MARSBUGS: The Electronic Astrobiology Newsletter Volume 8, Number 11, 19 March 2001. Editors: Dr. David J. Thomas, Math and Science Division, Lyon College, Batesville, AR 72503-2317, USA. dthomas@lyon.edu Dr. Julian A. Hiscox, School of Animal and Microbial Sciences, University of Reading, Reading, RG6 6AJ, United Kingdom. J.A.Hiscox@reading.ac.uk Marsbugs is published on a weekly to quarterly basis as warranted by the number of articles and announcements. Copyright of this compilation exists with the editors, except for specific articles, in which instance copyright exists with the author/authors. While we cannot copyright our mailing list, our readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing list. The editors do not condone "spamming" of our subscribers. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editors. E-mail subscriptions are free, and may be obtained by contacting either of the editors. Article contributions are welcome, and should be submitted to either of the two editors. Contributions should include a short biographical statement about the author(s) along with the author(s)' correspondence address. Subscribers are advised to make appropriate inquiries before joining societies, ordering goods etc. Back issues and Adobe Acrobat PDF files suitable for printing may be obtained from the official Marsbugs web page at http://welcome.to/marsbugs. The purpose of this newsletter is to provide a channel of information for scientists, educators and other persons interested in exobiology and related fields. This newsletter is not intended to replace peer- reviewed journals, but to supplement them. We, the editors, envision Marsbugs as a medium in which people can informally present ideas for investigation, questions about exobiology, and announcements of upcoming events. Astrobiology is still a relatively young field, and new ideas may come from the most unexpected places. Subjects may include, but are not limited to: exobiology and astrobiology (life on other planets), the search for extraterrestrial intelligence (SETI), ecopoeisis and terraformation, Earth from space, 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) SPECIAL ASTROBIOLOGY GUIDE AVAILABLE TO HIGH SCHOOL EDUCATORS Pennsylvania State University release 2) MARS' VOLCANOES MAY HAVE MELTED ICE, PRODUCING WATER NECESSARY FOR "LIFE" ON RED PLANET State University of New York at Buffalo release 3) A TNA WORLD? From the NASA Astrobiology Institute 4) SETI@ARECIBO: BIGGER IS BETTER By Seth Shostak 5) LOOKING FOR SIGNS OF LIFE IN ACID-WASHED ROCKS From the NASA Astrobiology Institute 6) SETI@ARECIBO: THE PLODDING PACE OF DISCOVERY By Seth Shostak 7) GALILEO GETS ONE LAST FREQUENT-FLYER UPGRADE NASA release 01-41 8) THROUGH THICK OR THIN: EXPLORING EUROPA'S OUTER LAYER OF ICE From the NASA Astrobiology Institute 9) SETI@ARECIBO: ARECIBO IS BETTER THAN EVER By Seth Shostak 10) 2001 MARS ODYSSEY LAUNCH PRESS KIT AVAILABLE By Ron Baalke 11) MARS SCOUTS CONCEPT WORKSHOP JPL release 12) ICE PROBE REVEALS FIRST-EVER IMAGES DEEP WITHIN ANTARCTIC STREAMS JPL release 13) ALL ABOARD THE METEOR EXPRESS OF LIFE By Jeff Hecht 14) SETI@Arecibo: Observatory Life By Seth Shostak 15) 2001 MARS ODYSSEY SET TO FIND OUT WHAT MARS IS MADE OF NASA release 01-46 16) MARSBUGS AT THE SCIENCE FAIR By David J. Thomas 17) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 18) CASSINI WEEKLY SIGNIFICANT EVENTS JPl release 19) THIS WEEK ON GALILEO JPL release 20) STARDUST STATUS REPORTS JPL releases --------------------------------------------------------------------- SPECIAL ASTROBIOLOGY GUIDE AVAILABLE TO HIGH SCHOOL EDUCATORS Pennsylvania State University release 9 March 2001 "Is there anybody out there?" High school teachers interested in the search for life in the universe may now order a free 16-page guide to the science of astrobiology available from Penn State. The guide, "Astrobiology: The Search for Life in the Universe," is based on last year's Frontiers of Science lecture series organized by Penn State's Eberly College of Science and sponsored by the pharmaceutical company Pfizer, Inc. The articles in the guide cover the six lectures that took place from January 22 to February 26, 2000, on the Penn State University Park campus. Researchers from several universities explained the mystery of the snowball Earth, the chemistry of the Earth's primordial soup, how phylogenetic trees and DNA clocks work, and the possibility of life on Mars. Originally, the guide appeared as a special report in the January 2001 issue of Research/Penn State magazine. It was written by David Pacchioli, associate editor of Research/Penn State, with help from undergraduate science writing interns. Pfizer, Inc. and the NASA Astrobiology Institute both contributed money to reprint 20,000 additional copies of the report. "It's a perfect example of how partnerships can produce wonderful products," says Lisa Brown, acting director of the Pennsylvania Space Grant Consortium (PSGC) and education and public outreach coordinator for the Penn State Astrobiology Research Center (PSARC). PSGC organized the reprint of the guide and is now working to distribute it to educators. "These articles are a great way to introduce high school students and teachers to the broad, interdisciplinary field of astrobiology," Brown says. Print copies are available to high school teachers who are interested in bringing the world of astrobiology into their classroom. Please contact Lisa Brown, lisabrown@psu.edu or 814-863-7687, for more information. The guide is also available on the Research/Penn State web site at http://www.research.psu.edu/rps/0101/ or as a PDF file (3.06MB) at http://www.research.psu.edu/rps/0101/Astrobiology.pdf. Space.com will feature the articles that appeared in the guide. Contact: Dana Bauer, Phone: 814-865-33477, danabauer@psu.edu ---------------------------------------------------------------- MARS' VOLCANOES MAY HAVE MELTED ICE, PRODUCING WATER NECESSARY FOR "LIFE" ON RED PLANET State University of New York at Buffalo release 12 March 2001 Two of the oldest volcanoes on Mars, which have been active for 3.5 billion years, are providing clues to the possibility of life on the planet, according to preliminary analysis by University at Buffalo geologists of new data from the Mars Orbiter Camera (MOC) and the Mars Orbiter Laser Altimeter (MOLA), currently orbiting the planet. The scientists are presenting their results here today (March 12, 2001) at the 32nd Lunar Planetary Science Conference. Located in the southern hemisphere of Mars, the volcanoes, named Tyrrhena Patera and Hadriaca Patera because they look like overturned saucers (patera is Latin for saucer), may still be active, said Tracy Gregg, Ph.D., UB assistant professor of geology and principal investigator. "What's most intriguing about these volcanoes is that they are surrounded by channels," said Gregg. "Of all the volcanoes on Mars, these volcanoes have the largest and greatest numbers of channels associated with them, indicating that there was a lot of water around when they were forming, though there doesn't appear to be any around now." She noted that the presence of life on Mars would require water, which currently is impossible because of the planet's frigid climate. Gregg said that the channels, now essentially dry riverbeds, may have formed because the volcanoes, which act as giant thermal-energy units, could have melted ice on the ground. The water would have flowed downhill, away from the volcano's center, carving the channels. "The combination of the heat and energy from the volcanoes and the liquid water makes conditions ripe for the evolution of life, at least as we understand it on Earth," said Gregg. She added that volcanoes also are a source of many of the essential chemicals that may be necessary for the evolution of biological organisms. Gregg and her colleagues are basing the preliminary analysis of new data gathered by the MOC and the MOLA. The data-high-resolution pictures taken by the camera-are transmitted by radio to Earth. The scientists then download them from the Malin Space Science Systems Web site at http://www.msss.com. "The MOC is a very high-resolution camera that allows us to see features on Mars as small as 1 meter across, so we can start to see some really significant things, like individual boulders and piles of sediment, which is allowing us to really piece together Martian history," she said. The MOLA provides very detailed topography, measuring height differences as small as 1-2 centimeters, she added. "When this mission is complete, we'll know the surface of Mars to within 1 meter," Gregg said. "There are areas on Earth we don't know that well, such as Antarctica and the entire ocean floor." As more data pour in from this mission, Gregg and her colleagues will be continuing to analyze them, trying to learn more about how evidence of water on Mars may provide clues to questions about whether or not life has existed on the red planet. NASA's Planetary Geology and Geophysics Division funds Gregg's research. Image caption: [http://www.buffalo.edu/scripts/newnews/index.cgi?article=marsvolcan] The presence of gullies along the sides of volcanos on Mars (above) indicates the planet once may have held water, according to UB geologist Tracy Gregg. Contact: Ellen Goldbaum, goldbaum@buffalo.edu Phone: 716-645-5000 x1415 Fax: 716-645-3765 An additional article on this subject is available at http://www.space.com/scienceastronomy/solarsystem/mars_landscape_0103 15.html. --------------------------------------------------------------------- A TNA WORLD? From the NASA Astrobiology Institute 12 March 2001 We all know that DNA makes up the building blocks for life on Earth. But DNA-deoxyribonucleic acid-is highly complex. It could not have appeared spontaneously; it must have evolved from a simpler form. Scientists have put forth the theory that RNA-ribonucleic acid-was the predecessor to DNA and evolved into that more-complex molecule. But while RNA is slightly simpler than DNA, it too is very complex. So what is the ancestor of RNA? One recent report suggests that it may have been yet another nucleic acid called (L)-a-threofuranosyl oligonucleotides, also known as TNA. Dr. Albert Eschenmoser and his colleagues at the Scripps Research Institute in La Jolla, California, and the Federal Institute of Technology in Zürich, Switzerland, chemically synthesized TNA in a number of steps. They found that complementary TNA strands can form stable double helices. The TNA strands can also pair up with complementary strands of RNA and DNA. This ability is thought to be one of the requirements of any system that would be considered a possible ancestor of RNA. A second requirement is that it should be a simpler molecule than RNA. According to Eschenmoser, the synthesis of TNA is part of a comprehensive decade-long project aimed at understanding the origin of RNA. To investigate potential RNA precursors, the scientists have been creating nucleic acids that are structurally similar to RNA. They study the properties of the alternatives, such as TNA, and compare them with corresponding properties of RNA. TNA seems to be very similar to RNA in some regards, but overall it is a simpler molecule. Part of this simplicity stems from the structure of its sugar-phosphate backbone. The sugar-phosphate backbone of DNA provides the structural support for a coded sequence of information-bearing molecules-the bases adenine, thymine, cytosine and guanine (A, T, C and G, for short). In RNA, the T is replaced by a U-uracil. Keeping the image of the double helix in mind, the bases form the steps of a spiral staircase while the sugar-phosphate backbones form the railing. The backbone of DNA and RNA is composed of sugar molecules-ribose for RNA and deoxyribose for DNA-that contain five carbon atoms. In TNA that backbone is composed of sugar molecules-threose-that contain only four carbon atoms. Under nonbiological conditions, threose forms easily than ribose. "But it is not only the number of the carbon atoms that makes threose an intrinsically simpler molecule than ribose," Eschenmoser says. It is also the fact that, unlike ribose, "the simplest formation of threose requires only a single type of starting material." TNA does not occur naturally today. Scientists have to create it in the lab in order to study it. Since we can't go back in time to witness the evolution of nucleic acids, we will never be able to prove whether natural TNA made an appearance on Earth. Indeed, says Eschenmoser, "talking about TNA as a a possible ancestor of RNA is actually premature." But scientists can examine the basic properties of TNA and determine whether they could have formed in a prebiotic-Earth environment. "The reason for synthesizing and studying it," Eschenmoser explains, is "to screen the structural neighborhood of RNA for potential nucleic-acid alternatives that could also have fulfilled the function of a genetic system." The fact that TNA is currently synthetic doesn't exclude the possibility that it could have formed on early Earth. Because the conditions of a primitive Earth were so different-little atmospheric oxygen, high ultraviolet radiation, possibly higher temperatures and volcanic activity-chemicals may have combined in very different ways than they do in today's environment. "Since the direct evidence has disappeared, it will require an inventive chemist to construct a persuasive scenario," says Dr. Leslie Orgel of the Salk Institute for Biological Studies. "The important issue is whether or not it is possible to make TNA using potentially prebiotic chemistry. That remains to be seen." Scientists studying the origins of DNA are confronted with a paradox. DNA needs certain proteins to replicate. But in order to make the correct proteins for this function, modern cells need to have DNA. Since DNA and the proteins are dependent on each other, it is hard to see how either of them could have come first. One answer to this riddle is the RNA world theory, which suggests that both DNA and proteins could be descendants of RNA. But where did RNA come from? To date, no one has been able to form RNA under in the laboratory under conditions that mimic those believed to have existed on primitive Earth. Some scientists also question whether nucleic acids with a backbone of ribose, or any other sugar molecule, would be stable enough to survive the harsh conditions of early Earth. So it is generally agreed that RNA must have evolved from an earlier form. While TNA is a good candidate, other polymers that exhibit self-replication and base pairing could have evolved into RNA. Pyranosyl RNA (p-RNA) and peptide nucleic acid (PNA) are two of these alternatives. TNA is "the best bet so far," says Orgel, "but PNA and p-RNA are also possible." Like TNA, p-RNA differs from RNA and DNA in the type of sugar that makes up its sugar-phosphate backbone. p-RNA can also pair up in double helices. But p-RNA double helices are structurally incompatible with those formed by DNA and RNA. So p-RNA would not have been able to exchange information with RNA, making it an unlikely RNA predecessor. Another alternative-PNA-may be a more likely candidate. PNA has the same chemical backbone as proteins and uses the same nucleic acid bases as RNA (A, T, U and C). It can mimic the behavior of DNA and can bind to single-stranded DNA. Recent experiments suggest that components of PNA can be synthesized under prebiotic conditions. Although PNA's rigid backbone seems to prevent it from carrying out the same catalytic functions as RNA, PNA is still a strong contender as RNA's ancestor. "PNA is a major contribution to our present knowledge of nucleic acid chemistry," Eschenmoser says. "Its formation under potentially geochemical conditions should be studied in order to judge whether it could have been a natural RNA precursor." What next? Eschenmoser plans to continue working on TNA, including the investigation of TNA analogs. "Continuing the Eschenmoser program is obviously important," says Orgel. But, he adds, "the search for completely different kinds of informational molecules, for example peptides that could replicate, is also worth pursuing." For more information on this article, see http://nai.arc.nasa.gov/index.cfm?page=tna_world. --------------------------------------------------------------------- SETI@ARECIBO: BIGGER IS BETTER By Seth Shostak From Space.com 12 March 2001 "Arecibo interface is up and running," I bark from a computer console. "OK, I'm taking control..." Jill Tarter replies flatly. "Check the IF levels, would you?" It's 6:00 PM, and Project Phoenix is once more checking out nearby star systems, listening for a radio tone that would betray an alien society. Every night, from 6:00 PM to 6:00 AM, we take over the world's largest antenna and aim it at Sun-like stars. "Truly amazing," notes Robert Ackermann, a software scientist at the SETI Institute, as he peers down at the telescope's imposing aluminum dish. "This is some weird hybrid of locomotive and battleship. Look at all the steel. It's hard to believe you can point this beast to within 6 seconds of arc." That's one-six hundredth of a degree-roughly the size of a lunar crater seen from Earth-or if you prefer, like hitting a dime from 350 yards. Not bad for an instrument whose moving parts weigh in at 340 tons. Get the full story at http://www.space.com/searchforlife/phoenix_diary__two_010312.html. --------------------------------------------------------------------- LOOKING FOR SIGNS OF LIFE IN ACID-WASHED ROCKS From the NASA Astrobiology Institute 14 March 2001 Extraordinary clues to the history of biological evolution on Earth often come from something as mundane as rocks. To better understand the close connection between life and geology-and how one affects the other-new laboratory methods are being developed to tease out the information that ancient rocks contain. Pioneering one such method is Dr. Frances Westall, paleobiologist for the Lunar and Planetary Institute and member of the NASA Astrobiology Institute. She and her colleagues are using acid vapor to isolate the remains of tiny microbial life forms. These fossils, entombed within ancient sedimentary fossil structures known as stromatolites, were once beyond the reach of scientific probing. But when acid washed, the fossils turn out to be tougher than the surrounding rock. As recently described in the journal Precambrian Research, the technique used by Westall and her colleagues involves delicately etching the rock with fumes of the corrosive acid hydrogen fluoride. The rock dissolves away to reveal microscopic crystalline structures that look like sausage-shaped rods, spheres with wrinkled cell walls and clusters of bacteria-the telltale signs of ancient biology. Modern-day stromatolites are created from alternating layers of sediment and cyanobacteria-a type of bacteria that photosynthesizes, giving off oxygen in the process. To form a stromatolite, the layers of cyanobacteria photosynthesize, grow and reproduce, creating a slimy mat that traps bits of clay, rock, sand, mud and organic debris. As this sediment accumulates and blocks sunlight, the microbes migrate up to start a new living layer. The old layer will gradually turn to stone-if it is sediment-rich and the moisture trapped within it evaporates quickly. As long as the bacteria continue living, reproducing and growing on top of previous populations, the layers of rock keep increasing. Ancient stromatolites, however, formed in a slightly different way than modern-day structures. "The very earliest stromatolites were formed by photosynthesizing, filamentous bacteria, which did not produce oxygen," says Westall. "The very ancient stromatolites, in fact, were a mixture of layers of microbial mats coated with layers of precipitated minerals-which were again covered by more layers of microbial mats, and so on," says Westall. "The process of trapping debris was not a major method of growth in the ancient stromatolites-the precipitation of minerals on the microbial mats was more important to growth and fossilization." Over time, minerals gradually replaced the structures of the organisms. The minerals eventually formed quartz, but the crystal structure of the organic-laced quartz is different from crystals that formed in the surrounding rock without the presence of organics. "When the acid etches away the pure quartz which surrounds the fossils," says Westall, "the fossils stand out because the quartz which replaces them is 'dirty' and has a slightly different crystal structure to the quartz which surrounds them." There have been some doubts as to whether ancient stromatolites really were constructed by bacteria, because previously no fossils were ever observed within them. The acid vapor process, however, used in conjunction with high-resolution imaging and microscopic analysis of thin sections and rock chips, has revealed what the skeptics said were missing: microscopic life forms-smaller than cyanobacteria. Cleaning up after 3.5 billion years of neglect Studying ancient fossils, Westall says, is a multi-step process. The rock specimen is examined for evidence of life, such as very fine, wavy or hummocky layering typical of ancient microbial mats. If such evidence is present, they then slice the sample into thin sections and use a microscope to check for any larger biological structures, such as filamentous bacteria. The final step uses acid vapor to etch the thin sections and other rock chips. This allows the scientists to search for smaller structures that are not readily visible in the thin sections. The acid vapor method thus makes it possible to identify many more types of organisms than could be identified previously. Westall believes that her research can contribute to building a database for understanding the diversity of early microbial evolution on earth. In a broader sense, Westall is trying to unravel the connection between geology and life. She said [that] her goals are to understand the geological context in which early life evolved and to understand the distribution of early life among a variety of environments. "Basically," says Westall, "early life coped extremely well in the extreme conditions existing on the early Earth, such as the lack of oxygen in the atmosphere, high ultraviolet radiation, possibly higher ambient temperatures, severe volcanic activity, and so on. But those 'extreme' conditions are only extreme by modern standards. They were normal by the standards of the early Earth, Mars, Europa, or even Venus. When the Earth starts dying down and conditions become 'extreme' again-meaning a more hot, desert-like situation because of the expansion of the sun before it explodes-bacteria will be there to the bitter end." Moreover, Westall argues, "extreme conditions on other planets would not be any impediment to life." Which is why, she says, "I'm interested in trying to understand Martian geological evolution, with a view to determining likely Martian environments for life." What next? Westall remains concerned about the problem of misidentifying microfossils. "I am working with some colleagues in the hopes of establishing some biochemical technique to determine if there is any signal still from the degradation products of microbes in the very old rocks from South Africa and Australia," she states. "But the search for ancient life and its distribution is a painstaking slow process requiring much methodical examination of the ancient rocks," she adds. "It will take years before we have a reasonable overview of what early life was like on Earth." Dr. Westall's research involves collaborations with many colleagues at the Lunar and Planetary Institute on Martian issues, as well as early Earth formation. Other collaborators include: Maud Walsh, Louisiana State University, on Early archaean microfossils; Bruce Jakosky, University of Colorado Boulder, on early Mars; David Deamer, University of California Santa Cruz, on prebiotic molecules and films; Andre Brack, Orleans, France, on prebiotic molecules; Andrew Steel and Jan Toporski, University of Porstmouth, UK, on ToF-SIMS analysis of organics, Martian meteorite contamination and fossil bacteria; Wouter Nijman and Sjoukje de Vries, University of Utrecht, Holland, on early Earth geology; Maartin de Wit, University of Cape Town, South Africa, on early Earth geology; and Martin van Kranendonk, Geological Survey of Western Australia, Perth, on early Earth geology. For more information on this article, see http://nai.arc.nasa.gov/index.cfm?page=acid_washed. --------------------------------------------------------------------- SETI@ARECIBO: THE PLODDING PACE OF DISCOVERY By Seth Shostak From Space.com 14 March 2001 "What? You think Lewis and Clark made discoveries every minute?" Gerry Harp was almost wild-eyed. "I bet most days they just silently shambled through underbrush." It's true. We get a lot of visitors to the control room; most of them excited by the prospect of seeing history in the making. They savor the thought of being onboard the Santa Maria as the New World quietly edges over the western horizon. Of course, if you really were onboard the Santa Maria, the western horizon would be about the last thing you'd get to look at. Someone else did that. You'd be busy fixing the rigging and sail, or holystoning the deck. It's not much different when you hunt for extraterrestrials. The Homo sapiens life forms that slump in front of the Project Phoenix workstations aren't really necessary except for the demands of maintenance and repair. We're down on the deck, often doing little more than filling in the logbooks, while the computers keep watch from the crows nest. Get the full story at http://www.space.com/searchforlife/phoenix_diary_three_010314.html. --------------------------------------------------------------------- GALILEO GETS ONE LAST FREQUENT-FLYER UPGRADE NASA release 01-41 15 March 2001 The resilient Galileo spacecraft doesn't know when it call it quits. So, NASA has outlined the details of one last mission extension, which includes five more flybys of the Jovian moons before a final plunge into the crushing pressure of the giant planet's atmosphere. Galileo has been orbiting Jupiter for more than five years and survived radiation exposure more than three times what it was built to withstand. Galileo's mission has previously been extended twice and during that time it has returned an enormous wealth of scientific information, including evidence of a sub-surface ocean on Jupiter's moon Europa. "We're proud that this workhorse of a spacecraft has kept performing well enough that we can ask it to keep serving science a little longer," commented Dr. Jay Bergstralh, Acting Director of Solar System Exploration at NASA Headquarters, Washington, DC. On May 25, Galileo should pass about 123 kilometers (76 miles) above the moon Callisto, the second largest of Jupiter's 28 known moons. The effects of Callisto's gravity will set up the space probe for a swing over both polar regions of the intensely volcanic moon Io in August and October. Galileo will take pictures, measure magnetic forces, and study dust and smaller particles. Science goals include studying the extent of volcanism on Io, both in new and previously active sites; determining whether Io generates its own weak magnetic field; and gaining a better understanding of a doughnut-shaped ring, the Io Torus, that encircles Jupiter and contains electrically charged gases. In 2002, having completed its imaging mission, Galileo will continue studies of Jupiter's massive magnetic field with seven instruments. In January, the orbiter will fly near the equator of Io. In November, it will swing closer to Jupiter than ever before, dipping within about 500 kilometers (about 300 miles) of the moon Amalthea, which is less than one-tenth the size of Io and less than half as far from Jupiter. Scientists will use Galileo measurements to determine the mass and density of Amalthea. They will also study dust particles as Galileo flies through Jupiter's gossamer rings and seek new details of the magnetic forces and the densities of charged particles close to the planet. Galileo's final orbit will take an elongated loop away from Jupiter. Then in August 2003, the spacecraft will head back for a direct impact and burn up as it plows into Jupiter's 60,000 kilometer-thick atmosphere. The National Research Council of the National Academy of Sciences approved this final act last December. "Galileo has already succeeded beyond expectations, and we have the opportunity to learn still more in coming months, but it is sad to see the end of the road up ahead," said Eilene Theilig, Galileo project manager at NASA's Jet Propulsion Laboratory, Pasadena, CA. "Exposure from Jupiter's intense radiation belts has impaired some of Galileo's instruments, but it is still producing valuable scientific results." The science program for the Galileo mission extension was recommended to NASA by a blue-ribbon panel of planetary scientists, who met last July, and will cost $9 million. "This mission extension accomplishes the highest priorities of the review panel in a cost effective way," said Paul Hertz, Galileo Program Executive at NASA Headquarters. Galileo was launched October 18, 1989, aboard NASA's Space Shuttle Atlantis. On December 7, 1995, a probe released earlier from Galileo made measurements while dropping through Jupiter's upper atmosphere. Galileo's top scientific accomplishments include: * Produced strong evidence that Europa has a melted saltwater ocean under the ice layer on its surface. The spacecraft has also found indications that Ganymede and Callisto have layers of liquid saltwater, too. * Detailed the varied and extensive volcanic processes on Io, catching plumes erupting, fire fountains in process and lava flows expanding, among other observations. * Delivered a probe that made the first measurements of Jupiter's atmosphere from within the atmosphere. * Made the first close approach to an asteroid and made the first discovery of a satellite orbiting an asteroid. * Discovered the first internal magnetic field of a moon. Ganymede's intrinsic magnetic field actually creates a "mini- magnetosphere" embedded within Jupiter's vast magnetosphere. * Provided the only direct observation of Comet Shoemaker-Levy's impact into Jupiter. JPL, a division of the California Institute of Technology in Pasadena, manages Galileo for NASA's Office of Space Science, Washington, DC. More information about Galileo is available on the Internet at http://galileo.jpl.nasa.gov/. Contacts: Donald Savage, Headquarters, Washington, DC, Phone: 202-358-1547. Guy Webster, Jet Propulsion Laboratory, Pasadena, CA, Phone: 818-354- 5011. Additional articles on this subject are available at: http://spaceflightnow.com/news/n0103/16galileo/ http://www.space.com/missionlaunches/missions/galileo_mission_extende d_010315.html --------------------------------------------------------------------- THROUGH THICK OR THIN: EXPLORING EUROPA'S OUTER LAYER OF ICE From the NASA Astrobiology Institute 16 March 2001 When NASA's Galileo spacecraft sent back images and data of the Jovian moon Europa, scientists began thinking seriously that life just might exist on this enigmatic, frozen world. Europa appears to have all the conditions necessary for the emergence of life: liquid water, organic chemicals, and energy. A layer of ice covers Europa, but there is strong evidence-the most convincing comes from Galileo's magnetometer-that a salty ocean may lie underneath. Organic chemicals are prevalent throughout the universe and could have been deposited on Europa by comets and meteors. Tidal forces exerted by Jupiter could provide enough energy for life, and if Europa is anything like its close neighbor Io, subsurface volcanism may provide yet another source of energy. While scientists are eager to explore Europa's putative ocean for signs of life, the ice layer covering the moon is also the object of a great deal of interest. For one thing, before any attempt can be made to access the ocean, the thickness of the ice layer needs to be determined. In addition, the ice layer itself may harbor life. "Our work has been on understanding the geology and geological systems of Europa, and what we have come to understand is that everything on the surface has a linkage to the ocean," says Richard Greenberg of the University of Arizona. "In the chaotic terrain-the areas where the ice appears to have melted down into the warmer ocean before refreezing-there are a number of niches where organisms could survive and prosper in the ice." Organisms couldn't live right on the surface of the ice because the temperature is a frigid -160°C (-260°F), too cold for even a microbe to survive other than in a state of complete hibernation. But brief exposure to the outer ice layer may provide the organisms in Europa's ocean with a steady source of nutrition. The food-oxidants produced by radiation bombarding the outer ice layer-would drain downward into the ocean at the areas of ice melt-through. The mixing of ice crust and subsurface ocean may provide microorganisms with another source of food as well. It is possible that when cracks opened in the ice layer, organisms living in the ocean would be exposed to the faint rays of the sun. "There's a whole zone within meters of the surface where organisms could photosynthesize, as long as they had access to sunlight," says Greenberg. Greenberg thinks the cracks in the ice could provide an ideal habitat for organisms on Europa. The cracks are caused by the tidal pull of the gas giant Jupiter, which squeezes Europa like a tennis ball. Greenberg believes that Europa's ice is only a few kilometers thick, and that the cracks reach down to the ocean below. If true, the tidal motion of Europa's ocean periodically would push water up and down in the cracks. In this way, the cracks would act as passageways where organisms can continually reach the surface. Robert Pappalardo of Brown University has very different ideas of how organisms might access the oxidants and sunlight on Europa's surface. Pappalardo disagrees with Greenberg about the thickness of Europa's ice; based on geophysical modeling, he believes Europa's crust is about 20 kilometers thick. Still, Pappalardo says that a thicker ice crust would not prevent interaction between the icy surface and the liquid ocean. He suggests that diapirs-columns of warmer ice that slowly plough their way upwards through the top ice layer-could provide the needed interchange. "On Earth, salt rises as diapirs through overlying higher-density sediments-notably in Iran and off the Texas Gulf coast," says Pappalardo. "We can best visualize the process by picturing a Lava Lamp. On Europa, warm ice forms the rising blobs, as these are buoyant relative to the colder and denser overlying ice. The blobs could carry ocean material and any potential organisms up toward the surface." The diapirs would act as a sort of elevator, bringing up the ocean- dwelling inhabitants and bringing down the oxidants formed on the surface of the moon. "As they impinge on the cold near-surface ice, diapirs can melt out pockets of the surface ice, allowing it and entrained oxidants to drain downward into the deep portions of Europa's ice shell and presumably back into the ocean. In this way, diapiric stirring can help move microbes toward the surface, and can move nutrients down into the ocean." Although the two scientists agree that interaction between the ice crust and ocean might support life, they strongly disagree about the thickness of that crust. Their disagreement is based on the estimated amount of energy available on Europa. Greenberg, for instance, believes Europa's constant tidal flexing generates enough heat to maintain both a liquid ocean and a thin ice crust. "The tides on Europa distort the shape of the body once every 85 hours," says Greenberg, "so Europa gets enough tidal heating from Jupiter to maintain both a liquid ocean and a thin crust. There's been a lot of evidence that this is so. The convection of water in the ocean is enough to heat the ice and cause melt-throughs. You just need to do the math, calculating heat rates and tidal rates for Europa, to understand how the planet is warm enough for a liquid ocean and a thin ice crust. "Rather than give any particular number for the thickness of Europa's crust," Greenberg continues, "the main line of argument is that the crust is thin enough for the ocean to be a factor, and thin enough for the cracks on the surface to reach down to the ocean below. With a crust 20-km-thick, that is very difficult." But Pappalardo cites models of Europa's tidal heat that predict a crust thickness of somewhere between 20 to 30 kilometers. Based on this data, and on speculation about other possible energy sources on Europa, he suggests it is highly improbable that Europa could generate the heat necessary to sustain a thinner ice shell. "One could imagine turning up the amount of interior heat flow from Europa's rocky core to such a great extent that the ice shell becomes only 6 or so kilometers thick," says Pappalardo. "This is an extreme possibility, one that has not been supported by geophysical modeling." "How would the heating be turned up so high?" Pappalardo asks. "To generate such heat flow, Europa would have to possess a rocky interior that is partially molten, and this interior would have to have been molten over the entire history of the solar system. If it were ever colder, it would not then be able to become molten. But so far, no geophysical model predicts such a hot Europa interior today." "Moreover, this scenario raises a potential conundrum," Pappalardo continues. "If Europa is tidally heated to such an extent that it has a molten rock interior, then this large amount of tidal dissipation would act to damp out Europa's high [orbital] eccentricity," reducing the tidal forces, "and the interior in turn would cool. In other words, it has not been demonstrated that Europa's high eccentricity is compatible with a rocky interior. There are many issues which such a model must address before it can be considered credible, let alone compelling." Ronald Greeley, professor of geology at Arizona State University, heads the NASA Astrobiology Institute's Europa Focus Group. In his opinion, what matters more than the question of thick or thin ice is the question of the age of Europa's surface. No one knows whether the cracks in Europa's ice were made recently or are millions of years old. "The age, or timing, of formation is extremely important," says Greeley. "With time, an originally thin crust might thicken as cooling progresses. Many investigators fail to say if they are referring to a given thickness for today's conditions, or if they are restricting comments to the time when the features they are investigating were first formed. Disregarding differences in opinion on how certain surface features might form, the ice crust thickness could be of different thicknesses in different places and at different times." Knowing the age of Europa's surface would tell us whether the moon has an active geology. Scientists try to determine the age of a moon or planet by counting the number of impact craters caused by asteroids. The theory is that the fewer the craters, the younger the surface. An active surface-like that of our own planet-tends to erase evidence of old impacts, while on a non-active surface-like our moon-the evidence can remain for billions of years. "Although," says Greeley, "Europa is lightly cratered from impacts, suggesting relative youth in the geologic context, the surface could still be millions of years old and not necessarily reflect today's crustal properties." Another problem with crater-counting is that impact rates differ according to location in the solar system. For example, Jupiter has such immense gravity that it attracts a lot of asteroids, which could increase the cratering rate on its moons relative to better- understood standards like our own moon. Unfortunately, only crude estimates are available for the rate of impacts in the present Jupiter environment. For Greeley, uncertainty about the age of Europa's surface leads to uncertainty about many of the moon's other proposed features. For instance, he says the only strong evidence that Europa's ocean is currently liquid is the magnetometer data sent by the Galileo probe. But that data is open to other interpretations, and is not absolute proof of a liquid ocean. "The real bottom line is that we do not currently have the right kind of information to say if liquid water exists today beneath the surface, nor can we say how thick an ice crust might be even if there is liquid water at depth. For definitive statements, these data must come from a future mission, such as the Europa Orbiter." What next? The Europa Orbiter is tentatively scheduled to arrive at Jupiter in 2010, and settle into a 200-kilometer orbit about Europa in 2011 or 2012. The proposed Orbiter will use radar to measure the thickness of the ice crust and to determine whether liquid water exists below the ice. Along with mapping the surface and measuring the topography of the moon, the Orbiter will also try to detect any signs of recent geological activity. For more information on this article, see http://nai.arc.nasa.gov/index.cfm?page=thick_or_thin. --------------------------------------------------------------------- SETI@ARECIBO: ARECIBO IS BETTER THAN EVER By Seth Shostak From Space.com 16 March 2001 "This telescope's no spring chicken," remarks astronomer Karen O'Neil wryly, "even if it is March." Indeed, the Arecibo dish is hardly the new 'scope on the block. It was conceived in 1959, and constructed in the early 1960s. There are a few employees at the observatory who've been here from the beginning, but not many. For most of the 140 folks who work here, Arecibo was always a facility, and not a dream. Telescopes usually outlast their builders. They're expensive, after all, which discourages thoughts of early disposal. California's famed Palomar telescope, with its insouciant art deco dome, is more than a half-century old. The venerable Yerkes 40-inch (1-meter), 70 miles (113 kilometers) northwest of Chicago, dates from the Victorian era. "Long in the tooth, yes. But Arecibo's still on the cutting edge," notes O'Neil incisively. That's because, like computer programs and frequent fliers, telescopes are routinely upgraded. The most recent major improvement to this economy-sized instrument was made between 1992 and 1997 when the Gregorian feed, housed in a 3-story high geodesic dome, was added to the Arecibo 'scope. Get the full story at http://www.space.com/searchforlife/phoenix_diary_four_010316.html. --------------------------------------------------------------------- 2001 MARS ODYSSEY LAUNCH PRESS KIT AVAILABLE By Ron Baalke 16 March 2001 The 2001 Mars Odyssey Launch Press Kit is now available at http://www.jpl.nasa.gov/presskits/odysseylaunch.pdf. Note that the press kit is a PDF file, and you will need to have Adobe Acrobat Reader installed on your computer to read the file. The Adobe Acrobat Reader is free, and you can download it from http://www.adobe.com/prodindex/acrobat/readstep.html. --------------------------------------------------------------------- MARS SCOUTS CONCEPT WORKSHOP JPL release http://spacescience.nasa.gov/an/marsscoutsworkshop/ 16 March 2001 Workshop dates and location: 22-24 May 2001, Pasadena, CA, USA. Convener: Scott Hubbard, NASA HQ Sponsored by: NASA Headquarters, Mars Program Office, Jet Propulsion Laboratory The NASA Mars Exploration Program is planning a series of Principal Investigator led, innovative science missions that emerge from the US science community. The first launch of such a mission could be as early as 2007. Mars Scout Missions address high priority science as defined by the Mars Exploration Payload Analysis Group document. They may also address new discoveries, particularly those discoveries that warrant rapid follow-up. NASA intends to use Mars Scouts to complement the core Mars Exploration Program of scientific missions. The Mars Exploration Program now seeks to encourage the development of new concepts for Mars Scout missions. Through the study of specific mission concepts, the Mars Exploration Program also seeks to understand the feasibility and programmatic constraints of a variety of mission types before the program releases a call proposals for a flight opportunity as early as 2007. Exploration of Mars is motivated by a desire to better understand the planet as a possible abode of past or present life, the evolution of the planet's climate, the geology of its surface and interior, and to prepare for future human exploration of Mars. Mars Scout missions are envisioned to be focused investigations of Martian biological, chemical and physical phenomena and processes. Mars Scouts will utilize observation platforms including, but not limited to, orbiters, landers, penetrators, rovers, aerobots, airplanes and gliders. This Request for Mars Scout Concept is for a 6-month study to examine a wide range of mission concepts that, if flown to Mars, would accomplish significant, high priority science, complement the goals of the core missions of the Mars Exploration Program, and would cost no more than approximately $300M ($FY01). Studies of mission concepts will identify achievable science objectives, infrastructure utilization, and technology development priorities. It is planned to award 6 to 10 Fixed Price study contracts valued at $100,000 to $150,000 each. Potential offerors are encouraged to form teams including academic, industrial and US Government research Centers. The competitive source evaluation and source selection process will include written and oral presentations to a review board at the Mars Scout Workshop scheduled for May 22-24, 2001. Specific information regarding written and oral submission is contained within the Request for Mars Scout Concepts. Participation in the Mars Scout Workshop will be limited to those interested in proposing for study funds. Notices of intent to propose are due on April 9, 2001. Submission of a Mars Scout Concept abstract describing the Mars Scout mission and a plan for the mission study are due on or before May 1, 2001. It is the intent of the workshop, and the following funded mission studies, to emphasize those innovative concepts that may not yet be ready for competitive evaluation. Potential participants will be informed of their status regarding study funds no later than June 8, 2001. Following the 6-month period of study a report on the results of the concept studies will be made by the funded investigators. These reports will be made in confidence to the Mars Program Director's Office at NASA HQ. The results of the concept studies will contribute to the development of the AO. Participation or non- participation in Mars Scout studies will not prejudice the subsequent selection of missions for flight. More information is available at the web site, above. --------------------------------------------------------------------- ICE PROBE REVEALS FIRST-EVER IMAGES DEEP WITHIN ANTARCTIC STREAMS JPL release 16 March 2001 Scientists have had their first inside look at ice layers, frozen debris and a surprising channel of water deep beneath an Antarctic ice stream, thanks to an ice probe designed by NASA's Jet Propulsion Laboratory, Pasadena, CA. Plunged more than 1,200 meters (more than 3,900 feet) down four boreholes drilled in the West Antarctic ice sheet, JPL's probe paves the way for the development of technology capable of withstanding extreme environments on Earth and other planets. The Antarctic Ice Borehole Probe Project, a collaborative effort of scientists at JPL and the California Institute of Technology in Pasadena, looked into the dynamics of the West Antarctic ice sheet. The Antarctic ice sheet, equal in size to the United States and Mexico combined, holds a potential treasure trove of information related to the geological history of this frozen continent and the mechanisms by which ice flows from this area to the oceans. Studies show that significant changes in glacier melting and flow rates could have a considerable impact on global sea levels. "This project fits into the bigger picture of planetary studies," said Dr. Frank Carsey, JPL's principal investigator on the project. "It provides us with some understanding of how to observe what goes on deep in ice caps-Earth's ice caps, Martian ice caps and ice caps on Europa." Europa is an ice-covered moon of Jupiter. The glaciological investigation took place at Ice Stream C, an area in the West Antarctic ice sheet where 150 years ago the ice suddenly stopped flowing in one area in the lower part of the stream. This so-called "sticky spot," currently flowing at a rate of 2 meters per year (about 6 feet), greatly differs from its neighboring streams, flowing at approximately 400 meters (1,300 feet) per year. Equipped with two cameras and lights, JPL's ice probe revealed what appears to be a basal water system, or series of water channels at the base of the ice stream. In places, this water-filled cavity measured approximately 1.4 meters deep (4.6 feet). Based on previous calculations, researchers expected the depth of a water basal cavity to be only in the millimeter range. To the researchers' surprise, they also found rock and other debris embedded in the ice much higher than expected. It was believed that frozen debris would be found no higher than two meters (almost seven feet) off the base of the ice stream. In contrast, the visual data shows frozen debris some 26 meters (85 feet) off the base, which has yet to be explained. A layering effect in the ice was also uncovered by the probe. Though not yet fully understood, it is thought that, upstream, ice and gravel have frozen onto the base of the ice sheet. With the ice streams constantly moving, water may slide under debris-laden layers, lifting them up, allowing the process to repeat. "The layered information will turn out to be very interesting," said Carsey. "These layers tell us about processes upstream." By analyzing these ice layers, researchers may learn how ice streams flow and stop flowing. The team's findings open up the doors to further glaciological research. "With the probe, we have now left the dark ages," said Hermann Engelhardt, Caltech's principal investigator on the project. JPL hopes to advance the probe's technology in the next year or two, adding biological sensors to search for evidence of life in the Antarctic ice sheet and eventually on other planets. Microbes are known to reside under mountain glaciers, where it is warmer and there are nutrients from impurities found between water crystals. "These locations are very old places. Some, such as on Mars, are hundreds of millions of years old," said Carsey. The base of a planet's polar cap chronicles the planet's climate and can reveal much about its history and biology, he said. Images of the team's findings are available at http://www.jpl.nasa.gov/pictures/iceprobe. The Antarctic Ice Borehole Probe Project is a collaborative effort of JPL and Caltech, supported by NASA, Washington DC, and the National Science Foundation, Arlington, VA. The ice probe was developed by JPL, a division of Caltech. Contact: Gia Scafidi (818) 354-0372 --------------------------------------------------------------------- ALL ABOARD THE METEOR EXPRESS OF LIFE By Jeff Hecht From SpaceDaily Don't worry about contact with aliens from other solar systems-they may be our distant cousins. According to an American astronomer, there is a slim chance that microbes could be carried from one solar system to another on rocks blasted from terrestrial planets by asteroid impacts, spreading life across the Galaxy. "About one meteorite ejected from a planet belonging to our Solar System is captured by another stellar system every 100 million years," Jay Melosh of the University of Arizona told the Lunar and Planetary Science Conference in Houston this week. Although radiation would threaten stowaway microbes, Russell Vreeland of West Chester University of Pennsylvania says it would be quite possible for meteorites to carry well-protected organisms over interstellar distances. Get the full story at http://www.spacedaily.com/news/life-01i.html. --------------------------------------------------------------------- SETI@ARECIBO: OBSERVATORY LIFE By Seth Shostak From Space.com 19 March 2001 "If I start to snore, just throw something at me." Peter Backus, who manages the Project Phoenix observing program, switches off the last of the lights in Bachelor Unit #1. It's 3:30 AM-an early night. The terminology rumbles through my sleepy brain: "Bachelor Unit #1." Sounds like something out of Stalinist Russia, with an ambience to match. The teak and plywood Bachelor digs are like dorms at an all wood college, sporting a single bathroom, a small kitchen and a Formica plank that might serve as a desk if you're desperate. Life at the observatory is Spartan, but as the veterans like to brag, it used to be a lot rougher. Not so long ago, the only accommodations were the dorm-like garrets known as the Visiting Scientist's Quarters. Bunk beds were standard issue. It's hard to imagine a quartet of guys living in those things for a few weeks without starting World War 3. In the mornings-late mornings-I stumble down the stairways to the cafeteria. The observatory recently constructed an outdoor dining area with high-grade, polished picnic tables; a roof to keep your chicken from drowning in the event of a sudden downpour; and an overhead fan to discourage flies. Not that there are many flies. The observatory is remarkably free of insects, a fact that the locals attribute to the living carpet of small frogs and lizards covering the hills. When it comes to a choice between insects and reptiles, I vote for the reptiles. Unlike the flies, lizards won't land on your beans. Get the full story at http://www.space.com/searchforlife/phoenix_diary_five_010319.html. --------------------------------------------------------------------- 2001 MARS ODYSSEY SET TO FIND OUT WHAT MARS IS MADE OF NASA release 01-46 When NASA's 2001 Mars Odyssey launches in April to explore the fourth planet from the Sun, it will carry a suite of scientific instruments designed to tell us what makes up the Martian surface, and provide vital information about potential radiation hazards for future human explorers. "The launch of 2001 Mars Odyssey represents a milestone in our exploration of Mars-the first launch in our restructured Mars Exploration Program we announced last October," said Dr. Ed Weiler, Associate Administrator for Space Science, NASA Headquarters, Washington, DC. "Mars continues to surprise us at every turn. We expect Odyssey to remove some of the uncertainties and help us plan where we must go with future missions." Set for launch April 7 from Cape Canaveral Air Force Station, FL, Odyssey is NASA's first mission to Mars since the loss of two spacecraft in 1999. Other than our Moon, Mars has attracted more spacecraft exploration attempts than any other object in the solar system, and no other planet has proved as daunting to success. Of the 30 missions sent to Mars by three countries over 40 years, fewer than one-third have been successful. The Odyssey team conducted vigorous reviews and incorporated "lessons learned" in the mission plan. "The project team has looked at the people, processes, and design to understand and reduce our mission risk," said George Pace, 2001 Mars Odyssey project manager at NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA. "We haven't been satisfied with just fixing the problems from the previous missions. We've been trying to anticipate and prevent other things that could jeopardize the success of the mission." Odyssey is part of NASA's Mars Exploration Program, a long- term robotic exploration initiative launched in 1996 with Mars Pathfinder and Mars Global Surveyor. "The scientific trajectory of the restructured Mars Exploration Program begins a new era of reconnaissance with the Mars Odyssey orbiter," said Dr. Jim Garvin, lead scientist for NASA's Mars Exploration Program. "Odyssey will help identify and ultimately target those places on Mars where future rovers and landers must visit to unravel the mysteries of the Red Planet". NASA's latest explorer carries three scientific instruments to map the chemical and mineralogical makeup of Mars: a thermal- emission imaging system, a gamma ray spectrometer and a Martian radiation environment experiment. The imaging system will map the planet with high-resolution thermal images and give scientists an increased level of detail to help them understand how the mineralogy of the planet relates to the landforms. The part of Odyssey's imaging system that takes pictures in visible light will see objects with a clarity that fills the gaps between the Viking orbiter cameras of the 1970s and today's high-resolution images from Mars Global Surveyor. Like a virtual shovel digging into the surface, Odyssey's gamma ray spectrometer will allow scientists to peer into the shallow subsurface of Mars, the upper few centimeters of the crust, to measure many elements, including the amount of hydrogen that exists. Since hydrogen is mostly likely present in the form of water ice, the spectrometer will be able to measure permanent ground ice and how that changes with the seasons. "For the first time at Mars we will have a spacecraft that is equipped to find evidence for present near-surface water and to map mineral deposits from past water activity," said Dr. Steve Saunders, 2001 Mars Odyssey project scientist at JPL. "Despite the wealth of information from previous missions, exactly what Mars is made of is not fully known, so this mission will give us a basic understanding about the chemistry and mineralogy of the surface." The Martian radiation environment experiment will be the first to look at radiation levels at Mars as they relate to the potential hazards faced by future astronauts. The experiment will take data on the way to Mars and in orbit around the Red Planet. After completing its primary mission, the Odyssey orbiter will provide a communications relay for future American and international landers, including NASA's Mars Exploration Rovers, scheduled for launch in 2003. The Jet Propulsion Laboratory, Pasadena, CA, manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, DC. Principal investigators at Arizona State University, the University of Arizona and NASA's Johnson Space Center will operate the science instruments. Lockheed Martin Astronautics, Denver, CO, is the prime contractor for the project, and developed and built the orbiter. Mission operations will be conducted jointly from JPL, a division of the California Institute of Technology in Pasadena, and Lockheed Martin. Contacts: Donald Savage, Headquarters, Washington, DC, Phone: 202-358-1547 Mary Hardin, Jet Propulsion Laboratory, Pasadena, CA, Phone: 818-354-0344 --------------------------------------------------------------------- MARSBUGS AT THE SCIENCE FAIR By David J. Thomas 19 March 2001 In an effort to encourage research and education in astrobiology, Marsbugs: The Electronic Astrobiology Newsletter is offering an award certificate science fairs at the regional level and above. Science fair coordinators can download the certificate from the Marsbugs web site (http://welcome.to/marsbugs) and print it onto parchment or presentation paper. Guidelines for awarding the certificates are included with the certificate file as well as at the web site. Science fair coordinators are encouraged to submit information about the winning students and projects, which will be published in forthcoming issues of Marsbugs, and also included on the award web page. The Marsbugs award in astrobiology was first presented at the North Arkansas Regional Science Fair held at Lyon College in Batesville, AR, USA. The winning entries were: Cosey Preddy (Senior Division), "Effects of UV radiation on squash seeds," Marshall High School, Marshall, AR. Ashley Treadwell (Junior Division), "The effect of UV exposure on Brassica Rapa," Marshall High School, Marshall, AR. For more information on the Marsbugs astrobiology award, contact Dr. Dave Thomas at 870-698-4269 (dthomas@lyon.edu). --------------------------------------------------------------------- NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.h tml 19 March 2001 Articles about astrobiology, exobiology and terraformation http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s1.html R. R. Britt, 2001. Secrets to Mars water hidden in volcanic remains. Space.com. J. Hecht, 2001. All aboard the meteor express of life. SpaceDaily. G. V. Levin, A. S. Yen, S. S. Kim, M. H. Hecht, M. S. Frant and B. Murray, 2001. O2- Ions and the Mars labeled release response [letter and response]. Science, 291(5511):2041. Articles about the search for extraterrestrial intelligence (SETI) http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s4.html S. Shostak, 2001. SETI@Arecibo: Arecibo is better than ever. Space.com. S. Shostak, 2001. SETI@Arecibo: bigger is better. Space.com. S. Shostak, 2001. SETI@Arecibo: observatory life. Space.com. S. Shostak, 2001. SETI@Arecibo: the plodding pace of discovery. Space.com. Articles about primordial evolution and prebiotic chemistry http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s5.html J. Karow, 2000. A precursor of RNA? Scientific American. K.-U. Schöning, P. Scholz, S. Guntha, X. Wu, R. Krishnamurthy and A. Eschenmoser, 2000. Chemical etiology of nucleic acid structure: the ?-threofuranosyl-(3'?2') oligonucleotide system. Science, 290(5495):1347-1351. --------------------------------------------------------------------- CASSINI WEEKLY SIGNIFICANT EVENTS JPl release 1-7 March 2001 The most recent spacecraft telemetry was acquired from the Madrid tracking station on Wednesday, March 7. The Cassini spacecraft is in an excellent state of health and is operating normally. The speed of the spacecraft can be viewed on the "Present Position" web page at http://www.jpl.nasa.gov/cassini/english/where/. Post Jupiter science operations continued this week with the spacecraft alternating between Optical Remote Sensing (ORS) and Magnetospheric Imaging Instrument (MIMI) data collection. Additional activities included a High Water Mark clear and fault protection log reset, uplink of a Reaction Wheel Assembly (RWA) bias overlay and an RWA momentum unload, reset of the Composite Infrared Spectrometer (CIRS) focal plane assembly temperature, and a CDS-A and CDS-B automatic SSR repair. The Spacecraft Office (SCO) presented the results of their study on reaction wheel versus thruster usage for the duration of interplanetary cruise. The recommendation was to minimize wheel use during interplanetary cruise while still preserving the prime science, instrument engineering, and spacecraft engineering objectives of the cruise period. Project management has decided that, starting with C27, the spacecraft will be placed on thruster control and the use of reaction wheels will be minimized. Over the next couple of months, Science Planning will be working with Mission Planning, the SCO, and management to negotiate the time on reaction wheels and hydrazine use for C28 and beyond. The Cassini Instrument Operations (IO) Team and the Multi Mission Image Processing Laboratory (MIPL) have produced and delivered 24,947 ISS images-17,782 from the NAC and 7,165 from the WAC-and 5,079 Visual and Infrared Mapping Spectrometer (VIMS) cubes since Jupiter observations began. The final approval meeting for Cruise 25 was held this week. The sequence has been radiated to the spacecraft and will begin execution on March 12. C26 Science Planning Virtual Team (SPVT) development completed with the handoff of the SPVT products to the Sequence Virtual Team (SVT). Activity has now begun for the C26 SVT and C27 SPVT development. The MIPL delivered version D25 of the Imaging Science Subsystem (ISS) and VIMS data processing software to operations this week. The delivery contains many small corrections made as a result of the Jupiter operations. The VIMS data from Fomalhaut through day 2001/025 were then reprocessed with the current set of Level 1A product generation software. This effort resulted in a consistent VIMS data set from Fomalhaut. RADAR and Radio Science Subsystem (RSS) Operations team members met to discuss the possibility of performing joint observations of Saturn's rings during the tour. Additional discussions will be held, and an in-flight test requested, to clarify the type of interference that RADAR observes from RSS. Interference was first observed before launch during Assembly, Test, and Launch Operations (ATLO) testing when RSS exercised all three of its bandwidths: X, S, and Ka. Mission Planning led a forum on SSR use during tour. Discussion covered placement of OPNAVs and high-value science in separate partitions. The proposed scheme reduces operational complexity and ground development. Mission Assurance sponsored a demonstration of the electronic SIRTF and JPL institutional Risk Management Tools for Cassini staff. These tools facilitate management of Project risk data by providing web-based interface to a risk database. Tools and metrics may be tailored to meet individual Project needs. These were the first of several Risk Management tools to be evaluated for use on Cassini. Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, CA, manages the Cassini mission for NASA's Office of Space Science, Washington, DC. --------------------------------------------------------------------- THIS WEEK ON GALILEO JPL release 12-18 March 2001 This week's major scheduled activity is a propulsive maneuver on Friday. This burn of the spacecraft's primary steering jets will help to refine the trajectory leading up to the next planned flyby of the satellite Callisto in late May. The bulk of the week is occupied with playback of the data stored on the on-board tape recorder from the December flyby of Ganymede. The Near Infrared Mapping Spectrometer (NIMS) will complete the playback of its global map of Jupiter. This was a series of six observations, which covered all 360 degrees of longitude and spanned from pole to pole on the giant planet. These observations provide information on the composition of Jupiter's clouds, and when combined with data from previous orbits, also show how the composition of the cloud layers can evolve with time. The Solid State Imaging camera (SSI) will return a Jupiter Feature Track observation, so called because one atmospheric feature is tracked for a long period of time to see how it changes. This observation consists of a series of images of the turbulent region to the northwest of the Great Red Spot. This region is especially active and interesting, and has been the site of thunderstorm activity in the past. The area was imaged on four successive rotations of the planet (over the course of about 32 hours), to observe storm evolution over longer time scales than previously seen by Galileo. The observation used several infrared filters, which will allow scientists to view clouds at different depths in the atmosphere. These observations will have four times better resolution than those taken by the Cassini spacecraft, which was observing at the same time. The Cassini measurements will provide a global context for the more detailed Galileo pictures. 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 --------------------------------------------------------------------- STARDUST STATUS REPORTS JPL releases 9 March 2001 There were four Deep Space Network (DSN) tracking passes in the past week and all subsystems are performing normally. The Cometary Interplanetary Dust Analyzer (CIDA), provided by the Max-Planck- Institut für extraterrestrische Physik of Garching, Germany, was successfully commanded to operate in its negative mode. This mode allows the spacecraft to collect negative ions from interstellar space. A request was given from Co-Investigator, Jochen Kissel, for CIDA to be changed from its positive mode to negatitive mode in order to verify that the instrument is performing normally. During the last three weeks, CIDA has detected two possible dust hits on its target, bringing the total number of impacts to nine since its launch in February 1999. The next collection period, when the instrument will collect negative ions, starts March 16. 16 March 2001 There were three Deep Space Network (DSN) tracking passes in the past week and all subsystems are performing normally. The spacecraft was oriented to point the German Cometary and Interplanetary Dust Analyzer (CIDA) instrument into the interstellar dust stream and maintain such an orientation for the next few months. CIDA has already detected 5 particle hits since being turned on about 1 month ago. The Stardust mural that is hanging in the main hall of NASA Headquarters is being moved to the Baltimore Science Center as part of its display tour around the country. The Stardust Outreach team made presentations on comets and asteroids at the Griffith Observatory in Los Angeles and on Stardust at the JPL/NASA Educator Resource Center in Pomona, California. Outreach also participated in the Native American Initiative Educator Workshop in Shonto, Arizona that featured Stardust and comet exploration. Principal Investigator, Don Brownlee, participated in the Lunar and Planetary Science Conference in Houston, Texas. For more information on the Stardust mission-the first ever comet sample return mission-please visit the Stardust home page at http://stardust.jpl.nasa.gov. --------------------------------------------------------------------- End Marsbugs, Volume 8, Number 11.