NASA Astrobiology Institute (NAI)

2011 DDF Selections

The NASA Astrobiology Institute is pleased to announce selections for research awards resulting from its 2011 Director’s Discretionary Fund competition. The selections cover a wide range of research topics, from an examination of microbial succession on islands of floating pumice to defining the habitable zone’s outer edge by combining climate evolution models with models of orbital and obliquity evolution.

Discretionary resources in the fiscal year 2012 NAI budget are extraordinarily limited. Since these are the funds from which we make 2011 DDF awards, we have been limited to a small fraction of the total award amounts of past years. Approximately $250K is allocated for the seven selected investigations described below.

Selections were based on external reviews, with selection priority given to proposals that

• integrate the research of and realize synergies among the current NAI teams;
• expand the scope of NAI research (and the NAI community) in innovative ways, accepting some risk in return for high pay-off potential;
• respond in a timely way to new scientific results or programmatic opportunities;
• develop connections between astrobiology research and other NASA science programs, particularly NASA’s Earth Science Program;
• directly support flight programs, particularly through instrument development;
• use funding particularly effectively, for example through leveraging or building on past investments; and/or
• support early career investigators

Selected Research Projects

Proposal Title: Tilt-A-Worlds: Chaotic Obliquities and the Limits of the Habitable Zone

Lead Investigator:
Rory Barnes, U Washington, VPL Team at the U Washington
Co-Investigators:
John Armstrong, Weber State U, VPL Team at the U Washington.  Shahn Domagal-Goldman (NASA HQ)
Summary:
The proposal seeks to couple orbital models to climate models to perform interdisciplinary, self-consistent investigations of these planets’ habitability. These models can help interpret observations of new exoplanets, extend the habitable zone, and help prioritize objects for direct spectroscopic follow-up. The investigators will release their coupled code to the community so that as exoplanets are discovered, their potential habitability can be quantified.

Proposal Title: Characterization of Soluble Organics in Carbonaceous Meteorites by Ultrahigh Resolution Mass Spectrometry and Isotope Analysis

Lead Investigator:
Michael Callahan, NASA Goddard Space Flight Center Team
Co-Investigators:
Conel Alexander, CIW Team, H. James Cleaves, CIW and Georgia Tech Teams
Summary:
Carbonaceous chondrites (CCs) are known to contain a complex suite of soluble and insoluble organic molecules that seem to share a common genetic heritage with organic matter in interplanetary dust particles and comets. To better understand the origin of organic matter in CCs and to better evaluate the importance of exogenous delivery to prebiotic chemistry, a more complete understanding of the organic inventory of CCs is necessary. The investigators will use ultrahigh resolution mass spectrometry (UHRMS) with high throughput screening methods to examine the soluble organic matter in a large set of CCs. This will be coordinated with bulk elemental and isotopic measurements of (1) the soluble and insoluble organic matter, and (2) the bulk meteorites before and after leaching. The investigators will also explore the possibility of using the total soluble organics as a fast and simple method of meteorite classification.

Proposal Title: Following a novel Earth biota: microbial succession and nutrient use on floating pumice spherules deposited by the Puyehue-Cordón Caulle volcanic eruption

Lead Investigator:
James Elser, Arizona State U Team
Co-Investigators:
Janet Siefert, Rice University and Arizona State Team
Summary:
The Puyehue-Cordón Caulle volcanic eruption on 4 June 2011 (and ongoing) deposited large amounts of ash and pumice in the area. Especially notable for astrobiology is the development of extensive islands of floating pumice spherules in regional lakes, including Lake Nahuel Haupi, the region’s largest. These spherules, initially sterile, will be colonized by microbes over time but ecological succession on such novel substrates has never been described. The investigators will characterize the development of these communities using state-of-the-art DNA sequencing techniques (Ion Torrent) and use modern isotope techniques to study how they obtain nutrient elements (N, P). The project will provide several benefits. It will be the first to document microbial composition and nutrient uptake for these novel lacustrine pumice islands. Such studies are of high astrobiological relevance, as microbial succession on the initially sterile pumice will shed light on similar scenarios during Earth’s history, such as colonization of land or dynamics following planetary impacts. The investigators will also learn about the suitability of such post-volcanic environments to support life, helping inform interpretation if such habitats are ever identified beyond Earth.

Proposal Title: Survivability of Organic Compounds Mixed with Martian Soil Analogue Against Shock Pressures: Investigation of the Effect of Asteroid Impacts on the Fate of Organic Matte

Lead Investigator:
Gözen Ertem, National Institutes of Health and CIW Team
Summary:
The goal of this proposal is to determine the survivability and fate of organic compounds mixed with martian soil analogue JSC-Mars I against the effects of asteroid impacts as a function of shock pressures. Information obtained through these laboratory experiments, along with on-going research investigating the effect of ionizing radiation on precursors of biologically important monomers will be utilized to create a database for the survivability of organics.

Proposal Title: Creating a Reference Set of Amino Acids Structures for Use in Multiple Astrobiology Investigations

Lead Investigator:
Steve Freeland, U Hawaii Team
Co-Investigators:
H. James Cleaves, CIW Team and Georgia Tech Team
Summary:

This award provides funding for a short-term collaboration to define and computationally generate an exhaustive reference-set of the many amino acid structures relevant to astrobiology by virtue of their prebiotic and/or biological plausibility. This research will pave the way for a project to characterize these chemical structures in terms of their fundamental biophysical characterization, and make this data available as a new resource for the broader astrobiology/origins of life community.

Proposal Title: Efficiency and mechanisms of oxygenic photosynthesis in the far-red light utilizing cyanobacterium, Acaryochloris marina

Lead Investigator:
Nancy Kiang, NASA Goddard Institute for Space Studies and VPL Team at the U Washington
Co-Investigators:
Steven Mielke, NASA Goddard Institute for Space Studies and VPL Team at the U Washington, David Mauzerall, Rockefeller University
Summary:
To support NASA’s goal to discover and characterize life on exoplanets, the investigators are engaged in research to elucidate plausible biosignatures of photosynthesis adapted to extrasolar light environments; specifically, what are plausible spectral absorbance signatures of pigments for oxygenic photosynthesis? Our principal objective is to identify an upper bound on photon wavelengths able to drive oxygenic photosynthesis. Doing so will: (1) Constrain the range of extrasolar environments in which spectral signatures of biogenic oxygen might be observed, thus informing future telescope missions; (2) Provide the fundamental understanding necessary to identify signatures of biological pigments in extrasolar spectra. The proposed project will complete and extend ongoing photoacoustic studies of the far-red light-utilizing cyanobacterium Acaryochloris marina, which is a model organism for photosynthesis adapted to alien light environments. The present specific objectives are to: (1) analyze the wavelength-dependence of in vivo energy-storage in A. marina; and (2) carry out photoacoustic measurements of the energy-storage efficiency of purified photosystem complexes isolated from A. marina. Meeting these objectives will advance understanding of photosynthesis in Acaryochloris, and provide insight on specific adaptations employed to accommodate far-red light environments.

Proposal Title: Measuring the Abundance and Diversity of Microorganisms in Earth’s Upper Atmosphere

Lead Investigator:
David Smith, U Washington, VPL Team at the U Washington
Co-Investigator:
Victoria Meadows and Peter Ward, VPL Team at the U Washington, Dan Jaffe, U Washington, Bothell, Dale Griffin, US Geological Survey, Michael Roberts, NASA Kennedy Space Center, Andrew Schuerger, U Florida
Summary:
The abundance and diversity of microbial life in Earth’s upper atmosphere remains poorly understood. This research will identify and quantify up to 60,000 microbial taxa. Beyond putting the upper atmosphere “on the map” as a significant region for microbial biomass on Earth, this study has the potential to (1) introduce the stratosphere as an important astrobiology analog environment; (2) broaden the traditionally accepted boundary for Earth’s biosphere and the physical limits for life; and (3) inspire novel methods for sampling planetary atmospheres.