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Executive Summary

Borehole installation of instrumented monitoring and sampling equipment for study of geochemical and biological processes in permafrost environments is the top research priority for the Indiana-Princeton-Tennessee Astrobiology Initiative. We are partnering with scientists from University of Waterloo, Canada and from the Geological Survey of Finland on completion of a scientific borehole that intersects sub-permafrost groundwater in fractured Archean strata at High Lake in the Nunavat Territory of Canada. The High Lake mining property is located in a greenstone belt containing both felsic and mafic metavolcanics and is the site of a significant copper-zinc deposit that is frozen to a depth of about 450 meters. In July of 2006, the artic field team (Onstott from Princeton, Pfiffner from Tennessee, Johnson from Indiana, Stotler from Waterloo, and Ruskeeniemi and Tallika from Finland) traveled to the High Lake property and set up a core processing lab. An anaerobic glove bag was assembled, cleaned, and filled with argon gas in preparation for recovery of permafrost cores suitable for microbiological sampling. Perfluorocarbon tracers were added to the drilling water and fluorescent microspheres were inserted into the bottom of the core tubes in order to assess contamination of the borehole water and rock by the drilling operation. Temperature monitoring strips were inserted between the core liner and the core barrel to measure the maximum temperature experienced during each core run. Cores for microbial analyses were collected every 7th core run for a total of 10 cores. Microbiological cores were immediately flushed with argon and quickly transferred into the anaerobic glove bag. The core liner was removed, core segments were photographed, and a sterile hammer was used to break the core prior to placing core fragments into separate containers for each investigator. In addition to samples collected for researchers on the artic field team, samples were collected for microbiological and geophysical studies at Michigan State University, Lawrence Berkeley National Laboratory, University of Rhode Island, University of Colorado, Oak Ridge National Laboratory, University of Toronto, the Jet Propulsion Laboratory, and the Lunar and Planetary Institute. A diverse group of researchers benefited from the cores collected at High Lake as a result of an effective call for participation that was circulated about twelve months prior to actual coring. This project is indebted to Wolfden Resources Incorporated (now owned by Zinifex, Australia) for extraordinary logistical support at the field site. Mine owners and operators were motivated to support this research by nothing more than the allure of exploration for life on Mars. The permafrost borehole project would not be possible without the enthusiasm and effort of geologists, drillers, and support staff working for the mining and expediting companies that enable our field expeditions.

As the scientific community increasing focuses on chemoautotrophic microorganisms in the deep biosphere of Earth and the potential role of chemoautotrophic metabolism in the origin of life of Earth and other planets, journal articles authored by IPTAI investigators and their collaborators are increasingly cited as key papers addressing abiotic sources of biosustianing energy. Saline ground waters in fractured crystalline rock at depths of 2-3 kilometers below in the surface in the Witwatersrand Basin of South Africa has been shown by IPTAI scientist to host microbial ecosystems sustained by hydrogen consumption linked to sulfate reduction. Sulfate and hydrogen in the Witwatersrand basin are continuously produced by water- rock reactions associated with radioactive decay of uranium. Radiolysis of groundwater water generates hydrogen as a primary product of disproportionation of water and generates sulfate as secondary product during reaction of hydrogen peroxide and pyrite. Based on data from sites in Canada, Finland and South Africa, deep groundwater in fractured rock represents a potential energy-rich environment for subsurface life and contains some of the highest levels of dissolved H2 ever measured in ground waters. These discoveries provide a compelling rationale to explore for life in the deep subsurface of Mars and other planetary bodies likely to contain parts-per-million or greater concentrations of long-lived radioactive elements in their lithosphere.

With supplemental funding from the NASA Astrobiology Institute Director’s Discretionary Fund, a series of multi-investigator experiments will be performed to identify geochemical and biological processes influencing the fate of biomarkers and microorganisms under simulated Martian environmental conditions (Mars Chambers). Three types of experiments are proposed: 1) survival of psychrotolerant and radiation resistant microbes and communities, 2) compound-specific fate of biomarkers including amino acids, lipids and hydrocarbons in the presence of hydrous sulfates, UV and heavy ion radiation, and 3) observation of forward contamination by robotic minicorer sampling. These experiments will provide physicochemical data on mineral/microbe/molecular interactions and will allow monitoring trace gas formation. Data collected during Mars chamber experiments will form a basis for discriminating among contaminating Earth-sourced biological molecules, indigenous Mars-source biological materials, and comet- or asteroid-sourced abiological organic molecules. These experiments will also provide appropriate tests of sensitivity and reliability of instrumentation planned for current and future Mars missions since they will be analyzed by instruments that are already selected for upcoming Martian spacecraft (e.g. Phoenix electrochemical experiment and Mars Science Laboratory instrument for Samples Analysis at Mars). Mars Chamber experiments will address the need for rigorous decontamination of rovers and assess the need for sample collection from depths of 1 meter or greater below the surface of Mars. Collaborating investigators on the Mars Chamber project come from the IPTAI and SETI teams in the NASA Astrobiology Institute as well as from the Jet Propulsion Laboratory, the Kennedy Space Center Laboratory, and SHOT Industries.

Figure 1. Rocky outcrops are seen surrounding the site of a scientific borehole at High Lake Mine, Nunavut Territory, Canada. Photograph taken by Peter Suchecki as part of project documentation.

Figure 2. Helicopters are used to transport equipment and supplies to the borehole site in order to prevent damage to the surrounding permafrost from vehicles. Inclined mast on the drilling rig indicates the orientation of the coring operation. Photograph taken by Peter Suchecki as part of project documentation.

Figure 3. Dan McGown from Princeton University is shown using a sterile hammer inside an anaerobic glovebag to subsample a rock core from the High Lake borehole. Photograph taken by Susan Pfiffner.