The branch conducts interdisciplinary basic research in exobiology to understand pre-biotic chemistry, and the origin, evolution, distribution, and future of life in the Universe. We provide an interface between the external academic community and NASA programs. Our work also informs the selection, design and development of NASA life detection missions; the design and fabrication of spaceflight instruments to evaluate habitability and detect biosignatures; and the interpretation of astrobiology mission and astronomical data.
The CheMin Instrument
The Exobiology Branch is home to David Blake, the Principal Investigator for the CheMin instrument on the Mars Science Laboratory, scheduled for launch in 2011.
The CheMin instrument utilizes X-ray diffraction and flourescence to provide difinitive minerology of rock samples (both elemental analysis and crystal structure determination).
Early Habitable Environments and the Evolution of Complexity
The Exobiology Branch is home to David Des Marais, the Principal Investigator of the NASA Astrobiology Institute (NAI) Ames Team, which focuses on Early Habitable Environments and the Evolution of Complexity. The overarching goal of this scientific program is to understand the creation and distribution of early habitable environments in emerging planetary systems. The Ames Team provides a program of integrative, mission-enabled and mission-enabling research on habitability and a thematically related program of education and public outreach focused around informal education in high-impact venues. Andrew Pohorille, Tori Hoehler, and Sandy Dueck are also members of the Exobiology Branch and hold key roles as Lead Co-Investigators on the team. To learn more about the NAI Ames Team, visit their website at www.amesteam.arc.nasa.gov.
Origin of Life Research
For nearly 40 years, the Exobiology Branch at Ames has been the main center for origins of life research at NASA, and a world leader in this scientific area. Currently, the branch has the unique feature of being the only center within the NASA Astrobiology Program that has a sustained, long-term program of theoretical and computational studies on the origins of life. This research program, which contains both molecular and system-level components, is leveraged by the supercomputing facilities at Ames and by Ames’ status as the NASA lead center in information science and technology.
The image shown above is the cover art for the latest issue of the Journal of Physical Chemistry, highlighting an article by Andrew Pohorille, a Principal Investigator in the Branch, with co-authors Christopher Jarzynski and Christophe Chipot, titled “Good practices in free-energy calculations”. From the abstract: “As access to computational resources continues to increase, free-energy calculations have emerged as a powerful tool that can play a predictive role in a wide range of research areas. … In this contribution, the current best practices for carrying out free-energy calculations using free energy perturbation and nonequilibrium work methods are discussed demonstrating that, at little to no additional cost, free-energy estimates could be markedly improved and bounded by meaningful error estimates.”
Dr. Pohorille is also the recepient of this year’s H. Julian Allen Award, bestowed by NASA Ames for best research paper. Titled “Calculating free energies using average force”, the paper appeared in the Journal of Chemical Physics (co-author Eric Darve), Volume 115, Number 20, November 2001. According to the Citation Index in the Web of Science the paper has been cited 111 times as of March 2010. From the abstract: “A new, general formula that connects the derivatives of the free energy along the selected, generalized coordinates of the system with the instantaneous force acting on these coordinates is derived. The instantaneous force is defined as the force acting on the coordinate of interest so that when it is subtracted from the equations of motion the acceleration along this coordinate is zero. The formula applies to simulations in which the selected coordinates are either unconstrained or constrained to fixed values.”
The Branch is also home to Dr. Arthur Weber, a SETI Institute researcher, who works together with his wife Esther to study the pre-biotic chemistry of sugars, and how these molecules may have led to the origin of life.
The Branch is housed in Building 239 at NASA Ames Research Center. Laboratory facilities available include analytical equipment for the characterization of gas and aqueous chemistry, instruments for the detection of various biomarkers including sugars and organics, microbiology facilities including the culture of microbial mat communities, electron and RAMAN microscopes, a molecular biology suite, and informatics computational capabilities.
Code SSX Highlights
Dr. David Summers presented a paper at the American Chemical Society National Meeting entitled: Abiotic fixation of nitrogen on terrestrial planets: Experimental results and their implications. Abstract: The abiotic fixation of nitrogen on the early Earth and other terrestrial planets is important for habitability, life, and geochemistry. Using Mars as an example, an atmospheric pressure […]
“Duetto,” a commercial spinoff of the CheMin instrument on Mars Science Laboratory (PI: Dave Blake, SSX) is being used for conservation efforts by the Getty Museum. The instrument, built by inXitu, Inc., analyzes art objects and antiquities in situ. Duetto was first used to analyze the collection of antiquities, outdoor sculptures and manuscripts at the […]
David Blake presented a paper titled “The Use of Field-Portable pXRD for the Rapid Identification of Counterfeit Pharmaceutical Products and Subsequent Excipient Identification and Quantification” at the 9th Pharmaceutical Powder X-ray Diffraction Conference held last week in Hilton Head Island, South Carolina. In the talk, Blake presented XRD data on real and counterfeit malaria drugs […]
The Terra portable XRD/XRF, which is a commercial version of the Ames CheMin instrument that is on the Mars Science Laboratory mission, was awarded the Gold medal as “Best New Product” at the 2009 PITCON conference this week. PITCON is the largest commercial instrument conference in the world. Terra is offered by inXitu, Inc., a […]
Tori Hoehler was a speaker/panelist at a public event at Chabot Space & Science Center. Hoehler and UC Berkeley professor Gibor Basri provided astrobiology and astronomy perspectives, respectively, as they interacted with a live audience to explore the subject of extrasolar planets. The panel discussion was the culmination of a night-long series of exoplanet-themed events […]
A paper characterizing a new extremophilic bacterium, isolated from a saturated salt crust from Searles Lake will be published in the April issue of /Applied and Environmental Microbiology/. The bacterium has been named in honor of the late NASA Ames geomicrobiologist, Dr. Melvin Silverman. /Halarsenatibacter silvermanii /Switzer Blum et al., sp. nov. grows by arsenate […]
Paper published March 27, 2009: David P. Summers, Juan Noveron & Ranor C. B. Basa, Energy Transduction Inside of Amphiphilic Vesicles: Encapsulation of Photochemically Active Semiconducting Particles, Orig. Life Evol. Biosp. 39(2009)127-140 […]
Dr Adrian Brown published two articles this week in The Space Review on the technical and bugetary reasons behind the delay of the Mars Science Laboratory mission. For more details, see http://thespacereview.com. […]
Attended the Division for Planetary Science Conference October 4 -9. I presented a talk entitled “Abiotic Nitrogen Fixation on Terrestrial Planets” (coauthors Bishun Khare, Ranor Basa, and David Rodoni) on October 8th. I also chaired session 54: Mars: Atmosphere II […]
Tori Hoehler (SSX) was a keynote speaker at an international conference on scientific ocean drilling in Bremen, Germany. The conference, attended by more than 600 scientists, government officials, and funding agency representatives, served to establish science and technology priorities for the next decade of deep-ocean drilling. At the request of the conference organizers, Hoehler’s presentation […]