Exobiology Branch (Code SSX)

The CheMin Instrument on the Mars Science Laboratory
The CheMin Instrument on the Mars Science Laboratory

Mission Statement

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.

Exobiology Branch 2015
Exobiology Branch 2015 – 1st row left to right. David Blake, Orlando Santos, Esther Weber, Mark Ditzler, David Des Marais, Linda Jahnke 2nd row left to right. Arthur Weber, George Cooper 3rd row left to right. Michael Kubo, Rocco Mancinelli, Jackson Lee, Tori Hoehler 4th row left to right. Sanjoy Som, Thomas Murphy, Andro Rios, Mike Wilson 5th row left to right. Fathi Karouia, Craig Everroad, Milena Popović, Samantha Yim, Niki Parenteau 6th row left to right. Joshua Reynolds, Bennett Kapili, Melissa Thang, Yasaman Mortensen 7th row left to right. Adrian Carabello, Leslie Bebout, Marisa Mayer, Angela Detweiler, Mastewal Abate, Oana Marcu Sandy Dueck, Joseph Solvason – Principal Investigators not pictured. Brad Bebout, Tom Bristow, Andrew Pohorille, David Summers

 

 

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.

CheMin field testing in Death Valley
CheMin field testing in Death Valley

 

A Miniature Gas Chromatograph-Ion Mobility Spectrometer
A Miniature Gas Chromatograph-Ion Mobility Spectrometer

 

The CheMin instrument utilizes X-ray diffraction and flourescence to provide difinitive minerology of rock samples (both elemental analysis and crystal structure determination).

CheMin
The CheMin instrument being integrated onto the MSL rover. Next stop, Mars!

 

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.

 

NAI Team
NAI Team

 

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.

 

Pohorille Article
Pohorille Article

 

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.

 

Weber Lab - The role of sugars in pre-biotic chemistry.
Weber Lab – The role of sugars in pre-biotic chemistry.

 

Facilities

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. Hoehler delivers keynote lecture at ISSM 2011

Tori Hoehler (SSX) delivered a keynote lecture at the 2011 meeting of the International Society for Subsurface Microbiology. Hoehler’s lecture, entitled, “Energetic constraints on subsurface life: A case study of methanogenesis in serpentinizing systems” focused on constraining the habitability of subsurface environments through thermodynamic and bioenergetic models. The lecture focused on a case study developed […]

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Seasonal Flows on Warm Martian Slopes

Short story: We have taken repeat images of dark flows at several sites on Mars using the Mars Reconnaissance Orbiter’s (MRO) High Resolution Imaging Science Experiment (HiRISE) camera. These features extend down slope from bedrock outcrops and appear to lengthen during warm seasons and fade in cold seasons. Flows recur over periods of months (to […]

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Ames’ Leslie Bebout is featured in an article
Lee Bebout

Ames’ Leslie Bebout is featured in an article about growing algae on long term space flights in the Algae Industry Magazine: http://www.algaeindustrymagazine.com/aim-interview-nasa-ames-dr-leslie-prufert-bebout/ May 22, 2011, by David SchwartzAlgaeIndustryMagazine.com […]

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Ames Scientists to be highlighted in KQED Quest episode
Blake in field

Ames Scientists David Blake (Exobiology), Tori Hoehler (Exobiology) and Chris McKay (Planetary Systems) will be featured in an upcoming Quest episode on KQED. The episode, which has a segment called “Searching for life on Mars with NASA Ames’ rover” will air on May 4th at 7:30 PM on KQED. The segment highlights Ames involvement in […]

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Hoehler presents invited lectures to the Max Planck Society and the Dark Energy Biosphere Institute
Hoehler presents invited lectures to the Max Planck Society and the Dark Energy Biosphere Institute

Tori Hoehler presented two invited lectures during the past two weeks. The first, entitled, “Equating energy and biological potential” was presented at a symposium on deep biosphere sediment microbiology. The symposium was organized by the Dark Energy Biosphere Institute. The second talk, entitled, “Physicochemical characteristics and biological potential of aqueous environments beyond Earth” was presented […]

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Hoehler presents Caltech Astronomy & Astrophysics Colloquium

Tori Hoehler (SSX) presented the Caltech Astronomy & Astrophysics Colloquium on February 2. The lecture, entitled, “Physical and chemical toeholds for exoplanet bioastronomy” was designed to demonstrate conceptually and by example that significant functional constraints can be emplaced on the core astrobiological concepts of habitability and biosignatures solely by reference to fundamental principles in chemistry […]

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Dr. Hoehler presents keynote address at Extremophiles 2010 Conference

Tori Hoehler presented a keynote address at the international Extremophiles 2010 conference in Ponta Delgada, Azores. The lecture was entitled, “Compound extremes and energy limitation in aqueous environments on Mars: A case-study of methanogenesis in serpentinizing systems“. The Extremophiles conference is an annual meeting highlighting new research into microorganisms that inhabit environments characterized by physicochemical […]

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Research Proposal Selected

An Exploration Systems Mission Directorate to support crew health and performance in space exploration proposal was successfully selected as a step 1 proposal under the leadership of Orlando Santos and Fathi Karouia from the Exobiology Branch to assess what changes are occurring within the astronaut’s microbial communities during long duration spaceflight that may induce health […]

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Seeking Signs of Life
Seeking Signs of Life

Seeking Signs of Life: A Symposium Celebrating the 50th Anniversary of NASA’s Exo/Astrobiology Program aired on Thursday October 14, 2010. http://www.livestream.com/astrobiology50th […]

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