MARSBUGS: The Electronic Astrobiology Newsletter Volume 9, Number 44, 25 November 2002. Editor/Publisher: David J. Thomas, Ph.D., Science Division, Lyon College, Batesville, AR 72503-2317, USA. dthomas@lyon.edu Contributing Editor: Julian A. Hiscox, Ph.D., 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 monthly 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 effectively 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. Information concerning the scope of this newsletter, subscription formats and availability of back-issues is available from the Marsbugs web page at http://welcome.to/marsbugs or http://www.lyon.edu/webdata/users/dthomas/marsbugs/. _____________________________________________________________________ CONTENTS 1) THE ENVELOPE OF LIFE, PLEASE Results from a reader poll 2) WHERE ON EARTH IS MARS? NASA/JPL release 3) SMOKING CRATERS: HOME TO MARTIAN LIFE? By David Tenenbaum 4) UCSD BIOENGINEERS USE COMPUTER MODEL TO PREDICT EVOLUTION OF BACTERIA UCSD release 5) SATELLITE STUDY ESTABLISHES FREQUENCY OF MEGATON-SIZED ASTEROID IMPACTS University of Western Ontario release 6) REPORT FROM THE FIELD: A PERSONAL PERSPECTIVE By Peter Backus 7) NASA AWARDS RESEARCH GRANTS NASA release 02-227 8) INTERNATIONAL SPACE UNIVERSITY: SCHOOL FOR THE STARS By Morris Jones 9) MUSEUM FOR PROTEIN PALEONTOLOGY? Based on U.S. Geological Society publication 10) FIRST MDRS FALL 2002 CREW ROTATION NEARS CONCLUSION By Charles Frankel 11) BALANCING BRAINS By Karen Miller 12) SURVIVING THE FINAL FRONTIER By Stephen Hart 13) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 14) CASSINI SIGNIFICANT EVENTS NASA/JPL release 15) MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 16) STARDUST STATUS REPORT NASA/JPL release _____________________________________________________________________ THE ENVELOPE OF LIFE, PLEASE Results from a reader poll From Astrobiology Magazine 9 November 2002 The editors of the Astrobiology Magazine are impressed with the depth of interest and knowledge in this growing field, so take a bow. The editors have introduced a new "Just Ask" feature which categorizes a number of interdisciplinary terms important to the new field of astrobiology. To enhance this dialog, we also have appended the flow of news stories with this snapshot of not only what you--the readers- -think, but also what the researchers don't necessarily know yet or soon hope to find out. What we think is true According to Astrobiology Magazine's polls, readers think: * primitive microbes (47%) will be the most likely life forms to find on another world * finding some kind of alien machine intelligence (11%) is not likely * life on Earth first arose from some kind of biological soup or RNA world(40%), not from cometary debris (20%) nor from interplanetary exchange (7%) * nuclear reactors are by far (52%) the most surprising extreme environment where life is found, followed by volcanoes, rock interiors, ocean vents, Antarctic lakes and the upper atmosphere (10%) * liquid water (41%) is the key factor needed to make a planet habitable, followed by a combination of all the elements [nutrient, water, oxygen, ozone, photosynthetic sources like sunlight, and carbon dioxide]. * similarly, the presence of water and fossils are the most likely signatures of life we would find on another planet. * the best candidates for life once existing in our solar system are Mars and Jupiter's moon, Europa. What we don't necessarily know yet "A good scientist is a person in whom the childhood quality of perennial curiosity lingers on. Once he gets an answer, he has other questions." --Frederick Seitz, President, Rockefeller University According to the inquiries from readers of Astrobiology, the most popular questions to be researched and answered are: 1) What is the largest one-cell organism? Is the limit mainly nutrient and waste diffusion? 2) What is the driest place on Earth? 3) How do astronomers tell a binary star from a planetary system? 4) What is the oldest place on Earth? 5) What are the unique Cambrian life forms? 6) What are the causes of the Cambrian explosion? 7) What kind of things would you find on Mars? 8) What is the quickest way to oxygenate Mars? Is any accelerated path from Earth's microbial history possible? 9) How does the doppler shift method of planet discovery work? 10) Are salt-loving (halophilic) organisms likely on Mars? 11) What is the origin of ocean salinity? 12) Was the early Earth anaerobic? If so, what life forms likely thrived? 13) Do carbon building blocks exist on any of the outer planets like Neptune or Uranus? 14) What telescopically is required to image an extrasolar planet in visible light? 15) Does life exist at high pressures? 16) Could you describe the goals of the NASA Kepler mission? 17) What is the life cycle of E. coli? 18) What organisms are specialized for the Great Barrier Reef, Australia? 19) Is water necessary for all life? 20) What is the role of oxygen in bacterial evolution? 21) Prior to the Cambrian explosion, did ocean life evolve in a more salty ocean? 22) How many light-years to the nearest suspected solar system? 23) What is the biomass subterranean on Earth? Quantity and types? 24) Can complex life as we currently classify it exist on a planet without oxygen? If not, what key hurdle does anaerobic living pose to complexity? 25) Can bacteria survive using metals as a primary nutrient? 26) What are the most extreme temperature and pressures found for growing organisms? On land and in deep sea? 27) What life-forms are found around black smokers? 28) Could you describe the role of symbiosis in evolution? 29) What are the latest Rover designs? 30) What is the best theory for how the Moon formed? 31) What happened to the ancient oceans on Mars? 32) What percentage of the earth's mass is contributed by the total biomass? 33) How does the carbon cycle work to keep the Earth "living" or habitable? 34) What is the newest solar system discovered by current search methods? 35) What evolutionary branch gave rise to the earliest mammals? 36) What evidence suggests that the moon arose from a Mars impactor striking the Earth? 37) How many planets predicted in the Milky Way? 38) What are the ecosystem breakdowns following ozone layer decay? 39) What evidence is there for the existence of liquid water beyond Earth, particularly in comets? 40) What is the origin and approximate age of the Mars gullies (sand tracks)? 41) What are the main challenges to seeing planets around other stars? 42) Do Antarctic microbes grow in ice fields? 43) Which moon in our solar system has an atmosphere most like Earth's? 44) What is the most classic illustration of a current species that has self-evidently undergone (presently is undergoing) evolution? 45) What boilerplate plans are available for colonizing Mars? 46) What life forms are expected in or near Lake Vostok, Antarctica? 47) How does the continental biomass compare to the ocean--quantity and forms? 48) Are solar flares associated with any biologically significant events terrestrially? 49) How would the most robust rover maneuver over terrain barriers equivalent to its wheel size? 50) Are any of Jupiter's moons potentially colonizable by Earth microorganisms? If not, could genetically engineered variants of ice-dwelling organisms adapt to Europa in place, for instance? 51) What are the primary handling contaminants in studying meteorites when found on Earth? How are these typically controlled for in bio- analyses? 52) How does the bacteria Pyrococcus adapt to boiling (sterilizing) conditions in situ? 53) Can you compare and contrast the survival architecture of photosynthesizing vs. fermenting microorganisms? 54) Before methanogens, what were the Earth's dominant success stories for the tree of life? 55) Speculate on the most likely kind of survivor today on Europa? 56) Is there a simple schematic or recipe method for understanding the key biomolecules that arose on Earth? Is there a particular reaction like carbon-dioxide catalyzed to water that became essential early on? 57) How do bacteria cope with hot dry conditions and can these survival techniques be adapted to terraform Mars? 58) What are the most probable mass extinction events in future Earth scenarios? 59) What key factors go into computer simulations of planet formation? Gravity + cooling + collisions? 60) What besides nutrient, waste and reproduction defines a living vs. non-living entity? 61) How does mitochondrial DNA figure in tracing the tree of life? 62) What are the specifics of the best rover wheel design for all (predicted and unexpected) terrain hazards? 63) Is there evidence of bacteria growing in sandstone with minimal water but without sporulation? 64) Define habitable zones? Is this terminology now out of scientific fashion? 65) Is there a planet discovery method based on pulsar timing events? 66) What protein biomolecules evolved from enzymes and how do these differ from other peptides and proteins? 67) What prebiotic chemistry is available in Titan's atmosphere? 68) How does carbon dating work for determining the age of dormant bacteria? Are there any classic examples of this being done successfully today? 69) Are there prebiotic chemistries that might not hydrolyze even amidst the sulfuric acid content of say Venus? 70) Do radiation levels on Mars today (UV) have a bearing on the conclusion that the surface is barren? What depth of soil will shield known extremophiles like Radiococcus? 71) What remote sensing signal is most indicative of active photosynthesis on Earth when viewed from space--and to what distances would this photosynthetic signal be discernable with current state- of-the-art sensors? 72) What is the evolutionary split between Archaea and Bacteria? 73) What technique is used to discern the wobble of a star with a planet vs. one without? 74) What are the most promising prebiotic molecules ever found on a meteorite? Other than water and carbon, are there actual amino acids? 75) Are the oceans still considered the originating ecosystem for all life on Earth? What evidence, if any, is there for continental origins including wetlands or swamps? 76) Does the Hubble Deep Field offer any revisions on the classic Drake equation for the total number of stars? 77) What microbes are found in geothermal vents? 78) What is a Trilobite? And what is its significance in evolution? 79) Were local climatic events influenced by the largest meteor strike on Earth? 80) Are viruses currently considered living parts of the tree of life or some alternative like a pollen grain (semi-dormant or host- dependent)? 81) Explain what is meant by left-handed vs. right-handed biochemistry, particularly in analyzing meteor chemistry? 82) What electrical storm hazards exist on Mars? 83) What in your opinion is the weirdest extinct animal? Additional information on this article is available at http://www.astrobio.net/news/article309.html. _____________________________________________________________________ WHERE ON EARTH IS MARS? NASA/JPL release http://www.jpl.nasa.gov/earth/features/mars.cfm 18 November 2002 Among the thousands of visitors to Mt. Etna this year, one group came not just to look at one of most famous volcanoes on Earth. Dozens of scientists trekked up Etna together this fall to observe what Etna has in common with Mars. Researchers interested in what makes the red planet tick can't study the planet in person--at least not yet. To help them interpret what they see in Mars images and other remote sensing data--and to test their instruments and procedures--they turn to Earth. Though the two planets are very different, Earth offers many similarities, or analogs, to Mars. Some of these, such as Antarctica, are definitely off the beaten track. Others, however, such as Mt. Etna, are places where ordinary travelers might find themselves-- although perhaps unaware that what they're seeing is anything like our neighboring planet. "A site can be like Mars in a variety of ways," says JPL geologist Dr. Tom Farr, one of the participants in the "Exploring Mars' Surface and its Earth Analogues" workshop at Mt. Etna. "Since Mars is really cold, the first places you think of are Antarctica and the Arctic. These places provide a way to see some of the processes that probably take place on Mars--glaciers and permafrost. But a place can also be like Mars by having similar geological features, such as volcanoes, or processes like erosion and weathering." Volcanoes in common The prominent volcanoes on Mars are large, old and apparently no longer active. "Though small by Mars' standards, Etna, like the majority of volcanoes on Earth, is basaltic," says Mars Odyssey Project Scientist Dr. Jeffrey Plaut, who was also in the Etna workshop. "We believe that Mars' volcanoes have the same composition." Etna also has an example of a volcanic process that scientists think may occur on Venus, the Moon, and possibly Mars, but until recently hadn't been seen before on Earth. "We see some long narrow channels on those planets that don't look like they were eroded by water," says Farr. "We inferred that they were produced by lava, but until their discovery on Etna, we had never actually seen that happen." Not all of Earth's volcanoes match those on Mars. "Mt. St. Helens is not a good analog," says Plaut, "it's silica-rich and is a result of plate tectonics that do not seem to occur on Mars". For good examples of large shield volcanoes, the most common type on Mars, Plaut picks Mauna Loa and Kilauea. "The big island of Hawaii, which is the largest volcano on Earth, has been a tremendous Mars analog." On Mars, super-sized volcanoes sculpted the landscape by releasing huge amounts of lava. It's possible to see what that sort of event did on Earth along the Columbia River in Washington. "Some of the largest lava flows on Earth took place there," says Plaut. The area was repeatedly flooded by lava, which formed the great basaltic cliffs called the Columbia River Basalts. And in Idaho's Snake River Plain, "rift lava seeped over a large flat surface creating a volcanic plain that serves as a good terrestrial analog for extensive sheet lavas on Mars as well as Venus and the Moon," says Farr. Mars in the desert Earth's deserts have many examples of geological processes at play on Mars. "Processes in arid environments tend to create dunes and landforms eroded and etched by winds like those we see on Mars," says Plaut. "We also like the desert because there's not much vegetation and the geology is exposed at the surface as it is on Mars." Drier and cooler than most deserts, the Atacama in Chile is often considered a Mars analog. In the warm deserts of Tunisia at the edge of the Sahara and California's Mojave, wind-blown sand creates Mars- like dunes and landforms. Deserts in North Africa, China, Asia, and North America are home to wind-sculpted ridges known as yardangs, also common in the martian landscape. On both planets, some of today's deserts were probably yesterday's lakes. The same process that created Utah's Bonneville Salt Flats may have shaped the dry lakebeds that dot the martian landscape. "Mars seems to have had catastrophic floods," says Plaut, "not unlike those that took place in the Bonneville area in the ice age. As the glaciers retreated, the rapid draining of a large lake carved up the landscape creating distinctive landforms. There was a lot of water and a lot of energy." One of the most famous planetary analogies and laboratories is Death Valley. "It's like Mars in its tectonic, erosional and sedimentation processes," says Plaut. "It looks like Mars, too. There's a spot called Mars Hill that reminds people very much of the Viking 2 Lander site." Impact zone Many a meteor made its last stop on Mars and on Earth. Mars' surface is pockmarked with impact craters. Here on Earth, most are buried or have eroded away. The Haughton Crater on Devon Island in the Canadian Arctic is a well-known site for Mars-related studies. More accessible is the meteor crater in Winslow, AZ. "It's fairly recent," says Plaut, "and well-preserved, like many we see on Mars." Geology may not be all that Mars and Earth have in common. In the search for life in extreme environments, like those which may exist on Mars, researchers are looking in places like Yellowstone and Hot Springs, AR. "Because the Mars environment is so cold and dry, getting liquid water to the surface today may require hot spring activity," says Plaut. "But people are studying all kind of ground water environments--hot or not--and caves as possible Mars analogs." As Mars exploration continues, new common ground between that planet and this one is likely to emerge. "Even as we learn more about Mars from the new missions," says Farr, "we'll go out and try to find places on Earth that are similar, continuing our search for better Mars analogs." Contact: Rosemary Sullivant Phone: 818-393-7490 An additional article on this subject is available at http://www.astrobio.net/news/article316.html. _____________________________________________________________________ SMOKING CRATERS: HOME TO MARTIAN LIFE? By David Tenenbaum From Astrobiology Magazine 19 November 2002 Mars may be smaller than Earth, but it's still huge to a roving spacecraft that can cover only 100 meters a day. For that reason, Mars mission planners must go to great lengths to find landing sites that might still carry evidence that life once existed on Mars. A key zone of speculation exists just beneath Mars' cold, dry, dusty and inhospitable surface--where two prerequisites for life, water and heat, may be found. Such heat may come from volcanism, and indeed Olympus Mons is the largest volcano in the solar system. Asteroid impacts (most likely in the first half-billion years of the solar system but conceivably even today) are a second possibility. When a big piece of rock crashes into Mars at about 5 kilometers per second, could that liberate enough heat to melt underground ice, drive the circulation of liquid water, and perhaps allow the formation or survival of life? Julie Rathbun, who now teaches astronomy and physics at the University of Redlands (Redlands, California), and Steven Squyres, a planetary scientist at Cornell University, decided to answer the question by modeling hydrothermal circulation--the flow of liquid water through geologic structures. "We were looking to see if a hydrothermal system would set up, and if so, what kind temperature it would establish, and for what period," says Rathbun. The model indicated that lakes might have lingered for thousands of years after an impact, conceivably long enough for life to form. The lakes were much warmer than the planet as a whole. And they may have been deep enough to connect to aquifers--underground water bodies-- where microbial life may already have been living. Like much of astrobiology, the study was a bit of a shot in the dark, Rathbun says. "A lot of efforts were incredibly theoretical, and ours was certainly one of those. But there hadn't been any strict physical modeling of what water would do in the temperatures available in an impact crater, just qualitative work." In the journal Icarus (June 2002), Rathbun and Squyres described two theoretical impact craters on Mars. In both cases, a lake formed from melted ice in the martian permafrost and was soon covered by ice. The smaller crater was 7 kilometers (4.3 miles) across, and the lake probably froze rather quickly. (Under current martian conditions, any water at the surface will rapidly boil and freeze, then eventually sublimate into the atmosphere.) The larger crater, with more astrobiological interest, was 180 kilometers (112 miles) in diameter. Water in parts of that lake ranged from 50 degrees C (122°F) to 100 degrees C (212°F). Depending on assumptions used for geologic conditions, the lake may have persisted for 15,000 years. Whether life could begin quickly enough to form in that transient lake, Rathbun admits, is "an open question." Although she says biologists have not provided "any hard and fast numbers" for how rapidly life could start, "a lot of biologists believe life would have emerged quickly" in the right circumstances. Virginia Gulick, an astrobiologist with the SETI (Search for Extraterrestrial Intelligence) Institute, agrees that craters may be hospitable to life. "From what we know about life, life requires water, an energy source, and time. Hydrothermal systems can provide such an environment." However, she notes that hydrothermal systems can also be powered by rising magma, volcanism and tectonic shifting. "It's not clear whether craters would be a better place to look, especially considering that hydrothermal systems powered by the intrusion of magma may last far longer--millions or hundreds of millions of years." In addition, she says the very warmth that makes craters such alluring targets may backfire. "Large impact events have a tendency to sterilize the surrounding environment, leaving the area initially devoid of life. However, with time life may migrate to such areas through warm water being circulated through the extensive fracture systems generated by the impact." While the search for past life on Mars may seem a long shot, Gulick thinks recent biological discoveries indicate otherwise. "We know on Earth that microbial life inhabits environments formerly thought to be inhospitable, such as in the deep subsurface, in the extremely cold and dry Antarctic soils, rocks and ice-covered lakes, in deep ocean basins at mid-oceanic rift hydrothermal systems, and also in high altitude (20,000 foot) icy volcano lakes. Given that life is found in these extreme environments on Earth, it isn't such a far stretch to think that similar microbial life may have existed deep in the subsurface of Mars." Similar speculation also indicates the type of life that may have lived in martian hydrothermal systems. Rathbun and Squyres expect to see evidence of organisms akin to those found in deep-sea vents and geysers on Earth. These members of the kingdom Archaea live in anaerobic (oxygen-free), high-temperature conditions; some metabolize rocks for energy and can live without sunlight. Rathbun agrees that the accuracy of estimates of conditions on Mars is only as good as the assumptions of martian conditions on which they rest. All bets are off, for example, if any water is absent from the near-surface environment of Mars. Perhaps the most important limitation of any Mars modeling effort is the reliance on estimates rather than data for key parameters. "Normally on Earth you have far more information about what you're trying to model," says Horton Newsom, a solar-system geologist from the University of New Mexico who has been speculating about hydrothermal systems on Mars for 20 years. "It's a much more difficult job to try to model on Mars, where you have no geological constraints." The lifetime of a lake, Newsom notes, "depends on the amount of heat, and permeability. But in geological material, permeability can vary over many orders of magnitude, and this has a major influence" on when the hydrothermal system will freeze up. Nonetheless, even transient hydrothermal systems might be a smart place to look, Newsom says. "In a 150-kilometer crater, you could have hot rock and hot water around for thousands of years. Even if life did not originate there, the lake will draw in groundwater, so you have essentially a giant Petri dish that can culture and grow microorganisms that may have grown elsewhere." Thus he, like Rathbun and Squyres, agree that large impact craters are promising sites for evidence of life. Indeed, Newsom says, two impact craters (Gusev and an unnamed, buried, 150-km crater rim) are top candidates for the Mars Exploration Rover, scheduled for launch in 2003. What's next? Short of actual exploration, perhaps the best way to verify the results of computer modeling, Rathbun says, would be to investigate historic craters on Earth, and check whether their conditions match those that the computer model predicts. Additional information on this article is available at http://www.astrobio.net/news/article315.html. An additional article on this subject is available at http://www.space.com/scienceastronomy/crater_life_021119.html. _____________________________________________________________________ UCSD BIOENGINEERS USE COMPUTER MODEL TO PREDICT EVOLUTION OF BACTERIA UCSD release 20 November 2002 In a study published in the November 14 issue of Nature, Bioengineers at the University of California, San Diego (UCSD) Jacobs School of Engineering used their computer model of E. coli (patent pending) to accurately predict how the bacteria would evolve under specific conditions. The results may have applications for designing tailor- made biological materials for commercial uses or for predicting the evolution of drug-resistant bacteria. "This is totally revolutionary that you can actually predict the outcome of such a complicated and intricate process as adaptive evolution," says Bernhard Palsson, UCSD Bioengineering Professor and study author. "One of the implications of this study is that we could possibly use such a system to predict the evolutionary stability of bacteria, and potentially predict the probability of a drug-resistant strain developing." The study also serves as an example of the power of systems biology, a hot emerging field dedicated to employing mathematics and computer simulation to understand how genes and proteins work together to control the function of cells. Nature dedicated its November 14 Insights issue to the topic, which included an overview article co- authored by UCSD Bioengineering Professor Jeff Hasty. Palsson first created a computer model of E. coli in 2000, and since then has shown that the model accurately mimics the behavior of the bacteria 80% of the time. He says he came upon this latest breakthrough almost by happenstance when his laboratory experiment of E. coli growing on glycerol did not match the rate of growth predicted by the computer model. On a hunch, he guessed that this particular strain of E. coli had not been exposed to glycerol before, and that if he gave the bacteria time to evolve, it might reach an optimum growth rate. To test the theory, Palsson created a "survival of the fittest" experiment, in which bacteria that grew well in glycerol was allowed to survive while less fit versions died off. He allowed the bacteria to evolve, which took about 40 days through 700 generations. The growth rate of the surviving strain matched the optimal growth rate predicted by the computer model. With this success in hand, Palsson's group replicated the in silico-to- laboratory experiment with a number of different substrate materials. Although beating drug-resistant bacteria is a foreseeable use of the technology, Palsson says a more immediate application is for tailoring microbes such as E. coli to make chemicals used in the synthesis of drugs and other products such as detergents. "This is could be a totally new technique for designing commodity microbes," says Palsson. "We could design a strain in the computer by adding or removing genes and then calculating the optimal performance of that strain. Once we have a strain that performs to the characteristics we want, we could move on to the real organism, manipulate the genetic content, and then use the adaptive evolutionary process to implement the design." This discovery by Palsson follows on another study reported in the November issue of Genome Research, in which Palsson used his computer model of the red blood cell to relate specific genetic mutations to exact variations of hemolytic anemia. It is the first model-based system for predicting phenotype (function of the cell or organism) based on genotype (an individual's DNA). Both studies illustrate how new knowledge can be gained by creating computer models of how cells functionso-called genetic circuits. "Every cellular function is a system requiring the overlapping interaction of dozens of gene products, and the coordinated action of multiple gene products can be viewed as a network, or a 'genetic circuit,' " says Palsson. "These genetic circuits represent cellular wiring diagrams. They are the collection of different gene products that together are required to execute a particular function such as metabolism." Over the past two decades, Palsson has been working at the enormous challenge of creating computer models of these biological functions. He employs a technique he calls constraints-based modeling basically describing what a cell does not do in order to define what it can do through a process of elimination. To date, Palsson has created in silico models of metabolism for E. coli, the red blood cell, Hemophilus influenzae, Helicobacter pylori and yeast. Palsson's lab is one of the few in the country to build a complete network of the circuitry in given cells. Other researchers in the field are describing simple control modules within the network of a cell, as outlined by UCSD Bioengineering Professor Jeff Hasty in an Insights article in the November 14 issue of Nature. "There are small mechanisms within the circuitry of cells which can have a major impact on function. Just as in an engineered electronic circuit, each module performs specific duties, such as switching a protein on or off, or generating oscillations in the amount of protein released based on the time of day," says Hasty. Researchers are beginning to build and test synthetic versions of these control modules. For example, Hasty has developed a model of a positive feedback loop, in which a gene produces a protein which in turn causes that gene to become more active. He says as scientists begin to synthesize these simple network modules in the context of mathematical models, it will set the stage for the controlling cellular function, which could have important applications in nanotechnology and gene and cell therapy. Hasty's long-term goal is to build synthetic genetic networks which could be inserted into a patient's cells to tightly regulate the expression of a desired protein, or even to cause an undesirable cell to self-destruct. Palsson's Paper in Nature: http://www.nature.com/cgi- taf/DynaPage.taf?file=/nature/journal/v420/n6912/full/nature01149_fs. html Palsson's Paper in Genome Research: http://www.genome.org/cgi/content/full/12/11/1687 Hasty's Paper in Nature: http://www.nature.com/cgi- taf/DynaPage.taf?file=/nature/journal/v420/n6912/full/nature01257_fs. html Palsson's Research Page: http://gcrg.ucsd.edu/ Contact: Denine Hagen Phone: 858-534-2920 _____________________________________________________________________ SATELLITE STUDY ESTABLISHES FREQUENCY OF MEGATON-SIZED ASTEROID IMPACTS University of Western Ontario release http://comms.uwo.ca/media/archives/releases/2002/sept_dec/nov19.htm 20 November 2002 In Hollywood films such as "Armageddon" and "Deep Impact" Earth is threatened by enormous asteroids. New research at The University of Western Ontario establishes a better baseline for the frequency of large impacts that may cause serious damage on the ground. Based on these new estimates the average chances the Earth will be hit by an asteroid impact capable of causing serious regional damage (roughly one megaton TNT equivalent energy) is close to once per century. The study, led by Peter Brown, Canada Research Chair in Meteor Science and Assistant Professor in the Department of Physics & Astronomy at Western, appears in the November 21 issue of the prestigious journal Nature. United States Department of Defense and Department of Energy satellites scanning the Earth for evidence of nuclear explosions over the last eight years detected nearly 300 optical flashes caused by small asteroids (one to 10 metres in size) exploding in the upper atmosphere. This provided Brown and his research team with a new estimate of the flux of near-Earth objects colliding with the Earth. The revised estimate suggests Earth's upper atmosphere is hit about once a year by asteroids that release energy equivalent to five kilotons of TNT. The object that exploded above Tunguska, Siberia in 1908 was considered "small" (30 to 50 meters across), yet its energy was big enough to flatten 2,000 square kilometers of forest. It would have completely destroyed a city the size of New York. Brown and his colleagues calculate that Tunguska- like events may occur as frequently as once every 400 years. "It is important to realize the impact estimates we have measured are averages from the last eight and a half years. Based on past observations, it seems likely there is also a non-random component to the impact flux at these smaller sizes which would suggest our estimates are lower bounds to the true impact risk," says Brown. "We use Earth's atmosphere as a detector of small asteroids or comets by watching for the bright flashes produced as they impact the upper layers of the atmosphere. This is an ideal way to see smaller objects (one to 10 meters) too small to be detected while still in space by ground-based telescopic surveys, but too large to be detected after they become bright fireballs by camera networks that watch the skies," says Brown. "Ultimately, this new method of obtaining information redefines our range of knowledge about how and when asteroids may hit the Earth. Eventually, this will help us also better determine their origins, effects, and orbits." Co-authors of the Nature paper are Richard E. Spalding, Sandia National Laboratories in Albuquerque, New Mexico; Douglas O. ReVelle, Los Alamos National Laboratory in Los Alamos, New Mexico; Edward Tagliaferri, ET Space Systems in Camarillo, California; and Brigadier General Simon "Pete" Worden, formerly of the United States Space Command in Colorado Springs, Colorado and now Director of Transformation, Air Force Space Command. Contacts: Peter Brown Phone: 519-661-2111 x86458 E-mail: pbrown@uwo.ca. Marcia Daniel (for copies of the Nature paper) Communications & Public Affairs Phone: 519-661-2111 x85468 E-mail: mdaniel@uwo.ca Additional articles on this subject are available at: http://www.space.com/scienceastronomy/asteroid_exploding_021120.html http://www.spacedaily.com/news/deepimpact-02w.html _____________________________________________________________________ REPORT FROM THE FIELD: A PERSONAL PERSPECTIVE By Peter Backus From Space.com 21 November 2002 Sometimes I walk around the dish in moonlight. The 300-meter dish is impressive, even overwhelming, during the day. At night, under the soft light of the Moon, and with wisps of fog in the bowl, it takes on another dimension. The huge dome and massive feed support structure, suspended hundreds of feet above, seem to float weightless in space. It's an inspiring scene and helps to puts things in perspective. Tonight, I'm thinking about how I came to be here, at this telescope in the moonlight. The story begins in the spring of 1982 when Dr. Paul Horowitz, a professor at Harvard University, brought his new "Suitcase SETI" system to Arecibo. "Suitcase SETI" was designed specifically for SETI, and to search for signals in real time. These two features were revolutionary at the time as scientists had been using signal processing equipment designed for more conventional radio astronomy and analyzing data as long as a year after collection. Get the full story at http://www.space.com/searchforlife/seti_backus_021121.html. _____________________________________________________________________ NASA AWARDS RESEARCH GRANTS NASA release 02-227 22 November 2002 NASA's Office of Biological and Physical Research selected 17 scientists to receive grants to conduct research in advanced human support technologies. These technologies could have a significant impact on the ability of humans to safely conduct long-duration space flight missions, improve environmental technologies, and may also improve quality of life on Earth. Grants are awarded for one to three year efforts and are worth up to $8.8 million over three years. Research under these grants will enhance safe human space flight in both the near-Earth orbit, where the International Space Station operates, and in exploration of the solar system beyond Earth orbit. Six of the grants are for new technologies in advanced environmental monitoring of space habitats. One grant addresses a strategy for advanced control systems. Two projects address advanced food technologies. Two projects focus on advanced technologies for extravehicular activity. Six others address novel approaches to waste processing, including air revitalization, water recycling, thermal control, and treatment of solid wastes. NASA received 113 proposals in response to the research solicitation released in March 2002. The proposals were peer-reviewed by scientific and technical experts from academia, government, and industry. In addition to technical and scientific merit, relevancy to NASA programs and feasibility of implementation were also selection criteria. For a listing of the selected researchers, listed by state, along with their institutions and their research titles, please see http://research.hq.nasa.gov/code_u/nra/current/NRA-02-OBPR- 01/winners.html. Contact: Dolores Beasley NASA Headquarters, Washington, DC Phone: 202-358-1753 _____________________________________________________________________ INTERNATIONAL SPACE UNIVERSITY: SCHOOL FOR THE STARS By Morris Jones From SpaceDaily 22 November 2002 Science fiction fans dream of the day when they will be able to enroll in Starfleet Academy, the prestigious institution that trains crews in Star Trek. At the moment, space technology isn't exactly at the same level of this cult show, but our educational institutions are moving closer to the high goals it portrays. Dozens of campuses around the world will train you in the fundamentals of aerospace engineering, and space-related activities find a niche in practically every area of academic work, from the humanities to medicine. But one institution will extend a student's horizons in ways that no other place can match. The International Space University was a bold concept when it made its debut in the late nineteen eighties. Now, with more than a decade of evolution behind it, ISU has grown from a nomadic institution that conducted short summer sessions in various places to an academy with its own dedicated campus in Strasbourg, France. ISU continues to attract dozens of students every year for its original style of summer sessions, through to its year-long Master of Space Studies program. Get the full story at http://www.spacedaily.com/news/isu-02a.html. _____________________________________________________________________ MUSEUM FOR PROTEIN PALEONTOLOGY? Based on U.S. Geological Society publication From Astrobiology Magazine 22 November 2002 For the first time, researchers have uncovered two genetically informative molecules from a single fossil bone. The finding opens the door for extending the genetic analysis of fossils, because the protein found will remain stable for millions of years compared to 10,000 or so for traditional DNA sequencing. In addition to the recovery of mitochondrial DNA, the complete sequencing of a bone protein, osteocalcin, makes this a breakthrough. Extending this work to additional fossils could change perceptions of evolutionary theory. Over the past decade scientists have made controversial claims to have recovered DNA millions of years old, from dinosaur bones and from insects trapped in amber. But getting the more stable protein sequences from fossils will likely prove to be a more compelling way to understand and characterize ancient species. Results of the study are published in the December issue of Geology, published by the Geological Society of America. Bison bones Christina Nielsen-Marsh of the University of Newcastle upon Tyne, along with colleagues at the University of Oxford, Harvard University, and Michigan State University, examined the molecular structure of two fossilized Bison priscus bones, one from Siberia and the other from Alaska. The bones are more than 55,000 years old, although their age is somewhat imprecise because they are beyond the limits of radiocarbon dating. The Siberian fossil ultimately revealed both mitochondrial DNA and a complete sequence of osteocalcin, a protein found in all bones that is involved in bone formation. The researchers demonstrate, using immunological data, that osteocalcin remains in bones heated to high temperatures (165 degrees C, ~300°F) for several hours and is measurable in bones that are around 120,000 years old, emphasizing the survivability of the protein. Protein paleontology According to Nielsen-Marsh, "The research has the potential to be applied to much older fossils and extend our knowledge about the genetic make-up of ancient species further back into geological time." The team is hoping that in the future their approach may be able to find the answers to long-standing evolutionary puzzles. Protein sequencing was carried out at Michigan State University, using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). Important steps in the development of this technique are credited to this year's Nobel Prize (Chemistry) winning scientist Koichi Tanaka. Using a variety of approaches, the osteocalcin from the ancient bison bone was fragmented and the information used to construct the amino acid sequence. Remarkably, the primary sequence of the protein was recovered intact, including the relatively unstable carboxylated glutamic acid (gamma- carboxyglutamic acid) residues. As a consequence of this study, the team has a new optimism regarding the potential for protein sequencing and extending molecular records farther back in time. Protein sequences can be directly related to the genetic code of DNA. The sequence of amino acids (the building blocks of proteins) record genetic information transferred from DNA. According to Nielsen-Marsh this is important because mutations in DNA over long periods of time result in changes in proteins that contribute to the evolution of life. Calculations suggest, however, that DNA may only survive for up to 100,000 years, whereas proteins may survive for up to 10 million. The traditional way of comparing ancient and modern species to determine how they have changed over time is morphology, where bones are compared for shape and size. This may involve a large margin of error, however, as it can be subjective and bones such as skulls are malleable and prone to changing shape. What's next According to Nielsen-Marsh, "By extracting biochemical information from fossils, scientists utilize tools that avoid these difficulties and offer more objective comparisons between ancient and modern species." This approach could possibly unearth new knowledge about evolutionary relationships. "This research is groundbreaking," continues Nielsen-Marsh, "because it finally puts to rest the question of whether indigenous proteins can exist in fossil bones beyond radiocarbon dating age. Moreover, intriguing data from our laboratories suggest that extending protein sequencing well beyond 55,000 years is a realistic possibility." Funding for the study was provided by the Wellcome Trust and the National Science Foundation. Additional information on this article is available at http://www.astrobio.net/news/article317.html. _____________________________________________________________________ FIRST MDRS FALL 2002 CREW ROTATION NEARS CONCLUSION By Charles Frankel Mars Society release 22 November 2002 The first Mars Desert Research Station crew rotation of the fall 2002 season is now nearing its conclusion. MDRS crew #7 was commanded by Franco-American geologist Charles Frankel and included Hilary Bowden (United Kingdom, journalist and health & safety officer); Stacy Cusack (USA, executive officer, CapCom and geologist); Pierre- Emmanuel Paulis (Belgium, educational liaison); Derek Shannon (USA, geobiologist); and Alain Souchier (France, engineer and CRV perator). In the course of their 14-day stint, the international crew brought the Desert Station up to speed, implementing a number of new systems added in the past few months by Frank Schubert, Jeff Zerr and co- workers. Most notable is the "Living Machine" water recycling system that routes waste water from the Hab to the H. T. Odum greenhouse, where it is purified by plants (mainly water lilies), pumped back to the Hab, filtered and sterilized by ultraviolet light for re-use in domestic chores. Fine-tuning of the system was achieved by on-board engineer Alain Souchier, with the input of Jeff Zerr through Mission Support. Biologist Derek Shannon did frequent screening for coliform bacteria in the recycled water--that came up negative--showing that the UV-filter performed flawlessly. Our Hab Cap Com and computer expert Stacy Cusack reorganized the Hab's computer and handled the important communication loop with Mission Support "back on Earth", which was manned several hours a day by CapComs Brian Enke and Tony Muscatello, backed up by engineers Paul Graham, Dennis Creamer, Pete Gray, Randall Severy, Jeff Zerr and Robert Zubrin, and scientist Julie Edwards. Stacy found her experience as crewmember and CapCom particularly enlightening: "I truly enjoyed interfacing with Mission Support on a daily basis. As a flight controller working in Mission Control in Houston, I never have the chance to be on the other side of the communications as a member of the crew. This was a great learning experience for me. I now have a better understanding of some of the challenges the space station crewmembers must overcome to be able to successfully complete their mission objectives, and to still have fun doing it." Life aboard the Hab was a cultural experience, characterized by its multi-national line-up. As crewmember Hilary Bowden remarked, "With half the crew speaking French, there was bound to be trouble! In fact, there was none. We had a great time together, talking about our Mars dreams and how they could be achieved." MDRS-7 had several scientific and engineering goals, including the deployment of a ground-penetrating radar, and the testing of a Cliff Reconnaissance Vehicle to image the layering on canyon walls. An expedition to a nearby impact crater was planned, as well as a nocturnal EVA to watch the Leonid meteor shower. Geological and biological surveys were conducted in Lithe canyon, to the north of the Hab, and at a colorful mesa visited for the first time on Stacy's birthday. "It will be a birthday I will never forget", says she, "I was especially honored when the crew came back from their EVA and told me they had named a beautiful mesa Stacy's Cake. Since that day I have had the opportunity to visit Stacy's Cake twice--I've collected many rock samples there and climbed to the top to deploy the Cliff Reconnaissance Vehicle." The Cliff Reconnaissance Vehicle, or CRV, was designed and operated by Alain Souchier, who "wished to test the vehicle in real conditions, in a desert landscape and with the restriction in mobility and dexterity imposed by a spacesuit. The CRV version that I brought had several improvements relative to the one tested here in February by Crew-2, including a larger width, four strengthened stabilization rods, and real time video transmission." Eleven tests of the CRV were conducted during the MDRS-7 rotation. On 30-degree slopes the vehicle's behavior was improved, while numerous overturnings of the tethered robot were encountered on vertical cliffs. In every case, however, the video camera beamed back useful pictures of the cliff layers that the crew geologists could easily interpret. The crew's expedition to Upheaval Dome, believed to be the exhumed basement of an impact crater, was a high point of the mission. Alain Souchier was moved by the experience: "There was something magical about standing in a spacesuit on the rim of a meteoritic impact crater, just as it was magical to ride our Kawasaki ATVs in spacesuits, at sunset, in the desert around the Hab." For Hilary Bowden, "there were lots of great moments. But watching the Leonid meteor shower in the middle of a cold desert night was one of the best." In spacesuits, with helmets on, the crew was able to count as many meteors as unimpeded observers elsewhere on Earth, with a maximum count of 6 meteors per minute around 4:00 AM MST. But the most thorough scientific investigation was performed by geobiologist Derek Shannon, who "looked for simple fossil life and simple, hardy extant life, as scientists will one day on Mars. Early in the mission, we found two stromatolites, simple fossil life that illuminates much of the early history of life on Earth, and could do the same on Mars. On the extant life front, our search for endoliths, hypoliths, and other extreme organisms that could very well be found on Mars, met with success in the second week, when we found lichens out in the field. Back in the lab, controlled experiments examining flecks from the interior fractures of nearby sandstone showed that tiny spheres were likely to be endolithic microbes." All in all, the MDRS-7 rotation was an enlightening experience that merged science, engineering, and a good deal of intuition and ingenuity. "With assistance from Mission Support, we were able to overcome every single problem we encountered", stressed Stacy Cusack. "I don't think Charles, Alain, nor I will ever forget our late night greenhouse repair operations. This experience just proves how adaptive humans can be when necessary. It also further reiterates how important it is to send humans to Mars. Robotic explorers will be necessary to support and assist the crew, but human beings are needed to perform true exploration. It is our natural instinct and intuition that help us achieve amazing things." Instructor and crewmember Pierre-Emmanuel Paulis recaps his experience by stressing how impressed he was "by the constant parallel between the history of our planet, that we were deciphering here in Utah--our origins--and the extraterrestrial future that we have the honor of preparing. The pioneering spirit that runs through us all is the bridge that connects past and future. We were blissed with the extraordinary beauty of the site, our shared passion for the exploration of space, and our scientific, technological, and educative spirit." The changeover to crew #8, to be commanded by John "Dusty" Samouce, will take place on the weekend of November 22. _____________________________________________________________________ BALANCING BRAINS By Karen Miller From NASA Science News 22 November 2002 Balancing is not as easy as it seems--just try to stand on one foot for a full minute, and you'll get a sense of the constant effort involved. It's one of those complex skills like reading that becomes so automatic with practice; we simply forget how tricky they were to learn. And, like reading, you might suppose it would take something extraordinary to make you forget. Indeed it does--like traveling to space. Researchers have found that astronauts who return from a space voyage can still balance, but they find it far more difficult. That's because, explains NASA neuroscientist Bill Paloski, their brains are no longer sure how to interpret the information that comes from their senses. When you balance, he says, you use information from as many as three sources: the proprioceptive sensors in your muscles, which tell you where your body parts are in relationship to each other, the vestibular system in your inner ear, which tracks the position of your head in space, and of course your eyes. The brain deals with all that information by building "a model." Computer programmers might call it a mental subroutine, but it's more than an algorithm. Models provide context for interpreting and reacting to sensory data. The brain generates such models all the time--it's the way we learn and adapt. We do it on Earth, say, when we learn a new language, or even when we get accustomed to new prescription glasses. Astronauts do it, too. On Earth, their brains have already constructed a model that tells them how to manage their bodies in 1-g (normal gravity). In space, they must build a 0-g (weightless) model. Then, back on Earth, they have to figure out that it's time to switch to the 1-g model again. The transition isn't always easy. When you encounter a completely new context like space, your brain has some work to do. It has to decide whether this will be a persistent context or not--whether it's worth building a model. And if it is, then it has to develop one. It takes time for the brain to learn how to interpret the new information, to form a new model, to figure out when to switch from one model to another. And during that transition, when the brain's confused about which model to use, it starts to interpret sensory data in odd ways. You get illusions, for example, that the world around you is moving, when all that's really moving is your head. Headaches and motion sickness are other symptoms of this disorienting transition. "The perceptual illusions that astronauts have are very interesting," he notes. Paloski, who works with astronauts at the Johnson Space Center, is trying to find out exactly what cues astronauts to switch models. He's doing this by sending their brains confusing sensory information, which, he believes, will force a shift from one state to another. About ten years ago, he recalls, during a post-flight neurological test that involved a rotating chair, an astronaut who had already regained the ability to balance somehow lost that ability all over again. Retested, the astronaut kept falling over, "just like on landing day." "Something happened in that person's brain that caused a switch, we think, from a terrestrial adaptation back to a 0-g adaptation. Probably the brain got confused by the funny signals it was receiving on the chair, and it chose to interpret those signals as saying, I must be back in space. And it flipped back to the model that was congruent with space flight." Now, Paloski is trying to recreate that effect. "We know that astronauts are just on the verge of readapting to Earth in the 2 to 4 day time frame after short duration space flight. So we thought, why don't we go to day 3, when we think somebody is just about adapted, and see if we can cause the brain to switch states." To do this, Paloski will put astronauts in a centrifuge. While they lie comfortably on their sides (the astronauts are tested one at a time), the device spins at varying rates of speed forward and back. After ten minutes of spinning, the astronauts are tested. They stand on a platform inside of a booth. All they have to do is stand as still as possible. But the platform and the booth are designed to isolate the different kinds of sensory information used in balancing- -visual, vestibular and proprioceptive. For example, the most important proprioceptive sensors for balance control are the stretch receptors in your ankles, and the platform can prevent the body from receiving that sensory information. "If you begin to sway forward," explains Paloski, "we move the platform to an angle that's identical to the angle you've moved through, so that your ankle angle never changes." By spinning astronauts and then testing them in the "balance booth," Paloski hopes to learn how to facilitate the transition from one state to another. His subjects will be crewmembers of shuttle mission STS-107, which is slated for launch in January 2003. "We plan to test these astronauts both before and after the mission," he says. Paloski's research might help astronauts regain their sense of balance faster, but there's more to it than that. For instance, a side effect of transitioning between models is motion sickness. Paloski's work could help doctors understand such maladies. It might also be possible to train astronauts to develop models before they're needed. Mars explorers, for example, might be able to generate a 1/3-g model long before they reach the red planet. And for us on Earth, Paloski's work may help, too. Ultimately his research is about making it easier to learn--and that's something we do every day of our lives. Additional information on this article is available at http://science.nasa.gov/headlines/y2002/22nov_balance.htm?list52260. _____________________________________________________________________ SURVIVING THE FINAL FRONTIER By Stephen Hart From Astrobiology Magazine 25 November 2002 It came from outer space. Life, that is. This concept has drifted around the universe of space science since at least as long ago as 1864, when William Thomson Kelvin told the Royal Society of Edinburgh "The hypothesis that life originated on this earth through moss-grown fragments from the ruins of another world may seem wild and visionary; all I maintain is that it is not unscientific." He repeated the assertion in 1871 at the Forty-First Meeting of the British Association for the Advancement of Science, using the less colorful term "seed-bearing meteoritic stones." In 1903, in the German journal Umschau, Svante Arrhenius removed the meteors from the equation. Instead, he wrote, individual spores wafted throughout space, colonizing any hospitable planet they lit on. Arrhenius named the theory panspermia. "Spores," says Gerda Horneck, of DLR German Aerospace Center in Köln, "can withstand a variety of different hostile conditions: heat, radiation, desiccation, and chemical substances (such as alcohol, acetone and others). They have an extremely long shelf-life. This is because the sensitive material, the DNA, is especially packed and protected in the spores." As tough as bacterial spores are, however, they cannot survive direct exposure to solar ultraviolet (UV) radiation, Horneck writes in Origins of Life and Evolution of the Biosphere, 2001. But while Arhennius's panspermia is out, Kelvin's fanciful "moss-grown fragments" may be back in, after a fashion. Horneck assessed the protective effect of meteorlike matter in an experiment on three flights of the Russian FOTON satellite in 1994, 1997 and 1999. FOTON carried an appliance called BIOPAN. Once in space, the BIOPAN lid flips open, like the top of a waffle iron, exposing experiments inside to the cold vacuum of space, and, when BIOPAN is in the sun, to ultraviolet and other radiation with no intervening atmosphere. FOTON rotates, so BIOPAN passes in and out of the sun both during rotation and during each 90 minute orbit. In an earlier experiment on the Long Duration Exposure Facility, flown by NASA from 1984 to 1990, Horneck found that even after six years in space, more than two-thirds of bacterial spores sprouted back on Earth. But those spores were protected by a thin aluminum cover as well as chemical protectants. Would dirt do? Horneck and her colleagues embedded spores from the common bacterium Bacillus subtilis in a variety of materials: clay, red sandstone, grit from the meteorite Millbillillie, simulated martian soil and sand from the martian meteorite Zagami. Some spores were laid in layers of the dust, others mixed and stored in artificial meteorites a centimeter on a side, still others exposed directly to space or shaded by a layer of dust. They remained exposed in BIOPAN for up to two weeks. "In the selection of the rock or soil samples, we got advice from experts working with meteorites and geologists interested in Mars research," Horneck says. "Some of the material (clay) was used in previous experiments and all others were used for the first time." Only one in a million spores exposed to space or merely shaded survived. Hard UV directly damages DNA, causing chemical crosslinking and changes in bases, Horneck says. But spores spared exposure to UV and other light-that is, stored in the dark-fared well, with between 50% and 97% survival, Horneck writes. Horneck tried two methods of protecting spores with various soils and sands. In the first, she made a sort of layer cake, alternating layers of spores with layers of soil or clay, etc. In the second, she mixed spores and soils in about the ratio found in earthbound soils-a hundred million cells per gram. In both cases, the spores were in direct contact with the soil grains. These spores survived as well as spores stored in the dark. On one flight, 100 percent of the spores exposed in such artificial meteorites survived. Horneck's results lend more support to the modern variant of Lord Kelvin's moss-grown rock idea. When large objects impact a planet, there's a sort of splash zone in a ring abound the impact. Large chunks of planet may shoot into space. Impacts this large were common late in the formation of the solar system. But even as recently as about 65 million years ago a meteor hit Mexico, ejecting so much material into the atmosphere that it's suspected of causing the extinction of the dinosaurs. "This concept, called also litho-panspermia, is based on the scenario that by an impact of a very large kilometer-sized meteor or comet, material is ejected from a planet and can reach escape velocity," Horneck explains. "There are certain areas at the rim of the impact crater, called the spallation zone, where by reflection of the shock wave the temperatures do not exceed 100 degrees Celsius" [212 degrees Fahrenheit, the boiling point of water]. That's cool enough to allow spores to survive ejection, the first stage of interplanetary travel. The second stage Horneck addressed in her research. "There are some studies simulating the reentry process," Horneck says of the last stage of an interplanetary trip. "It seems that spores can also survive this in the inner part of the meteorite. Entering the atmosphere goes very fast, and so only the outer layer is heated." "What we're talking about is life originating essentially on a planet, and asking can that life survive travel from one planet to another planet. In my opinion, for a spore, it's quite likely," says Rocco Mancinelli, of the NASA Ames Research Center. But spore-forming bacteria are not the only organisms that could survive. Mancinelli studies archaea and Synechococcus cyanobacteria (photosynthetic bacteria) that live in very salty environments. He also flew experiments on BIOPAN, similar to Horneck's. "The only thing I did not do is I did not mix the organisms with any soil or anything at all. They were just dried onto the 7 mm quartz disks, placed in a holder, put in BIOPAN, shot up into earth orbit and BIOPAN opened and they were exposed," he says. Most of Mancinelli's salt-loving organisms, or halophiles, survived space when stored in the dark. Except for radiation, the main threats of space are the lack of water and extremes of temperature. Mancinelli reasoned that even though they do not form spores, halophiles might survive because they routinely survive drying. "The particular organisms that I chose to fly were collected from an essentially dry crystal of salt. One was a pure sodium chloride crystal, where I got the archaean. The other one was a gypsum halide crystal, which is where I got the Synechococcus." But surprisingly, about 25 percent of the archaeans and about 35-40 percent of the cyanobacteria survived full exposure to the sun. So spores and even desiccated cells survive space and sunlight. But can they survive long enough to travel between, say, Mars and Earth? The LDEF mission showed spores surviving six years, and six years is a realistic time frame for travel between Earth and Mars, the other planet in our solar system most likely to harbor life, Mancinelli and Horneck agree. But for longer trips, all scientists can do is calculate. "If the time becomes too long, then the cosmic radiation that penetrates the rock would finally be lethal," Horneck says. "We have calculated (in the Mileikowsky paper in Icarus (2000) that in order to protect spores for 1 million years against cosmic radiation, a 1- meter-thick layer of the meteorite is necessary." Radiation from the Sun is not the only hazard microbes would face during long-term space travel. Meteoric material itself would emit some radiation over very long periods of time. "This is one of the things that I really think is limiting," Mancinelli says, "radiation from naturally occurring minerals within the meteor and within the organism itself. Through geological time these decay and give off enough radiation that it could chop up the DNA and destroy it." What's next? Horneck, Mancinelli and their colleagues have several experiments planned. Horneck's team has more BIOPAN experiments planned, she says. "My colleague, Petra Rettberg, has a further experiment for BIOPAN, called MarsTox." MarsTox will use special filters to simulate the radiation reaching the surface of Mars. The experiment will gauge the protective effect, or lack of protection, of several simulated Mars soils. [Unfortunately, the FOTON rocket that was to carry the BIOPAN MarsTox experiment into orbit failed at launch, and the experiment was lost.] Both Horneck and Mancinelli have plans for experiments on the International Space Station in 2004. "She's going to fly spores--she does spores--under various different conditions, including mixing them with simulated meteorite material," Mancinelli says. "And I'm going to fly a variety of different kinds of organisms that are non-spores that I think might withstand the stress of space environment. I'm trying to figure out what's the breadth of life that might survive exposure to the space environment and thus be transferred from planet to planet." Additional information on this article is available at http://www.astrobio.net/news/article318.html. _____________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.h tml 25 November 2002 Astrobiology, exobiology and terraformation articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s1.html Astrobiology Magazine, 2002. The envelope of life, please. Astrobiology Magazine. D. Tenenbaum, 2002. Smoking craters: home to martian life? Astrobiology Magazine. Terrestrial extreme environments articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s2.html S. Hart, 2002. Surviving the final frontier. Astrobiology Magazine. NASA/JPL, 2002. Where on Earth is Mars? Astrobiology Magazine. Human space exploration and microgravity effects articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s3.html K. Miller, 2002. Balancing brains. NASA Science News. Search for extraterrestrial intelligence (SETI) articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s4.html P. Backus, 2002. Report from the field: a personal perspective. Space.com. Evolutionary biology and chemistry articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s5.html U.S. Geological Society, 2002. Museum for protein paleontology? Astrobiology Magazine. Planetary protection articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s6.html R. R. Britt, 2002. New study downplays risk of killer asteroids hitting Earth. Space.com. University of Western Ontario, 2002. Satellite study establishes frequency of megaton-sized asteroid impacts. SpaceDaily. _____________________________________________________________________ CASSINI SIGNIFICANT EVENTS NASA/JPL release 14-20 November 2002 The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Wednesday, November 20. The Cassini spacecraft is in an excellent state of health and is operating normally. Information on the present position and speed of the Cassini spacecraft may be found on the "Present Position" web page located at http://saturn.jpl.nasa.gov/operations/present-position.cfm. On board activities this week included Radio and Plasma Wave Science High Frequency Receiver calibrations and high rate cyclics, an Imaging Subsystem (ISS) filter wheel test, Radio Science Subsystem (RSS) Ka-band uplink exciter/transmitter tests, uplink of the Probe Relay test looper program, and memory readouts of flight software ALF loads. The ISS filter wheel test mini-sequence exercised the Wide Angle Camera filter wheel sensor. The test was created to diagnose errors detected early last month. At that time ISS noticed that the number of times the filter wheel passed the "zero" point was not as had been predicted. Numerous filter wheel movements were performed during the test with no errors. The test was preceded by a power cycle that is presumed to have resolved the anomaly. RSS performed Ka-band Uplink Exciter/Transmitter (KUPL) tests #2 and #3. The tests were designed to exercise a newly installed ground system heat exchanger. The tests went smoothly with the exception of the Data Monitor and Display (DMD) not receiving the data properly. This problem with the DMD for the Ka-band transmitter ramp was subsequently corrected. Both tests met RSS success criteria and all looks well for the upcoming Gravitational Wave Experiment in C35. A mini-sequence was built to provide a looper program to command the probe relay receiver into byte mode during next week's probe relay test. The number of commands required made it prohibitive to include them in the background sequence. The looper program is absolutely timed and will not run until execution of the probe relay test. The RADAR team has analyzed the data taken after last week's uplink of version 3.0 FSW. The software loaded properly and executed the instrument expanded blocks as expected. Analysis of the instrument expanded blocks will continue, but to date the new flight software is operating as planned. Visual and Infrared Mapping Spectrometer FSW version 6.1 was delivered to the project software library this week. A delivery coordination meeting was held for the first official delivery of Remote Terminal Interface Unit (RTIU) software version 2.0. The RTIU system is used in the instrument test beds to connect the engineering model to the ground support equipment computers. The final sequence integration and validation (FSIV) products for the C35 background sequence have been published. The FSIV approval meeting will be held next week with the sequence uplinked to the spacecraft on Thanksgiving Day. The Attitude Control Subsystem and Command and Data Subsystem flight software teams successfully completed the Flight Software Uplink Readiness Review. This review is the first of three reviews prior to uplink and checkout of the new flight software in February-April of 2003, and is a major milestone in the development of the new software. The next reviews will be the Software Requirements and Certification Review in January followed by the Uplink Approval Review in February. The Attitude Control team completed the development of all the procedures for uplink and checkout of the new flight software. System level dry runs of the procedures will begin in December. Cassini outreach gave a workshop to 11 teachers at the Educator Resource Center in Pomona, California. The workshop focused on Saturn system science and included an introduction to a new hands-on activity. As Saturn gains visibility in the evening sky, Cassini's Saturn Observation Campaign members are scheduling viewing events. To date, five events have occurred. 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. _____________________________________________________________________ MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 20-22 November 2002 Ulysses Fossae in Tharsis (Released 20 November 2002) http://themis.la.asu.edu/zoom-20021120a.html Impact Crater (Released 21 November 2002) http://themis.la.asu.edu/zoom-20021121a.html Degraded Craters in Phlegra Montes (Released 22 November 2002) http://themis.la.asu.edu/zoom-20021122a.html All of the THEMIS images are archived at http://themis.la.asu.edu/latest.html. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, DC. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. _____________________________________________________________________ STARDUST STATUS REPORT NASA/JPL release 22 November 2002 Stardust has returned to normal cruise operations after its flyby of asteroid Annefrank earlier this month. The spacecraft is healthy and performing well. A trajectory correction maneuver that had been tentatively scheduled for after the asteroid flyby will not be performed, as the spacecraft is so well on course and no adjustment is needed. Stardust continues to collect interstellar dust particles. The position of the aerogel grid used for catching the dust particles was changed to keep the grid perpendicular to the dust flow. The Stardust flight team had one period of communication with the spacecraft through an antenna of JPL's Deep Space Network this week. As part of a technology demonstration, a New Mexico antenna of the National Radio Astronomy Observatory's Very Long Baseline Array successfully received a Stardust downlink signal. Additional tests may lead to the use of the Very Long Baseline Array as a new resource for navigational tracking of NASA missions. 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 9, Number 44.