MARSBUGS: The Electronic Astrobiology Newsletter Volume 7, Number 48, 15 December 2000. Editors: Dr. David J. Thomas, Math and Science Division, Lyon College, Batesville, AR 72503-2317, USA. dthomas@lyon.edu Dr. Julian A. Hiscox, School of Animal and Microbial Sciences, University of Reading, Reading, RG6 6AJ, United Kingdom. J.A.Hiscox@reading.ac.uk Marsbugs is published on a weekly to quarterly basis as warranted by the number of articles and announcements. Copyright of this compilation exists with the editors, except for specific articles, in which instance copyright exists with the author/authors. While we cannot copyright our mailing list, our readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing list. The editors do not condone "spamming" of our subscribers. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editors. E-mail subscriptions are free, and may be obtained by contacting either of the editors. Article contributions are welcome, and should be submitted to either of the two editors. Contributions should include a short biographical statement about the author(s) along with the author(s)' correspondence address. Subscribers are advised to make appropriate inquiries before joining societies, ordering goods etc. Back issues and Adobe Acrobat PDF files suitable for printing may be obtained from the official Marsbugs web page at http://welcome.to/marsbugs. The purpose of this newsletter is to provide a channel of information for scientists, educators and other persons interested in exobiology and related fields. This newsletter is not intended to replace peer- reviewed journals, but to supplement them. We, the editors, envision Marsbugs as a medium in which people can informally present ideas for investigation, questions about exobiology, and announcements of upcoming events. Astrobiology is still a relatively young field, and new ideas may come from the most unexpected places. Subjects may include, but are not limited to: exobiology and astrobiology (life on other planets), the search for extraterrestrial intelligence (SETI), ecopoeisis and terraformation, Earth from space, planetary biology, primordial evolution, space physiology, biological life support systems, and human habitation of space and other planets. --------------------------------------------------------------------- CONTENTS 1) SUPERMATERIALS REPEL SPACE DANGERS By Leonard David 2) THE NASA-AMES TERRAFORMATION WORKSHOP By Julian Hiscox and Martyn Fogg 3) NASA ROBOTICS MAY SOON HELP SPINAL CORD PATIENTS TAKE FIRST STEPS NASA release 00-194 4) NASA'S SECRET PLAN: A ROADMAP BEYOND THE SPACE STATION By Leonard David 5) ISU SCIENTIST ON TEAM THAT FINDS COMPELLING EVIDENCE OF ANCIENT LIFE ON MARS Iowa State University release 6) NEW REPORT OFFERS EVIDENCE OF PRIMITIVE LIFE ON MARS NASA/JSC release J00-84 7) MARS GLOBAL SURVEYOR READY FOR EXTENDED MISSION By Leonard David 8) NASA ASTROBIOLOGISTS TO PRESENT RESEARCH AT AGU NASA/ARC note 00-84AR 9) NEW ADDITIONS TO THE ASTROBIOLOGY, EXTREME ENVIRONMENTS AND TERRAFORMATION INDEX By David J. Thomas 10) CASSINI WEEKLY SIGNIFICANT EVENTS JPL release 11) THIS WEEK ON GALILEO JPL release 12) MARS GLOBAL SURVEYOR STATUS REPORT JPL release 13) STARDUST STATUS REPORT JPL release --------------------------------------------------------------------- SUPERMATERIALS REPEL SPACE DANGERS By Leonard David From Space.com 8 December 2000 A spacecraft takes a hole-making hit from a meteoroid and repairs itself. Huge but super-thin solar sails en route to Alpha Centauri are imbedded with rip-stopping carbon nanotubes. Human waste is used as a death-defying way to shield Mars-bound astronauts against lethal blasts of radiation. Experts here at NASA's Langley Research Center point to the physical fact: It's a material world after all. These scientists are developing new, experimental materials that in the future could help protect astronauts and spacecraft from the harsh, often unpredictable world of deep space. Get the full story at http://www.space.com/businesstechnology/technology/selfhealing_craft_ 001208.html. --------------------------------------------------------------------- THE NASA-AMES TERRAFORMATION WORKSHOP By Julian Hiscox and Martyn Fogg 11 December 2000 One of the stated goals of NASA's Astrobiology Institute is to investigate the possibility of whether life can spread beyond its home planet. "What is the potential for survival and biological evolution beyond the planet of origin?" This boils down to where we are going as a species, and the really big question is, "Could Mars have a biosphere once again?" In October 2000, a two-day conference entitled "The Physics and Biology of making Mars Habitable" was organized by Chris McKay at the NASA Ames Research Center to discuss the possibility of one-day changing the climate of Mars to a more Earth-like environment, suitable for terrestrial species to flourish. Twenty-six papers, by an international cast of authors, were listed on the program and the attendance was so good that the venue had to be transferred to a larger auditorium. Over the past thirty years the concept of planetary engineering-more popularly known as "terraforming"-has moved from the arena of science fiction towards serious scientific attempts to determine its future practicality. The word terraforming was first coined by science fiction writer, Jack Williamson, and can be defined as a process by which a barren extraterrestrial planetary environment can be altered to one that is suited for life. Any argument that such an idea remains fantasy is countered by our emerging appreciation of the fact that mankind already has the ability to alter the Earth's global parameters and has been doing so for some time. For example, the annual amount of rock mobilized in mineral extraction and construction already exceeds that washed off the continents by natural erosion. The atmospheric composition is now partly manmade. Emissions of greenhouse gases (largely as by-products of industry) probably have caused an increase in the mean global surface temperature of between 0.5° and 1°C since pre-industrial times. It is true that these changes have been unplanned, but if we consider adding intention to a proven technological ability, then planetary engineering on Mars does not seem such a wild proposition. Mars is the most obvious choice in the Solar System for considering future habitability, simply because it was probably habitable in the past. There is now abundant evidence that liquid water once existed on the surface of Mars, suggesting that the carbon dioxide atmosphere was thicker than it is today. Schools of thought are divided between whether ancient Mars was "warm and wet" or "cold and icy"; whatever the truth, it seems certain that during their first billion years of existence the surface conditions on Earth and Mars resembled each other more closely than at present. The first scientific papers on the possibility of terraforming Mars appeared in the early 1970's. Over the thirty years since then, as interest has grown, the number of papers in print has risen to over fifty, dealing with a variety of aspects of the problem, such as technological and biological aspects of planetary engineering and the ethics involved in such an undertaking. During his opening address, McKay reminded the audience that terraforming studies have been summed up by one technical-level book per decade, each one over double the length of the last. In 1976, NASA published On the Habitability of Mars: An Approach to Planetary Ecosynthesis, edited by Mel Averner and Robert MacElroy. In 1981 New Earths by James Oberg appeared; and in 1995 SAE International published Terraforming: Engineering Planetary Environments by Martyn Fogg. Judging by the quantity of new work presented at the conference, this doubling time looks set to fall. Engineering A naive view of planetary habitability would demand environmental conditions similar to those of the Earth: a mean global temperature of 15oC, an atmospheric composed of 20% oxygen and 80% nitrogen at one bar pressure, and lots of water. However, the Earth is not the only way for a planet to be habitable. The requirements for plants are different and in some ways less stringent from those required by humans, and those of bacteria more different still. In fact, it is worth noting that for a large part of the Earth's history, the atmosphere was anaerobic (and hence more Mars-like in composition) and the planet was populated only by microorganisms. The potential barrier between the climate on present day Mars and that required for microorganisms and certain primitive plants is much smaller than that required by vertebrates such as humans. Thus, even if a human- habitable Mars is the long-term goal of terraforming, it will be anaerobic biota that will first pioneer the Red Planet. Whilst there have been a number of studies of initial planetary engineering operations of Mars, the paradigm that has received the greatest attention is the runaway greenhouse hypothesis. This depends on the existence of surface reservoirs of labile carbon dioxide, indicated by climate models, such as dry ice in the polar caps and gas adsorbed on mineral grains in surface strata. An artificial warming of the martian surface would drive some of this CO2 into the gas phase, thickening the atmosphere, increasing its greenhouse effect and hence warming the surface still further. This in turn would release more CO2 etc., with the prospect of bringing about a runaway growth of the atmosphere to a warmer and wetter equilibrium. Two of the key terraforming questions are how can the runaway greenhouse be initiated and what artificial warming increment will be needed? Previous proposals have included salting the martian atmosphere with synthetic trace greenhouse gases, reducing the albedo of the surface with a layer of dark dust and providing Mars with additional illumination from orbiting mirrors. One model, due to Robert Zubrin of the Mars Society, suggested that the runaway greenhouse might be triggered by a global warming increment of just 4oC, endowing Mars in the long run with a CO2 atmosphere of 0.5 - 1 bar and tropical temperatures suitable for life. A paper presented by Martyn Fogg, which was based on a more detailed computer model, came to much less optimistic conclusions regarding the runaway greenhouse effect. He claimed that artificial warming increments of about 40oC are more likely to be needed to compensate for a probable shortfall in CO2, but that climate-forcing this great is by no means ruled out in view of the large number of proposed planetary warming techniques on the table. One of the most promising terraforming techniques currently being investigated is the possibility of being able to create long-lived synthetic greenhouse gases on Mars, with chemical bonds capable of surviving its harsh ultraviolet milieu, that could generate significant surface warming in just parts-per-million quantities. One family of compounds that fits this bill are the perfluoro gases (e.g. CnF2n+2, SF6, SF5CF3 etc.) and claims have been made in the past that a 1 - 10 ppm mix of these compounds might be capable of warming the surface of Mars by up to 40oC. Detailed investigation of this issue, in particular an analysis of the infrared spectrum of C2F6, was presented by Margarita Marinova of the Massachusetts Institute of Technology. Even more extraordinary was the paper by Mimi Gerstell of the California Institute of Technology who presented quantum mechanical calculations of the global warming potential of hypothetical greenhouse gases, such as CF3SCF3 and SF4(CF3)2, which, whilst physically possible, currently exist only on paper. The number of trace greenhouse gases that might be available for terraformers to deploy appears to be significantly greater than previously imagined. Manufacturing the amount needed to greenhouse Mars would require roughly the power consumed by a city the size of Chicago: undoubtedly beyond the scope of pioneering settlements, but not if such settlements evolve into a planetary civilization. Nobody on the Earth deliberately manufactures more efficient greenhouse gases, but a modest research project to this end could yield some fascinating results with regard to the ideal mix of gases for terraforming Mars. Building bricks Once the initial warming has taken place, to establish a biosphere on Mars three essential bricks must be present: carbon dioxide, water and nitrogen. All the available evidence suggests that in the past the climate of Mars was more clement than today. In order for the climate to have been warmer there must have been more carbon dioxide to act as a greenhouse gas, and obviously water to explain all of the dried-up water features on Mars such as lakes, rivers and outflow channels. Therefore a key question that scientists have to answer is where have all these volatiles gone? The loss of the atmosphere through escape to space is insignificant at the current rate, and perhaps only the equivalent of two meters of water spread over the entire planet, have been lost over the past four billion years. Other loss mechanisms include the impacts of asteroids and comets blowing away the atmosphere. By far the greatest mechanism of loss is probably the irreversible formation of carbonates and nitrates. For example, carbon dioxide dissolves in water to form carbonic acid, which falls to the surface via rain. The acid then combines with silicate minerals to form carbonates such as calcite and dolomite. On the Earth this carbon dioxide gets recycled because the carbonates are washed into the sea and are ultimately buried and subducted at the boundaries of tectonic plates. As the temperature increases, the carbon dioxide is driven off from the carbonates and is recycled back into the atmosphere. Due to the absence of plate tectonics on Mars, it is highly likely that the carbon dioxide is trapped in the form of carbonates. However, we have no clear idea of the amount of carbonates or nitrates. Spectrometers that currently orbit Mars have yet to detect carbonate rocks in the abundance that we expect. In order to search for carbonates (and nitrates), which are the key to unlocking Mars' past and maybe its future, we need to brush, dig and drill. Currently the cumulative experience of Viking's One and Two and Pathfinder is an exploration of the upper eleven centimeters of the martian surface, at three sites. However, if there is a showstopper to terraforming Mars, it is the potential availability of nitrogen, rather than the abundance. Estimates suggest that nitrogen is the seventh most abundant element in the cosmos. Nitrogen is the fourth most abundant in life after oxygen, carbon and hydrogen, which means that life is approximately 5% nitrogen by mass. The average atmospheric pressure at the martian surface is approximately six millibars, 2.7% of which is nitrogen. Back-of-the-envelope calculations indicate that if this were converted into biomass then one would get 4.4 kg of nitrogen per cubic meter, compared to the Earth's biomass, which averages 3.6 kg of nitrogen per cubic meter. So the total quantity of nitrogen available for biology on Mars is not limiting, it is the chemical form of nitrogen. Although, we cannot be certain, there are probably vast nitrogen deposits on Mars in the form of nitrates. On the Earth, lightning and shock heating of the atmosphere caused by the passage of meteorites produce nitrogen oxides that end up as nitrate salts, the largest accumulation of these occurring in the near- lifeless Atacama Desert. Roughly 300 millibars of nitrogen is converted to nitrates in approximately a billion years (at the current lightning rate) and there is no reason why this process could not have occurred on ancient Mars. Biology The aim of planetary engineering is to alter Mars such that terrestrial life could be introduced onto the planet. This can first occur when conditions on Mars become comparable to those found in the most hostile and Mars-like place on the Earth, the Dry Valleys on Antarctica. Simple ecosystems would first be introduced. This would be necessary so that the sterile martian regolith could be converted into a soil suitable for use by plants. James Graham of the University of Wisconsin-Madison pointed out that the best way to picture how and when biology would be introduced onto Mars is to imagine walking down a mountain, from its bare and windswept peaks to its balmy foothills. First bacteria would be seeded, followed by lichens, simple "plants" such as algae and mosses, and then trees and so on. Also, microbes could be used to help alter the martian climate by releasing carbon dioxide from carbonates and nitrogen from nitrates. Imre Friedman from the University of Florida described two species of cyanobacteria he had discovered, Chroococcidiopsis and Matteia, with phenomenal powers of survival in the face of cold and desiccation. In order to facilitate the survival and growth of terrestrial organisms as soon as physically possible on a partially altered Mars, Julian Hiscox of Reading University and Penny Boston of Complex Systems Research suggested two main mechanisms of adaptation could be utilized individually or in concert. These are genetic manipulation and/or directed selection under simulated martian conditions. There remain many unknowns in the planetary engineering of Mars. First and foremost is the question of the volatiles. Secondly, and perhaps more importantly, is whether terrestrial life can survive at one third the gravity found on the Earth. We know that one-gee is good, and that zero-gee is bad. However, there are no data points in between, and perhaps experiments could be planned to utilize the centrifuge on the International Space Station. Increasingly, the terraforming of Mars is appearing to be a feasible proposition, given a sustained effort to colonize the space frontier. The conference provided several new experiments and models, which bring the reality of deliberate planetary engineering one step closer. However, the people to carry out the task will almost certainly be the martians of the future not the earthlings of the present. --------------------------------------------------------------------- NASA ROBOTICS MAY SOON HELP SPINAL CORD PATIENTS TAKE FIRST STEPS NASA release 00-194 11 December 2000 NASA engineers and University of California, Los Angeles (UCLA), neurophysiologists are creating a robot-like device that could help rehabilitate thousands of Americans with spinal cord injuries. "We are developing a prototype robotic stepper device that when complete will be used as part of rehabilitation that can potentially help some people now wheelchair-bound take their first steps," said Jim Weiss, program manager for collaborative neural repair at NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA. "This system can do the work of four therapists and help monitor a patient's progress in a controlled manner." The device, still in the development phase, will look like a treadmill with robotic arms, and will be fitted with a harness to support the patient's weight. The arms resemble knee braces that attach to the patient's leg, guiding the legs properly on the moving treadmill. The robotic stepper device is one of several projects in the Neural Repair Program at the UCLA Brain Research Institute and JPL. UCLA neurologists now believe that by using the robotic stepper device in rehabilitation, some patients functionally confined to wheelchairs may be able to learn to walk again, and those with limited movement could improve their level of walking. NASA and UCLA researchers emphasize the robotic stepper is still in development and is not yet ready for use in rehabilitation. However, the device could be part of clinical trials at UCLA in about three years. "We see tremendous potential for rehabilitation that uses this form of therapy," said Dr. Reggie Edgerton, professor in the departments of physiological science and neurobiology at UCLA. "Some rehabilitation centers around the world are starting programs that will allow therapists to train individuals affected with spinal injuries, stroke and perhaps other neuromotor disorders to improve their mobility and stepping capacity," Edgerton said. "This robotic device could help therapists in those rehabilitation efforts." Current rehabilitation therapies are labor-intensive, and require up to four therapists. Unlike therapists, who only sense and observe a patient's progress, the robotic device takes precise measurements of the person's force, speed, acceleration, and resistance, counting each step the patient takes. These precise measurements help therapists monitor the day-to-day progress of their patients and provide valuable information on the effectiveness of the therapy. These measurements will be used by a control system that can assist the robotic stepper device as needed. JPL robotic engineers have worked alongside therapists to develop the device, which has highly sensitive sensors that collect up to 24 different data readings of the patient's activity. The device, connected to a computer, displays the information on the screen for the therapist to monitor. According to Weiss, the same device could also someday be useful to astronauts and help them walk safely after prolonged periods in space, such as extended missions on the International Space Station. JPL and UCLA are actively pursuing efforts to commercialize the robotic system. JPL technically supported UCLA in filing a patent application in August. "Many technologies developed at NASA for space exploration have tremendous medical applications. We can provide practical solutions based on our engineering experience," said Dr. Antal Bejczy, senior research scientist and lead engineer on the robotic stepper device at JPL. JPL is managed for NASA by the California Institute of Technology in Pasadena. Contacts: Michael Braukus Headquarters, Washington, DC Phone: 202-358-1979 Carolina Martinez Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-9382 Harlan Lebo University of California, Los Angeles Phone: 310-206-0510 --------------------------------------------------------------------- NASA'S SECRET PLAN: A ROADMAP BEYOND THE SPACE STATION By Leonard David From Space.com 12 December 2000 NASA is blueprinting a matrix of steps for sending human explorers beyond low Earth orbit. The hush-hush planning is designed to give the next president of the United States options for shaping the space agency's agenda beyond the International Space Station. Elements of what NASA insiders call the "Decadal Plan" scripts a buildup of space hardware at Earth-Moon and Earth-Sun libration points in the 2010 to 2012 time frame. Human servicing of spacecraft at libration points, like the Next Generation Space Telescope, would create a gateway for space travelers to reach the Moon, asteroids, and Mars. At these locales of gravitational limbo, spacecraft can remain essentially planted in one spot. Astronauts would service equipment positioned at these sites, such as powerful space telescopes. Once an astronaut outpost is established-more than 621,000 miles (1 million kilometers) distant from Earth-it would act as a gateway to other destinations. From the outpost, crews could be dispatched to the Moon's surface, or sent to near-Earth asteroids, as well as transit outward to Mars. Get the full story at http://www.space.com/missionlaunches/missions/nasas_secret_plan_00121 2.html. --------------------------------------------------------------------- ISU SCIENTIST ON TEAM THAT FINDS COMPELLING EVIDENCE OF ANCIENT LIFE ON MARS Iowa State University release 12 December 2000 An Iowa State University professor is part of a research team that has found compelling evidence that Mars once supported primitive life. The researchers discovered evidence of bacteria in a martian meteorite. Tiny magnetite crystals-so called magnetofossils-embedded in the meteorite were confirmed to be the type produced only by a biological process unique to magnetotactic bacteria. Dennis Bazylinski, associate professor of microbiology, was one of nine researchers conducting the four-year investigation, which was funded by NASA's Astrobiology Institute. A report of their research is in the December issue of the scientific journal, Geochimica et Cosmochimica Acta. [http://www.elsevier.nl/cgi- bin/cas/tree/store/gca/cas_sub/browse/browse.cgi?year=2000&volume=64& issue=23&aid=2555] "Finding these type of magnetic crystals in any material from another planet is an amazing and important finding," said Bazylinski. He leads one of the few labs capable of culturing these magnet-producing bacteria, which are common in many freshwater and marine environments on Earth. The researchers studied the magnetite crystals that were located in carbonates in the martian meteorite. The 4.5 billion year-old meteorite was found in Antarctica in 1984. Earlier research has confirmed that the carbonates formed on Mars, signaling that the magnetite crystals also were formed on Mars. Magnetite crystals produced by magnetotactic bacteria are chemically pure and generally defect free and have a distinctive size and shape. Their properties are so unusual that they have only been seen in magnetite crystals produced through biological processes by organisms. The researchers discovered that about one-fourth of the magnetites in the meteorite are identical to the magnetites produced by a strain of magnetotactic bacteria called MV-1, which has been isolated and studied extensively by Bazylinski. "There is currently no known chemical means of producing these magnetite crystals with their unique morphologies," Bazylinski said. "The significance to astrobiology and geobiology is that many scientists have been searching for 'biomarkers' for life, that is, chemical, isotopic, and/or mineral indications that life was present, either in extreme habitats or in ancient materials on Earth and, of course, now in extraterrestrial materials. The need for biomarkers is obvious and these magnetite crystals might prove to be an excellent biomarker." Since the team began the research in 1996, observations from the Mars Global Surveyor have indicated that Mars had a strong magnetic field at about time that the carbonate containing the unique magnetites was formed. "Now we are trying to answer the question of whether magnetotactic bacteria could have actually lived on Mars," Bazylinski said. "And we have found certain aspects of their metabolism which suggest that they might have been able to do so." The journal Science recently published research showing evidence of widespread sediment layers on Mars, which the researchers interpret to be the product of many lakes. Because these lakes may have provided a habitat for magnetotactic bacteria, this finding supports the possibility that the bacteria may have existed on Mars, Bazylinski said. In addition to Bazylinski, the scientists are Kathie Thomas-Keprta, Simon Clemett, and Susan Wentworth, Lockheed Martin at Johnson Space Center; David McKay and Everett Gibson, NASA/JSC; Joseph Kirschvink, California Institute of Technology; H. Vali, McGill University, Montreal; and Christopher Romanek, Savannah River Ecology Laboratory. Contacts: Dennis Bazylinski, Microbiology, 515-294-2561 Teddi Barron, News Service, 515-294-4778 Additional articles on this subject are available at: http://news.bbc.co.uk/hi/english/sci/tech/newsid_1070000/1070229.stm http://spaceflightnow.com/news/n0012/14marslife/ http://www.msnbc.com/news/463318.asp http://www.spacedaily.com/news/mars-life-00o.html --------------------------------------------------------------------- NEW REPORT OFFERS EVIDENCE OF PRIMITIVE LIFE ON MARS NASA/JSC release J00-84 13 December 2000 A new scientific report offers compelling evidence that primitive life existed on Mars. Tiny magnetite crystals, identical to those used by aqueous bacteria on Earth as compasses to find food and energy, have been found in the martian meteorite ALH84001. The report on the finding is in the December issue of Geochimica et Cosmochimica Acta. Written by a group of scientists led by Kathie Thomas-Keprta of Lockheed Martin at Johnson Space Center and funded by the NASA Astrobiology Institute, the report strongly supports the primitive life on Mars hypothesis of David McKay and co-authors in 1996. Co- authors of the new report on a four-year investigation are Dennis Bazylinski of Iowa State University, Joseph Kirschvink of the California Institute of Technology, Simon Clemett and Susan Wentworth of Lockheed Martin at the Johnson Space Center, David McKay and Everett Gibson of NASA's Johnson Space Center, H. Vali of McGill University in Montreal, and Christopher Romanek of the Savannah River Ecology Laboratory. Magnetite (Fe3O4) is produced inorganically on Earth. But the magnetite crystals produced by magnetotactic bacteria are different- they are chemically pure-and defect-free. Their size and shape are distinct. Magnetotactic bacteria arrange these magnetite crystals in chains within their cells. Their characteristics make the magnetite crystals very efficient compasses, which are essential to the survival behavior of the bacteria. No one has found terrestrial inorganic magnetites, produced either naturally or in the laboratory, that mimic all the properties displayed by biogenic magnetites. "The process of evolution has driven magnetotactic bacteria to make perfect little bar magnets, which differ strikingly from anything found outside biology," said co-author Kirschvink, a geobiologist. "In fact, an entire industry devoted to making small magnetic particles for magnetic tapes and computer disk drives has tried and failed for the past 50 years to find a way to make similar particles. A good fossil is something that is difficult to make inorganically, and these magnetosomes are very good fossils." Scientists generally agree that ALH84001 is a member of the group of 16 meteorites found on Earth that originated on Mars. The potato-sized igneous rock is the oldest of them-about 4.5 billion years. It lay in Antarctic ice for more than 13,000 years. But the biogenic-type magnetite crystals are embedded in carbonates within ALH84001. Previous work by co-author Chris Romanek has shown that these carbonates formed on Mars. Thus the magnetite crystals must also have formed on Mars. "These crystals are so tiny, ranging from 10 to 200 nm, that nearly a billion of them would fit on the head of a pin," said Thomas-Keprta. Using electron microscopy, team members examined the martian magnetites still embedded in the carbonate and also removed about 600 crystals and examined the individual particles to determine their chemical composition and crystal geometry. The authors found that about a quarter of the martian magnetites from ALH84001 are identical to magnetites produced on Earth by magnetotactic bacteria strain MV-1, which has been extensively studied by co-author Bazylinski, a geobiologist and microbiologist who has developed many ways of culturing these difficult-to-grow microorganisms. "There is currently no known chemical means of producing these magnetite crystals with their unique morphologies," he said. Co-author Clemett noted that "Mars is smaller than Earth and it developed faster. Consequently, bacteria able to produce tiny magnets could have evolved much earlier on Mars." When the team asserted in 1996 that martian meteorite ALH84001 showed signs of life existing on Mars, that planet was not known to have ever had a strong magnetic field. But since then, the Mars Global Surveyor has observed magnetized stripes in the crust of Mars that show a strong magnetic field existed early in the planet's history, about the same time as the carbonate containing the unique magnetites was formed. "ALH 84001 has been of great heuristic value in the field of astrobiology," said Baruch Blumberg, director of the NASA Astrobiology Institute. "Independent of its support or rejection, it has raised stimulating hypotheses that will help to focus our definition of how life, or variants of it, can be recognized." Vic Baker at the University of Arizona and Jim Head of Brown University have inferred abundant water on early Mars from the morphology of canyons prevalent on Mars. In a recent issue of Science, Michael Malin and Ken Edgett present evidence of widespread sediment layers on Mars that they interpret as produced by numerous lakes. Adrian Brearly of the University of New Mexico has found traces of ancient water, in the form of clay minerals, in ALH84001. Mars has long been understood to provide sources of light energy and chemical energy sufficient to support life. Early Mars, the authors note, may have had even more chemical energy produced by active volcanism and hydrothermal activity. Contact: John Ira Petty Johnson Space Center, TX Phone: 281-483-5111 --------------------------------------------------------------------- MARS GLOBAL SURVEYOR READY FOR EXTENDED MISSION By Leonard David From Space.com 13 December 2000 NASA has given a thumbs-up for an extension of the Mars Global Surveyor's (MGS) mission to study the Red Planet until April 2002. Doing so enables scientists to zoom in on prospective touchdown zones for future robotic landers. MGS is to end a nominal assignment of mapping the planet from orbit for one martian year on February 1, 2001. Mars takes 687 Earth days to travel around the Sun, making a martian year almost two Earth years long... ..."The extended mission allows us to fill in the gaps and complete the global inventory of Mars," said Jim Garvin, Mars exploration program scientist at NASA Headquarters. "MGS will be able to look across seasonal boundaries, where we have repeat seasonal coverage, to look for changes," he told SPACE.com. Get the full story at http://www.space.com/scienceastronomy/solarsystem/mgs_update_001212.h tml. --------------------------------------------------------------------- NASA ASTROBIOLOGISTS TO PRESENT RESEARCH AT AGU NASA/ARC note 00-84AR 14 December 2000 Astrobiologists at NASA's Ames Research Center have organized a special Astrobiology and Planetary Atmospheres Session to be held Monday, December 18 at the American Geophysical Union (AGU) conference in San Francisco. The special astrobiology session will take place from 1:30 PM-5:00 PM in Room MC-303 at the Moscone Center. Astrobiology organizers include Drs. David Morrison and Christopher McKay of Ames Research Center and Dr. Frank Drake of the SETI Institute. Session presenters include NASA and non-NASA astrobiologists. An abridged schedule follows. Session P12A, Planetary Atmospheric Processes and Astrobiology *1:30 PM "The Decay of Solar Activity and its Implications for the Solar System," F. M. Walter, State University of New York, Stoneybrook. *1:50 PM "Earth's Early Atmosphere-Controlling Factors," G. Arrhenius, Scripps Institute of Oceanography, UCSD. *2:20 PM "Nitrogen Fixation on Early Earth and Mars," R. Navarro- Gonzalez, Institute Ciencias Nucleares, Mexico, C. P. McKay, NASA Ames Research Center. *3:10 PM "Interstellar Quinones and the Evolution of Our Biochemistry," J. P. Dworkin, M. P. Bernstein, S. A. Sandford and L. J. Allamandola of the Astrochemistry Lab, NASA Ames Research Center. *3:40 PM "Molecules in Comets: An Interstellar Medium-Solar System Connection?" E. A. Bergin, Harvard-SC for Astrophysics. *3:55 PM "Laboratory Investigation of the Atmospheric Chemistry of Titan," J. P. Ferris, Rensaller Polytechnic Institute, NY. *4:40 PM "Can (Do) Methanogens Live on Mars?" T. A. Kral, University of Arkansas, C. P. McKay, NASA Ames Research Center. Other Ames astrobiologists will present talks or posters at the conference, including: *December 17 at 2:05 PM, "Minimum Energy Requirements for Sustained Microbial Activity in Anoxic Sediments," T. Hoehler, NASA Ames Research Center. (The talk will focus on the extreme adaptations organisms make in order to survive in low-energy environments.) *December 19 at 8:30 AM, "Impact Production of (Greenhouse Gases) on Early Earth and Mars," M. E. Kress, University of Washington, K. J. Zahnle, C. P. McKay, NASA Ames Research Center. For a detailed schedule, please see http://www.agu.org/cgi- bin/sessionsf?meeting=fm00&part. For press registration information, please see: http://www.agu.org. The Moscone Center is located at 747 Howard Street in San Francisco. Astrobiology is the study of the origin, evolution, dissemination and future of life in the universe. NASA's Ames Research Center in California's Silicon Valley is the Agency's lead center for astrobiology. In addition, the central administrative office of the NASA Astrobiology Institute (NAI), a research consortium involving academic, non-profit and NASA field centers, is located at Ames. Information about the NASA Astrobiology Institute will be available in the Exhibit Hall. Contacts: Kathleen Burton NASA Ames Research Center Moffett Field, CA Phone: 650-604-1731 or 604-9000) kburton@mail.arc.nasa.gov AGU Moscone Center press room San Francisco, CA Phone: 415-905-1007 (for general AGU information during meetings) --------------------------------------------------------------------- NEW ADDITIONS TO THE ASTROBIOLOGY, EXTREME ENVIRONMENTS AND TERRAFORMATION INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.h tml 15 December 2000 Articles about astrobiology, exobiology and terraformation http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s1.html BBC, 1998. New hope of finding life on Mars. BBC News. BBC, 2000. Centre to probe life in space. BBC News. BBC, 2000. Scientists search for space 'bugs'. BBC News. G. Clark, 1999. Still solo, mars global surveyor picks up slack in NASA's Mars program. Space.com. L. David, 2000. Mars Global Surveyor Ready for Extended Mission. Space.com. L. Miles, 1999. Bugs in space. BBC News. National Academy of Sciences, 2000. Photos suggest ancient martian lakes. National Academy of Sciences, USA. SpaceDaily, 2000. Iowa professor claims compelling evidence for magnetotactic Mars bacteria. SpaceDaily. Spaceflight Now, 2000. New report offers evidence of primitive life on Mars. Spaceflight Now. D. Whitehouse, 1998. Searching for life on Europa. BBC News. D. Whitehouse, 1999. Bacteria found in Antarctic ice core. BBC News. D. Whitehouse, 1999. Hunting for ET. BBC News. D. Whitehouse, 1999. Life on Mars-new claims. BBC News. D. Whitehouse, 1999. Martian 'bacteria' matched to Earth. BBC News. D. Whitehouse, 2000. Red planet's wet and warm past. BBC News. D. Whitehouse, 2000. Study reopens martian 'fossil' debate. BBC News. D. Whitehouse, 2000. Water may flow on Mars. BBC News. Articles about human space exploration and the microgravity environment http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s3.html L. David, 2000. NASA'S secret plan: a roadmap beyond the space station. Space.com. L. David, 2000. Supermaterials repel space dangers. Space.com. Articles about primordial evolution and prebiotic chemistry http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s5.html BBC, 2000. Life's leap to land. BBC News. --------------------------------------------------------------------- CASSINI WEEKLY SIGNIFICANT EVENTS JPL release 30 November - 6 December 2000 The most recent spacecraft telemetry was acquired from the Madrid tracking station on Wednesday, December 6th. The Cassini spacecraft is in an excellent state of health and is operating normally. The speed of the spacecraft can be viewed on the "Where is Cassini Now?" web page at http://www.jpl.nasa.gov/cassini/english/where/. Activities this week included the completion of the fourth and final instance of the Phase B 5-Day repeating template, and start of the Phase C partial template for Jupiter observations. Template activities include the Imaging Science Subsystem (ISS) 2x2 movie, Composite Infrared Spectrometer (CIRS) North/South scans, ISS 1x4 Satellite Search, Cassini Plasma Spectrometer (CAPS) orientation to place -X axis to sun and rotate, and Radio and Plasma Wave Science (RPWS) calibration. MIMI, RPWS, Visual and Infrared Mapping Spectrometer (VIMS) and ISS instrument teams each provided a brief status report at the weekly Status and Scope meeting. The MIMI data for Jupiter are looking very nice. The INCA sensor is seeing Jupiter in energetic neutral atoms (ENA) at about the source strength predicted by Voyager. In the latest images, Jupiter can be seen without long time integrations. LEMMS is monitoring both solar and Jovian energetic particle fluxes, and CHEMS is primarily looking at solar wind pickup ions. RPWS has now successfully carried out all scheduled calibrations occurring in Cruise 23 and the data look good from all of them. The calibrations have been designed to sweep the RPWS +X and -X antennas through the direction to Jupiter where a sharp null in the received signal will occur. VIMS continues to work normally. Atmospheric studies are looking at methane bands and H3+ emissions from the Polar Regions. Spectra of at least two satellites have also been recorded. VIMS team scientists are pleased with the data. Instrument Operations (IO) and the Multi Mission Image Processing Laboratory (MIPL) produced and delivered 2,102 ISS images and 29 VIMS cubes last week bringing the totals since the start of Jupiter activities up to 11,132 images and 83 cubes. ISS has prepared a set of sequences to run in the Integration Test Laboratory (ITL) next week. These are to test certain operations strategies and in-flight performance. A Magnetosphere and Plasma Science (MAPS) Working Group meeting was held at the University of Michigan this week. The purpose of this meeting was to integrate the fields and particles instrument observational desires for the whole tour. Significant progress was made in understanding the requirements for the magnetosphere survey and the observational campaigns needed to determine the magnetospheric processes. The Attitude Control Team presented a feasibility study on active tracking of the Huygens probe during its descent into Titan's atmosphere. Both Huygens and Cassini personnel participated. The initial assessment was favorable. Further studies and analysis are underway. ULO personnel have finalized the selection of modules to be included in the January delivery of MSS D7.4. Final testing in ITL for these modules is scheduled for mid December. System Engineering (SE) coordinated a briefing by the Mission Support & Services Office (MSSO) to project members to better understand the rules and procedures needed for Cassini software distribution. Specifically, Science Opportunity Analyzer (SOA) is about to be delivered and needs to be provided to various Distributed Operations sites. Cassini ACEs hosted two observers this week. Both individuals sat with an ACE for at least 4 hours and were briefed on the various real-time ACE tasks and functions. Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, CA, manages the Cassini mission for NASA's Office of Space Science, Washington, DC. --------------------------------------------------------------------- THIS WEEK ON GALILEO JPL release 11-17 December 2000 This week Galileo's efforts continue on maintaining the continuity of a Fields and Particles instrument survey of the Jovian magnetosphere. The survey data are very valuable as they are Galileo's contribution to a dual-spacecraft observation campaign to examine the influence of the solar wind on the Jovian magnetosphere. Two engineering activities are performed during the week. On Friday, the spacecraft performs standard maintenance on its propulsion systems. On Sunday, the spacecraft executes a small turn to keep its radio antenna pointed toward Earth. The Fields and Particles instruments on Galileo are the Dust Detector, Energetic Particle Detector, Heavy Ion Counter, Magnetometer, Plasma Detector, and Plasma Wave instrument. The second participant in this dual-spacecraft observation campaign is the Cassini spacecraft. Cassini will pass by Jupiter in December, enroute to arrival at Saturn in 2004. The rarity of having two spacecraft in position to collaborate in observing the same phenomena makes the data gathered by both spacecraft extremely valuable. Galileo is using its onboard tape recorder to store survey data that cannot be immediately transmitted to Earth. The tape recorder is necessary because Galileo's main computer memory (circa 1980s) is configured to store only about 7 hours of survey data. When the radio antennas of the Deep Space Network (DSN) are being used by other spacecraft and Galileo's data buffer is near capacity, Galileo dumps the contents of the data buffer onto the tape recorder to prevent buffer overflow and data loss. When the next DSN antenna scheduled for Galileo comes along, the survey data that have been stored on the tape recorder are retrieved, packaged and transmitted to Earth. This week, Galileo uses its tape recorder 10 times to store survey data, and is able to play back data for approximately 80 hours. For more information on the Galileo spacecraft and its mission to Jupiter, please visit the Galileo home page at one of the following URL's: http://galileo.jpl.nasa.gov http://www.jpl.nasa.gov/galileo --------------------------------------------------------------------- MARS GLOBAL SURVEYOR STATUS REPORT JPL release 6 December 2000 Launch / Days since Launch = November 7, 1996 / 1491 days Start of Mapping / Days since Start of Mapping = April 1, 1999 / 615 days Total Mapping Orbits = 7,817 Total Orbits = 9,420 Recent events The spacecraft continues to operate nominally in performing the beta- supplement daily recording and transmission of science data. The mm092 sequence executed successfully from 00-335 (11/30/00) through 00-337 (12/2/00). The mm093 sequence has performed well since it started on 00-338 (11/3/00). It terminates on 00-341 (11/6/00). The mm094 sequence, successfully uplinked on 00-340 (12/5/00), begins executing on 00-342 (12/7/00). No special science scans were conducted this week. Spacecraft health All subsystems report nominal health. Uplinks There have been 8 uplinks to the spacecraft during the last week, including instrument command loads and the sequences cited above. There have been 5,000 command files radiated to the spacecraft since launch. Upcoming events The mm095 background sequence will be uplinked on 00-343 (12/8/00). Science Campaign F commences on 00-345 (12/10/00) and lasts until 00- 356 (12/21/00). Radio Science Occultation Egress Scans, scheduled for 00-353 (12/18/00) through 00-356 (12/21/00), will be commanded by the mz065,mz066, & mz067 mini-sequences. --------------------------------------------------------------------- STARDUST STATUS REPORT JPL release 8 December 2000 There were six Deep Space Network tracking passes during the past week. All subsystems are performing normally onboard the spacecraft. Stardust successfully performed trajectory correction maneuver #4 (TCM-4). The spacecraft fired its one-pound thrusters for 113 seconds, to equal the required burn time. For the first time when performing a TCM, radiometric X-band Doppler data were taken. A Doppler, or velocity, change of +131.6 Hz was observed, comparing very well to the predicted change of +129.8 Hz. The orientation to point the spacecraft's thrusters in inertial space put the bottom of the spacecraft toward the Sun, requiring batteries to provide the necessary power for the burn. The lowest point in the battery state of charge was observed to be 79.8%. The navigation camera heating sequence continues with both charge- coupled device and mirror motor heaters on. As the Sun shone on the bottom of the spacecraft where the navigation camera radiator is located, the spacecraft stayed in that attitude for an additional 18 minutes to add another heat source for the navigation camera. The charge-coupled device's temperature rose an additional 13 degrees to 25 C, and the mirror motor's temperature rose an additional 6 degrees to 27 C during this attitude. The navigation camera charge-coupled device heater remains on and will be kept in this configuration for another two weeks in order to provide the maximum heating time. The solar opposition maneuver was accomplished when the spacecraft slewed back to Earth point following TCM-4. The Stardust project continues to participate in Deep Space Network (DSN) loading studies for late 2003 and early 2004 with NASA and all projects operating at this time. There are currently not enough DSN resources to meet the tracking requirements of all missions and these meetings are exploring setting NASA priorities, reviewing and validating requirements, risk mitigation strategies and building new DSN facilities. For more information on the Stardust mission-the first ever comet sample return mission-please visit the Stardust home page at http://stardust.jpl.nasa.gov. --------------------------------------------------------------------- End Marsbugs, Volume 7, Number 48