Researchers from NAI's Marine Biological Laboratory Team continue their study of the deep biosphere, reporting the latest results in Nature. This new study reveals that bacterial communities dwelling on ocean-bottom rocks are more abundant and diverse than previously thought, especially relative to the overlying water column. The microbes appear to ?feed? on the oceanic crust through seawater-rock alteration reactions involving the oxidation and hydration of glassy basalt. [Source: NAI Newsletter]

Posted by Keith Cowing at 3:22 PM | Permalink | Comments (0)

Astrobiology December 2007, 7(6): 987-1005

http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2007.0075

We examine means for driving hydrothermal activity in extraterrestrial oceans on planets and satellites of less than one Earth mass, with implications for sustaining a low level of biological activity over geological timescales. Assuming ocean planets have olivine-dominated lithospheres, a model for cooling-induced thermal cracking shows how variation in planet size and internal thermal energy may drive variation in the dominant type of hydrothermal system--for example, high or low temperature system or chemically driven system.

Continue reading "Hydrothermal Systems in Small Ocean Planets" »

Posted by Keith Cowing at 9:46 AM | Permalink | Comments (0)

Astrobiology December 2007, 7(6): 971-986

http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2006.0096

Dissolved H2 concentrations up to the mM range and H2 levels up to 9-58% by volume in the free gas phase are reported for groundwaters at sites in the Precambrian shields of Canada and Finland. Along with previously reported dissolved H2 concentrations up to 7.4 mM for groundwaters from the Witwatersrand Basin, South Africa, these findings indicate that deep Precambrian Shield fracture waters contain some of the highest levels of dissolved H2 ever reported and represent a potentially important energy-rich environment for subsurface microbial life. The

Continue reading "Hydrogeologic Controls on Episodic H2 Release from Precambrian Fractured Rocks--Energy for Deep Subsurface Life on Earth and Mars" »

Posted by Keith Cowing at 9:45 AM | Permalink | Comments (0)

Astrobiology December 2007, 7(6): 933-950

http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2006.0119

Numerical models are employed to investigate sources of chemical energy for autotrophic microbial metabolism that develop during mixing of oxidized seawater with strongly reduced fluids discharged from ultramafic-hosted hydrothermal systems on the seafloor. Hydrothermal fluids in these systems are highly enriched in H2 and CH4 as a result of alteration of ultramafic rocks (serpentinization) in the subsurface. Based on the availability of chemical energy sources, inferences are made about the likely metabolic diversity, relative abundance, and spatial distribution of microorganisms within ultramafic-hosted systems.

Continue reading "Geochemical Constraints on Sources of Metabolic Energy for Chemolithoautotrophy in Ultramafic-Hosted Deep-Sea Hydrothermal Systems" »

Posted by Keith Cowing at 9:43 AM | Permalink | Comments (0)

Astrobiology December 2007, 7(6): 905-932

http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2007.0128

In June 2003, the geochemical composition of geothermal fluids was determined at 9 sites in the Vulcano hydrothermal system, including sediment seeps, geothermal wells, and submarine vents. Compositional data were combined with standard state reaction properties to determine the overall Gibbs free energy (

Continue reading "Temporal Changes in Fluid Chemistry and Energy Profiles in the Vulcano Island Hydrothermal System" »

Posted by Keith Cowing at 9:42 AM | Permalink | Comments (0)

With support from NAI Teams at the Carnegie Institution of Washington and UC Berkeley, researchers at the American Type Culture Collection and their colleagues have a new paper in PLOS One describing a novel lineage of proteobacteria which are dominant in iron-rich hydrothermal vent sites on the Loihi Seamount near Hawai'i. They form a unique morphological structure which could serve as a fossil biomarker.

[Source: NAI Newsletter]

Posted by Keith Cowing at 8:47 PM | Permalink | Comments (0)

NAI's Marine Biological Laboratory Team has a new paper in Science detailing aspects of population structure for microbial communities at two neighboring hydrothermal vents. Using environmental DNA sequencing techniques, they found the two populations reflect the geochemical conditions of each vent. [Source: NAI Newsletter]

Posted by Keith Cowing at 12:00 PM | Permalink | Comments (0)

Scientists from NAI's University of California, Berkeley Team have a new paper out in Nature outlining evidence for the presence of an ancient ocean on Mars. The study points to a large body of liquid water at the pole which could have shifted Mars' spin axis. This shift would have in turn deformed the shoreline of this ocean relative to the rest of the surface topography, in accordance with observations. [Source: NAI Newsletter]

Posted by Keith Cowing at 8:25 AM | Permalink | Comments (0)

Speaker: Steven D'Hondt (University of Rhode Island); Date/Time: Monday, April 30, 2007 11AM PDT

For more information and participation instructions, visit: http://nai.arc.nasa.gov/seminars/seminar_detail.cfm?ID=102 [Source: NAI Newsletter]

Posted by Keith Cowing at 10:01 PM | Permalink | Comments (0)

NAI's Marine Biological Laboratory and Carnegie Institution of Washington Teams are contributing authors on a new paper in Earth and Planetary Science Letters presenting a new model for the evolution of Proterozoic deep seawater composition based on rare earth elements. Their data suggest transitional, suboxic conditions in the deep ocean (vs. sulfidic), which likely limited nutrient concentrations in seawater and, consequently, may have constrained biological evolution. [Source: NAI Newsletter]

Posted by Keith Cowing at 8:25 PM | Permalink | Comments (0)

Underwater robots work together without human input, Princeton University

"This August in Monterey Bay, Calif., an entire fleet of undersea robots will for the first time work together without the aid of humans to make detailed and efficient observations of the ocean. The mathematical system that allows the undersea robots to self-choreograph their movements in response to their environment might one day power other robotic teams that - without human supervision - could explore not just oceans, but deserts, rain forests and even other planets."

Posted by Keith Cowing at 11:31 PM | Permalink | Comments (0)

Undersea Vehicles to Study Formation of Gold and Other Precious Metals On the Pacific Ocean Floor, WHOI

"The joint expedition includes a 32-day WHOI research program funded by the U.S. National Science Foundation to the Pacmanus vent sites in the Eastern Manus Basin. The remotely operated vehicle Jason will be used to survey and map the vent areas around an Ocean Drilling Program hole drilled in 2000."

Posted by Keith Cowing at 12:46 AM | Permalink | Comments (0)

Descent Into the Ice, NOVA, PBS

"A team of "glacionauts" ventures into a labyrinth of unexplored and hazardous glacier caves on France's Mt. Blanc."

Editor's note: Highly recommended.

Posted by Keith Cowing at 3:26 PM | Permalink | Comments (0)

Researchers from NAI's University of Rhode Island Team and their colleagues have studied the use of phosphorus vs. sulfur in the membrane lipid sythesis pathways of organisms resident in the ocean's subtropical gyres.

Continue reading "Strategies for Evolutionary Success - Sulfolipids" »

Posted by Keith Cowing at 12:19 AM | Permalink | Comments (0)

Dave Goldberg at Lamont Doherty Earth Observatory, and his colleague Howard Shuman, Professor of Microbiology at Columbia University, have funding and an immediate opening for a summer student / intern at Columbia on a microbiology project involving subseafloor samples. If you have a student who is looking for an interesting summer job, please contact Dave directly at 845-365-8674 or goldberg@ldeo.columbia.edu [Source: NAI Newsletter]

Posted by Keith Cowing at 11:56 PM | Permalink | Comments (0)

The Integrated Ocean Drilling Program Management International (IODP-MI) and Joint Oceanographic Institutions (JOI) announce an international workshop on subseafloor life. The workshop will be held in Vancouver, British Columbia, October 3-5, 2006.

Continue reading "IODP International Workshop: Exploring Subseafloor Life With the Integrated Ocean Drilling Program" »

Posted by Keith Cowing at 10:10 PM | Permalink | Comments (0)