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2007 Annual Science Report

Reporting  |  JUL 2006 – JUN 2007

Carl Pilcher
NAI Director: Carl Pilcher
Letter from the Director: 2007 NAI Annual Report

The year covered by this Annual Report (July 1, 2006 to June 30, 2007) was one of great accomplishment and change for the NAI. It also set the stage for some extremely important events in the development of the Institute to follow.

One change early in the year that was personal as well was my moving from NASA Headquarters to become the NAI Director. One of the first events that followed was an in-person meeting of the NAI Executive Council to map out a strategy for the coming year, particularly for dealing with the 50% budget cut to the astrobiology program as a whole. The Principal Investigators agreed to 30% team budget cuts, both to adjust to lower Institute funding and to free up funds for new initiatives. They recommended that we create a substantial Director’s Discretionary Fund (DDF) to pursue timely new research areas and that we select new teams from the fourth NAI competition (CAN-4) held the previous year. Both of these recommendations were achieved before the reporting year was over.

The DDF process began with a January workshop hosted in Boulder by our University of Colorado team. Forty-five PIs and other team members explored the potential for increasing the “strategic impact” of NAI research and related activities. Preparation for the workshop included excellent and much appreciated briefings presented remotely by NASA Headquarters managers on current and future missions (podcast archives of these briefings are available at The interactions at the workshop led to several exciting new project ideas and inter-team collaborations, some of which were pursued immediately. Finally, many of these and other projects were proposed for DDF funding and 18 selected, roughly half research projects and half conference or workshop support (see for summaries of the selections) . A stream of important results and outcomes began in the summer of 2007 and is continuing.

Shortly after announcing the DDF selections in April, we were able to announce selection of 4 new teams from the CAN-4 competition. This was made possible by strong support for the NAI at NASA Headquarters, particularly from the new Associate Administrator (AA) for Science, Alan Stern; his Planetary Science Division Director, Jim Green; and Senior Scientist for Astrobiology John Rummel. The new teams began at a reduced “slow start” funding level for their first 18 months, but we look forward to their investigations being fully funded over their 5-year Cooperative Agreements. (See the Director’s Corner in the May 21, 2007 Newsletter or the NAI website for a description of the research of the new teams.)

Shortly after the new team selections were announced and just before the end of the reporting year, a National Research Council committee was appointed to review the performance of the NAI since its inception. This review had been part of the original planning for the Institute in 1997-98. The committee’s report, which was released in December 2007, is already playing a major role in shaping the Institute’s future. (An electronic copy of the report may be downloaded free of charge at

Of course the year also included a number of major research accomplishments. Space limits me here to mentioning just a few.

“The Marine Biological Laboratory NAI team led by Mitch Sogin charted, for the first time, the underexplored 'rare biosphere’ of the deep oceans: It has been recognized for some time that the oceans harbor much more phylogenetic diversity than is present in the dominant microbial populations, and that this “genetic reservoir” may provide an enormous source of novel genetic information. Using a new high-throughput genetic sequencing technique, Mitch, Julie Huber, and colleagues showed that there are thousands to tens of thousands of bacterial species present at abundances perhaps as low as a few per liter of seawater, in comparison to cumulative abundances of the dominant species of 10^8^ -10^9^ per liter. The high degree of genetic diversity in this rare population indicates that it is old on evolutionary (and geologic) time scales. One implication is that rare organisms could rapidly become dominant if a change in environmental conditions favored them over the then dominant population.

In another striking discovery about sub-surface microbial life, the Indiana-Princeton-Tennessee NAI team (IPTAI) led by Lisa Pratt of Indiana University and T.C. Onstott of Princeton University has discovered an isolated microbial community nearly two miles underground that appears to derive all its energy from radioactive decay rather than directly or indirectly from sunlight. In this case radioactive decay leads to the decomposition of water into hydrogen and oxidants that convert naturally occurring sulfide minerals to sulfate. The dominant microbial species in this ecosystem then reduces the sulfate using the hydrogen as an electron donor, reforming water in the process. Isotopic noble gas analyses of the ecosystem’s bulk water indicate that it has been completely isolated from surface processes for millions to tens of millions of years. The ecosystem thus appears able to maintain itself completely independently of sunlight. If strictly geological processes such as radioactive decay and geochemical oxidation can sustain microbial communities indefinitely, then subsurface environments on Mars and other rocky planets could potentially sustain life even though they lack a surface photosynthetic biosphere.

The SETI and Virtual Planetary Laboratory NAI teams led by Rocco Mancinelli and Vikki Meadows, respectively, both made major contributions to an extensive reappraisal of the potential for the existence and detection of habitable planets around M-stars. (SETI paper can be downloaded here. VPL paper can be downloaded here) M-stars make up about 75% of all stars in the galaxy. Hence the question of whether or not they may have habitable planets is important to constraining how frequently habitable planets occur. It had been thought that habitable M-star planets were not likely because of the close proximity of the habitable zone to the parent star, the zone’s narrowness, and M-stars’ relatively high level of activity. However, in a pair of papers published simultaneously in the journal Astrobiology, the two teams concluded that the potential for habitable planets is sufficiently great that M-stars should be included in programs that seek to find habitable worlds and evidence of life.

Scientists from NAI’s UCLA and University of Colorado teams published new geologic and geochemical analyses of ancient rocks from Akilia Island in West Greenland that were the subject of a controversial Nature paper ten years ago. Their new studies, which include a thorough geologic map of the area and ion-microprobe as well as 3-dimensional (confocal) Raman spectroscopic analyses, provide strong evidence that these rocks contain chemical fossils of life that existed on Earth more than 3.8 billion years ago.

A major NAI education project, “NASA and the Navajo Nation,” culminated this year with an NAI-hosted Sustainability Seminar in Window Rock, AZ. The seminar brought together a broad spectrum of educators from across NASA and the Navajo Nation and its surrounds to use this cross-cultural project and the lessons-learned as a context for exploring ideas, sharing resources, and networking toward future collaborations.

The NAI selected 5 new Postdoctoral Fellows during the year (see the June 11, 2007 Newsletter and the Director’s Corner in the March 30, 2007 Newsletter), and saw honors bestowed on a number of its members. The honors included the American Society for Microbiology (ASM) awarding Mitch Sogin, PI of NAI’s Marine Biological Laboratory team, the USFCC/J. Roger Porter Award for his research in environmental microbial diversity, and Norm Pace, of NAI’s University of Colorado team, the Abbott/ASM Lifetime Achievement Award for his outstanding contributions and research in the field of microbial ecology; Margaret Tolbert from NAI’s University of Colorado (UC) team receiving the 2007 UC-Boulder Hazel Barnes Prize, the University’s most prestigious faculty award; T.C. Onstott of the NAI’s IPTAI team “being named one of this year’s 'Time 100,’: an annual list of “the 100 men and women whose power, talent or moral example is transforming the world,” according to list-maker Time magazine; Lou Allamandola of the NASA Ames Research Center team being awarded the 'Presidential Rank of Meritorious Senior Professional;’ Julie Huber of NAI’s Marine Biological Laboratory team receiving a highly selective 2007 L’Oréal USA Fellowship for Women in Science, one of five awarded annually to recognize and reward up-and-coming female scientists who are conducting innovative and groundbreaking research; Maggie Turnbull, a 2004 NAI Postdoctoral Fellow, now at the Space Telescope Science Institute, being named a 'Genius’ by CNN for her work cataloging stars most likely to develop planets that could support life and intelligent civilizations; and Sara Seager of NAI’s Carnegie Institution of Washington team, now at MIT, making Popular Science’s 'Fifth Annual Brilliant 10’ list for her work on astronomical biosignatures. Congratulations to all for recognition well deserved!

The next reporting year will no doubt be as intense and event-filled as the past one, and hopefully even more gratifying. One of the biggest milestones will be the fifth (CAN-5) competition for Institute membership. This competition and NAI management processes in general will incorporate recommendations made by the NRC review committee, with major impact on the future of the Institute. I look forward to writing this letter next year, reporting on the new member teams; on results from the 2007 DDF projects and workshops; on the major scientific, education/public outreach, and programmatic accomplishments of the year; and on the bright future of the NAI and astrobiology.

Carl Pilcher
January 2008