Astrobiology December 2007, 7(6): 1023-1032

http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2006.0091

The shallow habitable region of cratonal crust deforms with a strain rate on the order of 1019 s1. This is rapid enough that small seismic events are expected on one-kilometer spatial scales and one-million-year timescales. Rock faulting has the potential to release batches of biological substrate, such as dissolved H2, permitting transient blooms.

Continue reading "Did Earthquakes Keep the Early Crust Habitable?" »

Posted by Keith Cowing at 9:48 AM | Permalink | Comments (0)

Researchers from NAI's University of Hawai'i Team and their colleagues have a new paper in Geobiology reviewing recent work on the climatic, geochemical, and ecological events that preceded animal fossils, considering their portent for metazoan evolution. They also consider recent published research on the nature and chronology of the earliest fossil record of metazoans, and on the molecular-based analysis that yielded dates older than the last 35 million years of the Precambrian for the appearance of major animal groups.

[Source: NAI Newsletter]

Posted by Keith Cowing at 8:48 PM | Permalink | Comments (0)

The goal of research funded under the interdisciplinary P2C2 solicitation is to utilize key geological, chemical, and biological records of climate system variability to provide insights into the mechanisms and rate of change that characterized Earth's past climate variability, the sensitivity of Earth's climate system to changes in forcing, and the response of key components of the Earth system to these changes.

Continue reading "NSF Funding Opportunity: Paleo Perspectives on Climate Change (P2C2)" »

Posted by Keith Cowing at 8:45 PM | Permalink | Comments (0)

NAI's Astrobiology Drilling Program supported researchers in 2004 to obtain subsurface core samples from the Hamersley Basin in Western Australia. Those samples, representing the time just before the Great Oxidation Event, have been analyzed, and two research papers detailing the results (Anbar, et al. and Kaufman, et al.) appear in September 28, 2007 issue of Science. Both groups found unexpected, correlated changes that reveal the presence of small but significant amounts of O2 in the environment 2.5 billion years ago, ~50-100 milion years before the Great Oxidation Event, and a shift from lower O2 abundance prior to that time. [Source: NAI Newsletter]

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

Researchers from NAI's Carnegie Institution of Washington Team have a paper in Nature describing evidence that Earth's Mesoarchean atmosphere (3.2 and 2.8 Gya) possessed very low amounts oxygen. These findings contrast with prior claims that Earth's atmosphere underwent its first rise in oxygen during the Mesoarchean, and indicate that oxygen first rose above parts per million levels sometime between 2.45 and 2.4 billion years ago. [Source: NAI Newsletter]

Posted by Keith Cowing at 12:01 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)

Biomarkers in rocks prior to the rise in Earth's atmospheric oxygen 2.5 billion years ago show cyanobacteria released oxygen at the same levels as today. What was happening to that oxygen? A new paper in Nature from NAI's Penn State Team proposes that the rise of atmospheric oxygen occurred because the predominant sink for oxygen--enhanced submarine volcanism--was abruptly and permanently diminished during the Archaean-Proterozoic transition by a shift from predominantly submarine volcanism to a mix of subaerial and submarine volcanism.

Source: NAI Newsletter

Posted by Keith Cowing at 7:41 AM | Permalink | Comments (0)

An international team of researchers, including members of NASA Astrobiology Institute's (NAI) Virtual Planetary Laboratory team used NASA's Spitzer Space telescope to detect the presence of water vapor on the hot Jupiter Henry Draper (HD) Catalog 189733b. (The "b" after the number indicates that the reference is to a planet circling the star with that number.)

This is significant because several attempts to detect water on such planets either failed to find compelling evidence or made it clear that their claims should not be taken as fact. An article about this study was published recently in Nature magazine. The study's primary author, Giovanna Tinetti was a 2003 NAI Postdoctoral Fellow.

Posted by Keith Cowing at 11:03 AM | Permalink | Comments (0)

This new video from JPL shows how NASA astrobiologists are gathering exciting clues that will help them pick the best spots to search for possible signs of life beyond Earth. http://www.jpl.nasa.gov/videos/phoenix/phx20070724/ [Source: NAI Newsletter]

Posted by Keith Cowing at 12:17 PM | Permalink | Comments (0)

Deep inside a flooded mine in Wisconsin, scientists from NAI’s University of California, Berkeley Team have discovered an environment in which bacteria emit proteins that sweep up metal nanoparticles into immobile clumps. Their finding may lead to innovative ways to remediate subsurface metal toxins, and have exciting implications for identifying biosignatures on Earth and other worlds. The research, published in the June 14th issue of Science, was done in collaboration with a team from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory. [Source: NAI Newsletter]

Posted by Keith Cowing at 8:26 AM | Permalink | Comments (0)

Jennifer Heldmann has been invited to participate in a special COSPAR Colloquium on Mars Special Regions. This meeting is an essential step in developing an international consensus on the definition of "special" regions on Mars, which will in-turn determine the application of planetary protection requirements for future Mars lander missions. This 3-day meeting will take place in Rome, Italy on 18-20 September 2007. For more on COSPAR Colloquia visit: http://cosparhq.cnes.fr/Meetings/Colloq.htm

Posted by Keith Cowing at 4:17 PM | Permalink | Comments (0)

A NASA Astrobiology Institute Field Workshop "Biosignatures in Ancient Rocks (BAR)" will be held during September 18-28 in Ontario, Canada. See the details at http://psarc.geosc.psu.edu/RESEARCH/New_Conference/Ontario_new.htm [Source: NAI Newsletter]

Posted by Keith Cowing at 3:49 PM | Permalink | Comments (0)

NAI scientists from the Carnegie Institution of Washington Team and their colleagues have a new paper in Geology outlining their process in resolving the mysterious identity of the Devonian fossil organism Prototaxities as a fungus. The team analyzed carbon isotopic ratios of the fossil relative to plants that lived in the same environment 400 million years ago. [Source: NAI Newsletter]

Posted by Keith Cowing at 3:51 PM | Permalink | Comments (0)

UW Seminar: Four Billion Years of Climate Change (Lessons from the Precambrian): From Oxygen Poisoning to Snowballs & True Polar Wander Presenter: Joe Kirschvink

Date/Time: 5/29/2007 02:30 PM PDT

Continue reading "Seminar" »

Posted by Keith Cowing at 3:48 PM | Permalink | Comments (0)

Multidisciplinary work from members of NAI's SETI Institute Team and a host of collaborators across the NAI re-examines what is known at present about the potential for a terrestrial planet forming within, or migrating into, the classic liquid–surface–water habitable zone close to an M dwarf star. Their new paper, published in the current issue of Astrobiology, presents the summary conclusions of an interdisciplinary workshop sponsored by NAI and convened at the SETI Institute in 2005. [Source: NAI Newsletter]

Posted by Keith Cowing at 10:58 PM | Permalink | Comments (0)

Differently colored plants may live on extra-solar planets, according to two new papers in the current issue of Astrobiology authored by members of NAI's Virtual Planetary Laboratory Alumni Team and their colleagues. They took previously simulated planetary atmospheric compositions for Earth-like planets orbiting various star types (including M stars), generated spectra, and found that photosynthetic pigments may peak in absorbance in the blue for some star types, and red-orange and near-infrared for others. Their results also suggest that, under water, organisms would still be able to survive ultraviolet flares from young M stars and acquire adequate light for growth - which greatly increases the scope for habitability in these systems. [Source: NAI Newsletter]

Posted by Keith Cowing at 10:57 PM | Permalink | Comments (0)

NAI Postdoctoral Fellow Sean Raymond leads a team of authors from NAI's University of Colorado, Boulder, and University of Arizona Teams, and Virtual Planetary Laboratory and University of Washington Alumni Teams in a new publication in Astrobiology. They present analysis of water delivery and planetary habitability in 5 high-resolution simulations forming 15 terrestrial planets. Their results outline a new model for water delivery to terrestrial planets in dynamically calm systems, which may be very common in the Galaxy. [Source: NAI Newsletter]

Posted by Keith Cowing at 10:56 PM | Permalink | Comments (0)

New work from NAI NASA Ames Research Center Team members and their colleagues published recently in PNAS suggests that the cause for much of the extended red emission, or ERE, is due to closed-shell cationic polycyclic aromatic hydrocarbon, or PAH, dimers. Their work sheds light on the processes involved in carbonaceous dust evolution in the interstellar medium. [Source: NAI Newsletter]

Posted by Keith Cowing at 11:00 PM | Permalink | Comments (0)

Search for Habitable Planets Outside Earth's Solar System in Astrobiology

"Which planets outside of Earth's Solar System are most likely to be capable of supporting life is a question that will be the focus of both a NASA-sponsored workshop later this year and a special collection of papers in the Spring 2007 (Volume 7, Number 1) issue of Astrobiology, a peer-reviewed journal published by Mary Ann Liebert, Inc."

Posted by Keith Cowing at 1:48 PM | Permalink | Comments (0)

Special session at the 210th Meeting of the American Astronomical Society in Honolulu, Hawaii
Thursday May 31 (Morning) Convenors: Nader Haghighipour and Eric Gaidos (University of Hawaii NAI Lead Team)

Continue reading "Hot Earths: Formation, Detection and Structure" »

Posted by Keith Cowing at 8:29 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)

Special Session "Microbially mediated processes governing the redox cycling of metals" at the 2007 Goldschmidt Conference, Cologne (Germany) Session Organizers: Colleen Hansel, School of Engineering and Applied Sciences, Harvard University Andreas Kappler, Center for Applied Geoscience, University of Tübingen

Continue reading "Microbially mediated processes governing the redox cycling of metals" »

Posted by Keith Cowing at 8:33 PM | Permalink | Comments (0)

Speaker: Tim Raub (Yale University), Date/Time: Monday, February 26, 2007 11AM PST

Background: Using atmospheric chemical models of a Snowball Earth, scientists from NAI's Alumni Virtual Planetary Laboratory Team showed that, during long and severe glacial intervals, a weak hydrological cycle coupled with photochemical reactions involving water vapor would give rise to the sustained production of hydrogen peroxide. The peroxide, upon release from melting ice into the oceans and atmosphere at the end of the snowball event, could mediate global oxidation events.

Continue reading "NAI Director's Seminar "New and Emerging Perspectives on Late Precambrian 'Snowball Earth' Glaciation"" »

Posted by Keith Cowing at 1:19 AM | Permalink | Comments (0)

Using atmospheric chemical models of a Snowball Earth, scientists from NAI's Alumni Virtual Planetary Laboratory Team show that, during long and severe glacial intervals, a weak hydrological cycle coupled with photochemical reactions involving water vapor would give rise to the sustained production of hydrogen peroxide. The peroxide, upon release from melting ice into the oceans and atmosphere at the end of the snowball event, could mediate global oxidation events. Their results are published in the December 12th issue of PNAS. [Source: NAI Newsletter]

Production of hydrogen peroxide in the atmosphere of a Snowball Earth and the origin of oxygenic photosynthesis, PNAS

Continue reading "Snowball Earth and the Origin of Photosynthesis" »

Posted by Keith Cowing at 1:20 AM | Permalink | Comments (0)

Robert Hazen, from NAI's Carnegie Institution of Washington Team, published his 2005 Presidential Address to the Mineralogical Society of America in this month's American Mineralogist.

Continue reading "Mineral Surfaces and Life" »

Posted by Keith Cowing at 12:27 AM | Permalink | Comments (0)

The December 2006 issue of Geobiology is a collection of papers focusing on the history of Earth's biogeochemistry, from the earliest sedimentary rocks in Greenland to the late Proterozoic. The rise of atmospheric oxygen provides a thematic link.

Continue reading "Oxygen and Life in the Precambrian" »

Posted by Keith Cowing at 12:26 AM | Permalink | Comments (0)

NAI has approved funding for the development of a new, state-of-the-art facility capable of recreating past atmospheric and oceanic conditions, to be called VAL, the Variable Atmospheres Laboratory. Capable of simulating various combinations of oxygen, carbon dioxide, temperature, and hydrogen sulfide levels, this facility will be able to test new hypotheses for the cause of some of the Earth's major mass extinction events - such as the Permian and Triassic mass extinctions.

Continue reading "NAI Researchers to Recreate Conditions of the Early Earth" »

Posted by Keith Cowing at 12:23 AM | Permalink | Comments (0)

Philosophical Transactions of the Royal Society (B). Organised and edited by Charles Cockell, Sydney Leach and Ian Smith Published August 2006

Continue reading "Conditions for the Emergence of Life on the Early Earth: Special Issue Special Issue" »

Posted by Keith Cowing at 9:50 PM | Permalink | Comments (0)

Speakers: Sean Raymond (University of Colorado) and Avi Mandell (Goddard Space Flight Center) Date/Time: Monday, November 27, 2006 11AM PST

Continue reading "NAI Director's Seminar 11/27: Formation of Habitable Planetary Systems: Are We Normal?" »

Posted by Keith Cowing at 9:49 PM | Permalink | Comments (0)

Towards the end of our summer expedition while flying back to Eureka from our camp on Axel Heiberg, I spotted a lake with what appeared to be green ice on it.

Continue reading "Green ice, Ravens, Ice Caves and the Movie ‘Contact’" »

Posted by Dale Andersen at 6:58 PM | Permalink | Comments (0)

Andrey Bekker of NAI's Carnegie Institution of Washington Team and his colleagues have an article in press for Precambrian Research which details the carbon isotope record for the carbonate platform in the Great Lakes area.

Continue reading "Carbon Isotope Record from ~2.2 Ga Rocks in the Great Lakes Area" »

Posted by Keith Cowing at 10:54 AM | Permalink | Comments (0)