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2008 Annual Science Report

Reporting  |  JUL 2007 – JUN 2008

Carl Pilcher
NAI Director: Carl Pilcher
Letter from the Director: 2008 NAI Annual Report

I am very pleased to release this latest NAI Annual Report, covering the period from July 1, 2007 to June 30, 2008. We have modified the NAI website to make this report (and those of the past several years) more accessible and user friendly. In addition to viewing the Annual Report by team, as before, you can now also view it by Astrobiology Roadmap Goal and Objective, as well as by Tags associated with each Project Report.

The NAI passed a number of major milestones this year. The first was the December 2007 publication of the National Research Council (NRC) Assessment of the NAI, the culmination of a “blue ribbon panel” review of the Institute’s effectiveness in its first decade of operations. In the opening pages of the Assessment, the NRC panel wrote “Overall, the committee is unanimous in finding that the NAI has fulfilled its original mandate. The NAI has played a key role in supporting the development of astrobiology and has positively affected NASA’s current and future missions.” The 67-page report goes on to describe in detail the accomplishments of the NAI over its 10-year history and recommends that support for the NAI be continued.

In January 2008, NASA released Cooperative Agreement Notice Cycle-5 (CAN-5) soliciting proposals for new NAI teams. Proposals were received in April, reviewed over the summer, and in October NASA announced the selection of ten new science teams. This is a major endorsement by NASA of the NAI’s past success and its future potential. The new teams and the four continuing teams began working together in early 2009 to integrate their activities and ensure that the whole is greater than the sum of its parts—a watchword for the NAI.

At the request of NASA Headquarters, NAI Central designed a new website for the NASA Astrobiology Program, which was launched in March 2008. The new site creates a web presence for the Exobiology, ASTID and ASTEP programs and integrates them with the NAI website in one seamless web presence. NAI is operating the integrated website for NASA Headquarters.

The NAI 2007 Director’s Discretionary Fund awardees began their work during the reporting year. Reports on their progress and outcomes are posted online. The 2008 DDF award competition was posted in the Spring of 2008, following the CAN-5 competition, and selections were announced in late summer.

Five new NAI Postdoctoral Fellows were selected during the past year (see the November 13, 2008 and March 7, 2008 Newsletters). During the Summer of 2007, six young researchers were awarded grants from The Lewis and Clark Fund for Exploration and Field Research in Astrobiology, in partnership with the American Philosophical Society. Their work took them to far-flung places around the globe including Greenland, The Andes, and Iceland. In the Summer of 2008, another 9 young researchers received Lewis and Clark awards.

Three proposals were selected for the NAI Minority Institution Research Support (MIRS) program: LeeAnne Martinez, an Associate Professor of Biology at Colorado State will work with NAI UCLA scientists to explore horizontal transfer of operational genes that may lead to the incorporation of endosymbionts by diatoms; Prabhakar Misra, Professor of Physics and Astronomy at Howard University, will work with the NAI NASA Goddard Space Flight Center (GSFC) team on “Spectroscopy and Analytical Protocols for Organic Molecules of Relevance to the Origin of Life on Mars and Earth;” and Erik Melchiorre, Associate Professor of Geology, California State University, San Bernardino, will work with the NAI University of Hawaii (UH) team on “Planetary Habitability and the Origins of Life: Evaluation of Mineralogical Evidence for Extremophile Colonization within Terrestrial Subduction Zones.”

The NAI participated in the 2008Astrobiology Science Conference (AbSciCon) held in Santa Clara, California. In addition to the many NAI scientists who attended and presented papers, the Institute once again hosted a Student Poster Competition. NAI Focus Groups met to discuss their work, and the NAI provided support for the Astrobiology Graduate Student Conference (AbGradCon) which took place in tandem with AbSciCon.

The Encyclopedia of Life (EOL), an outgrowth of work by NAI’s Marine Biological Laboratory (MBL) team, made its debut in 2008. The EOL will be a living catalogue of biodiversity, with one webpage for each of Earth’s 1.8 million species.

An NAI Central proposal entitled “NASA and the Navajo Nation 2: The Moon” was selected for funding by the NASA Science Mission Directorate E/PO Program. This award enables the continued collaboration with leaders and educators from the Navajo Nation toward the production of educational materials which bring together astrobiology science and Navajo cultural knowledge, in particular of the Moon.

It was of course another exciting year of scientific advances. NAI-supported research included the following:

An international team of researchers including members of NAI’s Virtual Planetary Laboratory at the University of Washington (VPL@UW) team used NASA’s Spitzer Space Telescope to detect the presence of water vapor on the hot jupiter HD 189733b.

New experiments by members of the NAI NASA Ames team showed that small, simple enzymes can be readily created de novo. This study presents a potential scenario for the origin of the earliest biopolymers, and sheds new light on the potential for life beyond Earth.

NAI’s Pennsylvania State University (PSU) team proposed 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.

NAI’s UH team developed a climate model that accounts for the advance and retreat of subsurface martian ice layers. The model reveals forty major ice ages over the past five million years, and predicts the present distribution of subsurface ice on Mars. Their findings outline expectations of ice stratigraphy at the NASA Mars Phoenix Mission’s landing site.

Analyzing subsurface core samples from the NAI’s Astrobiology Drilling Program in the Hamersley Basin, Australia, researchers found unexpected, correlated changes that reveal the presence of small but “significant amounts of O~2~ 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.

NAI’s MBL team continued to detail aspects of population structure for microbial communities in the deep marine biosphere, at two neighboring hydrothermal vents. Using environmental DNA sequencing techniques, they found the two populations reflect the geochemical conditions of each vent.

Researchers from NAI’s Carnegie Institution of Washington (CIW) team found evidence that Earth’s Mesoarchean atmosphere (from 3.2 to 2.8 billion years ago) possessed very low amounts of 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.

NAI’s University of Arizona Team reported that the geochemistry of phosphorus on the early Earth was controlled by more reduced phosphorus compounds such as phosphite, rather than orthophosphate. This alternate view of early Earth phosphorus geochemistry provides a new mechanism for the formation of prebiotic phosphorus compounds.

Research by NAI’s UH Team indicates that astronomers will eventually be able to discriminate between extrasolar Earth-like planets with surface oceans and those without using the shape of phase light curves in the visible and near-IR spectral regions. Their results suggest several new ways of directly identifying water on distant planets.

Scientists from NAI’s CIW Team discovered amino acids in two meteorites at concentrations ten times higher than levels previously measured in similar meteorites. The result suggests that the early solar system was far richer in the organic building blocks of life than previously thought, and that fallout from space may have spiked Earth’s primordial broth.

A team of researchers including scientists from NAI’s VPL@UW Team have developed an approach for predicting the color of plants on extrasolar planets. The study considered the development of photosynthesis on a planet orbiting a parent star different from the sun. The wavelengths of light used for photosynthesis would depend on the parent star’s spectrum and other factors, potentially leading to organisms with spectral signatures quite different from those of Earth’s light-harvesting biota.

NAI CIW and UCLA team scientists used sulfur isotope signatures in ancient sediments and a photochemical model of sulfur dioxide photolysis to interpret the evolution of the atmosphere over the first half of Earth’s history.

An NAI CIW Team study revealed that Europa’s poles may not have always been located in the same place. This movement of the pole and subsequent change in rotation axis is only possible if Europa’s outer shell is decoupled from the core by a liquid layer, so the study reinforces evidence for a subsurface global ocean on Europa.

A study by NAI’s Montana State University team probed the hydrogenase enzyme, a large, complex enzyme that plays a major role in anaerobic metabolism. The researchers produced a crystal structure of the enzyme at unprecedented resolution, revealing a new level of detail in the enzyme’s active site, and providing clues about its evolution. These results further our understanding of the transition from the abiotic (non-living) world to the biological world.

Researchers from NAI’s University of California, Berkeley team investigated Box Canyon, Idaho. Incised into a basaltic plain with no drainage network upstream, and with approximately 10 cubic meters per second of seepage emanating from its vertical headwall, the canyon is a veritable poster child for groundwater seepage erosion. But the new study indicates that the canyon’s was formed instead by a catastrophic megaflood 45,000 years ago. The results imply that flooding of this kind may have caused similar features on Mars.

Researchers from NAI’s MBL team continued their study of the deep biosphere. A new study revealed that bacterial communities dwelling on ocean-bottom rocks are more abundant and diverse than previously thought, especially relative to the overlying water column. The results appear to reflect a range of diverse chemical microenvironments that
develop during sea-floor basalt alteration.

NAI’s teams at NASA GSFC, CIW, and the University of Wisconsin, showed that nucleic acids of extraterrestrial origin are present in the Murchison meteorite. Carbon-rich meteorites such as Murchison are thought to be responsible for delivering organic material to the young Earth. The results demonstrate that meteoritic nucleic acids could have been cosmic precursors to RNA and DNA, and may have played a key role in the origin of life on Earth.

Many NAI members were recognized in the past year for their achievements. Jim Kasting, a member of the PSU and VPL@UW teams was elected to be a Fellow of the American Academy of Arts and Sciences. ASU team member Jim Elser was elected a Fellow of the American Association for the Advancement of Science.

SETI Institute and CIW team member Jill Tarter received the prestigious TED Prize. The Prize, an initiative of the TED Conference, is awarded annually and grants three extraordinary individuals a wish to change the world, one hundred thousand dollars, and support in making the wish come true. Jill’s wish is “_that you would empower Earthlings everywhere to become active participants in the ultimate search for cosmic company._”

James Farquhar from NAI’s CIW Team received a 2008 Guggenheim Fellowship. James will use the Fellowship to support a sabbatical with Don Canfield (University of Southern Denmark), continuing their research on sulfur metabolisms and sulfur isotope fractionation.

Ames team members received several honors. David Des Marais has been elected a Fellow of the American Geophysical Union. Jack Lissauer received the 2007 Chambliss Astronomical Writing Award from the American Astronomical Society for the advanced astronomy textbook, “Planetary Sciences,” co-authored with Imke de Pater of the University of California at Berkeley. And Lou Allamandola has been ranked among the top living chemists based on his “h-index,” which some argue is the fairest measure of research achievement known.

And last, but by no means least, UH team member G. Jeffrey Taylor received the 2008 Carl Sagan Medal for Excellence in Public Communication in Planetary Science, awarded by the American Astronomical Society (AAS) Division for Planetary Sciences to recognize outstanding public communication by an active planetary scientist.

The richness of this summary, which captures only a small fraction of all that has transpired in the astrobiology community this past year, illustrates how vibrant and compelling the field has become. I look forward with you to many more exciting discoveries and developments in the coming year.

Carl Pilcher
February 2009