The Upper and Lower Boundary Condition on the Atmosphere
ROADMAP OBJECTIVES: 1.1 4.1 7.2 -
Adaptation to Salinity in Microbial Communities
Lake Tyrrell, Australia, has been identified as a site with considerable potential as a Mars analog (Benison and Laclair, Astrobiology, 2003). This periodically dry, pink, hypersaline lake (Figure 1) is located in northwestern Victoria, Australia
ROADMAP OBJECTIVES: 2.1 4.1 5.1 5.2 5.3 6.1 -
Identifying Microbial Life at Crustal Rock-Water Interfaces
ROADMAP OBJECTIVES: 4.1 4.2 5.2 5.3 6.1 7.1 -
Project 4. Prebiotic Molecular Selection and Organization
Studies in molecular self-organization continued to focus on 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 -
Permian-Triassic Extinction Scientific Drilling Project
ROADMAP OBJECTIVES: 4.1 4.2 5.2 5.3 -
Origin of Multicellularity and Complex Land-Based Ecosystem
ROADMAP OBJECTIVES: 3.4 4.1 4.2 5.2 -
Leigh Project
ROADMAP OBJECTIVES: 3.2 3.3 4.1 4.2 5.1 5.2 5.3 6.1 -
Project 3. Prebiotic Chemical and Isotopic Evolution on Earth
In the past year Doctoral Student David Johnston and Co-I Farquhar determined for the first time the different types of isotopic signatures produced by different sulfur metabolisms. including sulfate-reducing bacteria, sulfite-disproportionating bacteria, and sulfur-disproportionating bacteria. These observations permitted calibration of the first global sulfur isotope models.
ROADMAP OBJECTIVES: 3.1 4.1 4.2 7.1 -
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 -
Oxygen Metabolism and Oxidatie Stress in Anaerobic Microorganisms (Ferry)
ROADMAP OBJECTIVES: 3.3 4.1 4.2 5.1 6.1 -
The Virtual Planetary Laboratory – The Life Modules
Field research on the freshwater bacteria of Cuatro Cienegas, Mexico (Siefert). These communities are good proxies for early earth type bacterially-dominated systems. To understand the community dynamics that lead to microbialite (general term for structures produced by microbial precipitation) the metagenomes of two microbialites, from two separate regions of the system were performed using 454 sequencing technology.
ROADMAP OBJECTIVES: 4.1 4.2 5.3 6.1 6.2 7.1 7.2 -
7.4.4. Equilibrium Fe-Isotope Fractionation.
Over the past year PhD student Pamela Hill (ESS, UCLA) and COI Schauble, with assistance from Anat Shahar, Ed Young, and Eric Tonui, have continued experiments with diethyl ether/aqueous solution mixtures aimed at measuring the effects of solution chemistry and oxidation state on iron-isotope fractionations. Initial results are shown in Figure 1
ROADMAP OBJECTIVES: 4.1 -
Experimental Study of Radiolytic Oxidation of Pyrite: Implications for Mars-Relevant Crustal Processes
In subsurface environments, radiolysis can produce gradients of both electron acceptors and electron donors that are possible sources of metabolic energy [2]. Radiation-induced chemical reactions have particular significance in geologic environments where molecular oxygen derived from the atmosphere is a negligible input.
ROADMAP OBJECTIVES: 3.3 4.1 4.2 5.1 5.2 5.3 6.1 7.2 -
Laboratory Microbial Simulations (House)
ROADMAP OBJECTIVES: 3.4 4.1 5.1 5.2 7.2 -
Habitable Planets
ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1 4.3 -
Database of Stellar Spectra to Support Extrasolar Planet Modeling
We established a database of stellar spectra during the past year to serve as a
dynamic repository within the VPL website for accurate reference spectra of stars
that are considered relevant hosts in the search for habitable exoplanets.ROADMAP OBJECTIVES: 1.2 4.1 6.2 7.2 -
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 -
Modeling Early Atmospheric Composition and Climate (Kasting)
ROADMAP OBJECTIVES: 4.1 -
Molecular Survey of Microbial Diversity in Hypersaline Ecosystems
ROADMAP OBJECTIVES: 3.1 3.2 3.4 4.1 4.2 5.1 5.2 5.3 6.1 -
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 5.1 5.2 5.3 -
From Stars to Genes
ROADMAP OBJECTIVES: 4.1 4.3 -
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 -
Extraterrestrial Organics
ROADMAP OBJECTIVES: 1.1 2.2 3.1 4.1 4.3 -
Genomic Record of the Earth’s Early Biosphere (Hedges)
ROADMAP OBJECTIVES: 4.1 4.2 -
Philosophical Issues in Astrobiology
ROADMAP OBJECTIVES: 3.1 3.2 3.4 4.1 5.1 5.2 -
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 -
Exploring Conditions for Habitability in Our Solar System
Subsurface Habitability on Mars: Armstrong and Sondossi (2005) are exploring the stability of deep subsurface environments (3-6 km) on Mars. Thermal diffusion models indicate that temperature fluctuations at these depths are minor, and provide reasonable environments for sub-surface life, perhaps probed by the recent detection of methane in Mars’ atmosphere.
ROADMAP OBJECTIVES: 2.1 2.2 4.1 6.2 7.1 -
Isotopic Studies of the Precambrian Earth and Element Cycling Processes (Pitt)
ROADMAP OBJECTIVES: 1.1 4.1 6.1 -
Evolution of a Habitable Planet (Kump)
ROADMAP OBJECTIVES: 1.1 4.1 4.2 4.3 5.2 6.1 -
Understanding the Earth’s Early Environment
ROADMAP OBJECTIVES: 1.1 4.1 7.2 -
Ecology of a Hawaiian Lava Cave Microbial Mat
ROADMAP OBJECTIVES: 4.1 5.1 5.2 5.3 6.2 -
Seafloor Eruptions: Access to Deep Hydrothermal Biosphere
This project is an on-going study of the microbial and geochemical changes associated with seafloor eruptions at mid-ocean ridges. The intrusion of a magma dike into the neovolcanic zone of a mid-ocean ridge is the “quantum” event in the accretion of the upper ocean crust. Such ridge axis diking/eruptive events are episodic perturbations that trigger a sequence of interrelated and rapidly evolving physical, chemical, and biological processes associated with the formation of ocean crust.
ROADMAP OBJECTIVES: 4.1 5.1 5.2 6.1