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.

The selections are as follows:

Tilt-A-Worlds: Chaotic Obliquities and the Limits of the Habitable Zone, Lead Investigator Rory Barnes
This project 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.

Characterization of Soluble Organics in Carbonaceous Meteorites by Ultrahigh Resolution Mass Spectrometry and Isotope Analysis, Lead Investigator Michael Callahan
The investigators will use ultrahigh resolution mass spectrometry with high throughput screening methods to examine the soluble organic matter in a large set of carbonaceous chondrites. 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.

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
The Puyehue-Cordón Caulle volcanic eruption on 4 June 2011 (and ongoing) deposited large amounts of ash and pumice, and extensive islands of floating pumice spherules in regional lakes have been observed. 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, being the first to document microbial composition and nutrient uptake for these novel lacustrine pumice islands.

Survivability of Organic Compounds Mixed with Martian Soil Analogue Against Shock Pressures: Investigation of the Effect of Asteroid Impacts on the Fate of Organic Matter, Lead Investigator, Gözen Ertem
This project will 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 will be utilized to create a database for the survivability of organics.

Creating a Reference Set of Amino Acids Structures for Use in Multiple Astrobiology Investigations, Lead Investigator, Steve Freeland
This project is 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.

Efficiency and mechanisms of oxygenic photosynthesis in the far-red light utilizing cyanobacterium, Acaryochloris marina, Lead Investigator, Nancy Kiang
This project will identify an upper bound on photon wavelengths able to drive oxygenic photosynthesis, constraining the range of extrasolar environments in which spectral signatures of biogenic oxygen might be observed, thus informing future telescope missions; and providing the fundamental understanding necessary to identify signatures of biological pigments in extrasolar spectra.

Measuring the Abundance and Diversity of Microorganisms in Earth’s Upper Atmosphere, Lead Investigator, David Smith
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 introduce the stratosphere as an important astrobiology analog environment; broaden the traditionally accepted boundary for Earth’s biosphere and the physical limits for life; and inspire novel methods for sampling planetary atmospheres.