2003 Annual Science Report
NASA Johnson Space Center Reporting | JUL 2002 – JUN 2003
The JSC Astrobiology Center is very diverse team that has about as many non-JSC members as it does JSC members. Since we are unable to add new civil servants, only 3 civil servants participate significantly in any of the projects or the education and outreach activities, and only two of them can spend significant time on the science projects. Most of the JSC team consists of contractor scientists, two of which are also graduate students while working at JSC, summer student interns, a NAI post-doctoral fellow, and scientists from nearby institutions. Our team represents a variety of disciplines, including geology, mineralogy, microbial extremophiles, geochemistry, and planetology.
The uniting theme for the JSC team is sample and material analysis to provide characterization data on terrestrial samples, astromaterials, and experimental samples. The types of data sought are usually features related to microbial life and the byproduct of microbial activities. Such features include morphology of living microbes and their surroundings, including biofilms on geologic substrates, as well as the morphology of fossilized forms of this living biota. In addition to morphology, chemistry and mineralogy of microbial produced features and fossilized microbes are of great interest to us. We typically use probe instruments (scanning electron micrograph (SEM), transmission electron microscopy (TEM), electron microprobes, TOF-SIMs, double laser beam mass spectrometers, and Confocal and epi-fluorescence microscopy to acquire information on living or dead microbial life. The overall goal is to relate chemistry, mineralogy, atomic structure, morphology, spectral interactions, and other properties for specific types of features so that multiple data can be used to characterize or fingerprint life in all its forms (including ancient fossils and bioassisted mineral precipitates). But we also strive to understand the processes that create the characteristics of life, the processes that alter or fossilize life, and the processes that produce and preserve interaction between life forms and rocks or minerals. Fingerprints of life are valuable for themselves, but they may also contain the history of that life and its environment over time.
The ability to confidently identify the presence of life or the former presence of life has been taken for granted in many types of terrestrial samples. However, as we are looking more and more at astromaterials from beyond Earth and taking a fresh look at terrestrial Archean samples, many in the scientific community have realized that it is not always obvious or easy to determine whether life was or is present in the rocks, minerals, soils, and fluids of Earth or another planet.
Consequently, our overall goal is to develop better techniques for detecting and understanding life and develop a biosignature classification system that assigns biosignature potential ranked by probability. It will be absolutely necessary to do this for returned Mars samples, but these techniques should first be well tested on terrestrial samples, and should also be applied to other types of samples as well: meteorites, cosmic dust, cometary dust, and samples from various satellites and small bodies. Because of the extreme interest in the possibility of life elsewhere, we must develop strong criteria for detecting it and certifying it. That is the current overreaching goal of the JSC team. That may also become the core objective for all of NASA in the coming decade or two.
During the past year we have made progress on some ongoing projects and have started several new ones. A brief description of each project and a few highlights of our progress is given below:
During the past 12 months, our JSC Astrobiology Institute team has published more than 100 scientific papers and abstracts:
Peer-reviewed publications: 73
Published abstracts: 87
The peer-reviewed publications include book chapters. Most of the abstracts are extended abstracts. Most of the published abstracts were also presented at meetings as talks or sometimes posters. In addition to talks associated with published abstracts, we gave at least 25 more scientific talks to various meetings and technical groups, amounting to about 90 scientific talks and posters total.
We have subdivided our several small projects into five main work projects listed below:
(1) New Technique Development and Application
- Continued development of using antibodies and state-of-the-art array approach may be used to search for life on Mars on robotic missions.
- Hopanes, a reliable established class of chemical biosignature, has been successfully detected in ELISA tests during Mars microgravity experiments performed for NASA’s KC-135 flight program.
- Limulus Amebocyte Lysate (LAL) and Prophenoloxidase system (PPO) — We have developed very sensitive methods to detect microbial contamination based on the Limulus Amebocyte Lysate (LAL) and Prophenoloxidase system (PPO). These methods are to detect LPS, glucan and peptidoglycan down to sub-picogram level in pharmaceutical applications that have adapted them to rock, soil and metallic surfaces.
- Use of multiple fluorescent probes gives a visual representation of disseminated organic material in geologic materials such as interplanetary dust particles (IDPs) and rock varnish.
- New analyses of Nakhla, Mars meteorite, by double laser spectrometry shows presence of complex organics.
(2) Organic Biosignatures
- We have used antibodies to detect category 1 and other biomarkers in rock samples. Extraction takes a few minutes and analysis a few hours.
- We have presented use of new antibodies to detect hopanes and have shown proof of operation during Martian gravity.
- The analysis of the carbon in AHL84001 carbonate globules is organic carbon. The C-ring analyzed is consistent with the detection of polycyclic aromatic hydrocarbons (PAHs) associated with the carbonate globules. We found that carbon was approximately uniformly distributed throughout the carbonate, although the C-ring and C=O to total carbon (which is mainly in carbonate) is highest in the rim carbonate.
(3) Terrestrial Analogs and Martian Meteorites
- We discovered novel strains related to the bacterial genera Coprothermobacter, Geobacillus, Clostridium, Anaerobaculum, and also a previously uncultivated spirochete in ultradeep gold mines in South Africa.
- Microbial communities in hypersaline environments suggest that mineralization is controlled through biofilm production, and extreme desiccation of those films contributes to evaporate mineral deposits on a micrometer scale.
- Atacama Desert bacteria isolates suggest variation of species through elevation changes.
- Mn carbonates with complex textures were found in Nakhla.
- Rock varnish preserves C disseminated throughout the varnish microlayers, but is generally a poor morphological preserve for bacteria in older varnish samples. Hematite in the banded iron formation has a better preservation of microorganisms than seen in older ferricrete or hematite in rock varnish.
- A variety of microbes and viruses thrive in permanently ice-covered Antarctic lakes, even though the ice filters out more than 98% of the light.
- “Hot” (2°C) springs emerging from the upper surface of some Canadian Arctic glaciers contain microbial life.
- Carbonate globules in igneous rocks are extremely complex and are often associated with secondary silica-rich phases — preliminary evidence suggests that this silica phase forms at relatively low temperatures and is not a melt glass.
(4) Mineral Biomarkers
- Tiny magnetite in ALH84001 was confirmed as indistinguishable from magnetite made by bacteria.
- Magnetite in ALH84001 continues to strongly support the early life on Mars hypothesis.
- Manganese minerals formed in caves and on rock varnish with the help of bacteria may provide possible biomarkers for use on Mars.
- Transmission Electron Microscopy tomography has confirmed the original geometry MV-1 and ALH84001.
- Nanobacteria may have ribonucleic acid (RNA) and nucleate calcium phosphate precipitation.
- Recent experiments show that Dolomite has demonstrated that sulfate reducing bacteria may initiate the formation of this mineral.
(5) Archean Biosignatures
- Hydrothermal systems preserved in the Archean Pilbara succession suggest that abiotic hydrothermal processes dominate sedimentation, making it very difficult to isolate biotic signatures.
- In the search for signs of microbial mats in zones of quieter sedimentation away from vents, promising results have come from fine-grained clastic sediments in the Paddy Market Formation. The formation consists of thinly laminated shales and sandstone — probably turbiditic in origin.
Education and Public Outreach
Our Education and Public Outreach (EPO) program is one of the most active in the NAI. Their work his past year includes workshops, classroom activity product development, display events, CD authoring, public presentations, and the support of many undergraduate interns. We helped design and build the major museum exhibit called Microbes!, which is continuing its tour of major U. S. science museums. Members of the JSC Astrobiology Institute Team held more than 50 press interviews, TV and radio appearances, and other media events during the past 12 months. In addition, we made dozens of general public presentations and classroom presentations around the world. All of these Education and Public Outreach projects are documented in the detailed report. We believe we have an exemplary program in this area and we intend to continue its rapid pace.
CollaborationWe have put together two teams from Historically Black and Hispanic Universities and have helped them get independent funding through proposals. We now have an Astrobiology group at Highlands University in New Mexico, which is a subunit of the JSC Astrobiology Institute. In addition, a member of our local team (Penny Morris-Smith) has been awarded a significant grant to incorporate minority students and from Texas Southern University, the University of Houston (downtown campus) into some of our projects as interns, visiting faculty, and graduate students. We will also work with the Houston Museum of Natural History on this project. In summary, we have added three universities to our active group, all specifically in astrobiology. We have raised more than half a million dollars from other sources to support these efforts.
We currently also have a Memorandum of Understanding in negotiation between NASA Headquarters to work with a group at the Geological Survey of Canada specifically on Astrobiology topics, generally focused on biosignatures. This MOU was signed this past calendar year.
As indicated in our science project reports, we are now actively working with a number of universities as documented also in previous progress reports. These collaborations have proven to be valuable and have provided our team with considerable expertise, which we originally lacked, specifically in microbiology, genomics, microbial ecology, and field and laboratory procedures for sampling, culturing, preserving, and working with microbes. However, we now have two new astrobiology labs at JSC to continue nanobacteria and Microarray Assay for Solar System Exploration (MASSE) hopane research, the MASSE extraction test bed prototype development and a lab for clean and sterile preparation of geologic samples and astromaterials. These new laboratories opened May 2003 to better serve our research collaboration with Carnegie, Montana State and the University of Arizona. We are now capable of interacting better with other NAI teams on a scale that we have not had before.
We also have an established a working relationship with the Madrid Center for Astrobiology for work on the MASSE project. They are helping develop the array technology and we are working on the antibody-antigen reactions. We will both participate in final design and in the test program, and they will start field tests at the Rio Tinto in September of this year. They will be partners on any flight hardware that we are successful in getting onto a mission.
In addition to the Centro de Astrobiologia (CAB), we also have an established and strong partnership with Carnegie Institute through MASSE PI, Andrew Steele. His project engineer and PostDoc are housed at JSC, utilizing our new laboratory space.
Overall, we believe we have made considerable progress this year and we look forward to more collaboration with other NAI members in the coming year.