MARSBUGS: The Electronic Astrobiology Newsletter Volume 8, Number 49, 21 December 2001. Editors: Dr. David J. Thomas, Science Division, Lyon College, Batesville, AR 72503-2317, USA. dthomas@lyon.edu Dr. Julian A. Hiscox, School of Animal and Microbial Sciences, University of Reading, Reading, RG6 6AJ, United Kingdom. J.A.Hiscox@reading.ac.uk Marsbugs is published on a weekly to 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 copyright our mailing list, our readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing list. The editors do not condone "spamming" of our subscribers. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editors. E-mail subscriptions are free, and may be obtained by contacting either of the editors. Article contributions are welcome, and should be submitted to either of the two editors. Contributions should include a short biographical statement about the author(s) along with the author(s)' correspondence address. Subscribers are advised to make appropriate inquiries before joining societies, ordering goods etc. Back issues and Adobe Acrobat PDF files suitable for printing may be obtained from the official Marsbugs web page at http://welcome.to/marsbugs. The purpose of this newsletter is to provide a channel of information for scientists, educators and other persons interested in exobiology and related fields. This newsletter is not intended to replace peer- reviewed journals, but to supplement them. We, the editors, envision Marsbugs as a medium in which people can informally present ideas for investigation, questions about exobiology, and announcements of upcoming events. Astrobiology is still a relatively young field, and new ideas may come from the most unexpected places. Subjects may include, but are not limited to: exobiology and astrobiology (life on other planets), the search for extraterrestrial intelligence (SETI), ecopoeisis and terraformation, Earth from space, the biology of terrestrial extreme environments, planetary biology, primordial evolution, space physiology, biological life support systems, and human habitation of space and other planets. _____________________________________________________________________ CONTENTS 1) IF SANTA WERE A MARTIAN From the Jet Propulsion Laboratory 2) NASA CATARACT STUDY MAY HELP ASTRONAUTS SEE CLEARLY NASA release 01-245 3) NASA AND AMERICAN LIBRARY ASSOCIATION BRING SPACE TO THE BOOKSHELF NASA release 01-247 4) THE FIRST SULFUR EATERS By Leslie Mullen 5) NASA SCIENTIST FINDS SOME METEORITES NOT SUGAR-FREE NASA release 01-253 6) ALL-TERRAIN ROVERS MAY SCALE MARS' CLIFFS NASA release 01-251 7) DECODING E.T.: IN SEARCH OF A COSMIC ROSETTA STONE By Doug Vakoch 8) MISSION ACCOMPLISHED From ESA News 9) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 10) THIS WEEK ON GALILEO NASA/JPL release 11) MARS GLOBAL SURVEYOR STATUS REPORT NASA/JPL release _____________________________________________________________________ IF SANTA WERE A MARTIAN From the Jet Propulsion Laboratory 17 December 2001 If Santa Claus were a Martian, he'd be in for one bumpy ride. That's the assessment of navigators and engineers controlling the flight of NASA's 2001 Mars Odyssey spacecraft as it currently flies four times daily above the north polar region of Mars. "If he were flying above the North Pole of Mars, my advice to Santa would be 'Hang tight onto your reins,'" said Odyssey navigator John C. Smith. "You could be in for a rough ride." In the midst of aerobraking maneuvers that are lowering the spacecraft's orbit around Mars, the Odyssey team has discovered an unexpected and somewhat unpredictable north polar atmospheric disturbance that is making the job a real adventure, Smith said. Fasten your seatbelt Called the "polar vortex," this cold, low density region forms each winter in the atmosphere above the planet's latitudes 70 degrees north and higher. The region between the polar vortex and the rest of the atmosphere is called the "transition zone." In this zone, strong winds swirl around the pole and the zone itself weaves in and out in the typical fashion of a terrestrial jet stream. It is an area where sometimes surprising shifts in the atmospheric density can become fasten-your-seatbelt territory for Odyssey. "When we're in the transition zone, the atmosphere is very unpredictable," said Smith. Scientists and engineers have long known that Mars' atmosphere "breathes"--moving up and down, growing or decreasing in density with the effects of dust storms, winds and other influences. But scientists and navigators are just getting to know up-close the peripatetic polar vortex and its shifty transition zone. Aerobraking: it's a drag Launched April 7, the Odyssey spacecraft entered orbit around Mars October 24. Over a three-month period that ends in January, Odyssey's orbit is being lowered and circularized through aerobraking, carefully designed passes through the top of the atmosphere that slow the spacecraft through the effects of atmospheric drag. Mars weather reports come from Odyssey's older sibling, Mars Global Surveyor, which has been in orbit around Mars for four years. So where, exactly, is the polar vortex? "That's a good question," said Smith. "We ask that every day. "We have daily meetings to decide--'do we need to lower ourselves farther down to get more drag out of the atmosphere, or do we need to raise ourselves higher in the atmosphere to keep from getting overheated?'" said Smith. Talk about the weather Every day at 11:30 AM Pacific time, scientists from the Surveyor and Odyssey teams hold a telephone conference to talk about the weather-- on Mars--and how it might impact the next 24 hours' worth of Odyssey's aerobraking maneuvers. They depend upon Mars Global Surveyor and Odyssey data to assess Martian atmospheric behavior, with a special watch for the large Martian dust storms which can increase in a big way the air density at aerobraking altitudes of about 100 kilometers, or about 60 miles. Then at 1:00 PM each day, this atmospheric advisory group joins the project navigation and spacecraft teams to work out the next aerobraking maneuvers. In planning each aerobraking pass through the atmosphere, the team walks a fine line between getting the desired amount of drag out of the pass without subjecting the spacecraft to overheating from unforeseen pockets of dense air. "Basically, we use the Mars weather report on what the atmosphere is going to be like and make sure we fly at an altitude to keep the spacecraft safe while getting sufficient drag," said Smith. Try to go with the flow "We monitor it closely and try to go with the flow on the variability," Smith said. "We have to take into account how much the prediction could be wrong and use that as margin. When the atmosphere is as highly variable as it is in this region, it means we have to be a little more cautious." With concerns about atmospheric changes that any pilot could relate to, "it might be said this is as close as we've ever come to flying on another planet," said Dr. Richard Zurek of JPL, who co-chairs the atmospheric advisory group to the project. But, says Smith, "It's a little different from flying. We don't have the option of flying around a disturbance. We have to fly right through it. We can raise our altitude or lower it, but we can't avoid going through that region." More information on this article is available at http://www.jpl.nasa.gov/solar_system/features/vortex.html. An additional article on this subject is available at http://www.spacedaily.com/news/mars-odyssey-01s.html. _____________________________________________________________________ NASA CATARACT STUDY MAY HELP ASTRONAUTS SEE CLEARLY NASA release 01-245 17 December 2001 A recent NASA study that showed astronauts who have spent more time in space are more likely to have cataracts will pave the way for developing new techniques to protect space travelers. A research team led by Dr. Francis A. Cucinotta of the Radiation Health Office at NASA's Johnson Space Center in Houston studied 48 cataract cases in current and retired astronauts. The team discovered a significant increase in cataracts for those who had higher "lens doses" from space radiation. They also found those exposed to higher amounts of space radiation got cataracts at a younger age than astronauts who received lower dosages. The team linked the increased incidence of cataracts to the presence of heavy-ion radiation in space--outside Earth's protective atmosphere. The study suggests that long-duration space station crewmembers are at higher risk for cataracts than space shuttle astronauts. In the past, space shuttle crewmembers spent less time in space and often in lower inclinations where Earth's magnetic field offers some protection from radiation. NASA is developing countermeasures to further protect space travelers. These include reducing exposure to ultraviolet (UV) radiation from sunlight, use of selective UV-blocking eyewear, adding shielding on the International Space Station, and conducting research to investigate the effectiveness of anti-oxidants like vitamins C and E and beta-carotene in slowing the progression of age-related and radiation-induced cataracts. Research studies on cataracts and the effectiveness of anti-oxidants will be performed by NASA-funded investigators at Brookhaven National Laboratory in Upton, NY, where particle accelerators can reproduce the high-energy heavy ions that occur in space. NASA already is improving the space station's existing radiation shielding, especially in the living areas like the sleeping quarters and the galley where astronauts spend most of their time. Materials with high hydrogen-content like polyethylene have been shown to reduce radiation. NASA also actively monitors space radiation levels so astronauts can move to the best-shielded locations if radiation levels increase because of solar disturbances. In addition, NASA follows standard radiation-protection practices recommended by the U.S. National Academy of Sciences Space Science Board and the U.S. National Council on Radiation Protection and Measurements to determine acceptable levels of risk for astronauts. To help protect astronauts' health, NASA is improving the astronaut optometric exam to include digital imaging and analysis of the crystalline lens of the eye. This will allow NASA to better understand the different types of cataracts occurring in astronauts and their progression from mild to more severe. This current study was not able to determine whether astronauts as a group are more susceptible to cataracts than other people, since good vision and health are two criteria for astronaut selection. However, NASA is reviewing a proposal to perform a follow-on study that would compare astronauts to a group of people with similar characteristics who have not participated in space missions. Results from this study should be available in three to five years. The results of the study, Space Radiation and Cataracts in Astronauts, by F. A. Cucinotta, F. K. Manuel, J. Jones, G. Iszard, J. Murray, B. Djojonegoro and M. Wear, have been published in the November 2001 issue of the journal Radiation Research. An abstract of the study is available on the Internet at http://spaceresearch.nasa.gov/general_info/pressrel.html [also available at http://apt.allenpress.com/aptonline/?request=get- abstract&issn=0033-7587&volume=156&issue=05&page=0460]. Contact: Dwayne Brown Headquarters, Washington, DC Phone: 202-358-1726 _____________________________________________________________________ NASA AND AMERICAN LIBRARY ASSOCIATION BRING SPACE TO THE BOOKSHELF NASA release 01-247 18 December 2001 NASA and the American Library Association (ALA), Chicago, have launched a three-year program aimed at educating and exposing both children and adults to the wonders of space travel and the benefits of space research. Called "NASA @ your library (TM)," the program is being developed by NASA's Office of Biological and Physical Research, Washington, and ALA's Development Office to raise awareness and interest in math and science, encourage young people to pursue careers in science and increase the visibility of NASA programs and scientific findings. "Libraries can help NASA take the excitement and potential of space research to every person in every community across America. Young Americans across the country will be able to identify new career opportunities, and citizens in every community will glimpse how the same science that will take us beyond the planet could transform every American's future on the planet," said Dr. Kathie L. Olsen, NASA's Associate Administrator of Biological and Physical Research, Headquarters, Washington. NASA and ALA will develop a pilot program to share and promote scientific information on NASA research and demonstrate the expertise of librarians in selecting excellent books. A program-specific Web site and traveling exhibit will be developed, and six library sites will be selected as models. The traveling interactive exhibit will spend a month at libraries across the country and will have four special, electronic, weekly presentations specifically created for different segments of the community. Participating libraries will receive a small incentive grant to implement the program. "Through 'NASA @ your library,' we will send a strong message that both public libraries and NASA have a wealth of information freely available for all citizens," said ALA President John W. Berry. "Libraries bring you a world of resources." NASA and ALA will develop an action kit for distribution to public libraries: a poster, guidelines for expansion of library collections to support the NASA Web site and exhibit, public library activities to encourage more young people to become scientists and program training--both in-person and Web-based--for librarians and others. A national advisory committee will be appointed, and the Association for Library Service to Children, a division of ALA, will manage the grant. NASA's Office of Biological and Physical Research (OBPR) conducts peer-reviewed, interdisciplinary, fundamental and applied research to address the opportunities and challenges to NASA that are provided by the space environment and the human exploration of space. The ALA, founded in 1876, is the oldest and largest library association in the world. More information on NASA's Office of Biological and Physical Research is available at http://spaceresearch.nasa.gov. Contact: Dwayne C. Brown NASA Headquarters, Washington, DC Phone: 202-358-1726 _____________________________________________________________________ THE FIRST SULFUR EATERS By Leslie Mullen From the NASA Astrobiology Institute 18 December 2001 Some of the oldest rocks on Earth can be found amid the spiky grass and orange-red dust of Northwestern Australia. While most rocks have been altered over time through geological processes, the Australian rocks have remained relatively unchanged since their inception 3.47 billion years ago. Earlier this year, Yanan Shen of Harvard University, Donald Canfield of Odense University in Denmark, and Roger Buick of the University of Washington announced they found evidence for life in the ancient Australian rocks. The scientists found indications of a type of bacteria that consume sulfate and produce sulfide as a waste product. Sulfate-reducing bacteria had been known to exist at least 2.72 billion years ago, but this finding pushes the date of their existence back an additional 750 million years. This would mean that sulfate-reducing bacteria are one of the oldest known life forms on the planet. The scientists don't actually have samples of the ancient bacteria, but they believe they have proof that bacteria had been in action. After measuring the ratio of sulfur isotopes in the rocks, the scientists concluded that the sulfides were produced biologically. Isotopes are different forms of an element that have the same number of protons in the nucleus but different numbers of neutrons. The different isotopes of an element have slightly different chemical and physical properties. For instance, the most common form of sulfur is sulfur-32, which contains 16 protons and 16 neutrons in its nucleus. Sulfur-32 is lighter than sulfur-34--a heavier version of sulfur that has 2 extra neutrons. When sulfate is plentiful, the bacteria prefer to eat the lighter sulfur isotope. When the bacteria eat the lighter sulfate, the sulfide they eliminate as a waste product is also lighter. In the Australian rocks, the sulfide contains 12 parts per thousand (or "per mil") less of the heavier sulfur isotopes than the sulfates. In other words, the waste product had more of the lighter isotopes than what was generally found in the available food supply. This seems to indicate that the lighter isotope sulfur was selectively eaten by bacterial organisms. The scientists say that some natural chemical and geological processes can separate lighter and heavier sulfur isotopes, but it requires temperatures above 300 degrees Celsius (572 degrees Fahrenheit). According to Buick, the rocks have never been heated to that extent. "We can tell their peak temperature from the associated assemblage of metamorphic minerals," says Buick. "In this instance, inorganic isotopic fractionation processes can be easily excluded." Determining the rock's exposure to temperature is important--high temperatures would indicate sulfate reduction by either inorganic processes or by a class of organisms known as the Archaea. Sulfate- reducing Archaea live in many places, including hot environments like volcanic vents under the sea. But if the Australian rocks were only exposed to lower temperatures, this would indicate bacterial sulfate reduction. "Low-temperature sulfate-reducers are, as far as we know, restricted to the bacteria," says Buick. "Hence, if our North Pole sulfate- reducers lived at low temperatures, then they were most likely bacteria." The rocks were found in a hot, arid region of Australia ironically named "North Pole." But the rocks originally formed in shallow pools of water. This watery birth can be seen in the rock's sedimentary materials, in rippled features formed by waves, and in the minerals precipitated by evaporation of seawater. Buick says that these ancient pools of water were cool rather than hot. The rock contains barite, and Buick believes this barite was originally gypsum. Gypsum chemically separates, or "precipitates," from seawater at cooler temperatures. If, however, the barite in the rock has always been barite, this would imply high temperatures. Barite precipitates from hydrothermal fluids at high temperatures. Bruce Runnegar of UCLA believes that the barite in the rocks has always been barite. He says the barite resulted from the rock's exposure to the high temperatures of hydrothermal vents. Runnegar does not believe that bacteria reduced the sulfate in the rocks. Instead, he says the sulfate was reduced through exposure to hydrothermal fluids emitted from underwater volcanic vents. Runnegar says this photochemically-induced sulfate reduction can occur at temperatures ranging between 175 to 250 degrees Celsius (347 to 482 degrees Fahrenheit). "Oxygen isotope data show that the North Pole hydrothermal fluids were heated to at least 150 degrees Celsius," says Runnegar. Runnegar and his team also measured an additional sulfur isotope in the Australian rocks. While Buick and his colleagues measured the ratios of two different isotopes--sulfur-34 and sulfur-32--Runnegar's team measured sulfur-32, sulfur-33, and sulfur-34. Measurements of the sulfur-33 isotope led Runnegar's team to a different conclusion of how the sulfate was reduced. "The extra dimension shows effects that cannot be explained by ordinary chemistry of the kind that bacteria use," says Runnegar. "The only known explanation for the chemistry we observe involves reactions in gases--hence the need to bring atmospheric chemistry into the picture." Runnegar says that less energy is required to separate oxygen atoms from sulfur-32 than sulfur-34. This is why the bacteria preferentially choose to consume sulfur-32, but also why sulfur-32 tends to be reduced more often than sulfur-34 by inorganic processes. "Bacteria just make use of the rules of chemistry," says Runnegar. "Consequently, it can be very difficult to recognize the difference between bacterial sulfate reduction and non-biological thermochemical sulfate reduction from the pyrite [sulfides] preserved in rocks." Runnegar also points out that the sulfides measured by Buick's team came from the insides of large crystals of barium sulfate. He says that this location makes it unlikely that bacteria were involved. Buick acknowledges that hydrothermal processes affected the sulfur minerals after they were deposited. He also says that atmospheric processes could also have affected the sulfur isotopes before deposition. But he argues that these two processes cannot fully explain the features found in the rocks. "Above and beyond these events, there are mineralogical and isotopic features that can't be easily explained by one or the other or both," says Buick. "These features are best interpreted as biological." In addition, Buick says there are other signs of biological activity in the rocks. Immediately overlying the rocks are stromatolites-- layers of sediment that are constructed by microbes in shallow pools of salt water. In modern environments, photosynthetic bacteria form stromatolites. "As there are two types of microbial photosynthesis, one yielding oxygen by the familiar plant process but the other producing sulfate, it could be that the organisms responsible for building the stromatolites were the same bugs that filled the water with sulfate," says Buick. Buick says that the presence of sulfate-reducing bacteria almost 3.5 billion years old suggests that a wide range of microorganisms had already colonized the early Earth, forming a rudimentary food chain. "Sulfate reducers need dead organic matter to be able to reduce the sulfate, so there must have been other organisms that were primary producers," says Buick. "They also need a source of sulfate, which may have come from anoxygenic photosynthesizers." This would constitute "a simple but complete ecosystem--photosynthetic sulfate- producers that fed other bacteria that lived by reducing the sulfate." Because the North Pole rocks are rare in their age and state of preservation, the chance of pushing the record even further back in time is not great. In order to find evidence of sulfate-reducing bacteria in rocks older than 3.5 billion years, Buick says we may have to look beyond Earth. "From spectral analysis, we know that there are lots of sulfate minerals on the surface of Mars," says Buick. "If that planet was warmer, wetter and inhabited more than 3.5 billion years ago, we might be able to find older signs of biological sulfate-reduction there, provided of course that NASA sends a bloody good field geologist with lots of experience of particularly ancient rocks in remote places." What next? Runnegar and his colleagues are still writing up data from their tests on the Australian rocks. They plan to continue their work in Australia and elsewhere. Buick and his colleagues are likewise continuing their studies of the ancient Australian rocks. Yanan Shen is doing further analyses of some new samples that Buick collected at North Pole while on a NASA Astrobiology "Mission to Early Earth" field trip. Donald Canfield, meanwhile, is studying many living sulfate-reducers to test their contention that low-temperature sulfate-reducers are only found in one part of the Tree of Life. "These will hopefully add even more strength to our conclusions," says Buick. "I would dearly love to go to South Africa to look at some almost-as-ancient sulfate minerals there, to see if they have similar physical and chemical features to the North Pole rocks. And to Mars, of course!" More information on this article is available at http://web99.arc.nasa.gov/NAI/stories/sulfur_eaters.cfm. An additional article on this subject is available at http://www.spacedaily.com/news/life-01zw.html. _____________________________________________________________________ NASA SCIENTIST FINDS SOME METEORITES NOT SUGAR-FREE NASA release 01-253 19 December 2001 A discovery by a NASA scientist of sugar and several related organic compounds in two carbonaceous meteorites provides the first evidence that another fundamental building block of life on Earth may have come from outer space. A carbonaceous meteorite contains carbon as one of its important constituents. Previously, researchers had found in meteorites other organic, carbon-based compounds that play major roles in life on Earth, such as amino acids and carboxylic acids, but no sugars. The new research is reported in a paper, "Carbonaceous Meteorites as a Source of Sugar-related Organic Compounds for the Early Earth," by Dr. George Cooper and co-workers at NASA's Ames Research Center, Moffett Field, CA. The work is published in the December 20 issue of Nature. "Finding these compounds greatly adds to our understanding of what organic materials could have been present on Earth before life began," Cooper said. "Sugar chemistry appears to be involved in life as far back as our records go." Recent research using ratios of carbon isotopes have pushed the origin of life on Earth to as far back as 3.8 billion years, he said. An isotope is one of two or more atoms whose nuclei have the same number of protons but different numbers of neutrons. Scientists have long believed meteorites and comets played a role in the origin of life. Raining down on Earth during the heavy bombardment period some 3.8 billion to 4.5 billion years ago, they brought with them the materials that may have been critical for life, such as oxygen, sulfur, hydrogen and nitrogen. Sugars and the closely related compounds discovered by Cooper, collectively called "polyols," are critical to all known life forms. They act as components of the nucleic acids RNA and DNA, constituents of cell membranes and cellular energy sources. "This discovery shows that it's highly likely organic synthesis critical to life has gone on throughout the universe," said Kenneth A. Souza, acting director of astrobiology and space research at Ames. "Then, on Earth, since the other critical elements were in place, life could blossom." Cooper identified a small sugar called "dihydroxyacetone" and several sugar-like substances, known as sugar acids and sugar alcohols, in his study of the Murchison and Murray meteorites. All these are important for life today. He also found one sugar alcohol, glycerol (also known as glycerin), that is used by all contemporary cells to build cell walls. In addition, Cooper discovered preliminary evidence of other compounds that may contain larger sugars critical in cellular metabolism, such as glucose. There still are many unknowns though about the chemistry that existed before the origin of life on Earth, according to Cooper. "What we found could just be interesting space chemistry, and polyols could be just relatives of the compounds that actually gave rise to early life." More research on the meteorites is essential to determine the significance of these findings, he concluded. The Murchison meteorite, found in Australia in 1969, is a famous example of a carbonaceous meteorite that contains numerous amino acids and a variety of other organic compounds that are thought to have played a role in the origin of life. The Murray meteorite, which fell to Earth in 1950, is similar to Murchison in its organic content. Related information about the Cooper paper in Nature can be found at http://www.nature.com. Further information about the Murchison meteorite is available at http://www.touchanotherworld.com/CurrentPhoto/CPcarbonaceous.htm. NASA's Exobiology Program provided funding for the research. Contacts: Donald Savage NASA Headquarters, Washington, DC Phone: 202-358-1547 Kathleen Burton Ames Research Center, Moffett Field, CA Phone: 650-604-1731 Additional articles on this subject are available at: http://www.cnn.com/2001/TECH/space/12/19/rock.sugar/index.html http://www.msnbc.com/news/675239.asp http://science.nasa.gov/headlines/y2001/ast20dec_1.htm?list52260 http://www.spaceref.com/news/viewpr.html?pid=6943 _____________________________________________________________________ ALL-TERRAIN ROVERS MAY SCALE MARS' CLIFFS NASA release 01-251 20 December 2001 NASA researchers are developing new prototype robots that can drive up steep hills and descend almost-vertical cliffs. Working alone or as a team, these autonomous robotic explorers may go where no rover has gone before--the cliffs of Mars. Recent Mars Global Surveyor images suggest water outflows near cliff edges and the possibility of rich water-borne mineral deposits that extend all the way to the cliff base. "We know that some of the most exciting Mars science and history will be in very rough, currently inaccessible terrain. Getting to those hard-to-reach spots--navigating and exploring them--will require altogether new types of robotic vehicles," said Paul Schenker, supervisor of the Mechanical and Robotics Technologies Group at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif., and principal investigator for the All-Terrain Explorer. "These include rover systems that can surmount the hilly base of cliffs, even descend from cliff edges to study cliff stratigraphy. Some years from now, rovers may literally be hanging out on Mars," he said. In a demonstration near JPL, a new mobility system navigates a cliff face. Two "tether-bot" rovers station themselves at the cliff's edge, assisting a third steerable "cliff-bot" as it actively descends and ascends the steep terrain. "They're a true team, tightly coordinating their behaviors, sharing what they sense," Schenker said. "They communicate instantaneously, make mutually informed decisions and jointly implement their control actions. We can think of them as a climber with two good friends. We're not yet at the point of human competence, where one robot can go it all alone." The rovers can cooperate in a number of ways: controlling tension to avoid slackness in the tethers, matching velocity of tether payouts to cliff-bot navigation, maintaining stability to prevent cliff-bot tip-over and hauling actions to initiate the "climber's" uphill driving when the going gets really rough. Over the past year, the JPL researchers also successfully developed and demonstrated a single rover that can traverse sandy natural terrain on slopes of 40 to 50 degrees. Similar to an agile animal, this mechanically reconfigurable All-Terrain Explorer behaviorally adapts its stance and balance, reacting to visually perceived changes in the terrain ahead and motion cues from onboard accelerometers. "These technology advances should enable broader robotic exploration of planetary surfaces, letting rovers truly follow the water, thus giving us a better look at possibilities of past or present life on Mars," Schenker said. "Similarly, there are potentially important terrestrial applications, including urban and rural search-and-rescue operations." Basic research on the All-Terrain Explorer rovers continues, and engineers envision that their work may well be part of a future Mars mission to explore the steep hills and gullies, nooks and crannies of the Red Planet. More information on this work is available at http://prl.jpl.nasa.gov/projects/ate/ate_index.html. NASA's Cross Enterprise Technology Development Program provided funding for this work. The California Institute of Technology in Pasadena manages JPL for NASA. JPL is the lead NASA center for robotic exploration of the solar system. Contacts: Michael Braukus NASA Headquarters, Washington, DC Phone: 202-358-1979 Carolina Martinez Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-9382 _____________________________________________________________________ DECODING E.T.: IN SEARCH OF A COSMIC ROSETTA STONE By Doug Vakoch From Space.com 20 December 2001 ...Some scholars have suggested that we might gain insights into decoding extraterrestrial messages that may be embedded in such a signal. These insights, they suggest, come from the experience that linguists have gained in the course of decoding ancient languages on Earth. As a case in point, the key to decoding ancient Egyptian hieroglyphics was found in a slab called the Rosetta stone, found by Napoleon’s army during a French military campaign in Egypt. This stone contained the same text written in three languages. And because European linguists were extremely familiar with one of the three languages, they could draw links between the three versions and thereby translate the writing system they hadn’t previously been able to crack, Egyptian hieroglyphics. Unfortunately, if we get a message from extraterrestrials, we can’t count on them laying out direct translations between one of their languages and, say, English or Swahili. And that, say anthropologist Ben Finney and historian Jerry Bentley, could limit how much we can learn from extraterrestrials. While we may be able to understand basic mathematics and astronomy, once extraterrestrials begin to describe their cultures, interstellar comprehension may suffer considerably. If fact, Finney and Bentley point out that early successes in decoding scientific parts of an extraterrestrial message might actually stand in the way of understanding more culturally- specific parts of the message. Get the full story at http://www.space.com/searchforlife/seti_rosetta_011220.html. _____________________________________________________________________ MISSION ACCOMPLISHED From ESA News http://www.esa.int 21 December 2001 After three months, the expedition is over: its 14 crew members have at last set foot on planet Earth again. They never really left it of course: they were all volunteers for the long-term bedrest experiment conducted by ESA, CNES and NASDA at the MEDES space clinic near Toulouse. All have just completed a tour of duty of 90 days lying down, their heads tilted 6 degrees below their feet--an unnatural position that goes a long way to simulating some of the effects of weightlessness on the human body. Closely monitored by MEDES clinical staff, the volunteers have been simulating a long-duration space mission. We spoke to two of them. Frank, a young sports enthusiast and Gilbert, a married man with three children, were both glad their ordeal was over--but they would not have missed it for the world. "I would do it again if I had the chance," said Frank. "The hardest part for me was not being able to make real use of my own body but I think it was well worthwhile. Of course, our morale was always high. We were a select group of volunteers and we knew we were contributing to space research and to medical research here on Earth--what has been learned also has applications for patients who have to spend a long time bedridden." Did he ever think of calling the whole thing off, aborting the mission? "Never, the whole thing was a challenge for all of us I think and it was fascinating to see how your body adapted." Gilbert agreed, "at the end of the experiment I felt really free. I am standing again and in a few days I'll be home with my wife and children". What did they think of the experiment? "Well, it was an experiment--and an experience for my wife, too, to spend three, four months with the children on her own. My children are quite proud of their father, I think, and of course they're glad I'll be home for Christmas." "When I saw the advertisement for volunteers, I knew I had to try for it. Simulating a long space mission was a challenge all right. Standing up for the first time a few days ago symbolized landing. It was quite something after three months lying down to rediscover the vertical, the sense of weight." For both Frank and Gilbert the experience has been an enriching one. "You're part of something important," said Gilbert, "and 90 days lying down gives you a chance to discover things about yourself, too." During the three months of the bedrest mission, no visitors--neither family, friends nor curious journalists--were allowed to visit the volunteers. "We were not isolated though, we all had a telephone, an Internet connection and of course the TV," said Frank. Gilbert adds "We had excellent communications with the outside world. Also there were two of us in each room and we often met together. After all we were a group of 14. We discussed things with each other--and with the MEDES psychologists." So what were the toughest moments? "The first few weeks," said Frank. "I suffered from dizziness, vertigo, muscle aches and back pains but the medical support staff were superb." "It's adaptation," said Gilbert. "That first month, when your whole organism is adapting to a new environment was hard, like seasickness if you like, but you're determined to see it through." Now, all the volunteers have to re-adapt. "Dizziness, vertigo and muscle pains again," said Frank, "but the medical team here is really excellent, and we know we can count on their support over the next few months." Both men hope to be back at work in January, although it will be three to six months before their bodies have completely readjusted to normal, vertical living. Over the next two years MEDES will keep a careful eye on them all. A second volunteer team is due to start another 90-day bed mission next Spring. Have Frank and Gilbert any advice for the newcomers? "You have to know what you're letting yourself in for," said Frank. Not surprisingly, Gilbert was in full agreement. "You have to be motivated," he said, "you have to want to do it." Would they do it again? "Of course", said Frank. "Absolutely," agreed Gilbert. Related news * Lying down on the job http://www.esa.int/export/esaHS/ESAO09Z84UC_research_0.html * Three months in bed to simulate effects of long-duration Space Station missions http://www.esa.int/export/esaHS/ESAXG12VMOC_research_0.html Related links * Bed-rest study http://www.spaceflight.esa.int/file.cfm?filename=bedrest * MEDES web site http://www.medes.fr/home.html Images supporting this release are available at http://www.esa.int/export/esaHS/ESASNXZ84UC_index_1.html _____________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.h tml 21 December 2001 Articles about human space exploration and the microgravity environment http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s3.html F. A. Cucinotta, J. Jones, F. K. Manuel, G. Iszard, J. Murrey, B. Djojonegro and M. Wear, 2001. Space radiation and cataracts in astronauts. Radiation Research, 156(5):460-466. Articles about the search for extraterrestrial intelligence (SETI) http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s4.html D. Vakoch, 2001. Decoding E.T.: in search of a cosmic Rosetta stone. Space.com. Articles about evolutionary biology and chemistry http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s5.html R. R. Britt, 2001. Sugar compounds found in space rocks. MSNBC. G. Cooper, N. Kimmich, W. Belisle, J. Sarinana, K. Brabham and L. Garrel, 2001. Carbonaceous meteorites as a source of sugar-related organic compounds for the early Earth. Nature, 414(6866):879-883. L. Mullen, 2001. The first sulfur eaters. SpaceDaily. NASA Science News, 2001. Sweet meteorites. NASA Science News. SpaceRef, 2001. NASA scientist finds some meteorites not sugar-free. SpaceRef.com. R. Stenger, 2001. Space sugar sweetened primordial soup. CNN. _____________________________________________________________________ THIS WEEK ON GALILEO NASA/JPL release 17-23 December 2001 This relatively quiet week is primarily concerned with playback of recorded data from the October 15 flyby of Io. On Sunday, this routine is interrupted briefly as the spacecraft executes a small turn in place to keep the communications antenna pointed towards Earth. During this third pass through the tape-recorded data, we are primarily concerned with extending the amount of data played back, returning observations that had not been returned previously, and recovering portions of observations that were lost in transit during previous transmissions. Pictures expected from the Solid State Imaging camera (SSI) this week include views of the active volcanoes Loki and Pele, and high- resolution images of the scarp or cliff feature Telegonus. The Telegonus pictures were taken while Galileo was within one minute of its closest approach to Io, which was at a distance of 184 kilometers (114 miles). The Near Infrared Mapping Spectrometer (NIMS) will be returning its own views of Pele and Loki, as well as a high- resolution look at the south polar region of Io. Data from the Fields and Particles instruments (the Energetic Particle Detector, the Magnetometer, the Heavy Ion Counter, the Plasma Subsystem, and the Plasma Wave Subsystem) are also slated for return this week. These data were collected both during the closest flyby to Io, and as part of an earlier recording made as the spacecraft passed through the Io Torus, a donut of charged particles that circles Jupiter near the orbit of Io. In addition, the steady collection of real-time data by the Magnetometer, the Dust Detector, and the Extreme Ultraviolet Spectrometer continues throughout the week. For more information on the Galileo spacecraft and its mission to Jupiter, please visit the Galileo home page at one of the following URL's: http://galileo.jpl.nasa.gov http://www.jpl.nasa.gov/galileo _____________________________________________________________________ MARS GLOBAL SURVEYOR STATUS REPORT NASA/JPL release 12 December 2001 Launch / Days since Launch = November 7, 1996 / 1862 days Start of Mapping / Days since Start of Mapping = April 1, 1999 / 986 days Total Mapping Orbits = 12,354 Total Orbits = 14,037 Recent events The spacecraft is operating nominally in performing daily recording and transmission of science data. TES and MOC images are being supplied to the Mars Odyssey team to support their aerobraking campaign. The MM155A sequence has performed well since it started on 01-318 (11/14/01). It terminates on 01-347 (12/13/01). MM156A starts tonight at 01-346 (12/12/01), 23:57 SCET UTC. Roll Only Targeted Observations (ROTOs) have been suspended to reduce the probability of entering C-Mode during Mars Odyssey aerobraking. The Spacecraft Team continues to investigate MGS difficulties in star processing following slew maneuvers like ROTOs. The team is designing tests and identifying steps needed to mitigate C-mode entry following ROTOs. MGS has completed 207 ROTOs to date. The MZ147 High-rate Gyro Data Collection mini-sequence executed successfully on 01-345 (12/11/01). The MZ148 contingency mini- sequence was uplinked, then terminated as planned due to the success of MZ147. The data show that the high-rate gyro bias estimates used during the September and October ROTOs would not have caused the loss of attitude knowledge that resulted in C-mode entry. Spacecraft health All subsystems report good health and status. Uplinks There have been 17 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files, instrument command loads, and the High-rate Gyro Data Collection mini-sequences cited above. 6,022 command files have been radiated to the spacecraft since launch. Upcoming events MGS will continue to support the Odyssey mission during the aerobraking phase by supplying TES and MOC images of the Martian surface. Martian dust storms can bloom into the upper atmosphere, significantly increasing the atmospheric density and posing a threat to Odyssey. The MGS images will provide the Odyssey team the opportunity to avoid the dust storms if they occur. _____________________________________________________________________ End Marsbugs, Volume 8, Number 49.