The Astrobiology Network

Astrobiology Science News 3 July 2009

Phoenix Mission Research Points to Martian Climate Cycles, University of Arizona
NASA Phoenix Results Point to Martian Climate Cycles, NASA
Collisional Stripping and Disruption of Super-Earths, astro-ph
The CN isotopic ratios in comets, astro-ph
Extreme coronagraphy with an adaptive hologram Simulations of exo-planet imaging, astro-ph
Oligarchic planetesimal accretion and giant planet formation II, astro-ph

Astrobiology Science News 2 July 2009

Astrobiology Science News 1 July 2009

Exomoon simulations, astro-ph
Cassini/VIMS hyperspectral observations of the HUYGENS landing site on Titan, astro-ph
Constraining the orbit of the possible companion to Beta Pictoris: New deep imaging observations, astro-ph
Spin-orbit misalignment in the HD80606 planetary system, astro-ph

NASA Solicitation: Exploration Systems Mission: Radiation Standards for Lunar Sortie Missions

]]> Synopsis - Jun 30, 2009
General Information

Solicitation Number: N/A
Reference Number: NNH09EXPLORATIONMISSION
Posted Date: Jun 30, 2009
FedBizOpps Posted Date: Jun 30, 2009
Recovery and Reinvestment Act Action: No
Original Response Date: Jul 14, 2009
Current Response Date: Jul 14, 2009
Classification Code: B -- Special studies and analysis - not R and D
NAICS Code: 541330 - Engineering Services

Contracting Office Address

NASA/Goddard Space Flight Center, NASA Headquarters Acquisition Branch, Code 210.H, Greenbelt, MD 20771

Description

NASA/HQ is hereby soliciting information about potential sources to provide support for study and report on radiation standards for lunar sortie missions. This will consist of an Ad Hoc committee to perform an independent assessment of the program's technical quality, relevance to exploration objectives, and effectiveness in maturing and infusing technologies. This work will assist the Government in overseeing the Constellation, human research, exploration technology development and lunar precursor robotic programs as well as the Commercial Orbital Transportation Services Project. The Exploration Systems Mission Directorate (ESMD) is organized into two programmatic themes to carry out its mission. Projects in the Constellation Theme are structured to develop, demonstrate, and deploy flight systems that will enable sustained human exploration. The Advanced Capabilities Theme is structured into three major programs that provide critical products to reduce operational and technical risk for Constellation projects. The major programs are: the Human Research Program (HRP), which carries out investigations and risk mitigation related to astronaut health and performance; the Lunar Precursor Robotic Program (LPRP) which will launch the Lunar Reconnaissance Orbiter and the Lunar Crater Observation and Sensing Satellite, and the Exploration and Technology Development Program (ETDP), which addresses high priority technology needs for lunar exploration. The Government has a significant investment in this Program and has made commitments to internal and external entities that hinge on successful completion of this project. The efforts of this requirement are in direct support of NASA's exploration missions and strategies.

No solicitation exists; therefore, do not request a copy of the solicitation. If a solicitation is released it will be synopsized in FedBizOpps and on the NASA Acquisition Internet Service. It is the potential offeror's responsibility to monitor these sites for the release of any solicitation or synopsis.

Interested offerors/vendors having the required specialized capabilities to meet the above requirement should submit a capability statement of 10 pages or less indicating the ability to perform all aspects of the effort described herein.

Responses must include the following: name and address of firm, size of business; average annual revenue for past 3 years and number of employees; ownership; whether they are large, small, small disadvantaged, 8(a), HUBZone, and/or woman-owned; number of years in business; affiliate information: parent company, joint venture partners, potential teaming partners, prime contractor (if potential sub) or subcontractors (if potential prime); list of customers covering the past five years (highlight relevant work performed, contract numbers, contract type, dollar value of each procurement; and point of contact - address and phone number). All questions concerning this requirement should be emailed directly to Danit Rainey at 301.286.6717 or via email, Danit.Rainey@nasa.gov.

Please advise if the requirement is considered to be a commercial or commercial-type product. A commercial item is defined in FAR 2.101.

This synopsis is for information and planning purposes and is not to be construed as a commitment by the Government nor will the Government pay for information solicited. Respondents will not be notified of the results of the evaluation. Respondents deemed fully qualified will be considered in any resultant solicitation for the requirement.

The Government reserves the right to consider a small business or 8(a) set-aside based on responses hereto. All responses shall be submitted to Danit Rainey no later than July 14, 2009. Please reference NNH09EXPLORATIONMISSION in any response. Any referenced notes may be viewed at the following URLs linked below.

Point of Contact

Name: Danit P Rainey
Title: Contract Specialist
Phone: 301-286-6717
Fax: 301-286-0356
Email: Danit.Rainey@nasa.gov

Astrobiology Science News 30 June 2009

Astrobiology Science News 26 June 2009

The Frequency of Low-mass Exoplanets, astro-ph
DNA Nucleobase Synthesis at Titan Atmosphere Analog by Soft X-rays, J. Phys. Chem.
Solar X-rays may create DNA building blocks on Titan, New Scientist

Astrobiology Science News 25 June 2009

Astrobiology Science News 24 June 2009

Cosmic Rays: A Review for Astrobiologists

Cosmic rays represent one of the most fascinating research themes in modern astronomy and physics. Significant progress is being made toward an understanding of the astrophysics of the sources of cosmic rays and the physics of interactions in the ultrahigh-energy range. This is possible because several new experiments in these areas have been initiated. Cosmic rays may hold answers to a great number of fundamental questions, but they also shape our natural habitat and influence the radiation environment of our planet Earth. The importance of the study of cosmic rays has been acknowledged in many fields, including space weather science and astrobiology.

]]> Here, we concentrate on the astrobiological aspects of cosmic rays with regard to the enormous amount of new data available, some of which may, in fact, improve our knowledge about the radiation of cosmic origin on Earth. We focus on fluxes arriving at Earth and doses received, and will guide the reader through the wealth of scientific literature on cosmic rays. We have prepared a concise and self-contained source of data and recipes useful for performing interdisciplinary research in cosmic rays and their effects on life on Earth.

Key Word: Radiation.

Astrobiology. May 2009, 9(4): 413-436.

http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2007.0205

Why Is the Definition of Life So Elusive? Epistemological Considerations

A central question of astrobiology concerns the origin and distribution of life in the Universe. For this reason, astrobiology can be considered to fall within the science called transitional biology. If we accept that life originated by a process of prebiotic chemical evolution, the next question concerns the nature of the transitional pathway from inanimate chemical systems to the first forms of life on Earth. These possible transitional states are the subject matter of transitional biology as a discipline.

]]> A related question concerns attempts to synthesize living systems in the laboratory. In contrast to traditional biology, the definition of life has an important methodological role in transitional biology, yet we still do not have a generally accepted definition despite the immense accumulation of empirical data in the life sciences. This review analyzes three approaches to defining life and concludes that all three are problematic in that they attempt to define life with undefined terms, confuse a description with a definition, or define life arbitrarily in terms of minimal living systems.

Key Words: Definition of life--Astrobiology--Epistemology--Transitional biology--Interdisciplinary context--Order--Entropy--Information--Bioinformation--Complexity--Thermodynamic laws--Minimal living systems.

Astrobiology. May 2009, 9(4): 401-412.

http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2007.0201

Preservation of Biological Markers in Clasts Within Impact Melt Breccias from the Haughton Impact Structure, Devon Island

The 39+/-2Ma Haughton impact structure on Devon Island comprises a thick target succession of sedimentary rocks, mainly carbonates. The carbonates contain pre-impact organic matter, including fossil biological markers. Haughton is located in an area where no major thermal event has affected the sedimentary succession after heating caused by impact. This makes Haughton uniquely suitable for studies concerning the preservation of fossil biological markers following an impact event.

]]> Melt breccia is the most common impactite at Haughton. It is composed of clasts of the target, mainly carbonates, embedded in a fine groundmass. The groundmass is composed of material that was melted during impact. In this study, fossil biological marker maturity parameters (tricyclic terpane-hopane ratio and pregnane-sterane ratio) and an aromatic maturity parameter [methylphenanthrene ratio (MPR)] were used to compare the degree of thermal alteration in different size fractions of carbonate clasts (<0.5-4cm in diameter) and between edges and centers of large carbonate clasts (15-20cm in diameter). The data show that fossil biological markers can be preserved and detected in isolated large and small fractions of carbonate clasts that are embedded in an impact melt.

The results also indicate that there is a thermal gradient from the center of a clast to the edge of a clast, which suggests that biological markers are more likely to be found preserved in the center of a clast. The thermal maturity values point to a higher degree of thermal alteration in the melt breccia carbonate clasts than in the coherent carbonate bedrock.

Key words: Biomarkers--Impacts--Haughton Crater.

Astrobiology. May 2009, 9(4): 391-400.

http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2008.0270

Isotopic Composition of Methane and Inferred Methanogenic Substrates Along a Salinity Gradient in a Hypersaline Microbial Mat System

The importance of hypersaline environments over geological time, the discovery of similar habitats on Mars, and the importance of methane as a biosignature gas combine to compel an understanding of the factors important in controlling methane released from hypersaline microbial mat environments. To further this understanding, changes in stable carbon isotopes of methane and possible methanogenic substrates in microbial mat communities were investigated as a function of salinity here on Earth. Microbial mats were sampled from four different field sites located within salterns in Baja California Sur, Mexico. Salinities ranged from 50 to 106 parts per thousand (ppt).

]]> Pore water and microbial mat samples were analyzed for the carbon isotopic composition of dissolved methane, dissolved inorganic carbon (DIC), and mat material (particulate organic carbon or POC). The POC 13C values ranged from 6.7 to 13.5 0/00, and DIC 13C values ranged from 1.4 to 9.6 0/00. These values were similar to previously reported values. The 13C values of methane ranged from 49.6 to 74.1 0/00; the methane most enriched in 13C was obtained from the highest salinity area. The apparent fractionation factors between methane and DIC, and between methane and POC, within the mats were also determined and were found to change with salinity. The apparent fractionation factors ranged from 1.042 to 1.077 when calculated using DIC and from 1.038 to 1.068 when calculated using POC.

The highest-salinity area showed the least fractionation, the moderate-salinity area showed the highest fractionation, and the lower-salinity sites showed fractionations that were intermediate. These differences in fractionation are most likely due to changes in the dominant methanogenic pathways and substrates used at the different sites because of salinity differences.

Key Words: Hypersaline microbial mats--Methane stable isotopes--Apparent fractionation factors--Methanogenic pathways.

Astrobiology. May 2009, 9(4): 383-390.

http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2008.0260

Astrobiology Science News 23 June 2009

A Cryptoendolithic Community in Volcanic Glass

Fluorescent in situ hybridization (FISH) and 16S rDNA analysis were used to characterize the endolithic colonization of silica-rich rhyolitic glass (obsidian) in a barren terrestrial volcanic environment in Iceland. The rocks were inhabited by a diverse eubacterial assemblage. In the interior of the rock, we identified cyanobacterial and algal 16S (plastid) sequences and visualized phototrophs by FISH, which demonstrates that molecular methods can be used to characterize phototrophs at the limits of photosynthetically active radiation (PAR).

]]> Temperatures on the surface of the dark rocks can exceed 40*C but are below freezing for much of the winter. The rocks effectively shield the organisms within from ultraviolet radiation. Although PAR sufficient for photosynthesis cannot penetrate more than 250m into the solid rock, the phototrophs inhabit cavities; and we hypothesize that by weathering the rock they may contribute to the formation of cavities in a feedback process, which allows them to acquire sufficient PAR at greater depths. These observations show how pioneer phototrophs can colonize the interior of volcanic glasses and rocks, despite the opaque nature of these materials.

The data show that protected microhabitats in volcanic rocky environments would have been available for phototrophs on early Earth.

Key Words: Endoliths--Cyanobacteria--Early Earth--Life in extreme environments.

Astrobiology. May 2009, 9(4): 369-381.

http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2008.0278

Effects of a Spaceflight Environment on Heritable Changes in Wheat Gene Expression

Once it was established that the spaceflight environment was not a drastic impediment to plant growth, a remaining space biology question was whether long-term spaceflight exposure could cause changes in subsequent generations, even if they were returned to a normal Earth environment. In this study, we used a genomic approach to address this question. We tested whether changes in gene expression patterns occur in wheat plants that are several generations removed from growth in space, compared to wheat plants with no spaceflight exposure in their lineage. Wheat flown on Mir for 167 days in 1991 formed viable seeds back on Earth.

]]> These seeds were grown on the ground for three additional generations. Gene expression of fourth-generation Mir flight leaves was compared to that of the control leaves by using custom-made wheat microarrays. The data were evaluated using analysis of variance, and transcript abundance of each gene was contrasted among samples with t-tests. After corrections were made for multiple tests, none of the wheat genes represented on the microarrays showed a statistically significant difference in expression between wheat that has spaceflight exposure in their lineage and plants with no spaceflight exposure.

This suggests that exposure to the spaceflight environment in low Earth orbit space stations does not cause significant, heritable changes in gene expression patterns in plants.

Key Words: Triticum aestivum--Spaceflight--Gene expression--Wheat--Microarray.

Astrobiology. May 2009, 9(4): 359-367.

http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2008.0311