2014 Annual Science Report

Pennsylvania State University Reporting  |  SEP 2013 – DEC 2014

Executive Summary

Biosignatures from Earth and Beyond

The Penn State Astrobiology Research Center pushed ahead with notable advances in several very exciting areas. Overall, we continue to have a focus on developing new biosignatures, searching for biosignatures in relevant microbial environments, searching for biosignatures in ancient rocks, and the discovery and exploration of exoplanets. Our efforts focus on creating innovative approaches for the analyses of cells and other organic material, finding ways in which metal abundances and isotope systems reflect life, and developing creative approaches for using environmental DNA to study present and past life. Also, the Earth’s Archean and Proterozoic eons offer the best opportunity for investigating a microbial world, such as might be found elsewhere in the cosmos. The ancient record on Earth provides an opportunity to see what geochemical signatures are produced by microbial life and how these signatures are preserved over geologic ... Continue reading.

Field Sites
29 Institutions
8 Project Reports
23 Publications
8 Field Sites

Project Reports

  • Biosignatures in Extraterrestrial Settings

    The Biosignatures in Extraterrestrial Environments group works on finding and characterizing exoplanets, in particular through very high resolution spectroscopy; and developing new techniques for finding exoplanets and characterizing their properties. It also works on understanding the evolution and dynamics of planetary systems, including the solar system, and the role of astrophysical processes in establishing and sustaining life in extraterrestrial environments.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 4.1 4.3 6.2 7.1 7.2
  • Biosignatures of Ancient Rocks – Hedges Group

    Our work involves the design, assembly, and release to the public of a tree of life calibrated to geologic time (timetree). It is needed by astrobiologists to help determine the source of biomarkers for the presence of life in the geologic record.

    ROADMAP OBJECTIVES: 3.3 3.4 4.1 4.2 7.1 7.2
  • Biosignatures of Life in Extremely Energy-Limited Environments

    The terrestrial subsurface is the least explored habitat on earth and is characterized by darkness and reducing conditions that limit how fast microbes can obtain energy (low energy fluxes). The diversity and metabolic strategies of microbes in this environment are the subject of our investigation.

    ROADMAP OBJECTIVES: 4.1 4.3 5.1 5.3 7.1
  • Biosignatures of Life in Ancient Stratified Ocean Analogs

    Instigated by Macalady and Kump in 2010, this project investigates biosignatures of life in modern analogs for stratified ancient and/or extraterrestrial oceans. The primary field site is a sinkhole in Florida. Other field site include stratified ocean analogs in the Bahamas, New York State, and the Dominican Republic. A website monitoring the activities of an informal working group on Early Earth Photosynthesis is maintained by Macalady (http://www.geosc.psu.edu/~jlm80/EEP.html).

    ROADMAP OBJECTIVES: 2.1 3.3 3.4 4.1 5.2 5.3 6.1 7.1 7.2
  • Developing New Biosignatures

    This project works to develop new biosignatures based on element, molecules, or isotopes. For example, we are working with the method secondary ion mass spectrometry (SIMS) to analyze microorganisms or microfossils. We are also looking at the Isolation and analysis of F430, archaeol, and IPL-archaeol from the Cascadia Margin. We are also interested in DNA as a biosignature. For that work, we are extracting DNA from deep sea sediment and other difficult environments. Finally, we are also investigating prebiotic molecules in order to known which carbon-containing biomolecules can not be reasonable biosignatures.

    ROADMAP OBJECTIVES: 3.1 7.1 7.2
  • Biosignatures in Ancient Rocks – Kasting Group

    We have been working on two things: 1) the question of whether there are plausible “false positives” for life on extrasolar planets, i.e., high abiotic O2 and/or O3 levels that might be confused with evidence for photosynthesis, and 2) hydrodynamic escape of hydrogen from H2- or H2O-rich primitive atmospheres. We are developing a two-component model to describe this process. Old single-component models evidently do not obey the diffusion limit, so are are trying to remedy that.

    ROADMAP OBJECTIVES: 1.1 2.1 4.1 7.2
  • Biosignatures in Ancient Rocks – Kump Group

    We are analyzing FAR-DEEP cores that span the putative “oxygen overshoot” associated with the termination of the Great Oxidation Event, 2.0 billion years ago. The volcanic rocks in question are highly oxidized. Our hypothesis is that oxygen-enriched groundwaters altered these rocks during a time interval when atmospheric oxygen concentrations approached modern levels, falling subsequently to lower values characteristic of the ensuing billion years. Kump has also proposed a new explanation for the “second rise of atmospheric oxygen” in the Neoproterozoic (ca. 850 Ma).

    ROADMAP OBJECTIVES: 1.1 4.1 4.2 4.3 5.2 6.1
  • Biosignatures in Ancient Rocks – Ohmoto Group

    This project has been aimed at understanding the chemical and biological natures of the ocean-atmosphere-lithosphere systems during the Archean. A second objective is testing a hypothesis that the MIF-S isotope signatures, which characterize some Archean and younger sedimentary rocks, were generated during reactions between hydrothermal fluids and organic-rich sediments, rather than through atmospheric reactions.

    ROADMAP OBJECTIVES: 1.1 4.1 6.1