2008 Annual Science Report

SETI Institute Reporting  |  JUL 2007 – JUN 2008

Executive Summary

The SETI Institute (SI) NASA Astrobiology Institute (NAI) team is conducting a suite of coupled research projects in the co-evolution of life and its planetary environment. These projects address most of the Roadmap Objectives that are organized under the seven broader Roadmap Goals; Goal 1: Habitable Planets; Goal 2: Life in our Solar System; Goal 3: Origins of Life; Goal 4: Earth’s Early Biosphere and its Environment ; Goal 5: Evolution, Environment, and Limits of Life ; Goal 6: Life’s Future on Earth and Beyond; Goal 7: Signatures of Life. These projects begin by examining specific fundamental ancient transitions that ultimately made complex life possible on Earth. They conclude with a synthesis that brings many of the team’s investigations together into an examination of the suitability of planets orbiting M dwarfs for either single-celled or more complex life.

The astrobiology roadmap calls for a strategy “for recognizing ... Continue reading.

Field Sites
18 Institutions
9 Project Reports
0 Publications
0 Field Sites

Project Reports

  • Surface Processes and Surface-Subsurface Transport on Europa

    This project looks at Jupiter’s moon, which has a subsurface ocean under its icy surface. We have three main components — we are studying images taken by the Galileo spacecraft, we are looking at different geological features to determine their potential to be involved in the vertical transport of material to and from the surface ,and we are studying one process, impact gardening by small micrometeorites that churn the surface, in detail.

    ROADMAP OBJECTIVES: 2.2
  • Iron, the Oxygen Transition, UV Shielding, and Photosynthesis

    Our combined field and lab work has shown that iron oxide bearing minerals could be important in protecting photosynthetic organisms from UV radiation and that nanophase ferric oxyhydroxides in a clay matrix are particularly effective. We have collected several iron-rich samples from hot springs where microbes thrive and are completing characterizing the minerals present and their spectral properties. We are also identifying iron oxides and clay minerals on Mars in order to determine possible environments where microbes could have been protected from solar radiation.

    ROADMAP OBJECTIVES: 2.1
  • “Are We Alone?” Weekly Science Radio Show

    Production and distribution of a weekly, one-hour radio program whose subject matter is rooted in the discipline of astrobiology. The show consists of interviews with practicing scientists, reporters, and engineers, as well as other elements designed to make the program appealing to a wide range of the public, both domestic and international. Once monthly, a special edition of the show is devoted to skepticism: taking on pseudo-science and contrasting it with the workings of research.

    ROADMAP OBJECTIVES: None Selected
  • Expanding the List of Target Stars for Next Generation SETI Searches

    For decades the conventional wisdom considered M dwarf stars unsuitable hosts for habitable planets. We convened an interdisciplinary workshop of thirty scientists to reconsider the issue. They concluded that life could evolve on planets orbiting higher mass M dwarfs. This improves the prospects for finding extraterrestrial life since M dwarfs account for about 75% of all stars. Based on these results, we are preparing a list of more than a million “target” stars for a search for extraterrestrial intelligence (SETI) project.

    ROADMAP OBJECTIVES: 1.1 1.2 4.3 6.2 7.2
  • The High Lakes Project (HLP)

    The High Lakes Project is a multi-disciplinary astrobiological investigation studying high-altitude lakes between 4,200 m and 5,916 m elevation in the Central Andes of Bolivia and Chile. Its primary objective is to understand the impact of increased environmental stress on lake habitats and their evolution during rapid climate change as an analogy to early Mars. Their unique geophysical environment and mostly uncharted ecosystems have added new objectives to the project, including the assessment of the impact of low ozone/high solar irradiance in non-polar aquatic environments, the documentation of poorly known ecosystems, and the quantification of the impact of climate change on lake environment and ecosystem.
    Data from 2003 to 2007 show that solar irradiance is 165% that of sea level with instantaneous UV-B flux reaching 17W/m2. Short UV wavelengths (260-270 nm) were recorded and peaked at 14.6 mW/m2. High solar irradiance occurs in an atmosphere permanently depleted in ozone falling below ozone hole definition for 33-36 days and between 30-35% depletion the rest of the year. The impact of strong UV-B and UV erythemally-weighted daily dose on life is compounded by broad daily temperature variations with sudden and sharp fluctuations. Lake habitat chemistry is highly dynamical with notable changes in yearly ion concentrations and pH resulting from low and variable yearly precipitation. The year-round combination of environmental variables define these lakes as end-members. In such an environment, they host surprisingly abundant and diverse ecosystems including a significant fraction of previously undescribed species of zooplankton, cyanobacterial, and bacterial populations.

    ROADMAP OBJECTIVES: 1.1 2.1 4.1 4.3 5.1 5.2 5.3 6.1 6.2 7.1
  • Formation of Nitrogenated Aromatics in the Interstellar Medium

    We are investigating the chemical energetics and plausibility of reaction pathways leading to the formation of nitrogenated aromatics suggestive of purine and pyrimidine bases of RNA and DNA molecules using quantum chemistry.

    ROADMAP OBJECTIVES: 3.1
  • Training for Oxygen: Peroxy in Rocks, Early Life and the Evolution of the Atmosphere

    We try to find answers to a range of deep questions about the early Earth and about the origin and early evolution of life. How did the surface of planet Earth become slowly but inextricably oxidized during the first 2 billion years? We present evidence that it was not through the early introduction of oxygenic photosynthesis but through a purely abiotic process, driven by the tectonic forces of the early Earth and the weathering cycle. Only much later in Earth’s history, about 2.4 billion years ago, did photosynthesis kick in, boosting the oxygen level in the atmosphere to the levels that we enjoy now. If this is so, other Earth-like planets around other stars can be expected to undergo the same evolution from an early reduced state to an oxidized state.

    ROADMAP OBJECTIVES: 1.1 2.1 3.1 4.1 7.2
  • Abiotic Nitrogen Cycling

    This work considers how the chemistry in the atmosphere of Mars (and other “Earth-like” planets) may have affected life, including how prebiotic nitrogen species may have been formed for the origin of life, and how these atmospheres may have been changed. When too much nitrogen is removed from the atmosphere, this can result in a planet with too little atmospheric pressure to support liquid water and life on the surface.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 3.1
  • Planetary-Scale Transition From Abiotic to Biotic Nitrogen Cycle

    Nitrogen is an essential element for life. Understanding the planetary nitrogen cycle is critical to understanding the origin and evolution of life. The earth’s atmosphere is full of nitrogen gas (N2). However, this large pool of nitrogen is unavailable to most of the life on earth except a few microbes capable of “fixing” nitrogen into a form that can be used by other organisms (e.g., NH3, NH4+, NOx, organic-N). Without fixed nitrogen life would not have originated on earth and would most likely not occur on any other planet. The Atacama Desert in Chile is an enigma in that it contains vast nitrate (a type of fixed nitrogen) deposits. Elsewhere on earth, nitrate is either denitrified (transformed into N2 and released back into the atmosphere) through the activity of microorganisms, or is dissolved and leached from the system. Although the Atacama is the driest desert in the world we have shown that lack of water alone cannot account for the lack of nitrogen cycling in this desert. Preliminary data suggest that it may be due to the high oxidation level of the soil in combination with a lack of organic material in the soil.

    ROADMAP OBJECTIVES: 1.1 2.1 3.2 4.1 5.1 5.2 5.3 6.1