2009 Annual Science Report

Reporting  |  JUL 2008 – AUG 2009

Carl Pilcher
NAI Director: Carl Pilcher
Letter from the Director: 2009 NAI Annual Report

Starting NAI’s Second Decade

The year reported here, July 1, 2008 to June 30, 2009, marks a major transition and the start of the second decade of the NASA Astrobiology Institute (NAI). What began as an experiment in science management has matured into a vibrant community of geographically distributed researchers and educators linked together by some of the most modern collaborative technologies. The major transition was the start of the ten teams selected in the Cycle-5 NAI competition. The new teams were announced in October 2008, and began their tenure on Feb. 1, 2009.

The first order of business was getting to know one another. The main mechanism was a series of fifteen “virtual” seminars, one by each team (10 new and 4 continuing) and one by NAI Central, held twice a week from February through April. Each team presented its plans for research, education and public outreach (EPO), and related activities. NAI Central discussed how it facilitates and supplements the teams’ core research and EPO programs to make the Institute more than the sum of its parts. The seminars were recorded and archived on the NAI website, providing a complementary overview to this more detailed Annual Report. The seminars may be downloaded as podcasts or viewed on-line through any standard web browser.

The seminars were followed by the first major step to integrate the new and continuing teams. A Strategic Science Initiatives Workshop involving ~100 scientists including representatives of all NAI teams and three international partners was held in Tempe, AZ in May. The purpose of the workshop was to identify areas in which integration of the funded NAI research portfolio (and possibly related funded research efforts) would lead to greater scientific insights and productivity. Eight major areas with potential for greater productivity through integration emerged from the workshop:

The process of integrating science across the NAI and beyond into the broader astrobiology community is continuing. We’ll report on further on this in next year’s Annual Report.

The NAI 2008 Director’s Discretionary Fund (DDF) awardees began their work during the reporting year. Thirteen research projects and five workshops were awarded funds. The NAI 2007 DDF awardees also reported their results during the year. Their reports are available in this Annual Report or through the NAI DDF web page.

Six new NAI Postdoctoral Fellows were selected during the reporting year (see the November 13, 2008 and April 9, 2009 Newsletters). During summer 2009, 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 (see the June 16, 2009 Newsletter). Their work took them to such far-flung places as ancient rock formations in India, a sulfur-rich spring emerging through a glacier in the Canadian high arctic, and a biofilm-covered lava cave in Hawaii. :

Two minority institution faculty members were chosen for sabbaticals in the NAI Minority Institution Research Support (MIRS) Program. Rakesh Mogul of Cal State Polytechnic, Pomona is working at JPL to characterize a highly radiation-resistant bacterium isolated from the Mars Odyssey Spacecraft. Aaron Cavosie from the University of Puerto Rico, Mayaguez is working with the NAI team at the University of Wisconsin, Madison to study shocked zircons recording impacts very early in Earth’s history in what is now South Africa.

The Josep Comas i Solà International Astrobiology Summer School, held annually in Santander, Spain, has become a tradition in the astrobiology community. The 2009 program marked the school’s seventh year, and was devoted to an understanding of the characteristics and diversity of organisms that inhabit Earth’s extreme environments and the implications for the habitability of environments beyond Earth. About 40 students participated, most from the US and Europe, but including one each from Canada and Mexico.

In collaboration with the Nordic Astrobiology Network, the NAI’s University of Hawaii team organized an astrobiology summer school in Iceland in June/July 2009. Participants included 19 graduate students from the US, and 24 students from 16 other countries, with a focus on Nordic participants. Activities during the two week program included lectures on the topics of “Water, Ice and the Origin of Life in the Universe,” a student poster session, field sampling of thermophiles, and labwork and computer modeling NAI’s Education and Public Outreach program continued its high level of activity, with many new areas added as the newly selected teams got underway. The Ames Team’s Lassen Astrobiology Internship Program engaged high school students in field research within Lassen National Park. The MIT and ASU Teams joined forces to begin producing Virtual Field Trips at sites such as Yellowstone National Park and the Pilbara region of western Australia, the latter in partnership with the Australian Center for Astrobiology. The University of Wisconsin Team took us all out to the ball game as Astrobiology Night at the Ballpark kicked off the minor league Madison Duck’s summer season. Almost every one of the Teams hosted teachers in research or professional development opportunities, and numerous undergraduate students spent the summer in NAI labs working on astrobiology research projects.

Although it happened after the current reporting year, I would be remiss not to note here the awarding of the 2009 Nobel Prize in Physiology or Medicine to Jack Szostak, NAI member and PI in NASA’s Exobiology and Evolutionary Biology Program. Jack, a Howard Hughes Medical Institute investigator at Massachusetts General Hospital and Harvard Medical School, shared the Prize with Elizabeth H. Blackburn of the University of California, San Francisco, and Carol W. Greider of the Johns Hopkins School of Medicine. The Prize was awarded for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase.

Jack’s astrobiology research was the subject of an NAI Director’s Seminar he presented in November 2008. With the title What can we Learn About the Origin of Life from Efforts to Design an Artificial Cell?, Jack discussed recent experimental progress toward synthesizing self-replicating nucleic acid and membrane vesicle systems, and the implications these experiments have for our understanding of the origin of life.

Other Director’s Seminars included include presentations by Chris Scholin on Application of the Environmental Sample Processor (ESP) in Deep-sea and Coastal Ocean Biomes; Roger Summons on The Great Mass Extinction – a Sudden Event or a Slow Moving Train-Wreck?; and Norm Sleep on Habitability of Super-Earths. Complete archives of all the NAI seminar series are available on the NAI website.

Science Highlights

It was another exciting year of scientific advances, including the following:

Using new techniques, scientists from NAI’s Carnegie Institution of Washington team discovered that tiny beads of volcanic glasses collected on two Apollo lunar missions contain water. The new study suggests that the water came from the Moon’s interior and was delivered to the surface via volcanic eruptions over 3 billion years ago. The research was published in the July 10, 2008 issue of Nature.

Researchers from NAI’s Penn State, Marine Biological Laboratory, and UCLA teams completed a study of the subseafloor marine biosphere, which may be one of the largest reservoirs of microbial biomass on Earth. Their metagenomic analysis indicated that the subsurface environment is a distinct microbial habitat, different from other environments studied by metagenomics, particularly because of the predominance of uncultivated Crenarchaeota. Their results are published in the July 29, 2009 issue of PNAS.

Using data from the CRISM instrument on NASA’s Mars Reconnaissance Orbiter, astrobiologists from NAI’s SETI Institute and Marine Biological Laboratory teams found several phyllosilicate species, indicating a wide range of past aqueous activity, in the Mawrth Vallis on Mars. This work, published in the August 8 issue of Science, is further evidence that abundant water was once present on Mars and that hydrothermal activity may have occurred.

Members of NAI’s Carnegie Institution of Washington, Indiana University, and NASA Goddard Space Flight Center teams and their colleagues revisited the Miller-Urey experiments, with some surprising results. It turns out the classic experiment showing amino acids and other biologically relevant compounds are produced when inorganic compounds are exposed to a spark discharge isn’t the whole story. The 1953 Miller-Urey Synthesis had two sibling studies, neither of which was published. Vials containing the products from those experiments were recently discovered and analyzed using modern technology. Experiments simulating an ancient volcanic eruption produced a wider variety of amino acids than the classic one. The results were reported in Science.

The High Lakes Project, led by SETI Institute investigator Nathalie Cabrol, has been investigating the geophysical environment of high altitude lakes in the Central Andes of Bolivia and Chile since 2002. These lakes are one of the best terrestrial environmental analogs to early Mars. They returned to the high lakes in the Fall of 2008 to collect data characterizing the response of these lakes to climate variability. Nathalie and her team published an exciting blog of their expedition.

Research studying life without the sun continued. An ecosystem discovered 2.8 kilometers underground in the Mponeng Gold Mine near Johannesburg, South Africa two years ago has been shown to comprise only a single species of microbe, existing on energy from radioactivity, completely independently of the Sun. The community of rod-shaped bacteria of the species Desulforudis audaxviator was discovered in 2005-06 by members of the NAI’s Indiana-Princeton-Tennessee Astrobiology Initiative (IPTAI) Team. Their latest results were published in Science in October 2008.

Researchers from NAI’s University of Wisconsin team and their collaborators conducted a new analysis of dust from the comet Wild 2 returned to Earth by the Stardust mission. Published in Science, the analysis revealed an oxygen isotope signature suggesting an unexpected mingling of rocky material between the center and edges of the solar system. It appears that heat-processed particles may have been transported outward in the young solar system over four billion years ago.

The discovery of CO~2~ in the atmosphere of extrasolar planet HD 189733b was announced in Nature News. The exoplanet is a hot Jupiter orbiting a star 63 light years from Earth. While it’s extremely unlikely that this particular planet supports life, the ability to measure the presence of CO~2~ in its atmosphere bolsters the search for life outside the Solar System. Giovanna Tinetti, former NAI Postdoctoral Fellow, was lead author in the study.

Leading off 2009 with a flurry of press attention, NAI’s team at NASA Goddard Space Flight Center and their colleagues announced their discovery that methane occurs on Mars in extended plumes, and that the methane is likely released from discrete regions at specific times. Since methane can be produced by subsurface geological/chemical processes as well as life processes, there is still much to be done to determine the methane’s source and its implications for life on Mars. The team’s results were published in Science.

Detected through their molecular remains, fossils of early sponges were observed in ancient rocks in Oman. The fossils occur in strata that underlie a cap carbonate dated at >635 million years ago. This discovery suggests that shallow waters contained dissolved oxygen in concentrations sufficient to support early animal life at least 100 million years before the Cambrian explosion. Members of NAI’s MIT team led the effort, and published their findings in Nature.

A study of iron within hydrothermal vents led by former NAI Postdoctoral Fellow Brandy Toner (now at the University of Minnesota) was published in Nature Geoscience. The research showed that iron emitted from the vents can bind to organic particles and be distributed within the oceans. This bound iron doesn’t oxidize, and is much more easily processed by living organisms, thus affecting the potential for a “natural iron fertilization mechanism.” Co-authors include members of NAI’s Emeritus team at the Marine Biological Laboratory.

NAI’s Deep Time Drilling Project acquired several pristine cores from ancient rocks in Western Australia in 2004. In a paper on the analysis of these cores published in Science, University of Washington astrobiologists report clues about when and how the Earth’s atmosphere became oxygen rich. The analysis indicates that atmospheric oxygen rose in a temporary “whiff” about 2.5 billion years ago. The whiff lasted long enough to be recorded in the nitrogen isotope record, then oxygen dropped back to very low levels before the atmosphere became permanently oxygenated about 2.3 billion years ago. The timing of the rise of oxygen in Earth’s atmosphere is a key question in astrobiology. It is coupled not only to the question of when organisms capable of oxygenic photosynthesis first evolved on Earth, but also what signs of life might be found on young Earth-like planets around other stars.

Members of NAI’s NASA Goddard Space Flight Center team published a paper in PNAS describing the distribution and enantiomeric composition of certain amino acids in carbonaceous meteorites. Their results show an increased amount of “left handed” l-isovaline, a non-biological amino acid, in several meteorites. These results are inconsistent with UV circularly polarized light as the primary mechanism for l-isovaline enrichment and indicate that amplification of a small initial isovaline asymmetry in Murchison and Orgueil occurred during an extended aqueous alteration phase on the meteorite parent bodies. The large asymmetry in isovaline and other amino acids found in altered CI and CM meteorites suggests that amino acids delivered by asteroids, comets, and their fragments would have biased the Earth’s prebiotic organic inventory with left-handed molecules before the origin of life.

Members of NAI’s Penn State and Carnegie Institution of Washington Teams reported in Science that certain sulfur isotopes found in many sedimentary rocks older than 2.4 billion years may not be the result of photochemical reactions in an oxygen-free atmosphere as previously thought. Their research shows that the isotopic signature could instead be due to reactions between organic carbon-rich sediments and sulfate-rich seawater in ancient hydrothermal systems. If so, then the disappearance of the signature in sediments younger than 2.4 billion years may indicate changes in Earth’s hydrothermal system, rather than signaling the rise of oxygen in Earth’s atmosphere.

NAI Postdoctoral Fellow Oleg Abramov at the University of Colorado, Boulder led a modeling study published in Nature investigating the degree of thermal metamorphism of the young Earth’s crust caused by the Late Heavy Bombardment (LHB) which ended 3.9 billion years ago. The analysis revealed that there is no plausible situation in which the habitable zone could have been fully sterilized. The authors conclude that subsurface microbial life could have persisted throughout the LHB. They also propose that multiple, impact-induced temperature anomalies could have driven widespread hydrothermal activity, and that this was conducive to life’s emergence and early diversification.

Scientists and non-scientists now have easy access to information about when living species and their ancestors originated, information that previously was difficult to find or inaccessible. Free access to the information is part of the new Timetree of Life initiative developed by NAI’s Blair Hedges, professor of biology at the Penn State Astrobiology Research Center, and Sudhir Kumar, a professor of life sciences at Arizona State University.

According to a study from NAI’s Virtual Planetary Laboratory team at the University of Washington and colleagues at Caltech, the lifespan of Earth’s aerobic biosphere could be prolonged, even as the Sun’s luminosity increases over the next 2-3 billion years. Published in PNAS, the study points to the substantial reduction in atmospheric total pressure as life fixes and buries most of Earth’s present day atmospheric nitrogen. This would decrease atmospheric pressure broadening and with it the greenhouse effect, thereby regulating Earth’s surface temperature. This could tack an additional 1.3 billion years onto the lifespan of Earth’s aerobic biosphere, and have implications for the lifetime of aerobic biospheres on planets around other stars.

Members of NAI’s team at Penn State and their colleagues published a paper in PNAS exploring the viability of using isotopes of the element nickel as biomarkers. Nickel is an important trace nutrient for methanogens, which preferentially use one isotope of nickel over another in their metabolic processes. Nickel redox changes, unlike iron, generally require a biological mechanism. Nickel may therefore be a better isotopic biosignature than iron. Testing ancient sediments and observing nickel isotopic fractionation might pinpoint where and when methanogens arose.

Other Noteworthy News

Beth Shapiro, member of NAI’s Pennsylvania State University team received a MacArthur Fellow Award. This prestigious award is given to talented individuals, in a variety of fields, who have shown exceptional creativity, originality, dedication to their creative pursuits, and potential to make important contributions in the future.

Daniel Glavin of the NAI’s Goddard team was selected by the international Meteoritical Society as the recipient of the 2010 Nier Prize for his work on extraterrestrial organic chemistry. The prestigious Nier Prize is awarded to young scientists performing valuable research in fields related to meteoritics and planetary science.

University of Hawaii team member Tobias Owen received the 2009 Gerard P. Kuiper Prize, awarded by the American Astronomical Society Division for Planetary Sciences (DPS) to recognize and honor outstanding contributors to planetary science. The award is for scientists whose achievements have most advanced our understanding of the planetary system.

NASA Goddard scientist Jennifer Eigenbrode was selected as the recipient of the 2009 IRAD Innovator of the Year award. Her work has added important capabilities to the Sample Analysis at Mars (SAM) instrument, which will be included on the upcoming Mars Science Laboratory (MSL).

Jim Kasting, of the NAI’s VPL/University of Washington and Penn State teams won the Oparin Medal, the highest honor bestowed by the International Society for the Study of the Origin of Life (ISSOL). Among other awardees was the former president of ISSOL, Antonio Lazcano, who received a gold medal. ISSOL also elected its new president–Janet Siefert, an NAI member from Rice University.

The NAI sponsored several talks in a lecture series hosted by NASA Ames Research Center designed to celebrate several important scientific anniversaries in 2009 including Darwin’s 200th birthday, the 150th anniversary of his landmark publication On the Origin of Species, and the 400th anniversary of Galileo’s first use of the telescope. The NAI-sponsored talks were on the evolution of Astrobiology, technology, and Planetary Exploration.

The NAI is making a concerted effort to explore new tools for remote collaboration. During 2008 and 2009, the NAI began conversion of its videoconferencing system to HD, including upgrades to the team videoconferencing rooms and to the multipoint controller used for conferences that link large numbers of endpoints. In February 2009 the NAI began using Adobe Connect as the primary online meeting tool. We also began to explore science analysis and visualization tools that may be used for collaboration and data sharing across distance.

The NASA Astrobiology Program website, designed and operated by the NAI Central web team, was recognized by the International Academy of Digital Arts and Sciences as an Official Honoree of the 13th annual (2009) Webby Awards in the category of website/science.

This is a long letter, but it only begins to capture all that transpired in the NAI community during the period of this Annual Report. For more recent events, see our Newsletters and website, and for future events, stay tuned!

Carl Pilcher
April 2010