MARSBUGS: The Electronic Astrobiology Newsletter Volume 9, Number 47, 23 December 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) DIFFERENT KIND OF VENTING PROVIDES ALTERNATIVES FOR FINDING LIFE ELSEWHERE University of Washington release 2) HUNGARY'S FIRST ANTARCTIC EXPEDITION SETS OFF From Agence France-Presse and SpaceDaily 3) 30 YEARS AFTER LAST LUNAR TRIP, MANNED SPACE FLIGHT IS IN DOLDRUMS From Agence France-Presse and SpaceDaily 4) NASA TWINS PLAN MARTIAN RAMBLE NASA release 02-240 5) DARK STREAKS ON MARTIAN SLOPES MAY SIGNAL ACTIVE WATER By Agnieszka Baier 6) RESEARCHERS FIND POSSIBLE PRECURSORS TO EARLY LIFE ON EARTH IN METEORITE NASA/JSC release J02-122 7) A WARM, WET MARS TAKES A BATH By Nick Hoffman 8) ANYBODY OUT THERE? PART II By Oliver Sacks 9) ANTARCTIC ICE SEALS LIFE'S FATE University of Illinois at Chicago release 10) MORE SUN-LIKE STARS MAY HAVE PLANETARY SYSTEMS Vanderbilt University release 11) AIAA'S 1ST PLANETARY DEFENSE CONFERENCE: PROTECTING EARTH FROM ASTEROIDS FEBRUARY 2004, LOS ANGELES, CALIFORNIA AIAA release 12) MICROORGANISM ISOLATED IN "SPACE" Cardiff University release 13) MICROBES FROM EDGE OF SPACE REVIVED By Jenny Hogan 14) NASA TESTING K9 ROVER IN NEW "MARSCAPE" FOR FUTURE MISSIONS NASA/ARC release 02-136AR 15) MINIMALIST LIFE By Stephen Hart 16) CLOUDS DISCOVERED ON SATURN'S MOON TITAN Caltech release 17) SPACE SCENTS By Karen Miller and Tony Phillips 20) DOES LIFE ON EARTH HAVE A FUTURE? By Martin Rees 21) EARTH'S GROUNDHOG DAYS CONTINUE THIRTY YEARS LATER By John Carter McKnight 22) TELLING ET WE CARE By Douglas Vakoch 23) ROSTERS ANNOUNCED FOR MDRS CREWS 10, 11, AND 12 Mars Society release 24) DIAMONDS FOUND TO CONTAIN EVIDENCE OF ANCIENT ATMOSPHERE University of California, San Diego release 25) CHALLENGING YEAR AHEAD FOR SPACE STATION NASA release 02-256 26) MARS DESERT RESEARCH STATION CREW NINE SUMMARY By the members of MDRS Crew 9 27) EUROPA: CHEWY OR CRUNCHY? By Lee Siegel 28) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 29) CASSINI SIGNIFICANT EVENTS NASA/JPL releases 30) GALILEO MILLENNIUM MISSION STATUS NASA/JPL release 2002-231 31) INTERNATIONAL SPACE STATION SCIENCE OPERATIONS STATUS REPORT NASA/MSFC release 02-320 32) MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU releases 33) MOC BEGINS THIRD MARS YEAR IN MAPPING ORBIT NASA/JPL/MSSS releases MOC2-321 to MOC2-324 34) STARDUST STATUS REPORTS NASA/JPL releases _____________________________________________________________________ DIFFERENT KIND OF VENTING PROVIDES ALTERNATIVES FOR FINDING LIFE ELSEWHERE University of Washington release 6 December 2002 The Lost City hydrothermal vent field discovered just two years ago this week is giving scientists reason: * To believe that similar systems may be or have been present on water-bearing, tectonically active planets. Researchers also believe that systems like Lost City may be common on Earth, according to Deborah Kelley, University of Washington associate professor of oceanography and one the three people on the first manned dive to the field the day after it was discovered. * To speculate that life on this planet may have started in the relatively warm, alkaline waters rich with methane and hydrogen that result when seawater reacts with mantle rock. Today the mantle in most places is capped by oceanic crust. But early in Earth's history mantle rocks may have been much more exposed to seawater, providing ample opportunity for conditions to support microbial life at the seafloor. Different from previously studied vent systems Kelley says Lost City is distinctive because it sits on mantle rock that's about 1.5 million years old and its hydrothermal venting--in which water circulates into the seafloor, gaining heat and chemicals until there is enough heat for the fluids to rise buoyantly and vent back into the ocean--is much different from previously explored vent fields. It doesn't appear that volcanic activity drives hydrothermal venting at Lost City; fluids from there give no chemical evidence of having been in contact with magma chambers. This is unlike any system found at the Earth's spreading centers where magma chambers are present. At speading centers very young seafloor is created--often dramatically during volcanic eruptions--and vented water can be as hot as 700 degrees F. Instead, venting at Lost City occurs because of heat generated by chemical changes in the rocks: seawater permeates deeply into the fractured surface of the mantle rocks where it transforms the mineral olivine into a new mineral, serpentine, in a process called serpentinization. The heat generated during serpentinization is not as great as that at volcanically active sites but it is enough to power hydrothermal circulation and produce vent fluids of 105 to 170 degrees F, Kelley says. The result is a field of dramatic vents not made of sulfide but of carbonate minerals, or limestone. The most massive, at 18 stories, is the tallest vent structure ever seen anywhere. The vents support a community of microorganisms able to live off the fluids rich with methane and hydrogen, both byproducts of serpentinization. Lost and found The Lost City hydrothermal vent field was discovered December 4, 2000, in the mid-Atlantic, at about 30 degrees north latitude, during a National Science Foundation-funded expedition that had not set out to seek a hydrothermal vent field. It is nine miles from the nearest volcanically active spreading center. * It is on the summit of the mountain known as Atlantis Massif, one reason for the name Lost City. * Mantle rock is usually many kilometers beneath the seafloor but at the Atlantis Massif, the Earth's forces thrust mantle rock up exposing it directly at the seafloor. Spreading and faulting stripped much of the mountain down to the underlying mantle rocks. * The extent of the hydrothermal field is unknown. In the limited time researchers were there they saw about 30 active and inactive carbonate chimneys. Tallest is the 180-foot vent scientists have named Poseidon. Previously studied vents mostly reach 80 feet or less with the tallest being a 135-foot vent on the seafloor off the coast of Washington (which toppled in recent years). * The new vents are nearly 100 percent carbonate, the same material as limestone in caves, and range in color from a beautiful clean white to cream or gray, in contrast to black smoker vents that are a darkly mottled mix of sulfide minerals. It's easy to imagine there could be many more such systems, Kelley says. Within a mere 60-mile radius of the Atlantis Massif are three similar mountains subject to the same fracturing, the same intrusion of seawater and perhaps the same reactions with mantle material. And those four represent a tiny fraction of the potential sites along the 6,200 mile Mid-Atlantic Ridge, Indian ridges and the Arctic Ridge, also considered slow- and ultra-slow-spreading centers. Kelley will lead the second scientific expedition to Lost City from April 9 to May 9, 2003. Images are available at http://www.washington.edu/newsroom/news/images/lostcity. Contact: Debora Kelley Phone: 206-543-9279 E-mail: kelley@ocean.washington.edu Sandra Hines Phone: 206-543-2580 E-mail: shines@u.washington.edu An additional article on this subject is available at http://www.spacedaily.com/news/life-02zzd.html. _____________________________________________________________________ HUNGARY'S FIRST ANTARCTIC EXPEDITION SETS OFF From Agence France-Presse and SpaceDaily 7 December 2002 Hungary's first ever expedition to the Antarctic set off from Budapest Friday headed for Chile, its last stop before the land of ice and snow at the South Pole. A team of five men and two women, who will be followed by four more people on December 27, plans to "research sites where global warming is causing icecaps to melt after millions of years," expedition leader Balazs Nagy told AFP. "We are interested in the way life is developing in places where the icecaps are melting. We expect to find living organisms in these regions--it is a new phenomenon," he said. The group will travel to the King George Islands, a research center that specializes in studying the "frozen oasis", added Nagy, who is a geography professor at Budapest's Lorant Eotvos Scientific University. Get the full story at http://www.spacedaily.com/2002/021207041743.qx1611l5.html. _____________________________________________________________________ 30 YEARS AFTER LAST LUNAR TRIP, MANNED SPACE FLIGHT IS IN DOLDRUMS From Agence France-Presse and SpaceDaily 8 December 2002 Thirty years ago this week, Apollo 17 headed out across space, bringing the curtain down on the United States' extraordinary conquest of the Moon. At the time, for a public buoyed by the success of the Apollo missions and nourished on the vision of "2001: A Space Odyssey," Man seemed to have a dazzling, unlimited future in space. Next stop: Mars. Then the outer planets, starting perhaps with the satellites of Jupiter. And after that--who knows? The air fizzed with talk of human colonies dotted across the Solar System, of "terraforming" lifeless planets into lush gardens, and the possibilities for interstellar travel were given a serious airing. Three decades on, the reality is sadly very different. No one has even set a date for a manned trip to Mars. Indeed, Man no longer even visits the Moon. Get the full story at http://www.spacedaily.com/2002/021208050103.wgxeaaxt.html. An additional article on this subject is available at http://www.cnn.com/2002/TECH/space/12/11/apollo17.anniversary/index.h tml. _____________________________________________________________________ NASA TWINS PLAN MARTIAN RAMBLE NASA release 02-240 9 December 2002 NASA's Mars Rover science team will preview mission goals and potential landing sites at a special session of the American Geophysical Union meeting in San Francisco. NASA's unique twin Mars Exploration Rovers will head for the mysterious Red Planet in just over one year. "The twin rovers will be able to travel the distance of several football fields during their missions. They will carry sophisticated instruments that effectively make them robotic geologists, acting as the eyes and hands of the science team on Earth," said Dr. Mark Adler, mission manager at NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA. "We are very busy at JPL building and testing the two rovers and the spacecraft that will land them safely on Mars," he said. Remote sensing instruments will be mounted on a rover mast including high-resolution color stereo panoramic cameras and an infrared spectrometer for determining the mineralogy of rocks and soils. When interesting scientific targets are identified, the rovers will drive over to them and perform detailed investigations with instruments mounted on their robotic arms. Rover instruments include a microscopic imager, to see micron-size particles and textures; an alpha-particle/x-ray spectrometer, for measuring elemental composition; and a Moessbauer spectrometer for determining the mineralogy of iron bearing rocks. Each rover will carry a rock abrasion tool, the equivalent of a geologist's rock hammer, to remove the weathered surfaces from rocks and analyze their interior. "All the instruments on the payload are undergoing intensive calibration and test activities in preparation for flight," said Dr. Steve Squyres, principal investigator for the science payload at Cornell University, Ithaca, NY. "Once at Mars, the instruments will be used, together with the rover's ability to traverse long distances, to study the geologic history of the two landing sites. The scientific focus of the investigation is study of each site's past climate and water and biological activity," Squyres explained. NASA scientists are in the process of picking the landing site for each rover. Four sites look the most promising. "Three of the sites, Terra Meridiani, known as the Hematite site, Gusev, and Isidis show evidence for surface processes involving water. These sites appear capable of addressing the science objectives of the rover missions: to determine if water was present on Mars and whether there are conditions favorable to the preservation of evidence for ancient life," said Dr. Matt Golombek, landing site scientist at JPL. The fourth site, Elysium, appears to contain ancient terrain, which may hold clues to Mars' early climate when conditions may have been wetter. The launch period for the first rover opens May 30, 2003, and the second rover's launch period opens June 25, 2003. The first rover will reach Mars January 4, 2004, and the second arrives January 25, 2004. Each rover will have a primary mission lasting at least three months on the martian surface. The Jet Propulsion Laboratory manages the Mars Exploration Rover mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena. More information about the mission is on the Internet at http://mars.jpl.nasa.gov/mer. Contacts: Donald Savage NASA Headquarters, Washington, DC Phone: 202-358-1727 Mary Hardin Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-0344 _____________________________________________________________________ DARK STREAKS ON MARTIAN SLOPES MAY SIGNAL ACTIVE WATER By Agnieszka Baier University of Arizona release 9 December 2002 Salty water driven by hot magma from Mars' deep interior may be forming some of the mysterious dark slope streaks visible near the Red Planet's equator, according to University of Arizona scientists. They have determined the dark slope streaks generally occur in areas of long-lived hydrothermal activity, magma-ground-ice interactions, and volcanic activity. Some of the dark slope streaks are brand new- -they have formed after the Mars Global Surveyor spacecraft began detailed mapping of the planet in April 1999. Others have been observed to fade away on decadal time scales. Their findings support the hypothesis that Mars remains hydrologically active and that water could be shaping the planet's landscape today. Dark slope streaks were first detected using Viking Orbiter images during the early 1980s. At that time, Holly Ferguson and Baerbel Lucchitta of the USGS in Flagstaff suggested that these features may be explained by wet debris flowing down the slopes. But all other explanations exclude a role for water and instead involve wind erosion, dust avalanching, or landslides. While acknowledging that dry processes can create such features, the UA researchers argue that some of the streaks' characteristics can be better explained by water seeps. "There is no identifiable characteristic of a dark slope streak that can definitively say whether it was formed by water-related processes or not. But there are certainly some features which strongly suggest the role of water," says Dr. Justin C. Ferris, National Research Council Postdoctoral Fellow at the U.S. Geological Survey in Denver, CO. Ferris, formerly at UA, has been working on this issue with James M. Dohm, Victor R. Baker, and Tom Maddock, III of the UA department of hydrology and water resources. "It's been said that martian geomorphology could also be called forensic geomorphology, because we are always looking for the 'culprit' behind the formation of certain features. However, too many scientists, in their quest for a culprit, forget that it could be a 'gang,' Ferris says. "Dry mass-wasting processes might be good explanations for a particular type of dark slope streaks occurring in certain areas, but it isn't for all the features we observe," he adds. "Interestingly, most regions that contain dark slope streaks show evidence of ground ice or water and magma interactions," notes James Dohm, a UA planetary geologist and collaborator in the study. "Published geologic maps of Mars have portrayed the planet as dynamic and hydrologically active throughout most of its history," says Dohm, who has been geologically mapping Mars for almost two decades. "The possibility of presently active hydrological activity as revealed in the Mars Global Surveyor and Odyssey missions is extremely exciting," he adds. The dark slope streaks, while not identifiable by any one feature, do have a number of traits in common: * They often originate at or near the interface between two visibly different rock units and within topographic depressions. * They often occur on valley walls and occasionally continue on to valley floors. * They usually run down the slope and braided, finger-like features resembling deltas form at their ends. * Any one feature has a constant albedo, (that is, the fraction of sunlight it reflects) but albedos vary in a group of dark slope streaks. * Also, there are signs of erosion above the source of some of these streaks, which on Earth is common when water is eroding a gully or a valley. What most greatly suggests water is involved is that these streaks do not uniformly occur in regions of Mars with similar materials, topography, and slopes. Geologists would expect this only if dry processes were involved. Also, the streaks occur both on steep and very gentle slopes--something not expected for features formed by landslides or avalanches. Where is the culprit then? There are places on Earth where subsurface water breaks to the surface as springs. When water runs below ground at elevated temperatures for a long time, it can become enriched in dissolved salts and other minerals. This happens especially in arid regions. "The same may be happening in Tharsis or Elysium, which we believe are the long-lived zones of magma-driven activity," Dohm says. "Large intrusions of magma at depth may provide the heat to drive a regional hydrothermal system." This briny groundwater may be emerging through springs on the slopes of impact craters, in depressions, or along faults and fractures, Dohm adds. Since brines have a lower freezing point than pure water, they could exist at the martian surface at current low temperatures and pressures. "Thus, the briny water could flow slowly down slope, leaving behind a ghostly image that we call a dark slope streak," Ferris says. "This hypothesis implies that there is current hydrological activity on the surface of Mars." "And where you have a long-lived heat source and ample water, there is an exciting potential for subsurface life," Dohm adds. Contacts: Justin C. Ferris Phone: 303-236-5039 E-mail: ferris@hwr.arizona.edu, jcferris@usgs.gov James M. Dohm Phone: 520-626-8454 E-mail: jmd@hwr.arizona.edu University of Arizona News Services Phone: 520-621-1877 _____________________________________________________________________ RESEARCHERS FIND POSSIBLE PRECURSORS TO EARLY LIFE ON EARTH IN METEORITE NASA/JSC release J02-122 http://www.jsc.nasa.gov/news/releases/2002/J02-122.html 11 December 2002 In a study published today in the International Journal of Astrobiology, researchers state that a meteorite that fell to Earth over northwestern Canada in January 2000 contains a previously unseen type of primitive organic material that was formed long before our own solar system came into being. The Tagish Lake meteorite fell to Earth over the Yukon Territory of Canada on January 18, 2000. Parts of the meteorite were collected and kept frozen in an unprecedented level of cleanliness to ensure that it was not contaminated by any terrestrial sources. Through extensive testing using, in part, electron microscopes, the researchers found numerous hollow, bubble-like hydrocarbon globules in the meteorite. They believe these organic globules, the first found in any natural sample, are very similar to those produced in laboratory simulations designed to recreate the initial conditions present when life first formed in the universe. "While not of biological origin themselves, these globules would have served very well to protect and nurture primitive organisms on Earth," said Dr. Michael Zolensky, an author of the paper and a researcher in the Office of Astromaterials Research and Exploration Science at NASA's Johnson Space Center in Houston. "They would have been ready-made homes for early life forms." The type of meteorite in which the globules were found is also so fragile that it generally breaks up into dust during its entry into Earth's atmosphere, scattering its organic contents across a wide swath. "If, as we suspect, this type of meteorite has been falling onto Earth throughout its entire history, then the Earth was provided with these hydrocarbon globules at the same time life was first forming here," Zolensky said. "We were exceedingly fortunate that this particular meteorite was so large that some pieces survived to be recovered on the ground." Last year, researchers at NASA's Ames Research Center in Moffett Field, CA, announced that they had made basically identical hydrocarbon globules in the laboratory from materials present in the early solar system and interstellar space. "What we have now shown is that that these globules were in fact made naturally in the early solar system, and have been falling to Earth throughout time," Zolensky said. The researchers believe the Tagish Lake meteorite came from the outer asteroid belt, toward Jupiter, and that similar organic materials may have been falling onto the moons of Jupiter, including Europa. "It is interesting to speculate about the presence of these organics in the ocean we believe may be present under the ice cap of this moon," Zolensky said. A team of five researchers collaborated on the two-year study. The team was led by Keiko Nakamura of Kobe University in Japan, who was funded by the Japan Society for the Promotion of Science. Nakamura is now working at JSC under a postdoctoral grant from the U.S. National Research Council. Co-authors of the study include Zolensky, who was funded by the NASA Cosmochemistry Program; Satoshi Tomita and Kazushige Tomeoka, both of Kobe University, who were funded by the Japan Society for the Promotion of Science and the Japanese Ministry of Education, Science, Sports and Culture, respectively; and Satoru Nakashima of the Tokyo Institute of Technology, who was also funded by the Japan Society for the Promotion of Science. Contact: Catherine E. Watson Johnson Space Center, Houston, TX Phone: 281-483-5111 An additional article on this subject is available at http://www.spacedaily.com/news/life-02zze.html. _____________________________________________________________________ A WARM, WET MARS TAKES A BATH By Nick Hoffman From SpaceDaily 12 December 2002 Last week, at a special session of the American Geophysical Union's annual Fall meeting in San Francisco, over two dozen experts in Mars' climate and hydrology met to discuss issues relating to how river- like channels formed on the planet, focusing especially on the very earliest evidence dating back to the Noachian era (3.5 to 3.9 billion years ago). At this time, giant asteroids were still crashing down from space at rates thousands of times those we experience today, blasting craters hundreds of km in diameter and forming the cratered highlands of Mars, Mercury, and the Moon. No Earth rocks survive from that time--plate tectonics has wiped the slate clean--so we rely on evidence from beyond the Earth to tell us about conditions in the dawn of the Solar System. The Moon and Mercury appear to have been airless rock balls at this time, and the record of impacts is preserved in their cratered surface, but Mars had an atmosphere, which interacted with the impacts and the warmth of the young Sun to produce weather patterns and erosion. Many of the early craters on Mars are partly eroded and filled-in, perhaps by Earth-like streams, rivers, and lakes. The big question which has been asked for decades is "how Earthlike was that Early Mars?". Embedded in this is the more fundamental question "Was there life on Early Mars?". Those questions were addressed in an all-day session at the busy AGU convention, which commenced with a series of poster presentations in the morning and then moved to an oral session with brief contributions from the key scientists working in the field today, and then a broad-ranging open discussion which was able to reach a remarkable consensus on most of the issues. At the end, the conventional view of a "warm and wet" early Mars took a back seat to a new cold and dry Early Mars, with occasional damp moments. Get the full story at http://www.spacedaily.com/news/mars-water- science-02f.html. Additional articles on this subject are available at: http://www.spacedaily.com/news/mars-water-science-02g.html http://www.cnn.com/2002/TECH/space/12/08/mars.odyssey.ap/index.html _____________________________________________________________________ ANYBODY OUT THERE? PART II By Oliver Sacks 16 December 2002 So if the Earth's history is anything to go by, we should not even expect any higher life in a planet which is still young--it may take, even if life has appeared, and all goes well, many billion years for evolutionary processes to get that far. Moreover, all these "steps"- -the evolution of aerobes from anaerobes; of eukaryotes from prokaryotes; of multicellular organisms from unicellular ones; and of complex beings with intelligence and consciousness from the first multicellular forms--may have occurred against daunting orders of probability, as Stephen Jay Gould and Richard Dawkins, in their different ways, have brought out. Gould speaks here of life as a "glorious accident," and Dawkins of evolution as "climbing Mount Improbable." And life, once started, is subject to vicissitudes of all kinds, from meteors and volcanic eruptions to global overheating and cooling; from dead ends in evolution to mysterious mass extinctions; and finally (if things get that far) from the fateful proclivities of a species like ourselves. Yet since there are microfossils almost four billion years old, life must have appeared within one or two hundred million years of the earth's cooling off sufficiently to have liquid water. This makes one think that life may develop readily, perhaps inevitably, given the right physical and chemical conditions on a planet. Such conditions could easily have occurred on Mars (before it dried and froze) or Venus (before it boiled). For Mars was once wet and warm, with seas and hydrothermal vents, and perhaps deposits of clay and iron ore, and it is especially in such places that we might hope to find evidence of past life. NASA has examined samples on Mars with its robot Explorers, but it has not been possible yet to make on-the-spot searches for microfossils, only to test for biogenic oxidation or metabolic products. No martian sample has been returned to Earth. (There was, of course, great excitement a few years ago when it seemed that ALH 84001, the martian meteorite, might contain minute fossilized structures.) There must be thousands of martian meteorites on Earth, and the notion of "seed-bearing meteoritic stones" was raised by Lord Kelvin in 1871, and the notion of free spores drifting through space and seeding life on other planets ("panspermia") was postulated by the Swedish chemist Arrhenius a few years later (an idea revived in the twentieth century by Francis Crick and Fred Hoyle). The idea was considered implausible for more than a century, but is once again a hot subject for discussion. For now, it is evident that the insides of sizeable meteors do not get heated to sterilizing temperatures, and that bacterial spores, or other resistant forms, could, in principle, survive within them, protected by the body of the meteor not only from heat but from radiations deadly to life. Meteors were being flung in all directions during the period of Heavy Bombardment four million years ago. Chunks of the Earth must have been ejected into space then, as well as chunks of Mars and Venus--a Mars and Venus which might, at the time, have been more hospitable to life than Earth itself. But we may not need to look too far afield for such meteors. We already know, from the samples returned by the Apollo missions, that there are early Earth and martian meteors on the moon in considerable quantities. Now, perhaps, the time has come to plan a new mission to the moon, to allow mining and soil-concentration experiments that utilize technology unimaginable in the 1970s (such as portable polymerase machines to search the soil for ancient DNA). Here, perhaps, more easily than anywhere else, we may hope to find traces of the earliest life forms from Earth, or Venus, or Mars, and determine how life first started in our solar system. And yet a romantic part of us cries out for more, for evidence of higher life, of human-order beings who can communicate their existence to us directly. So we need to keep SETI, our electromagnetic ears, open for more distant signs of life, as well as sampling our neighbors in this solar system. Who is to say what the next few years or decades will uncover? For myself, since I cannot wait, I turn to science fiction on occasion; and, not least, back to my favorite Wells. Though it was written a hundred years ago, "A Lunar Morning" has the freshness of a new dawn, and it remains for me, as when I first read it, the most poetic evocation of how it may be when, finally, we encounter alien life. (c)2002 Oliver Sacks Reprinted by permission of the NASA Arts Program. Additional information on this article is available at http://www.astrobio.net/news/article331.html. _____________________________________________________________________ ANTARCTIC ICE SEALS LIFE'S FATE University of Illinois at Chicago release 16 December 2002 Microbes discovered packed in an ice-sealed, briny lake in Antarctica may help advance techniques to search for signs of life locked in the subterranean ice on Mars, and provide a model for what lakes on Earth may have looked like during severe glacial periods. The findings were reported in the online edition of the Proceedings of the National Academy of Sciences the week of December 16. A team of researchers led by Peter Doran, assistant professor of earth and environmental sciences at the University of Illinois at Chicago, discovered an unusual and extreme aquatic ecosystem in Lake Vida--among the largest of many lakes in Antarctica's McMurdo Dry Valleys located about 2,000 miles due south of New Zealand. The team found a liquid lake of super-concentrated salt water, seven times saltier than normal seawater, locked beneath 19 meters (62 feet) of lake ice--a record lake ice cover on Earth. The salty water has been isolated from the atmosphere for at least 2,800 years. Ice core samples taken from above the pool of brine revealed frozen bacteria and algae that came back to life after gradual melting. The scientists believe the chilly brine may harbor life as well. "Any primary producers potentially living in the brine down deep are not getting sunlight, so they would have to be chemosynthetic, that is, getting energy from the surrounding chemicals instead of sunlight," said Doran. "The microbes frozen in the ice above seem to be life that was living shallow in the lake at some time, then water flowed on top of the thick ice cover and froze." Carbon-14 dating showed microbes gathered from ice near the brine to be more than 2,800 years old. Doran said the brine is likely to be at least that old, forming as salts settled down into it while thick ice grew outward from the sealed, freeze-resistant salty lake. Doran and his research team bored holes to take ice samples from Lake Vida back in 1996 after scanning the lake with ground penetrating radar. "It's a beautiful tool for this because radar doesn't like salt," said Doran. "As soon as radar sees salt, it disappears, so there's a really clear line of where the salt begins." With those findings, the research team mapped Lake Vida with indications of where salt water appeared trapped. They bored down through ice, taking core samples but stopping in slushy water about three meters above the brine lake. One reason for not drilling lower was fear that special ice-melting chemicals used to help the drilling might have contaminated samples of brine. The research overturns earlier assumptions that Lake Vida was frozen solid. "That's an important conclusion because Lake Vida is in an area that has a fairly cold mean annual temperature," said Doran. "It actually pushes back our estimates of what it takes to freeze a lake ecosystem." NASA is interested in the research because the Lake Vida ecosystem serves as a classroom of sorts, providing lessons for launching martian ice probes that may yield frozen microbes. "It's pretty much common knowledge that Mars had a water-rich past and likely went from a warmer to a colder climate, although this last point is coming under much debate lately," said Doran. "Mars is very cold. It has a thin atmosphere now and cannot support liquid water on the surface, although there's evidence that there may be something in the near- surface--maybe a brine, or something like that." "If the planet went through a cooling, Mars must have had perennially ice-covered lakes, then this ice-sealed type of environment," said Doran. "Unless we find evidence of life still there today, I see Lake Vida as being like life's last romp on Mars, potentially, in an ice-sealed lake. Lake Vida gives us an excellent model of how long a lake ecosystem can survive before you snuff it out by turning down the temperature. How does the ecosystem respond, what does it look like and, more importantly, if we go back and collect samples, where do we look and what are we looking for to find evidence of these types of lakes?" NASA and the National Science Foundation are jointly funding a follow-up study to test miniature coring equipment and to dip a straw-like device into the brine of Lake Vida to suck out samples. "We'll do it like we're on a planetary mission," said Doran. "While we don't expect to find 'Lake Vidas' on Mars today, it's a good analogue for something in Mars' past. Also, if there are brines leaking out from Mars' subsurface today, they could well come from a buried 'Lake Vida.'" Besides Doran, the research team authors include Christian Fritsen of the Desert Research Institute of Reno, NV; Christopher McKay of the NASA Ames Research Center; and John Priscu and Edward Adams of Montana State University. Support for the research came from grants from the NSF and the NASA Exobiology Program. Contact: Paul Francuch News Bureau, Office of Public Affairs University of Illinois at Chicago Chicago, Illinois Phone: 312-996-3457 E-mail: francuch@uic.edu _____________________________________________________________________ MORE SUN-LIKE STARS MAY HAVE PLANETARY SYSTEMS Vanderbilt University release 17 December 2002 If David Weintraub and Jeff Bary are right, there may be a lot more planets circling stars like the Sun than current models of star and planet formation predict. The associate professor of astronomy at Vanderbilt and his graduate student are taking a critical look at T Tauri stars. These are stellar adolescents, less than 10 million years old, which are destined to become stars similar to the Sun as they age. Classical T Tauri stars--those less than 3 million years old--are invariably accompanied by a thick disk of dust and gas, which is often called a protoplanetary disk because it is a breeding ground for planet formation. Most older T Tauri stars show no signs of encircling disks. Because they are not old enough for planets to form, astronomers have concluded that most of these stars must lose their disk material before planetary systems can develop. Weintraub and Bary are pursuing an alternative theory. They propose that most older T Tauri stars haven't lost their disks at all--the disk material has simply changed into a form that is nearly invisible to Earth-based telescopes. They published a key observation supporting their hypothesis in the September 1 issue of the Astrophysical Journal Letters and the article was highlighted by the editors of Science magazine as particularly noteworthy. The two researchers currently are preparing to publish additional evidence in support of their hypothesis. The dense disks of dust and gas surrounding classical T Tauri stars are easily visible because dust glows brightly in the infrared region of the spectrum. Although infrared light is invisible to the naked eye, it is readily detectable with specially equipped telescopes. The second group of T Tauri stars that are somewhat older--between three to six billion years--and show no evidence of disks have been labeled as "naked" or "weak line" T Tauri stars. Because there is no visible evidence that naked T Tauri stars possess protoplanetary disks. So astronomers have concluded that the material must have been absorbed by the star or blown out into interplanetary space or pulled away by the gravitational attraction of a nearby star in the first few million years. According to current theories, it takes about 10 million years to form a Jupiter- type planet and even longer to form a planet like Earth. If the models are correct and if most Sun-like stars loose their protoplanetary disks in the T Tauri stage, then very few stars like the Sun are likely to possess planetary systems. This picture doesn't sit well with Weintraub, however. "Approaching it from a planetary evolution point of view, I have not been comfortable with some of the underlying assumptions," he says. Current models do not take the evolution of protoplanetary disks into account. Over time, the disk material should begin agglomerating into solid objects called planetesimals. As the planetesimals grow, an increasing amount of the mass in the disk becomes trapped inside these solid objects where it cannot emit light directly into space. The constituents of the disk that astronomers knew how to detect-- small grains of dust and carbon monoxide molecules--should quickly disappear during the first steps of planet building. "Rather than the disk material dissipating," says Bary, "It may simply become invisible to our instruments." So Weintraub and Bary began searching for ways to determine if such "invisible protoplanetary disks" actually exist. They decided that their best bet was to search for evidence of molecular hydrogen, the main constituent of the protoplanetary disk, which should persist much longer than the dust grains and carbon monoxide. Unfortunately, molecular hydrogen is notoriously difficult to stimulate into emitting light. It must be heated to a fairly high temperature before it will give off infrared light. The fact that T Tauri stars are also strong X-ray sources gave them an idea. Perhaps the X-rays coming from the star could act as an energy source capable of stimulating the molecular hydrogen. To produce enough light to be seen from earth, however, the molecular hydrogen could not b mixed with dust and had to be at an adequate density. Studying various theories of planet formation, they determined that the proper conditions should hold in a "flare region" near the outer edge of the protoplanetary disk. The next step was to get observation time on a big telescope to put their out-of-the-mainstream theory to the test. After repeated rejections, they were finally allocated viewing time on the four- meter telescope at the National Optical Astronomical Observatory in Kitt Peak, Arizona. When they finally took control of the telescope and pointed it toward one of their prime targets--a naked, apparently diskless T Tauri star named DoAr21--they found the faint signal for which they were searching. "We found evidence for hydrogen molecules where no hydrogen molecules were thought to exist," says Weintraub. When Bary calculated the amount of hydrogen involved in producing this signal, however, he came up with about a billionth of the mass of the Sun, not even enough to make the Moon. As they argued in their Astrophysical Journal Letter article, they believe that they have detected only the proverbial tip of the iceberg, since most of the hydrogen gas will not radiate in the infrared. But the calculation raises the question of whether the molecular hydrogen that they detected is part of a complete protoplanetary disk or just its shadowy remains. Although they do not completely answer the question, additional observations that the two are readying for publication provides additional support for their contention that DoAr21 contains a sizeable but invisible disk. The new observations are the detection of the same molecular hydrogen emission line around three classical T Tauri stars with visible protoplanetary disks. The strength of the hydrogen emission lines in the three is comparable to that measured at DoAr21. In addition, they have calculated the ratio between the mass of hydrogen molecules that are producing the infrared emissions and the mass of the entire disk in the three systems. For all three they calculate that the ratio is about one in 100 million. "If the ratio between the amount of hydrogen emitting in the infrared and the total amount of hydrogen in the disk is about the same in the two types of T Tauri stars, which is not an unreasonable assumption, this suggests the naked T Tauri star has a sizable but hard-to-detect disk," says Bary. Weintraub and Bary admit that they have more work to do to in order to convince their colleagues to adopt their theory. They have been allocated time on a larger telescope, the eight-meter Gemini South in Chile and plan to survey 50 more naked T Tauri stars to see how many of them produce the same molecular hydrogen emissions. If a large number of them do, it will indicate that they have discovered a general mechanism involved in the planetary formation process. They also intend to search for a second, fainter hydrogen emission line. If they find it, it will provide additional insights into the excitation process. Currently, the number of naked T Tauri stars that have been discovered is much greater than the number of known classical T Tauri stars. If Weintraub and Bary are proven right, however, and a significant percentage of the naked T Tauri stars develop planetary systems, it means that solar systems similar to our own are a common sight in the universe. An additional article on this subject is available at http://spaceflightnow.com/news/n0212/17planetary/. _____________________________________________________________________ AIAA'S 1ST PLANETARY DEFENSE CONFERENCE: PROTECTING EARTH FROM ASTEROIDS FEBRUARY 2004, LOS ANGELES, CALIFORNIA AIAA release http://www.aiaa.org/calendar/index.hfm?cal=5&id=865 17 December 2002 Synopsis AIAA's 1st Planetary Defense Conference: Protecting Earth from Asteroids will address technical issues associated with, and relative to, the defense of Earth from approaching near-Earth objects (comets and asteroids). This forum shall approach the threat from the perspective of three levels of warnings: 1) short term (less than 10 years warning of possible impact); 2) medium term (10 to 30 years warning); and 3) long term (>30 years warning), with an overarching intent to define several possible threat scenarios and develop potential responses for each. Focused conference topics will: * Examine current and future detection capabilities and options; * Consider current and future techniques, hardware, and systems available to mitigate threats; * Discuss national and international policy implications of mounting a planetary defense effort; * Develop recommendations for future work, strategies, and policies; * Develop recommendations for demonstrations/experiments/near-term activities; and * Discuss public safety and disaster preparedness implications of possible asteroid or comet impacts. General Chair William Ailor The Aerospace Corporation E-mail: william.h.ailor@aero.org _____________________________________________________________________ MICROORGANISM ISOLATED IN "SPACE" Cardiff University release 17 December 2002 How far up into the sky does the biosphere extend? Do microorganisms exist at heights of 40 km and in what quantity? To answer these questions several research institutes in India collaborated on a path-breaking project to send balloon-borne sterile "cryosamplers" into the stratosphere. The program was led by cosmologist Professor Jayant Narlikar, Director of the Inter-University Centre for Astronomy and Astrophysics in Pune, with scientists at the Indian Space Research Organisation and the Tata Institute of Fundamental Studies contributing their various expertises. Large volumes of air from the stratosphere at heights ranging from 20 to 41 km were collected on 21 January 2001. The program of analysis of samples in the UK was organized by Professor Chandra Wickramasinghe of Cardiff University, co-proponent with the late Sir Fred Hoyle of the modern [hypothesis] of panspermia. This [hypothesis] states that the Earth was seeded in the past, and is still being seeded, with microorganisms from comets. Last year a team of biologists at Cardiff University's School of Biosciences reported evidence of viable bacteria in air samples at 41km in such quantity that implied a world-wide settling rate of one ton of bacterial material per day. Although living bacteria were seen they could not be grown in the laboratory. Dr. Milton Wainwright of Sheffield University's Department of Molecular Biology and Biotechnology was asked to apply his skills to growing the organisms. Dr. Wainwright isolated a fungus and two bacteria from one of the space derived samples collected at 41 km. The presence of bacteria in these samples was then independently confirmed. These results are published in this month's issue of FEMS Letters (Wainwright et al, 2002), published by Elsevier. The isolated organisms are very similar to known terrestrial varieties. There are however notable differences in their detailed properties, possibly pointing to a different origin. Furthermore, it should be stressed that these microorganisms are not common laboratory contaminants. Dr. Wainwright says, however, "Contamination is always a possibility in such studies but the "internal logic" of the findings points strongly to the organisms being isolated in space, at a height of 41km. Of course the results would have been more readily accepted and lauded by critics had we isolated novel organisms, or ones with NASA written on them! However, we can only report what we have found in good faith". The new work of Wainwright et al is consistent with the ideas of Hoyle and Wickramasinghe that in fact predict the continuing input onto the Earth of "modern" organisms. In recent years and months there has been a growing body of evidence that can be interpreted as support for the [hypothesis] of panspermia--e.g. the space survival attributes and general space hardiness of bacteria. Contact: Professor Chandra Wickramasinghe Wickramasinghe@cardiff.ac.uk, 02920-874201 Additional articles on this subject are available at: http://www.newscientist.com/news/news.jsp?id=ns99993186 http://www.space.com/scienceastronomy/space_bugs_021217.html http://www.spacedaily.com/news/life-02zzg.html _____________________________________________________________________ MICROBES FROM EDGE OF SPACE REVIVED By Jenny Hogan From New Scientist (http://www.newscientist.com) 17 December 2002 Microbes collected from the edge of space have been brought back to life in the lab. This enabled the high-flying organisms to be identified, almost two years after they were found in air samples collected by a weather balloon cruising at 41,000 meters (135,000 feet) over southern India. The two species of bacteria (B. simplex, S. pasteuri) and one fungus (E. albus) are similar to common ground-dwelling microbes that lurk in soil and vegetation, says Milton Wainwright of the University of Sheffield, UK, who worked out how to culture the cells. How the bugs got there is not known, but there are three possibilities: they were carried up on winds, they sneaked into the samples on Earth, or they have flown through space and are aliens making their way down to our planet. The latter possibility fits with a [hypothesis] developed by Chandra Wickramasinghe and the late Fred Hoyle in the 1970s, which proposes that life originated elsewhere in the Universe and hitched a lift to Earth on a passing comet. Wickramasinghe, at the Cardiff University Centre for Astrobiology in Wales, is Wainwright's co-author on the new paper, along with the Indian scientists that sent up the balloon. If the microbes were indeed drifting in from space, Wickramasinghe calculates that up to a ton could be landing each year, based on the density of microbes found in the air samples. Up draught Wainwright admits that the simplest explanation is that the organisms, found above 99 per cent of the Earth's atmosphere, have terrestrial origins. But, he asks, how did they get up there? Turbulent winds at ground level are certainly capable of sweeping particles up into the atmosphere. But this kind of weather is confined beneath the tropopause, which acts like a lid at about 17,000 meters. Volcanic eruptions can push matter through the tropopause. But there were no such events in the months before the samples were taken, and gravity would be expected to drag any microbes back down in a few days. However, the man-made greenhouse gases called CFCs have been found at similar altitudes, showing that global air currents can pierce the tropopause. Martin Juckes, an atmospheric scientist at the Rutherford Appleton Laboratory, UK, says that air flows upwards at the tropics at about one meter per hour, and may carry material with it. But whether particles as large as microbes could be carried to such heights is not known. Freeze-dried The third possibility, that the microbes represent experimental contamination, is dismissed by Wainwright. The experimental protocol was carefully designed to exclude contamination before the samples were collected during the balloon flight (New Scientist print edition, 4 August 2001). And contamination after the samples had been returned to Earth is unlikely, he argues, because the microbes were freeze-dried. This was due to the cold, dry conditions at 41,000 meters, he says. To coax them into growing, Wainwright had to soak them in a nutrient solution. They refused to multiply when spread on the jellies usually used to culture samples--but any contaminant cells would have shown up at this stage, he says. Journal Reference: FEMS Microbiology Letters, article 10778 Additional information on this article is available at http://www.newscientist.com/news/news.jsp?id=ns99993186. _____________________________________________________________________ NASA TESTING K9 ROVER IN NEW "MARSCAPE" FOR FUTURE MISSIONS NASA/ARC release 02-136AR 18 December 2002 NASA scientists and engineers are testing new technologies using a K9 rover in a newly built "Marscape" test facility in preparation for future missions to Mars. Testing is being conducted at NASA Ames Research Center in California's Silicon Valley in a 3/4-acre "Marscape" that has been designed to resemble the terrain on Mars. Constructed at a cost of about $74,000, the test facility incorporates the environmental and geological features of Mars that hold the greatest scientific interest. The Marscape features a dry lakebed and outflow channel, a meteorite impact crater, a volcanic zone containing a dry hydrothermal spring and an area that scientists describe as "chaotic terrain." "The goal of the K9 project is to integrate and demonstrate new robotic technologies that will enable NASA to meet the science goals of future Mars missions," said Maria Bualat, a computer engineer at NASA Ames who is the K9 rover project lead. Scientists hope to utilize new robotic technologies during NASA's Mars Science Laboratory (MSL) mission anticipated in 2009. "The whole purpose of this research project is to ensure that this rover is as autonomous and reliable as possible. Autonomous instrument placement capability is essential for future Mars exploration," said Dr. Liam Pedersen, principle investigator for the K9 rover instrument placement project. Developed jointly at NASA Ames and NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA, the K9 rover is a six-wheeled, solar-powered rover weighing 145 pounds (65 kg) that measures 63 inches (1.6 m) high. The K9 rover is modeled after a rover named "FIDO" (Field Integrated Design and Operations) developed at JPL about four years ago. The rover's avionics, instrumentation, and its autonomy software were developed at NASA Ames. The rover carries a variety of instruments on board, including a compass, an inertial measurement unit and three pairs of monochromatic cameras used for navigation and instrument placement. The rover also carries a pair of high-resolution, color stereo cameras and the CHAMP, an arm-mounted, focusable microscopic camera developed at the University of Colorado, Boulder. The rover's stereo cameras create a 3-D virtual map of the exploration site that scientists use to help navigate the rover to its intended target. "Approaching science targets such as rocks and placing instruments against them to take measurements is an essential task for a planetary surface exploration rover," Pedersen explained. "This is necessary to acquire samples, determine mineralogy, obtain microscopic images and other operations needed to understand the planet's geology and search for evidence of past or present life." Due to Mars' distance from Earth, even with commands being transmitted at the speed of light, it currently takes three martian days to complete the process of directing a rover to a targeted rock and placing the instrument on the rock to begin scientific analysis of it. Scientists at NASA Ames hope to be able to accomplish that objective in a single day, thereby increasing the efficiency of obtaining science data in future missions. David Smith, a computer scientist at NASA Ames, leads the research group that is responsible for developing the rover's automated planning and scheduling software. In previous missions, there has been very little automation of the planning and scheduling process for planetary rovers, according to Smith. "What's unique about this software being developed at NASA Ames is that it generates contingency plans to provide an alternative that can be executed when things go wrong," Smith said. "There is a great deal of uncertainty in operating a robotic system on Mars, so you need to be able to consider alternatives. By having options available, you increase the science return." To increase the versatility of the software, scientists at NASA Ames, JPL and Carnegie Mellon University are developing a universal architecture for robotics software named CLARAty, funded by the Mars Technology Program, to develop robotics capabilities at NASA centers and universities for future missions. "NASA near-term Mars missions have very ambitious science goals that will require high levels of autonomy onboard the robot," said Bualat. "Our goal is to have a 'smart robot' that we can send off to Mars in 2009 that will take care of itself." The K9 rover project's annual cost of approximately $1 million is funded jointly by the Intelligent Systems Project under the Computing, Information and Communications Technology (CICT) Program administered by NASA's Office of Aerospace Technology, and by the Mars Technology Program, administered by the Office of Space Science, NASA Headquarters, Washington, DC. Reproduction quality images of the K9 rover are available at http://amesnews.arc.nasa.gov/releases/2002/02images/k9/k9.html Contact: Michael Mewhinney NASA Ames Research Center, Moffett Field, CA Phone: 650-604-3937 or 650-604-9000 E-mail: Michael.S.Mewhinney@nasa.gov An additional article on this subject is available at http://www.spacedaily.com/news/mars-general-02k.html. _____________________________________________________________________ MINIMALIST LIFE By Stephen Hart From Astrobiology Magazine 18 December 2002 The life surrounding hydrothermal vents came as a surprise when two scientists got the first close-up look at a vent community in 1977. And it wasn't long before biologists began wondering whether such environments might closely resemble the hotbed of earth's earliest life. The idea that some microbes could love temperatures that killed others fired the imagination of Karl Stetter, a microbiologist at the University of Regensburg in Germany. "I did a lot of bug hunting during the last 22 or 23 years since I became interested in hot stuff among the microbes," he says. Stetter's latest hot-vent discovery came from the Kolbiensey Ridge, just north of Iceland--the ironic land of ice and volcanoes--which he calls "one of my major hunting grounds." Stetter collected samples of hot rocks about 120 meters deep, using the Jago research submarine. The two-part find began with a new species of the archaean Igniococcus (fire ball), which Stetter and crew grew in the laboratory. But a close look at the Igniococcus cells revealed something completely new: tiny, spherical cells stuck to the surface of many Igniococcus cells. These spheres measured merely 400 nanometers, around a quarter of the diameter of Igniococcus. Electron microscopy revealed internal features of the small spheres, indicating that they were indeed cells. Stetter and colleagues from the University of Regensburg and the Max Planck Institute, in Heidelberg, published the findings in May 2002 in the journal Nature. "We are able to separate them now, the tiny guys, from the big ones, and we are studying their biochemical properties and their enzyme activities and of course their genes and also their habits of life," Stetter says. One of the first steps in studying the new organism was attempting to grow it separately from Igniococcus. That failed. While some of the small cells appear to float free in a mixture of the two organisms, Stetter's "tiny guys" would not grow without their bigger hosts. The hosts, however, got along fine without their riders. Next, Stetter wanted to know where these cells fit on the tree of life. The team turned to the gold standard of molecular taxonomy, the ribosomal RNA (rRNA) genes. But so-called universal probes, capable of detecting rRNA genes of all previously known organisms, didn't detect DNA from the new organism. "So these so-called universal probes, which work the same with humans, with animals, with plants, with all eukaryotes and with bacteria and archaea, they did not work in this organism," Stetter says. Turning to another method of detecting DNA, the researchers found two rRNA genes, both archaeal in nature, in the mixture of the two organisms, but only one when the host was grown alone. The rRNA genes of the tiny organism didn't resemble those of any known organism. The authors conclude "Therefore, the tiny cocci represent a new archaeal phylum. On the basis of its extremely small cell size, we name it 'Nanoarchaeota' (the dwarf archaea) and the corresponding species 'Nanoarchaeum equitans' (riding the fire sphere)." Microbiologists have previously established three phyla of archaea, the Crenarchaeota, the Euryarchaeota and the Korarchaeota, known only from environmental DNA samples. Finding a new species is one thing. Claiming that it represents a new and distinct fourth phylum of Archaea is quite another. Carl Woese, the father of the rRNA tree of life, and certainly one of the world's foremost experts on archaea, does not see the claim as too much of a reach. "They're pretty good experimentalists, so if they say that, I would accept it," he says. But he's anxious to see the complete genome published. "They also have a genome sequence which they haven't published, unfortunately. It's being done by a company of which Stetter is a partner." The for-profit company, called Diversa, has completed the Nanoarchaeum equitans genome, Stetter says. "They sequenced the DNA and at present we are writing up a paper together. So it will definitely be published and the results look very exciting." What's next? Since May, Stetter has found relatives of Nanoarchaeum in several locations around the world. All of these belong in the newly created phylum, Stetter says. But their rRNA differs from that of Nanoarchaeum equitans enough to place them in different families, hinting at a large, widespread group of previously overlooked organisms. "For example, nanoarcheotes are also in Yellowstone National Park," he says, "and we found them in Kamchatka, even, in eastern Siberia. And I bet my last hat that they are also in many other places around the world and nobody has ever detected them so far." Because the paper describing the genome remains in preparation, Stetter won't say exactly what the sequence reveals or what use Diversa might make of it. "This is a very unusual organism and therefore it looks promising," he says. "On the other hand, it's a really tiny guy, and so one could learn more about the essentials which are necessary for a living organism. I don't know for what kinds of things it could be used in the future, but such a tiny organism, maybe even artificial life." Speaking of artificial life, Craig Venter and his colleague Hamilton Smith have announced an initiative to build a genome from scratch. Might Venter be interested in Nanoarchaeum? "I think so, yeah, he could be very interested," Stetter says, laughing. "This is the smallest genome of a complete organism known so far." The genome, Stetter says, turns out to be slightly smaller than 0.5 megabases, about a tenth of the size of the E. coli genome, and even smaller than the former small-genome record holder, the bacterium Mycoplasma genitalium. Woese says "It's as small as you can go as far as I know, in terms of self-replicating organisms." No comparable archaean is known, he continues. "This is sort of something that's unique." Nanoarchaeum sits, Stetter says, very deep in the tree of life, an indication that members of the phylum may resemble the earliest cells and the earliest common ancestor of all life on earth. "We have speculated a bit, you know, in the [May '02] Nature paper. But it's not speculation any more. So it's a really very deep branch and how deep we will show in our [upcoming] paper," he says. But even the phylum Nanoarchaeota may not be the last word, Stetter says. "I think that this is just the tip of a really hot, completely unknown iceberg, that there may be other lineages around which are similarly deeply branching." Additional information on this article is available at http://www.astrobio.net/news/article332.html. _____________________________________________________________________ CLOUDS DISCOVERED ON SATURN'S MOON TITAN Caltech release http://www.gps.caltech.edu/~antonin/titan/ 18 December 2002 Teams of astronomers at the California Institute of Technology (Caltech) and at the University of California, Berkeley, have discovered methane clouds near the south pole of Titan, resolving a fierce debate about whether clouds exist amid the haze of the moon's atmosphere. The new observations were made using the W. M. Keck II 10-meter and the Gemini North 8-meter telescopes atop Hawaii's Mauna Kea volcano in December 2001. Both telescopes are outfitted with adaptive optics that provide unprecedented detail of features not seen even by the Voyager spacecraft during its flyby of Saturn and Titan. The results are being published by the Caltech team in the December 19 issue of Nature and by the UC Berkeley and NASA Ames team in the December 20 issue of the Astrophysical Journal. Titan is Saturn's largest moon, larger than the planet Mercury, and is the only moon in our solar system with a thick atmosphere. Like Earth's atmosphere, the atmosphere on Titan is mostly nitrogen. Unlike Earth, Titan is inhospitable to life due to the lack of atmospheric oxygen and its extremely cold surface temperatures (-183 degrees Celsius, or -297 degrees Fahrenheit). Along with nitrogen, Titan's atmosphere contains a significant amount of methane. Earlier spectroscopic observations hinted at the existence of clouds on Titan, but gave no clue as to their location. These early data were hotly debated, since Voyager spacecraft measurements of Titan appeared to show a calm and cloud-free atmosphere. Furthermore, previous images of Titan had failed to reveal clouds, finding only unchanging surface markings and very gradual seasonal changes in the haziness of the atmosphere. Improvements in the resolution and sensitivity achievable with ground-based telescopes led to the present discovery. The observations used adaptive optics, in which a flexible mirror rapidly compensates for the distortions caused by turbulence in Earth's atmosphere. These distortions are what cause the well-known twinkling of the stars. Using adaptive optics, details as small as 300 kilometers across can be distinguished at the enormous distance of Titan (1.3 billion kilometers), equivalent of reading an automobile license plate from 100 kilometers away. The images presented by the two teams clearly show bright clouds near Titan's south pole. "We see the intensity of the clouds varying over as little as a few hours," said post-doctoral fellow Henry Roe, lead author for the UC Berkeley group. "The clouds are constantly changing, although some persist for as long as a few days." Titan experiences seasons much like Earth, though its year is 30 times longer due to Saturn's distant orbit from the sun. Titan is currently in the midst of southern summer, and the south pole has been in continuous sunlight for over six Earth years. The researchers believe that this fact may explain the location of the large clouds. "These clouds appear to be similar to summer thunderstorms on Earth, but formed of methane rather than water. This is the first time we have found such a close analogy to the Earth's atmospheric water cycle in the solar system," says Antonin Bouchez, one of the Caltech researchers. In addition to the clouds above Titan's south pole, the Keck images, like previous data, reveal the bright continent-sized feature that may be a large icy highland on Titan's surface, surrounded by linked dark regions that are possibly ethane seas or tar-covered lowlands. "These are the most spectacular images of Titan's surface which we've seen to date," says Michael Brown, associate professor of planetary astronomy and lead author of the Caltech paper. "They are so detailed that we can almost begin to speculate about Titan's geology, if only we knew for certain what the bright and dark regions represented." In 2004, Titan will be visited by NASA's Cassini spacecraft, which will look for clouds on Titan during its multiyear mission around Saturn. "Changes in the spatial distribution of these clouds over the next Titan season will help pin down their detailed formation process," says Imke de Pater, professor of astronomy at UC Berkeley. The Cassini mission includes a probe named Huygens that will descend by parachute into Titan's atmosphere and land on the surface near the edge of the bright continent. The team conducting the Gemini observations consists of Roe and de Pater from UC Berkeley, Bruce A. Macintosh of Lawrence Livermore National Laboratory, and Christopher P. McKay of the NASA Ames Research Center. The team reporting results from the Keck telescope consists of Brown and Bouchez of Caltech and Caitlin A. Griffith of the University of Arizona. The Gemini observatory is operated by the Association of Universities for Research in Astronomy under a cooperative agreement with the National Science Foundation, involving NOAO/AURA/NSF as the U.S. partner. The W. M. Keck Observatory is operated by the California Association for Research in Astronomy, a scientific partnership between the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. This research has been funded in part by grants from NSF and NASA. An additional article on this subject is available at http://www.cnn.com/2002/TECH/space/12/19/titan.clouds/index.html. _____________________________________________________________________ SPACE SCENTS By Karen Miller and Tony Phillips 18 December 2002 "That which we call a rose, by any other name would smell as sweet." Shakespeare knew a few things about romance... and roses. But here's something he never considered: roses in space. Would they smell as sweet in Earth orbit? It's not as silly as it sounds--at least perfume industry giant International Flavors & Fragrances (IFF) didn't think so. New fragrances are much sought after in the competitive perfume industry. Some years ago IFF researchers began to wonder: Could space-traveling flowers yield something new and exotic? The answer might prove profitable, they figured. And so began perhaps the most romantic space experiment ever done. In 1998, IFF teamed with the Wisconsin Center for Space Automation and Robotics (WCSAR), a NASA Commercial Space Center (CSC) at the University of Wisconsin. WCSAR's job is to help companies research new products in space. NASA's Space Product Development program at the Marshall Space Flight Center supports 15 such CSC's around the country. WCSAR researchers had developed a plant growth chamber called ASTROCULTURE? for the middeck of the space shuttle. It provides plants with the appropriate temperature, humidity, light, and nutrients during spaceflight, explains Dr. Weijia Zhou, WCSAR director. ASTROCULTURE? was perfect for IFF's purpose, and so on October 28, 1998, a tiny rose selected by IFF was able to leave Earth for a 10-day flight onboard the shuttle Discovery (STS-95). IFF researchers quickly learned that what we call a rose does indeed smell sweet in space, but it does not smell the same. Fragrance, in flowers, is a variable and elusive commodity, evolved solely to help plants reproduce by attracting the insects and animals they need to spread their pollen [and thus, their sperm] around. Although we tend to think of floral smells as sweet and appealing, flowers produce a variety of odors, depending on the preferences of their pollinators. If bees are lured by the same kinds of smells that we like, carrion flies, for example, may be drawn by ranker odors, like that of skunk cabbage. But whatever they smell like, the odors themselves come from "volatile oils," also known as essential oils, because they carry the essential fragrance of the plant. These highly concentrated plant extracts all share certain traits; for example, they readily bind to receptors in olfactory neurons. They also tend to be soluble in alcohol, but not water, and they often feel oily. Most important is that they evaporate at room temperature. Indeed, the fragrances used in perfumes are classified on a scale from 1 to 100, according to how readily they dissipate. A plant's production of volatile oils is strongly affected by its environment, explained Dr. Braja Mookherjee, who, until his recent death, was Director of Global Natural Products at IFF. Some plants, for example, produce more oils at night when their pollinator is active, and some produce more in the daytime. Temperature, humidity, and the age of the flower are influential, too. It's no wonder, said Mookherjee, that low-gravity should affect a flower's smell just as other environmental factors do. The flower that flew on STS-95 was a miniature rose called "Overnight Scentsation"--a plant no more than seven inches high, with two buds just ready to open. The rose needed to be small to fit inside ASTROCULTURE?, which is a 17 by 9 by 21 inch enclosure. "Ninety-nine percent of miniature roses have no odor," said Mookherjee, but Overnight Scentsation is an exception. It emits a fragrance, which Mookherjee described as "a very green, fresh rosy note." In low gravity, said Mookherjee, the rose actually produced fewer volatiles than it did on Earth. But the fragrance that it did generate was critically altered. The flower in space had a more "floral rose aroma," which is aesthetically pleasing. And, no, the astronauts didn't just sniff the flower. To collect the scent, they reached into the ASTROCULTURE? chamber and touched the rose using a tiny silicon fiber. Less than one centimeter long, and only 1 to 2 millimeters in diameter, the fiber was coated with a special liquid to which molecules around the flower petal adhere. After the shuttle returned to Earth, IFF researchers took the fiber and analyzed the molecules they found on it. "We identify the constituents, we know the quantity, and then we can synthesize [the fragrance] here in the lab," explained Mookherjee. The fragrance of a rose is made up of nearly 200 different compounds, he added. The rose was sampled four times throughout the STS-95 shuttle mission. Each time, says Mookherjee, they got a different result. The scent that they finally arrived at was the average of those samplings, and the new fragrance has since been incorporated into "Zen", a perfume produced by the Japanese company Shiseido. The collaboration between IFF and WCSAR will continue on STS-107, a shuttle mission slated for launch in January 2003. This time the plan is to send up two different plants--a rose and an Asian rice flower--again placed in the ASTROCULTURE? facility. Like Romeo and Juliet, the flowers will touch each other. This as well as the low gravity, said Mookherjee, will alter the molecules they emit. The ability to do research in space, concluded Mookherjee, gives a whole new dimension to the field of fragrance studies. "It's a fantastic opportunity," he said... one that the Bard himself might have appreciated. Additional information on this article is available at http://science.nasa.gov/headlines/y2002/18dec_scents.htm?list52260. _____________________________________________________________________ DOES LIFE ON EARTH HAVE A FUTURE? By Martin Rees King's College Cambridge 18 December 2002 The following lecture was recently given by Sir Martin Rees, Britain's Astronomer Royal, to the British Association for Advancement of Science. Sir Martin Rees is a professor at Cambridge University and the author of Our Cosmic Habitat. Those of us who are now middle-aged can remember the murky live TV pictures of Neil Armstrong's "one small step". We imagined follow-up projects: a permanent "lunar base", rather like the one at the South Pole; or even huge "space hotels" orbiting the Earth. Manned expeditions to Mars seemed a natural next step. But none of these has happened. The year 2001 didn't resemble Arthur C. Clarke's depiction, any more than 1984 (fortunately) resembled Orwell's. The Apollo program was an isolated episode, motivated primarily by the urge to "beat the Russians". It's 30 years since the last lunar landing. To young people, the Apollo program is a remote historical episode: they know the Americans landed men on the Moon, just as they know the Egyptians built the pyramids; but the motivations seem almost as bizarre in the one case as in the other. The 1995(?) film Apollo 13--a "docudrama", starring Tom Hanks, of the near-disaster that befell three astronauts on a voyage round the Moon--was for me (and I suspect for many others of similar vintage) an evocative reminder of an episode we followed anxiously at the time. But to a young audience, the outdated gadgetry and the "right stuff" values seemed almost as antiquated as a traditional "Western". The practical case for manned spaceflight gets ever-weaker with each advance in robotics and miniaturization. But the use of space for communications meteorology and navigation has forged ahead. Space exploration for scientific purposes can be better (and far more cheaply) carried out by fleets of unmanned probes, exploiting the advances that have given us, using the same technical advances that have given us mobile phones and high-power laptop computers here on Earth. But what is the future for manned spaceflight? The International Space Station is neither practical nor inspiring. Thirty years after men walked on the Moon, a new generation of astronauts is going round and round the Earth, in more comfort than MIR (its Soviet predecessor) offered, but much more expensively. The reduction in the number of astronauts to three makes it even less likely that they will be able to pursue any serious or interesting projects: they will be preoccupied simply in "housekeeping" tasks. There is maybe just one argument for the space station: if one believes that in the long run space travel will become routine, it ensures that the 40 years experience of the US and Russia isn't dissipated Does our future lie in space? There have been two "space tourists" so far: Dennis Tito, an elderly American financier, and Mark Shuttleworth, a South African internet entrepreneur. Each of them paid 20 million dollars. There is a queue of others who wish to follow them, even at that price. But there would be far more if the tickets were cheaper. Present launching techniques are as extravagant as air travel would be if the plane had to be rebuilt after every flight. Spaceflight will only be affordable when its technology comes closer to that of supersonic aircraft. Tourist trips into orbit may then become routine. And when circling round and round the Earth seems so tame and routine that it palls, some will yearn to go further--to the Moon, or even to Mars. If a private consortium were ever to fund a high-risk expedition to Mars, it might well follow the cut-price "Mars direct" strategy advocated by the maverick American engineer Robert Zubrin. An unmanned rocket-load of supplies, together with a factory to make fuel for the return trop, would be sent in advance. The crew would then follow--heading straight for Mars, rather than using the huge and expensive International Space Station as a staging-post. Would anyone want to go? There may be a parallel here with terrestrial exploration. This was driven by a variety of motives. The explorers who set out from Europe in the 15th and 16th century were mainly bankrolled by monarchs, in the hope of recouping exotic merchandise or colonizing new territory. Some, for instance Captain Cook's three 18th century expeditions to the South Seas, were publicly funded, at least in part as a scientific enterprise. And for some--generally the most foolhardy of all--the enterprise was primarily a challenge and adventure: the same motive that drives test pilots, mountaineers, round-the-world sailors and the like. Any of these motives could drive the first travelers to Mars, or the first long-term denizens of a lunar base. The level of risk would be no higher than it was for the "classic" explorers. Travelers into space would never be venturing into the unknown to the extent that the great terrestrial navigators were. There would admittedly be a 30 minute turnaround for messages to and from Mars. But traditional explorers took months to send messages home--or had no opportunity whatever, as in the case of Captain Scott and other polar pioneers. Space travel is difficult and extravagant primarily because it takes several ton of chemical fuel to propel one ton of payload away from the grip of the Earth's gravity. But if there were (say) ten times more power, or ten times more thrust for each kilogram of fuel, then mid-course adjustments could be made whenever necessary, just as we do when driving along a winding road. Keeping a car on the road would be a high-precision enterprise if the journey had to be programmed beforehand, with no chance of adjustments on the way. We don't yet know what technology might provide more efficient propulsion systems--nuclear or solar energy are two obvious options. It would greatly help if the propulsion system and the fuel needed to escape from Earth's gravity could be on the ground rather than having to be part of the cargo. One possibility is the space elevator--a rope made of carbon fiber extending 25,000 kilometers up into space, and held vertical by a geostationary satellite. This would allow payloads and passengers to be hoisted to geostationary orbit by power supplied from the ground. The rest of the voyage could be powered by a low-thrust (perhaps nuclear) rocket. If there were plenty of power, space travel would be an almost unskilled exercise. The target (the moon, Mars or an asteroid) is always in view. One just has to steer towards it, and use retrojets to brake by the right amount at journey's end. Before humans venture into deep space, the entire solar system will have ben explored and mapped by flotillas of tiny robotic craft, controlled by the ever more powerful and miniaturized "processors" that nanotechnology will make possible. Before any human explorers head for Mars, they will have sent not just the mechanical provisions envisaged by Zubrin, but perhaps also "seeds" for plants genetically- engineered to grow and reproduce on the Red Planet. Within a century there could be a permanent presence. Moreover, once the infrastructure was there, the journey could be at a modest cost. There are of course issues of environmental ethics. Would it be appropriate to exploit Mars, as happened when the pioneers advanced westward across the United States? Or should it be preserved as a natural wilderness, like the Antarctic? The answer would I think depend on what the pristine state of Mars actually is. If there were any life already on Mars--especially if it had different DNA, testifying to quite separate origin from any life on Earth--then there would be widely voiced insistence that it should be preserved as unpolluted as possible. What would actually happen would depend partly on the character of the first expeditions. If they were governmental (or international), Antarctic-style restraint might be feasible. On the other hand, if the explorers were privately-funded adventurers of a free-enterprise (even "anarchic") disposition, the Wild West model would be more likely to prevail. The focus will not forever be exclusively on Mars. As the visionary American scientist Freeman Dyson reminds us, the main habitable surface in the Solar System is not on the planets, but on the vast numbers of smaller bodies: he envisages life spreading and diversifying among asteroids and comets--even in the cold outer reaches of the Solar System. One scenario for the second half of the century--which I think is technically and sociologically realistic--would involve a permanently manned Lunar Base, some pioneers on Mars, and perhaps small artificial habitats cruising the Solar system, attaching themselves to asteroids or comets. Space will also be pervaded by robots and "fabricators", allowing large construction projects, using raw materials that need not come from Earth. In the centuries ahead, some groups could develop into communities quite independent of Earth, unconstrained by any restrictions. Some would surely exploit the full range of genetic techniques and diverge into a new species. There will be a new impetus to evolution and diversity--driven by genetics, perhaps by intelligent machines. The creatures that could, within a few hundred years, occupy sites in our Solar System, would all be recognizably humanoid. However, interstellar travel, if it ever happened, would be a task for post-humans--voyages lasting many generations, or in suspended animation, or via transmission of "encoded" information (a kind of "space travel" that could happen at the speed of light), leading to the assembly of artifacts or the "seeding" of living organisms in propitious locations. This would be as epochal an evolutionary transition as that which led to land-based life on Earth. But it could still be the beginning of cosmic evolution. The ultra-long range future A hackneyed anecdote among astronomy lecturers describes a worried questioner asking: "how long did you say it would be before the sun burnt the earth to a crisp?" On receiving the answer, "five billion years," the questioner responds with relief: "thank God for that, I thought you said five million." What happens in far future eons may seem blazingly irrelevant to the practicalities of our lives. But I don't think the cosmic context is entirely irrelevant to the way we perceive our Earth and its future. An iconic image from the 1960s was the first photograph from space, showing our home planet of land, oceans and clouds. The beauty and vulnerability of "spaceship Earth" contrasts with the stark and sterile moonscape on which the Apollo astronauts left their footprints. This image added no new facts--just a new perspective that many hoped would make us more mindful of the collective ties that bind us to our environment. Likewise, our perspective is changed if we realize the huge expanses of time that lie ahead. Our Sun is less than half way through its life, and our Universe has a future that could be infinite. We are not the culmination of evolution: indeed we are still near the cosmic beginning. Even if life is now unique to Earth it could eventually "take over" the cosmos. There is plenty of time for life to spread through the entire Galaxy, and even beyond. The entire Galaxy, extending for a hundred thousand light-years, could be "greened" in less time than it took for us to evolve from the first primates. We cannot conceive what might happen still further ahead. Intelligently-controlled modifications could lead to faster and more dramatic changes than Darwinian natural selection allows. The future may lie in artifacts created by us and in some way descended from us that develop via their own directed intelligence. Our universe has the potential to harbor a teeming complexity of life far beyond what we can even conceive. In the long term the universe may, in a sense, become alive. But how important is the Earth in this cosmic perspective? This depends on whether life is already pervasive in the universe, or if (as is equally conceivable) we on Earth are unique within the entire Galaxy. We have no idea--the SETI Institute in Mountain View, California is listening for signals that could come from intelligent aliens, or perhaps from intelligent machines that have been created by some long-dead civilization. Perhaps the cosmos is already teeming with life; perhaps, on the other hand, the odds are stacked so heavily against life's emergence that we on earth are unique. Is our earth cosmically important? It would in some ways be disappointing if searches for alien intelligence were doomed to fail. On the other hand, it would boost our cosmic self-esteem: if our tiny Earth were a unique abode of intelligence, we could view it in a less humble perspective than it would merit if the Galaxy already teemed with complex life. If the cosmos is already teeming with life, the Earth's fate would be of "merely" terrestrial significance. Life could "take over" the cosmos whatever happens here. Thomas Wright of Durham expressed this thought 250 years ago: "In this great Celestial Creation, the Catastrophy of a World, such as ours, or even the total Dissolution of a System of Worlds, may possibly be no more to the great Author of Nature, than the most common Accident in Life with us, and in all Probability such final and general Doomsays may be as frequent here, as even Birth, Days or Mortality with us upon this Earth." But suppose Earth is the unique abode of intelligence in the Galaxy. The fate of humanity could then have an importance that is truly cosmic--reverberating through the whole of Thomas Wright's "Celestial Creation": what happens here might conceivably make the difference between a near eternity filled with ever more complex and subtle forms of life and one filled with nothing but base matter. The first aquatic creatures that crawled onto dry land more than 300 million years ago, may have been unprepossessing brutes. But if they had been clobbered, the potential of land-based life would have been destroyed. Likewise even the most misanthropic among us should be mindful of the post-human potentialities that would be foreclosed were humans to be snuffed out. We should fervently hope that we avoid irreversible catastrophe at least until self- sustaining communities had started to establish themselves beyond the Earth. This thought should give us even stronger motives to cherish our Earth, this 'pale blue dot' in the cosmos, and not foreclose life's future--a future that could be even more prolonged than the time span over which simple life has evolved into humans. Perhaps also it offers an extra motive for being interested in the long-term role that humans may have in space. _____________________________________________________________________ EARTH'S GROUNDHOG DAYS CONTINUE THIRTY YEARS LATER By John Carter McKnight From SpaceDaily 19 December 2002 Today marks the thirtieth anniversary of the end of the Apollo program when Apollo 17 returned to Earth in a flawless splash down in the Pacific Ocean. It is also the day we abandoned the universe beyond low Earth orbit and to commemorate the event I propose that we move that quintessential American holiday forward a couple months and declare December 19--Groundhog Day. As in the Bill Murray movie of the same name, our space efforts have been stuck in a loop, endlessly repeating the same events over and over until maybe, finally, we learn something and free ourselves to move on. Thirty years should be enough repetition of tax-financed circling in LEO: let's draw some conclusions and get on with building a space-faring civilization. Get the full story at http://www.spacedaily.com/news/oped-02u.html. _____________________________________________________________________ TELLING ET WE CARE By Douglas Vakoch From Space.com 19 December 2002 To create interstellar messages that have a realistic chance of being understood across interstellar distances, we need to identify some information shared by humans and extraterrestrials. We need to identify a foundation for establishing a universal language that will let us bridge the gap between our world and theirs, all without the convenience of face-to-face contact. ...While it would be interesting to know that other civilizations possess sophisticated mathematics and that they understand some of the same chemical and physical processes of our shared universe that we do, if that were all we learned, wouldn't it be a bit anticlimactic? Even more interesting would be the discovery of insights unique to other civilizations. How then might we move beyond a discussion of physics and chemistry to discuss something about culture and individual behavior-on their world or ours? Get the full story at http://www.space.com/searchforlife/seti_altruism_vakoch_021219.html. _____________________________________________________________________ ROSTERS ANNOUNCED FOR MDRS CREWS 10, 11, AND 12 Mars Society release 19 December 2002 The Mars Society today publicly announced the crew rosters for Mars Desert Research Station Crews 10, 11, and 12. These rosters are given below. Crew 10: December 21 - January 5 Judd Reed will be the crew commander. He is computer scientist with a design for a new kind of computerized local navigation system based on topography. Peter Detterline is an astronomer, and director of the Boyertown Planetarium in Boyertown, PA. He will be leading the development of the new astronomical observatory at the MDRS Heather Smith is an exobiologist who is working with scientists at NASA Ames. She will be crew biologist. She is also an EMT. Jennifer Glidewell is a student of geology at the University of Houston. She will be crew geologist Gavin Whittle is a Marine Corp veteran who is now a midshipman at the U.S. Naval Academy. He will be crew engineer. Debi-Lee Wilkinson is an aerospace engineer who has done work across a range of areas, including closed loop life support. She will be the lead on the Greenhab water recycling experiment. In addition to the above, Crew 10 will also include in its roster for part of its duration William Green and Chad Rowland, both of the University of Michigan. Green and Rowland are both leading embers of the Michigan Mars Rover project, which has developed an analog pressurized rover exploration vehicle. They will bring the Michigan Mars Rover to the MDRS and train the crew in its use. Their tour of duty will run December 27 - January 6, allowing them to train and take part in Crew 11 as well. Crew 11: January 4-19 Roger Thompson will be the crew commander. He is a meteorologist and engineer from Colorado. Tiffany Vora is a PhD student in molecular biology at Princeton, and a veteran of MDRS rotation 3. She will be lead crew biologist. Katie Harris is a biology student at the University of North Carolina. She is a Canadian from Georgetown Ontario. In 1999, while still in high school, she won the Mars society's Hakluyt prize for the best letter written by a student to world leaders advocating a humans to Mars program. She will be serving as a member of the biology team. Shahar Lazar is an Israeli geologist. He will be serving as crew geologist. Allan Morrison is Canadian environmental engineer. He will have the lead responsibility for the greenhab. A very handy guy, he will also serve as crew flight mechanic more generally. Gernot Groemer is an Austrian astronomer and EMT. He will have the lead for running the MDRS observatory, and also serve as crew EMT. Crew 12: January 18 - February 2 Dr. Tony Mucatello will be the crew commander. He is a chemist involved in Mars in situ resource utilization R&D at Pioneer Astronautics. He was also the commander of the 2nd half of MDRS rotation 1 and is the director of Mars Society Mission Support. Dr. Kevin Shoemaker is an electronics and RF engineer from Colorado. He will be serving in the capacity of electronics wiz. Dr. Susan Francis is a geologist and writer currently working at Cambridge in the UK. Oleg Obramov is a planetary scientist from the U of Arizona. He and Susan together will comprise the geology team. Tara Ruttley is a biologist and biomedical engineer at NASA JSC. She is also an EMT. She will be crew biologist, leading the work in field microbiology and in monitoring the functioning of the greenhab water recycling system. She will also serve as crew EMT. Dr. Arno Wielders is a physicist, and president of the Mars Society Netherlands. In addition to supporting all other areas, he will have the lead responsibility for the astronomical observatory at the MDRS. For further information about the Mars Society, visit out web site at www.marssociety.org or contact info@marssociety.org. _____________________________________________________________________ DIAMONDS FOUND TO CONTAIN EVIDENCE OF ANCIENT ATMOSPHERE University of California, San Diego release http://ucsdnews.ucsd.edu/newsrel/science/mcdiamond.htm 19 December 2002 A team of scientists from the University of Maryland and the University of California campuses at San Diego and Los Angeles has discovered that diamonds can be natural time capsules, preserving information about the cycling of sulfur between the Earth's crust, atmosphere, and mantle some three billion years ago. "These findings show diamonds are much more than jewels," said Mark Thiemens, Dean of the Division of Physical Sciences at UCSD and a co- author of the paper. "They are valuable crystals through which geologists and atmospheric chemists can peer to gain insights into the earth's atmosphere as it existed billions of years ago. The fact that you can make measurements of the atmosphere some two to three billion years ago by looking at the composition of sulfur in diamonds is remarkable and especially valuable for those studying the ancient earth's geological processes." The findings are the latest demonstration that some of earth's oldest rocks contain "isotopic signatures"-distinctive forms of elements like sulfur and oxygen that can reveal information about many previously unknowable aspects of earth's early history, such as the evolution of the atmosphere and the origin of early sulfur- metabolizing life. In the December 20 issue of Science, Thiemens, Maryland geologist James Farquhar and colleagues at UCLA report that diamonds from a region in Botswana, Africa contain a distinctive ratio of three forms, or isotopes, of sulfur. The signature presence of this ratio indicates that the sulfur in these diamonds went through a nearly complete geochemical cycle. According to the researchers, that cycle began when sulfur dioxide and hydrogen sulfide gases were spewed into the atmosphere by an ancient volcano. The sulfur-bearing gases in the early atmosphere reacted with ultraviolet light to produce the signature sulfur isotope in aerosols that floated back to the earth's surface and were incorporated in ancient sedimentary rocks as sulfides. The tectonic plate containing this sedimentary rock eventually was carried downward beneath another plate into the underlying mantle through a process scientists call subduction. When diamonds formed in the mantle, the sulfides with their signature sulfur isotopes were trapped inside. These processes all happened about three billion years ago during the Archean period. Later, the diamonds containing the signature isotope were brought to the earth's surface by volcanic processes and eventually mined. "These findings have the potential to vastly increase our knowledge of earth's early history," said Farquhar an assistant professor at Maryland's Earth Systems Science Interdisciplinary Center and the department of geology. "This study conclusively demonstrates that distinctive isotopic signatures created in the earth's early atmosphere can not only be found in ancient rocks from the earth's surface, but that this signature can be transferred deep into the Earth's mantle. These isotopic signatures are nearly perfect tracers for the cycling of these elements between the earth's atmosphere, its surface, and its mantle." According to Bos Wing, one of Farquhar's post-doctoral researchers and a co-author of the study, the presence of atmospheric sulfur in the mantle my cause scientists to revise their views about the nature of early earth's sulfur reservoirs. "We now think there is a missing reservoir for sulfur that once cycled through the atmosphere of ancient earth. Further research might reveal that this missing reservoir resides deep in the earth's mantle. Such a future finding could, in turn, provide important insights into large-scale geophysical processes that have helped shape the evolution of earth," Wing said. Sulfur commonly exists as a combination of several forms (isotopes) of the element. A couple of years ago, Farquhar discovered that the photochemistry of earth's early atmosphere produced sulfur that had a slightly different ratio for three of these isotopes 32. Finding sulfur with this ratio of isotopes in diamond or other ancient rocks thus indicates that the sulfur was once in the atmosphere of the ancient earth. For the current study, bits of sulfide found in 12 diamonds from were analyzed at the W. M. Keck Foundation Center for Isotope Geochemistry at UCLA using an ion microprobe. This device shoots highly focused beams of cesium ions at polished sulfide bits no bigger than the thickness of a human hair that have been removed from the diamonds. The ion beam punches a tiny hole into sulfide, vaporizing a minute amount (less than a billionth of a gram). The probe device then performs mass analysis of the vaporized material to see if the signature isotopic ratio is present. "Our instrument, which is about 10 years old, was the first of a new generation of large-scale ion microprobes," said Kevin McKeegan, a professor in the UCLA department of Earth & Space Sciences and director of the center. "A recent upgrade of the device allows us to collect and analyze at once isotopes from multiple ion beams. This ability is essential for this study because it allows us to determine the sulfur isotope ratios with very high precision and accuracy." Two years ago, Thiemens and Farquhar, then a postdoctoral researcher working in Thiemens' UCSD laboratory, published a paper in Science that applied different techniques to identify this sulfur signature in the earth's earliest-known rocks. They revealed, for the first time, a record of chemistry from the earth's early atmosphere that was recorded by sulfur in the rocks. This gave scientists new insights into the evolution of oxygen, ozone, and ultraviolet light in the planet's early atmosphere--three changes that coincided with the early evolution and expansion of terrestrial life. "Because the fossil record is so spotty, the period from the earliest-known rocks, at 3.9 billion years ago, to 2.2 billion years ago has not allowed us to pinpoint when the atmosphere changed to support terrestrial life," said Thiemens, a professor of chemistry at UCSD. "This method provides a way, by examining the isotope chemistry of rocks, to track the record of oxygen in the early atmosphere and, more importantly, of ozone, which blocked the harmful ultraviolet radiation and paved the way for the expansion of terrestrial life." Until the team's discovery of the presence of signature isotopes in diamonds and other ancient rocks, ice cores were scientists' only window on the earth's atmospheric past. However, isotopic signatures from gases trapped in polar ice provide information about atmospheric constituents and conditions for the only about the past 200,000 years. Now, scientists around the world are using these sulfur isotopic signatures to look billions of years into the past to study earth's early atmosphere, the cycling of elements between early earth's crust, atmosphere, and mantle, the origin of early sulfur- metabolizing life, earth's earliest ice ages, the chemical layering of early oceans and early plate tectonic-like processes. The new technique can also be used to study other worlds. In a paper published two years ago in Nature, Farquhar and Thiemens applied it to martian meteorites and determined that the abundant sulfur on the surface of Mars was due largely to the same sorts of chemical reactions in the Red Planet's atmosphere that occurred on Earth. The current study was financed by the National Science Foundation, NASA's Astrobiology Institute, and the American Chemical Society. Images and graphics available at: http://www.urhome.umd.edu/newsdesk/scitech/release.cfm?ArticleID=45 Contacts: James Farquhar University of Maryland Phone: 301-405-4332 Mark Thiemens UCSD Phone: 858-534-6882 Lee Tune (media) University of Maryland Phone: 301-405-4679 Kim McDonald UCSD Phone: 858-534-7572 UCSD news on the web at http://ucsdnews.ucsd.edu _____________________________________________________________________ CHALLENGING YEAR AHEAD FOR SPACE STATION NASA release 02-256 20 December 2002 The coming year will be the most challenging ever for construction of the International Space Station. Already more than two-thirds of the way through the assembly of its core structure, international crews face a full and busy construction schedule. 2003 will be about power for the Station. Electricity-generating systems will almost triple in capacity during the next 12 months. The Station crew faces a unique challenge, while almost continuously rewiring their orbiting home and laboratory, the electrical work must be done with virtually all-household appliances and computers continuously running without interruption. "The year ahead will be the most complex so far in the history of the International Space Station and its construction in orbit," NASA Station Program Manager Bill Gerstenmaier said. "The Station literally becomes a new spacecraft with each assembly mission, and that will be true next year with dramatic changes in the operations of its cooling and power systems as well as in its appearance," he said. During 2003 three new research facilities will be delivered to the U.S. Destiny Laboratory, bringing the total number of research racks on orbit to 10. Approximately 30 experiments are planned on board the Station in 2003. Crewmembers will conduct biology, physics, chemistry, ecology, medicine, and manufacturing experiments and also study long-term effects of space flight on humans. In addition, the continuous detailed measurement of the acceleration environment of the Station will be extended to rigorously characterize background levels that could affect research data. 2003 is planned to be the final full year of assembly of the Station's core structure, with orbital assembly of the complex scheduled to be well into the home stretch as the year draws to a close. Five NASA Space Shuttle flights are scheduled to launch more than 80,000 pounds of components, supplies and experiments to the Station. The Shuttle missions will launch four new sections of the Station's backbone, or truss, to extend its length from the present 134 feet to 310 feet by the end of 2003. The new truss segments will include two new huge sets of solar array wings for the complex, totaling almost 6,300 square feet of surface area containing more than 65,000 individual solar power cells. The new truss segments include giant rotary joints to allow the tips of the Station "backbone" to continuously move, as the massive panels track the sun. The increased power will allow scientific experiments to expand aboard the complex in the years to come, far surpassing any previous research capability in space. "Today's station, after four years of orbital assembly, is unprecedented and spectacular," Gerstenmaier said. "But the complex in orbit today pales in comparison to what it is planned to become by early 2004--a research facility with unmatched capabilities," he said. Plans call for astronauts to conduct a world record 24 spacewalks next year for Station assembly; 18 of those while the Shuttle is docked to the Station, and six while the Station is flying solo. 2003 will be the third consecutive year to set a single-year record for the number of spacewalks. The installation of the new truss segments and unfurling of the arrays also will require unprecedented robotic operations. Those operations will use both the Shuttle and Station arms. The operations will rely heavily on the capabilities of the Station's space railway to move the Station's robotic arm along the truss to position new components. Three Expedition crews will live aboard the station during 2003, including the current Expedition Six crew of Commander Ken Bowersox, NASA Station Science Officer Don Pettit and Flight Engineer Nikolai Budarin. They will ring in the New Year in orbit. Another 31 people, representing at least five nationalities, are set to visit the Station during 2003 aboard the Shuttle and aboard Soyuz spacecraft taxi missions. Those visitors include Educator Astronaut Barbara Morgan, whose inspirational mission in late 2003 will carry students to the heights of orbit. As NASA looks toward an exciting 2003, a tremendously successful year of Station assembly is closing. Four Shuttle missions traveled to the station in 2002, delivering almost 90,000 pounds of new components. The deliveries included three new segments of the Station's truss backbone. The segments stretch 134 feet across the orbiting outpost and incorporate station "air conditioning," thermal control systems and radiators. The flights also delivered key components of the first "space railroad," a railcar that travels up and down a railway on the truss carrying a Canadian mobile base for the robotic arm. Also installed were two astronaut "handcars" to ease the transport of spacewalkers and their gear up and down the railway. Astronauts conducted a record 22 spacewalks during 2002. The final segment of the Station's backbone is scheduled for launch in January 2004. It will boost the completed length of the truss to 354 feet. The Station's mass will approach a half-million pounds. Contacts: Kyle Herring NASA Headquarters, Washington, DC Phone: 202-358-1874 James Hartsfield Johnson Space Center, Houston, TX Phone: 281/483-5111 _____________________________________________________________________ MARS DESERT RESEARCH STATION CREW NINE SUMMARY By the members of MDRS Crew 9 8-22 December 2002 This week marks the close of Crew 9 and the third rotation of the Mars Desert Research Station for the 2002 season. Crew 9 consisted Michael Gough, Nicole West, and Eric Kutner, from the United States, Ella Carlsson, from Sweden, Duncan Galloway, from Australia, and Adrian Hon, from the United Kingdom. The commander of Crew 9 was biologist Michael Gough who attempted two experiments at the MDRS. First, a psychology experiment involving the use of a collection of different colored clips. Colors were given a rank as a relative gauge of the crewmember's individual stress level or mood. Each member was then allowed to change a colored clip as often as he felt his stress level or mood changed during the progress of the simulation. By doing this, each crewmember could passively communicate his or her individual stress level during the progress of the simulation. Saliva samples were also taken each day and sent back to the University of Washington to examine changing cortisol levels as a reflection of stress levels among the crew. The second experiment was a field study in an attempt to isolate DNA among possible martian life forms. It was assumed that crews landing on the surface would want to know the molecular structure of any possible life forms found on Mars. Lichen growing on or near the edge of rock formations were collected and processed in a series of complicated laboratory procedures. These procedures, simple on Earth, proved to be a challenge at the MDRS isolated station and as a result only the control samples of the experiment revealed the presence of DNA. From Sweden, Ella Carlsson served as Executive Officer and crew engineer during our rotation. "The past two weeks has been a fantastic adventure and I feel so lucky that I was given this opportunity to be a crewmember on the MDRS. Ella enjoyed the opportunity to solve problems that continually arose at the Hab. "It is a lot of fun to be creative and try to solve the problems as they appear. This is an excellent example of why we must go to Mars. There is no machine that can be as creative as a human being!" Adrian Hon was the other crew biologist and collected input from the crew concerning the dietary need of a functioning crew. Adrian was also our Health and Safety Officer, communication expert and computer wizard on the mission. "Probably the most important messages that will stay with me from the two weeks I have spent at the MDRS is the realization of exactly how difficult it will be to conduct research and field activities on Mars and that communication with Mission Support and proper documentation is genuinely vital to the smooth operation of any mission." Adrian produced a revived MDRS Operations Manual, and Crew Change-over manual. The Crew 9 geologist was Nikki West, her primary duty and interest was in the quality of the water in the GreenHab. She discovered that coliform bacteria were a problem and found flaws in the previous test results stemming from improper sampling technique and incorrect lighting procedures while using the microscope. Nikki enjoyed exploring this desert region. "If Mars is a fraction as beautiful as this Earth, I hope to see it." MIT Astrophysicist and Australian, Duncan Galloway, was the scientist in charge of the Greenhab Living Machine. Working with the engineer, Duncan attempted to configure the Greenhab to optimize the health of the plants. Duncan found flaws in the system that prevented the plants from thriving and performed tests that concluded that it was ultimately the quality of the water that need to be improved. "Overall I have become convinced that good science can be done here, but only with a lot of preparation, careful planning, and probably more strategic, long-term approach by the Mars Society." In addition to Crew 9's science and engineering expertise, we were fortunate to have an artist in our crew to document our adventure. Filmmaker Eric Kutner was filming our activities, recording our thoughts, and, obtaining personal interviews from each of us about our experience. "The most rewarding element of my rotation has been getting to know my crewmates. We spent virtually every waking moment together and now I feel like I've known them for months. As crew documentarian, I tried to capture events while not making a nuisance of myself. I hope that I succeeded in doing this and that I am able to make an excellent film from my footage." During our rotation, problems arose concerning the proper function of the Living Machine as a waste recycling system. Fresh plants were received at the start our rotation and were place in the Greenhab, Living Machine. Some of these plants ultimately died due to poor water quality. Control plants under the same lighting conditions and temperature conditions did well in fresh water. A high intensity lamp was installed into the Greenhab to provide the plant with sufficient light during the short winter days. Also problematic was a temperamental sewage system that constantly blocked. Crew 9 spent a significant amount of time attempting to clear blockages from the system. It was determined that coliform bacteria was present in the Living Machine and Crew 9 took steps to improve the quality of the water. Construction of the MDRS astronomy site, telescope foundation, and telescope housing facility, was begun. Crew 9 assisted Mars Society personnel in the construction of the site. Twelve EVA's were performed. Crew 9 explored the upper plateau area to the west of the Hab and attempted to find a route to Factory Butte. The cliffs at Skyline Rim were successfully explored but a direct route to the massive butte to our west was not found. Geology samples were taken from various locations and sites of possible dinosaur bones were located. EVA was a rich and rewarding experience that every member of the crew enjoyed. Not only did it provide us with access to this beautiful region it also gave us valuable experience performing the necessary steps to initiate an egress from a spacecraft. Even though Crew 9 members had not met prior to the beginning of our rotation, we were able to achieve a level of camaraderie almost from the first few hours we met. As the commander of Crew 9 it was my honor and privilege to be selected to represent this outstanding collection of scientists, engineers, and artists. To find out more about the Mars society, visit our web site at www.marssociety.org or contact info@marssociety.org. _____________________________________________________________________ EUROPA: CHEWY OR CRUNCHY? By Lee Siegel From Astrobiology Magazine 23 December 2002 For geophysicist William B. Moore, the question of whether life exists on Jupiter's moon Europa boils down to whether the moon's center is chewy or crunchy. Many scientists doubt life can exist on Europa's surface because of extreme cold, lack of liquid water, the tenuous atmosphere and intense bombardment from Jupiter's radiation belts. Moore believes distant Europa receives too little sunlight to provide the energy needed for organisms to thrive on its apparently icy surface. Others argue the chemical energy needed for life is created when charged particles bombard Europa to produce oxidants. Nevertheless, says Moore, Europa's surface "would be a very difficult place to make a living." If Europan life exists at all it would most likely be found within an ocean beneath the ice, where organisms could get energy and mineral nutrients from eruptions of seafloor volcanoes, says Moore, a postdoctoral researcher at the University of California, Los Angeles, and member of the NASA Astrobiology Institute. If Europa has a hot, "chewy" center--that is, relatively low viscosity--it would be similar to the soft, partly molten interior of Jupiter's moon Io, which is the most spectacularly volcanic body in the solar system. So Moore says a "chewy" Europa likely would have seafloor volcanoes producing conditions conducive to life--just like the undersea volcanoes and hydrothermal vents along Earth's mid-ocean ridges. If Europa has a cold, "crunchy" center--with high viscosity--it would be rigid and volcanically dead like Earth's moon. Undersea volcanoes and life would be improbable, says Moore. Moore argues Europa must either be chewy or crunchy--and nothing in between--because of the way it orbits Jupiter and interacts with Io and Ganymede, two of the three other major moons discovered independently in 1610 by astronomers Galileo Galilei and Simon Marius. Radioactive decay is one potential source of internal heat for planetary and lunar bodies. But, Moore says, it is inadequate to cause volcanism in a body as small as Europa, which at 3,138 kilometers (1,950 miles) in diameter is a bit smaller than Earth's moon. Still, internal melting and volcanism could be triggered by tidal forces, namely, the gravitational pull from Jupiter, Io and Ganymede. So Moore plans to conduct computer simulations of the rates at which Europa and the other Galilean moons orbit Jupiter to find out if the orbits are consistent with a chewy or crunchy center for Europa--and thus with possible life or no life. "I anticipate in the next three to six months we will have some pretty solid results," said Moore, who is working on the project with UCLA postdoctoral researcher Ferenc Varadi and graduate student Susanna Musotto. If the simulation uses a crunchy Europa, and the result looks like the existing orbits of Jupiter's moons, that would tend to confirm Europa indeed is crunchy or volcanically dead, Moore says. The same would be true if a simulation with a chewy Europa resulted in orbits radically different than seen today, he added. If, however, a computer simulation with a chewy Europa results in orbits that resemble reality, "then we just don't know" what it means, Moore says. So he says his experiment is a negative test-- able to identify a Europa that is crunchy and thus volcanically dead, but not capable of proving it is chewy and volcanically active. Indeed, if simulations using either a chewy or crunchy Europa both resulted in orbits that looked like reality, it would raise questions about the extent to which the orbits were influenced by Europa's internal viscosity. "In principle, what he [Moore] is saying makes sense," says Hal Levison, staff scientist at the Southwest Research Institute in Boulder, CO. Whether the viscosity of Europa's center "has a big enough effect to be measurable or not remains to be seen. But it's a great experiment to be doing." Moore doubts there is life on Europa, but "I don't have good science to back myself on that yet. That's what I'm trying to do." Along with Mars and Saturn's moon Titan, Europa long has been considered one of the most likely places for life in our solar system, largely because of the ocean believed to exist under its icy outer shell. But Moore contends the presence of seafloor volcanism as a source of energy and nutrients is far more important than water in determining if Europa might harbor life. Europa, Io and Ganymede are influenced by tidal forces because their orbits around Jupiter are slightly oval-shaped or "eccentric" instead of perfectly circular. Those moons orbit Jupiter in what is called a Laplace resonance, which means "every time Ganymede goes around once, Europa goes around twice and Io goes around four times," Moore says. "This means they keep meeting up at the same place over and over again." Tidal forces from that resonance tend to "pump" the orbits of Ganymede, Europa and Io so they become more oval-shaped. It is "just like if you push a kid on swing at the high point of his swing," Moore says. "He keeps going higher and higher because you are pushing at the time you can speed him up." The moons tend to return to more circular orbits by wobbling to dissipate tidal energy internally, which produces heat. Tides occur not only in oceans, but also in solid rock--even on Earth. Moore says other researchers have estimated that Europa gets only seven percent of the tidal "squishing and squeezing" that Io receives because Europa is farther from Jupiter. How well that tidal energy heats up Europa's interior depends on the viscosity of material within Europa. "The chewier [less viscous] something is, the more efficiently this squishing and squeezing turn into heat," Moore says. In contrast, Earth's moon "is getting squished and squeezed by tides due to the Earth, but it is not volcanically active," he adds. "It is not dissipating tidal energy [as heat] because it's a cold, crunchy [viscous] object." Although tidal forces on the moon are smaller than tidal forces on Europa, Moore says the amount of force exerted on each moon is not the critical factor. Rather, a chewy object like Io will warm up due to tidal "squishing and squeezing" while a crunchy object like the moon will not, he says. Previous pencil-and-paper mathematical calculations of the orbits of Jupiter's moons assumed a solid or crunchy interior for Europa--with little heating due to tidal forces. Moore says his computer simulations will try to determine if those assumptions are valid. "Hopefully, the results can either say definitively that Europa is crunchy, or they say nothing," he says. Moore says his computer simulation will be more complex, with fewer assumptions, than previous mathematical calculations. For example, earlier calculations assumed lunar orbits were perfectly elliptical; his computer simulations will include minor "bulges" in those ellipses induced by the fact gravity from more than two objects is involved. But "the major difference will be that I will try out this alternative case--a chewy Europa--that simply was skipped before," he adds. A crunchy Europa should produce orbits that resemble reality and earlier calculations; a chewy Europa should be closer to circular to stay in resonance with Io and Ganymede, and thus would not resemble reality. Moore's effort to use computer modeling to determine whether Europa is crunchy and dead or chewy and perhaps volcanically active "is subject to a lot of uncertainty" and unlikely to give a definitive answer, says planetary scientist Paul Geissler of the University of Arizona's Lunar and Planetary Laboratory. One uncertainty is how any silicate rock beneath Europa's presumed ocean behaves when squeezed by tides. Another is the possibility that there are changes over time in how Io, Europa and Ganymede "push" on each other--changes that could make Europa's rocky interior either hot or cool, Geissler adds. "Computer modeling is the best we can do right now," Geissler says. "But in the long run, the answer is going to come from further observation." What's next? NASA hopes to launch a Europa Orbiter mission in 2008, with the primary goal of determining if there indeed is a global, subsurface ocean. But as far as whether Europa is chewy, volcanic and conducive to life, "it won't be able to determine much," Moore says. "The Europa Orbiter is stuck on the outside looking in. The ice blocks observation of the rocky interior, and the ocean prevents you from sensing much about the interior" because it allows the rocky interior and icy shell to move independently under tidal forces. Geissler, however, says the Europa Orbiter's radar sounding device should be able to detect a reflected radar echo from an ice-ocean boundary if the ice is only a few miles thick. If Europa is volcanically dead, the ice should be tens of miles thick. But Geissler believes a thin shell of ice would be evidence of heat rising from a volcanically active seafloor, preventing formation of thicker ice. Additional information on this article is available at http://www.astrobio.net/news/article336.html. _____________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dt