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2000 Annual Science Report

Astrobiology Roadmap Objective 17.0 Reports Reporting  |  JUL 1999 – JUN 2000

Roadmap Objective 17.0—Refine planetary protection guidelines and develop protection technology for human and robotic missions.

Project Reports

  • Biomarkers in Terrestrial Samples

    The importance of terrestrial samples to Astrobiology cannot be overestimated. Only by understanding the evidence for life preserved in the rocks and soil of Earth can we assess indications of possible life elsewhere in the universe. We currently have four main thrusts of this research: Modern Life in Extreme Environments, Ancient Life, Natural contamination of fossiliferous and non-fossiliferous lithologies, and Experiments.

    Modern Life in Extreme Environments

    We are studying samples from hot springs, caves, mines and endolithic environments to document the presence of microbial life and its physical and chemical biomarkers.

    Ancient Life
    We are studying rocks that contain the earliest physical evidence of life on Earth, in order to document the retention of microbial forms and other biosignatures in the geologic record. Furthermore, we are investigating the variety of environments in which the most ancient life is preserved. This will hopefully aid interpretation of where and possibly how life started.

    Natural contamination of fossiliferous and non-fossiliferous lithologies
    Fossiliferous rocks can become naturally contaminated through microbes living in cracks in both fossiliferous and non-fossiliferous lithologies, as well as microbes living between grains in harsh environments. We are looking at fossilized microbes in cracks in Early Archaean, carbonaceous, fossiliferous cherts, as well as in serpentinized deep sea ultramafics. Fossilized endolithic microorganisms in Arctic environments are also being investigated. Impact craters comprise another environment under investigation for fossilized endolithic organisms.

    Experiments
    We are conducting irradiation and shock experiments on terrestrial rocks to understand the effects of these stresses on samples from other planets. Some of the material being shocked is fossiliferous. Fossiliferous Early Archaean cherts are being experimentally metamorphosed to determine the effects of amphibolite/lower granulite metamorphism on the survival of carbonaceous microfossils. Films formed from prebiotic molecules are being artificially created as a comparison for biogenic films (biofilms) in order to distinguish differences between abiotic and biotic polymer films.

    ROADMAP OBJECTIVES: 6.0 7.0 17.0
  • Molecular Analysis of Microbial Ecosystems in Extreme Environments
    ROADMAP OBJECTIVES: 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 14.0 16.0 17.0
  • Coevolution of Life and Planets

    The Kirschvink lab has focused on several aspects of interest to the National Astrobiology Institute during the past 1.5 years, including evaluation and identification of Precambrian biosignatures, testing the Panspermia hypothesis with the Martian Meteorite ALH84001, placing constraints on Life on Europa, assessing effect of the Paleoproterozoic รข??Snowball Earth’. Members of the group include Postdoctoral Scholar J.W. Hagadorn, JPL Postdoctoral visitor Eric Gaidos, Graduate Student Benjamin Weiss, and Undergraduate Students Francis Macdonald and Tim Raub.

    ROADMAP OBJECTIVES: 6.0 7.0 8.0 9.0 10.0 11.0 12.0 14.0 17.0