MARSBUGS: The Electronic Astrobiology Newsletter Volume 7, Number 35, 18 September 2000. Editors: Dr. David J. Thomas, Math and Science Division, Lyon College, Batesville, AR 72503-2317, USA. dthomas@lyon.edu Dr. Julian A. Hiscox, School of Animal and Microbial Sciences, University of Reading, Reading, RG6 6AJ, United Kingdom. J.A.Hiscox@reading.ac.uk Marsbugs is published on a weekly to quarterly basis as warranted by the number of articles and announcements. Copyright of this compilation exists with the editors, except for specific articles, in which instance copyright exists with the author/authors. While we cannot copyright our mailing list, our readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing list. The editors do not condone "spamming" of our subscribers. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editors. E-mail subscriptions are free, and may be obtained by contacting either of the editors. Article contributions are welcome, and should be submitted to either of the two editors. Contributions should include a short biographical statement about the author(s) along with the author(s)' correspondence address. Subscribers are advised to make appropriate inquiries before joining societies, ordering goods etc. Back issues and Adobe Acrobat PDF files suitable for printing may be obtained from the official Marsbugs web page at http://welcome.to/marsbugs. The purpose of this newsletter is to provide a channel of information for scientists, educators and other persons interested in exobiology and related fields. This newsletter is not intended to replace peer- reviewed journals, but to supplement them. We, the editors, envision Marsbugs as a medium in which people can informally present ideas for investigation, questions about exobiology, and announcements of upcoming events. Astrobiology is still a relatively young field, and new ideas may come from the most unexpected places. Subjects may include, but are not limited to: exobiology and astrobiology (life on other planets), the search for extraterrestrial intelligence (SETI), ecopoeisis and terraformation, Earth from space, planetary biology, primordial evolution, space physiology, biological life support systems, and human habitation of space and other planets. --------------------------------------------------------------------- CONTENTS 1) THE HAUGHTON IMPACT CRATER AS A MODEL FOR MARS By Julian A. Hiscox 2) FREE LECTURE HIGHLIGHTS "SEEING THE UNSEEN" JPL release 3) NASA AND CITYARTS DEDICATE MURAL THAT'S OUT OF THIS WORLD NASA release 00-142 4) CONCEPTS AND APPROACHES IN MARS EXPLORATION By Bruce Moomaw 5) SPACE AGENCY CHOOSES LANDING SITE ON THE RED PLANET By Josh Chamot 6) DIG FOR LIFE ON MARS By Mark Schrope 7) LANDMARK COMMERCIAL AGREEMENT GIVES BIOTECHNOLOGY RESEARCH A NEW DIMENSION NASA release 00-143 8) EXPERIMENT SHOWS MARS NEEDS TO TAKE ANTIOXIDANTS FOR LIFE JPL release 9) THE PHYSICS AND BIOLOGY OF MAKING MARS HABITABLE-A TWO DAY WORKSHOP AT NASA AMES By Christopher P. McKay 10) NEW ADDITIONS TO THE ASTROBIOLOGY, EXOBIOLOGY AND TERRAFORMATION INDEX By David J. Thomas 11) CASSINI WEEKLY SIGNIFICANT EVENTS JPL release 12) THIS WEEK ON GALILEO JPL release 13) STARDUST STATUS REPORT JPL release --------------------------------------------------------------------- THE HAUGHTON IMPACT CRATER AS A MODEL FOR MARS By Julian A. Hiscox September 2000 Comets and asteroids have made a fundamental impact to both the geological and biological history of our planet. Many scientists believe that all of the water in our oceans was derived from the impact of icy comets. Many of the organic ingredients that made up the primordial soup, some four billion years ago, were probably either synthesized by impact events or delivered on the impacting bodies themselves. Indeed an impact event some 65 million years ago was directly responsible for the evolution and emergence of present day mammals--at the expense of the dinosaurs. We can see for ourselves how many impact events occurred by simply observing the Moon, which is absolutely covered in craters. Apart from these rather overt events, the impact of comets and asteroids has probably played a far subtler role in the development and evolution of life both on the Earth and possibly on Mars. For example, by delivering organic materials and water over localized areas that might otherwise lack these essential nutrients for life. One such region is the end of the Earth--Antarctica and the Arctic. They can be regarded as one of the most inhospitable places for life, which is why these places provide such good models for possible environments on ancient Mars. Yet careful analysis of these regions over the past few decades has indicated that microbial life can survive pretty much everywhere. For example, the Dry Valleys of Antarctica are the coldest, driest places on the planet, yet microbial communities, called cryptoendoliths, exist within surface layers of rock. The problem with using the Dry Valleys of Antarctica as a model for the human and robotic exploration of Mars is that the logistics and expense of going to these places is quite formidable. More importantly, the ecosystems in the Dry Valleys are extremely fragile and the prospect of scientists causing unintentional damage is deemed not worth the risk. One site that is moderately easy to access, and provides a good model for ancient Mars, is the Haughton impact crater on Devon Ireland, in the high Canadian arctic--a polar desert region. The crater formed some 23 million years ago and is approximately 20 km in diameter. The investigation of the Haughton crater is called the Haughton Mars Project and is a multidisciplinary investigation that is co-sponsored by NASA, the National geographic Society and various other bodies. The Haughton impact crater contains some seven lakes. The scientists studying this region have found that many of these lakes are hypersaline (more slat than the sea) yet contain abundant microbial life. By measuring rock densities they have determined that the impact event, and subsequent thermal pulse, generated a large amount of breccias. This rock is too compact for cryptoendoliths to colonise. However, some bacteria do live on the actual surface of rocks scattered on the crater floor. One of the scientists, Dr. Charlie Cockell formally at NASA Ames laboratory, and now at the British Antarctic Survey, studies the effect of ultraviolet (UV) radiation on these surface dwelling bacteria. By studying UV radiation in the Haughton impact site, Charlie and his colleagues hope to get a handle on the quantitative effects of increased UV exposure on microbial life. Many of these bacteria contain specialized proteins, which filter out harmful UV and can be up to 20% of their biomass. This research is of direct relevance to the possible evolution of life on Mars, because UV radiation would have played such a fundamental role in this process. The atmosphere of Mars has always been almost entirely composed of carbon dioxide (a greenhouse gas). Because Mars probably lacked plate tectonics, there has been no large-scale mechanism for recycling this gas, as occurs on the Earth. This would have had a profound effect on the martian environment. The atmosphere on ancient Mars chemically combined with mineral elements, becoming locked as carbonate. As the atmospheric pressure decreased, the amount of ozone and water vapor would have decreased, so increasing amounts of UV reached the surface. At some point the UV radiation would have been detrimental for any surface based life. Thus the studies at the Haughton impact crater can provide quantitative data on just how much UV bacteria can be exposed to in a natural environment and what, if any, adaptations occur. By returning year after year to the Haughton crater, the teams of scientists are building up large databases of information with regard to the effect of the environment on biology. Because the exploration of the crater site involves both human and robotic exploration this study is laying some of the groundwork for the human exploration of Mars. --------------------------------------------------------------------- FREE LECTURE HIGHLIGHTS "SEEING THE UNSEEN" JPL release 11 September 2000 "Seeing the Unseen: Using Spaceborne Radars in Earth and Planetary Exploration" is the latest in Jet Propulsion Laboratory's (JPL) free von Karman Lectures, taking place at JPL on Thursday, September 21 and at Pasadena City College on Friday, September 22. The lecture will focus on the advanced radar sensing technology currently being used to probe the surface and subsurface of Earth and other planetary bodies. Presented by Dr. Charles Elachi, director of JPL's space and Earth science programs, the lecture will highlight the endless discovery opportunities made possible by radar sensing, which can be used to produce images of targets that cannot be seen through other observing techniques. Elachi will cover the breakthroughs expected within the next decade when radar sensors will be used to probe the possible oceans below the surface of Jupiter's moon Europa, to map buried channels on Mars, to image the Earth in 3-D and to search for buried traces of old civilizations. Throughout his 30-year career at JPL, Elachi has played a significant role in transforming the Laboratory and NASA into world leaders in the field of spaceborne imaging radars. In the last decade, he has been responsible for the development of more than 45 flight instruments and missions for Earth science, astrophysics and planetary exploration at JPL and has received numerous national and international awards. Elachi holds several patents and has authored more than 200 publications in a variety of space and science fields. He is the author of three textbooks in the field of remote sensing and was deemed one of "Southern California's rising stars who will make a difference in L.A." by the Los Angeles Times in 1988. The von Karman Lecture Series is sponsored by the JPL's Public Services Office. Thursday lectures take place in JPL's von Karman Auditorium located at 4800 Oak Grove Dr. in Pasadena, while Friday lectures are given in Pasadena City College's Voslow Forum at 1570 E. Colorado Blvd. Both begin promptly at 7:00 PM, with seating available on a first-come, first-served basis. More information on the von Karman Lecture Series can be found at http://www.jpl.nasa.gov/lecture or by calling 818-354-0112. The California Institute of Technology manages JPL for NASA. Contact: Gia Scafidi Jet Propulsion Laboratory Phone: 818-354-0372 http://www.jpl.nasa.gov --------------------------------------------------------------------- NASA AND CITYARTS DEDICATE MURAL THAT'S OUT OF THIS WORLD NASA release 00-142 12 September 2000 More than 130 New York City youths had the opportunity to describe what it would be like to live on Mars, but not with words. These students used their imaginations and a paintbrush. They created a 7,000 square foot mural completed at the end of July that is one of the largest in New York City and is on the Bronx Community Elementary 64 building that faces the school yard. Students and community members painted the space scenes under the direction of artists Nicholas A. Enright and Nils Folke Anderson of Big Hands, a Bronx- based artist collaborative. Although NASA provided visual information to help spark the students' imaginations, the children relied mostly on their own creativity to interpret space exploration, past and present, with a focus on Mars. This permanent outdoor mural is partially funded by the NASA Art Program and the NASA Astrobiology Institute. The mural's producers, CityArts, a non-profit thirty-two years old public art organization will join NASA, Community Elementary 64, Big Hands and other civic, state and local officials in a dedication ceremony on September 13 at 4 PM EDT. The ceremony will take place on Townsend Ave, between E. 170 Street and E. 171 Street, Bronx, NY. The mural is a Mars Millennium Project sponsored by the White House Millennium Council, the U.S. Department of Education, the National Endowment for the Arts, and the J. Paul Getty Trust. The Mars Millennium Project challenges students to work in teams to produce a work of art or science that reflects their vision of the future. "Living on Mars" represents a new NASA millennium initiative of Administrator Daniel S. Goldin, who has tasked the NASA Art Program to reach out to diverse communities. Contacts: Sonja Alexander Headquarters, Washington, DC Phone: 202-358-1761 Tsipi Ben-Haim City Arts, New York, NY Phone: 212-966-0377 --------------------------------------------------------------------- CONCEPTS AND APPROACHES IN MARS EXPLORATION By Bruce Moomaw From SpaceDaily 12 September 2000 NASA has now essentially decided--in accord with the recommendations of most of the participants at last July's Houston conference on "Concepts and Approaches in Mars Exploration"--that the form of the Mars program needs to be drastically changed, in the direction of extensive reconnaissance of the planet before landing sites are picked out for unmanned sample-return missions. But what should the details of the new program be? Actually, another question comes before that one: to what extent should the new Mars program be planned out in advance? Several Conference participants pointed out that too much advance planning too far into the future can lead to serious trouble itself... Get the full story at http://www.spacedaily.com/news/mars-general- 00m.html. --------------------------------------------------------------------- SPACE AGENCY CHOOSES LANDING SITE ON THE RED PLANET By Josh Chamot From Space.com 12 September 2000 When NASA's next rovers truck along the red planet's surface, they may have company. The European Space Agency (ESA) is landing its own craft on Mars in 2004, and the likely target is Isidis Basin, one of NASA's highest priority landing sites. "At the moment, Isidis is the best choice," said Mark Sims, Project Manager for the ESA lander, Beagle 2. A final decision will be made in December. Just north of the martian equator, Isidis is "a scientifically interesting site," said Sims, and it fits the strict requirements necessary to land safely and function in Mars' harsh environment. The British-built Beagle 2 is set to tote a privately funded microscope to Mars. Even before the recent Mars mishaps, site choice has been more about not crashing than about finding the best science. While knowledge is the ultimate goal for any trip to Mars, there is little that can be done if the spacecraft doesn't land on its feet. Get the full story at http://www.space.com/news/spaceagencies/beagle_esa_000911.html. --------------------------------------------------------------------- DIG FOR LIFE ON MARS By Mark Schrope From New Scientist http://www.newscientist.com 13 September 2000 Find liquid water on Mars, and life may not be far behind. Many scientists believe that this water can only exist thousands of meters beneath the planet's surface. So a team of engineers at NASA's Jet Propulsion Laboratory in Pasadena, California, is developing a robotic mole that can drill deep into Mars and return samples to the surface through a tube that it constructs as it digs. JPL's martian mole moves through the ground like a pile driver, repeatedly raising an internal weight and then hammering it into the ground. On Mars it will be wired up to a set of solar panels on the surface that provide only enough power to illuminate a few light bulbs. So the designers had to make a machine that could penetrate the ground using only this meager power. The design JPL came up with has a hammerhead that spins at up to 20,000 revolutions per minute before engaging a central thread that drives it into the ground. This delivers roughly twice the force of a sledgehammer blow on Earth, and enables the mole to burrow at up to 10 meters per day. As it digs, the mole extrudes a tiny tube containing two passageways, which provide a link to the surface and back. Liquid xenon circulating through these tubes will carry samples that can be sieved and analyzed on the surface. One possible target for the mission is a potential aquifer that many scientists believe may exist about 5 kilometers down near the martian equator, says Brian Wilcox, the project leader. Another option is to aim for one of the planet's polar ice caps and study Mars's climate history over the past few million years by examining ice samples. The group has already built a prototype of the hammer mechanism and is now planning the tube extruder. In 2002, Wilcox plans to test the complete system in the Alaskan permafrost. He says his team could be ready to tackle Mars within a decade. "Drilling may well be the only way we can get to places that have a chance of having life on Mars today," says Michael Carr, a geologist at the US Geological Survey who is reviewing NASA's Mars program. New Scientist issue: 16 September 2000. Contacts: Claire Bowles claire.bowles@rbi.co.uk Phone: 44-207-331-2751 New Scientist Washington Office newscidc@idt.net Phone: 202-452-1178 An additional article on this subject is available at http://www.spacedaily.com/news/mars-driller-00b.html. --------------------------------------------------------------------- LANDMARK COMMERCIAL AGREEMENT GIVES BIOTECHNOLOGY RESEARCH A NEW DIMENSION NASA release 00-143 14 September 2000 NASA has entered into a groundbreaking agreement with the private sector to explore a new frontier in biotechnology, focusing on infectious disease research and developing a liver-assist device for patients in need of transplant surgery. Inspired by a news article on NASA's efforts to commercialize space activities, H. Fisk Johnson, Ph.D., president of Wisconsin-based, private venture capital company Fisk Ventures, Inc. (FVI), approached the Agency about a partnership which culminated in an agreement to develop commercial medical products using NASA's Bioreactor technology. "This is a great deal for the American people," said NASA Administrator Daniel S. Goldin. "It's a symbol of the success that can be achieved when government, private industry and academia work together on the exploration of new frontiers for scientific, technological and economic growth." Goldin and Johnson signed the agreement today in a ceremony at the U.S. Capitol. "Some of the best minds from NASA and our group collaborated over three years, conducting an extensive analysis to determine what was technically possible and the most likely to succeed in the market," Johnson explained. "This led us to NASA's ability to conduct research on cell cultures in the microgravity environment of space, and its unique cell-culture technology on the ground, that bridges the gap between what you can do in the traditional lab and what you can do in a space-based lab." NASA invented the rotating bioreactor as a way to study the impact of microgravity on cellular growth both here on Earth and in space. Traditional cell-growth research often produces single-cell, pancake- like cultures. The bioreactor works by spinning a fluid medium filled with cells. The spinning motion neutralizes most of gravity's effects, creating a near-weightless environment that allows cells to grow more freely, in a three-dimensional manner. FVI and In Vitro Technologies, Inc. of Maryland have formed a joint venture to turn this market-driven model into a scientific and commercial success. The new venture--StelSys, based in Baltimore, MD--will focus on commercializing microgravity research specifically in areas related to biological systems. "NASA's bioreactor technology is simply a tool box, and if you give a tool box to the right people, they can build a house," said Goldin. "We believe we've put this tool box in the right hands of the right people." "The goal is revolutionary improvements in health care," he continued, "including: * Biomolecule Production: Mature liver cells make unique biomolecules for the body. By using the bioreactor to simulate the natural conditions within the body, we could potentially harvest the biomolecules and use them as a jump-start on the road to new drugs or other therapies. This could help us to screen drugs, test them, and get them to patients more quickly. * Natural Vitamin D3 Production: People on kidney dialysis need Vitamin D3, but it is expensive to make and difficult to purify. The bioreactor will allow StelSys to mimic the natural D3 production in kidney cells and assess whether D3 can be produced easily and inexpensively. * Culturing Infectious Diseases: Some pathogens that cause disease cannot be grown effectively using traditional cell culturing technology. Use of the bioreactor could allow us to grow pathogens under conditions similar to those in the body. When scientists have the means to study these pathogens, they may be better able to develop and test treatments for them. * Liver assist device: Today, people with severe liver failure cannot survive without a transplant. The bioreactor could lead to the development of a machine to bridge the wait time between diagnosis and transplant, giving hope to the 25,000 Americans who die from liver disease each year." Johnson added, "Looking at this from both a scientific and business perspective, I am convinced there is great potential for microgravity and the bioreactor to unleash new developments with significant social and commercial value." Contact: Sarah Keegan Headquarters, Washington, DC Phone: 202-358-1902 --------------------------------------------------------------------- EXPERIMENT SHOWS MARS NEEDS TO TAKE ANTIOXIDANTS FOR LIFE JPL release 14 September 2000 Intense ultraviolet radiation that pierces Mars' thin atmosphere produces an abundance of oxygen ions, a common free radical, at the martian surface that destroys organic molecules--the building blocks of life--according to researchers at NASA's Jet Propulsion Laboratory, Pasadena, CA. Scientists have been puzzled since the mid-1970s when NASA's Viking landers failed to find any organic materials, not even traces delivered to Mars by meteorites. That discovery led scientists to recognize that there were oxidants in the martian soil capable of destroying organic molecules. It has taken until now for a team to come up with a comprehensive idea of what those oxidizing chemicals are and how they form. "We simulated the martian surface environment in our laboratory and found that the combination of ultraviolet radiation, mineral grain surfaces, atmospheric oxygen and extremely dry conditions produce superoxide ions. This is all that is necessary to make the reactive component of soil," said Dr. Albert Yen, a JPL planetary scientist and lead author of the study being published in Science magazine on September 15. This combination of surface conditions exists on Mars today and the superoxides are generated during daytime exposures to ultraviolet radiation. "Our research does not address whether life ever formed on Mars, but it does give us more information about where to look for life or evidence of past life," Yen said. "Evidence of life might exist beneath the surface or in the interiors of rocks that are protected from the superoxide ions. What we don't know is how far below the surface we would need to look." "Determining how deep that oxidizing layer is on Mars is the most important next step in searching for life there," said Caltech Professor Bruce Murray, a co-author on the study. The research team plans to study the movement of these oxygen radicals under simulated martian conditions to estimate how deep they may be distributed. Future experiments to search for subsurface organic molecules could be carried out by penetrators and/or by drilling from a surface lander. The martian soil experiment was conducted at JPL for NASA's Office of Space Science and the Office of Life and Microgravity Sciences and Applications, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena. Contact: Mary Hardin Jet Propulsion Laboratory Phone: 818-354-0344 An additional article on this subject is available at http://spaceflightnow.com/news/n0009/17marsoxides/. --------------------------------------------------------------------- THE PHYSICS AND BIOLOGY OF MAKING MARS HABITABLE-A TWO DAY WORKSHOP AT NASA AMES By Christopher P. McKay 15 September 2000 Tuesday and Wednesday (10 and 11 October; following the Monday federal holiday) Building 245 Main Auditorium Tentative schedule Tuesday 10 October 9:00 AM, Start M. Averner: Overview C. McKay: Introduction to terraforming 9:30 AM, Session I. Mars climate and photochemistry, Chairs: C. McKay, M. Fogg, J. Levine R. Haberle: Exchangeable reservoirs of CO2 and water on Mars: polar caps & atmosphere A. Zent: Exchangeable reservoirs of CO2 and water on Mars: regolith M. Marinova: Warming Mars using super greenhouse gases 10:30-11:00 AM, Break Y. Yung: Infrared absorption properties of novel super greenhouse gases R. Lorenz & E. Carlstrom: Maximum entropy models for future Mars M. Fogg: Mathematical models for terraforming 12:30-1:30 PM, Lunch R. Zubrin: Engineering approaches to warming Mars S. Thompson: Rain and circulation on future Mars J. Levine: O2 and O3 levels in a thick CO2 atmosphere on future Mars D. Catling: UV light on present and future Mars 3:00 PM, break 3:30 PM, Session II. Ecology, Chairs: J. Hiscox, P. Boston, C. Cockell I. Friedmann: Antarctic & desert ecosystems as analogs for the first martian ecosystems C. Cockell: Arctic ecology applied to Mars D. Bubenheim: Growing alpine plants on Mars 5:00 PM, end Wednesday 11 October 9:00 AM, Session II (continued). Ecology, Chairs: J. Hiscox, P. Boston, C. Cockell J. Graham: Ecological succession on Mars R. Mancinelli: Nitrogen cycling on Mars R. Navarro: Tropical treeline: growing pines on Mars 10:00-10:30 AM, Break M. Heath: Habitable planets for trees C. Cockell: Experiments with insects and worms at low pressure D. Bubenheim: From CLESS to Mars M. Nelson: From closed biospheres to Mars P. Boston: Biogeochemical cycling in the absence of plate tectonics 12:00-1:00 PM, Lunch 1:30 PM, Session IV. Genetics, Chair: C. McKay A. Ellington: Engineering life to survive and thrive on Mars J. Hiscox: What can be done with genetic engineering Session V. The long and the short of it. Chair: R. Zubrin C. McKay: Sending life to Mars: near term missions K. Zahnle & G. Laughlin: Long-term plans for enhancing the volatile inventory of Mars C. McKay: An approach to environmental ethics of planetary engineering K. S. Robinson: Planetary engineering in the broad social context R. Zubrin: Mars as the first step 5:00 PM, end Badges If you do not have a US government or military ID which can get you through the Ames gate, you must stop at the Ames Visitor Badging Office when you first arrive (it is open 6:00 AM to 6:00 PM). This Office will issue you a badge that will get you through the gate at Ames and serve as your symposium ID. You must show a photo ID to be issued your badge. If you have a government ID your Symposium ID will be at the registration desk at the symposium site (Building 245 Auditorium). Allow ample time (~30 minutes) to pick up your badge before the Meeting begins at 9:00 AM Tuesday. When you come to Ames (we are located just off Highway 101 between the cities of Mt. View and Sunnyvale CA. About 30 miles south of San Francisco airport and about 15 miles north of San Jose airport. Both San Francisco and San Jose Airports, and Ames are adjacent to Highway 101) There are signs on 101. Coming from San Francisco the second Moffett Exit (labeled Moffett Field; the first one is labeled Moffett Blvd) takes you up and over the freeway effectively making a left turn off the freeway into Moffett. The main gate to Ames is literally the exit off the freeway so you can't get lost. However don't try to enter the main gate since you won't have a badge or a car pass. Go toward the main gate in the right-most lane that is open and tell the guard that you want to turn into the parking area for the guardhouse. Inside is the visitor badge office and they will have a badge for you. They will also give you a map with instructions to the meeting site. The meeting is in building 245 in the auditorium on the second floor. As you enter the gate proceed straight toward the very large (dirigible) hanger. The road curves a bit but stay in the left lane. The first stop sign is McCord. Turn left on McCord and follow this to its end (4 or 5 stop signs) and it has changed its name to Mark. At the end of McCord/Mark follow the curve of the road to the right and this will take you directly to building 245. Building 245 is the building in the extreme Northeast corner of the Center. The most recent updates, as well as housing and travel information, are available at http://web.mit.edu/mmm/www/terraforming.html. Contact: Christopher P. McKay Space Science Division Mail Stop 245-3 Moffett Field, CA 94035 cmckay@arc.nasa.gov Phone: 650-604-6864 Fax: 650-604-6779 --------------------------------------------------------------------- NEW ADDITIONS TO THE ASTROBIOLOGY, EXOBIOLOGY AND TERRAFORMATION INDEX By David J. Thomas 18 September 2000 Astrobiology, exobiology and terraformation articles online http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s1.html J. Chamot, 2000. Space agency chooses landing site on the red planet. Space.com. J. I. Lunine, 1999. In search of planets and life around other stars. Proceedings of the National Academy of Sciences, 96(10):5353- 5355. B. Moomaw, 2000. Concepts and approaches in Mars exploration. SpaceDaily. M. Schrope, 2000. Digging for life on Mars. SpaceDaily. D. Segré, D. Ben-Eli and D. Lancet, 2000. Compositional genomes: prebiotic information transfer in mutually catalytic noncovalent assemblies. Proceedings of the National Academy of Sciences, 97(8):4112-4117. T. L. Sheppard, P. Ordoukhanian and G. F. Joyce, 2000. A DNA enzyme with N-glycosylase activity. Proceedings of the National Academy of Sciences, 97(14):7802-7807. A. S. Yen, S. S. Kim, M. H. Hecht, M. S. Frant and B. Murray, 2000. Evidence that the reactivity of the martian soil is due to superoxide ions. Science, 289(5486):1909-1912. Articles on human space exploration and the microgravity environment http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s3.html L. E. Freed, R. Langer, I. Martin, N. R. Pellis and G. Vunjak- Novakovic, 1997. Tissue engineering of cartilage in space. Proceedings of the National Academy of Sciences, 94(25):13885-13890. --------------------------------------------------------------------- CASSINI WEEKLY SIGNIFICANT EVENTS JPL release 7-13 September 2000 The most recent spacecraft telemetry was acquired from the Madrid tracking station on Wednesday, 9/13. The Cassini spacecraft is in an excellent state of health and is operating normally. The speed of the spacecraft can be viewed on the "Where is Cassini Now?" web page at http://www.jpl.nasa.gov/cassini/today/. The Cruise 21 sequence concluded this week with real time commands sent to the spacecraft to optimize the dust stream measurements for the Cosmic Dust Analyzer (CDA), to power off the Imaging Science Subsystem (ISS) Narrow Angle Camera (NAC) & Wide Angle Camera (WAC), and to turn ISS replacement heaters on. The Final Sequence Integration & Validation (SIV) Approval Meeting was held for Cruise 22. The sequence was then uplinked, registered and activated. C22 is the first of four sequences containing science activities supporting the Jupiter flyby. It contains the first instance of "repeating template" observations. The template is five days in duration, contains a specific set of observations, and will repeat continuously until ten days into the C23 sequence when a change in observations is desired. A total of four different templates has been designed for the Jupiter period. Templates will be used throughout the Jupiter sub-phase except for approximately Jupiter -25 days to +22 days. At that time templates are suspended and unique observations will occur. Templates were implemented due to the need for simplified operations during Cassini's cruise phase. Activities for the start of C22 included setting of the off sun time constraint, reaction wheel desaturation, loading of a new body vector, ISS power on, replacement heaters off, and IEB load, and the start of Cassini Plasma Spectrometer (CAPS), Cosmic Dust Analyzer (CDA), and Ultraviolet Imaging Spectrometer (UVIS) Flight Software (FSW) loads. The FSW load activity will continue into next week. Cruise 23 has completed the subsequence generation phase with all instrument teams and the Spacecraft Office supplying their detailed command requests for the background sequence. C23 is now in the Sequence Integration and Validation Phase, where all subsequences will be integrated together to produce the official background sequence. The CDA experimenters from the Max-Planck-Institut fur Kernphysic in Heidelberg, Germany, brought the engineering model of their instrument to the Integration and Test Laboratory (ITL) at JPL for detailed flight software testing. The integration of the instrument into the lab was completed and testing is underway. The Spacecraft Operations Office held a bimonthly Flight Software and Critical Sequence status review. All user acceptance testing of TC&DM V25.2 is complete and all reports are finished. This delivery includes telemetry (TLM), command (CMD) and the Distributed Object Manager (DOM). A Delivery Coordination Meeting (DCM) for installation has been held. The plan is to install on the SUNs first and then proceed with HPs. Invitations have gone out for two upcoming educator workshops: "Millennium Flyby Science" and "Radio Astronomy at Jupiter." Registration will continue for both workshops through Friday 6 October 2000. It is anticipated that both will be full prior to that date. More information may be obtained via the Cassini Educator Hotline at 818-393-5683 or e-mail sent to Cassini.Edu@jpl.nasa.gov. The "Millennium Flyby Travel Guide" has been released by Document Review and will be ready for web posting and printing later this month. The Travel Guide will be available on the Cassini Millennium Flyby web site at http://www.jpl.nasa.gov/cassini. --------------------------------------------------------------------- THIS WEEK ON GALILEO JPL release 11-17 September 2000 Having passed the farthest point from Jupiter in its current orbit, Galileo now heads back toward an encounter with Ganymede in December 2000. The spacecraft plays back data from two encounters this week. The first part of the week sees data returned from an observation performed during Galileo's May encounter with Jupiter. The second part of the week provides data from the spacecraft's February flyby of Io. Data return is interrupted three times this week. On Monday, the spacecraft performs standard maintenance on its onboard tape recorder. On Wednesday, the Solid-State Imaging camera (SSI) takes a series of optical navigation (opnav) images. On Thursday, maintenance on the spacecraft's propulsion systems is scheduled. Wednesday's opnav images are taken to replace similar images planned a couple of weeks ago. The spacecraft successfully took and transmitted those images, but they were not received here on Earth due to heavy rains in Goldstone, California. Goldstone is home to one of the three 70-m (230-foot) diameter radio antennas used by Galileo. The other two antennas, part of the Deep Space Network, are located in Madrid, Spain and Canberra, Australia. The optical navigation images will be used to determine the health of SSI, after a recent anomalous behavior from an internal light source. Seven different observations are returned this week. One observation from May is returned by the Fields and Particles instruments (F&P). The F&P instruments are the Dust Detector, Energetic Particle Detector, Heavy Ion Counter, Magnetometer, Plasma Detector, and Plasma Wave instrument. The remaining six observations are from the February flyby of Io and are returned by the Solid-State Imaging camera (SSI) and the Near-Infrared Mapping Spectrometer (NIMS). These latter observations are from a second pass through the observations stored on the tape recorder during the February encounter. This additional pass is scheduled for the return of additional data, replay of data lost in transmission to Earth, and/or reprocessing of data using different parameters. The return of the F&P observation continues from previous weeks, and contains the recorded portions of a month-long low-resolution survey of Jupiter's magnetosphere. The survey will provide scientists with measurements of the plasma, dust, and electric and magnetic fields in the inner and outer regions of Jupiter's magnetosphere, and in the transition out into the solar wind. In addition, the low-resolution data provide contextual information for high-resolution recordings also made by the F&P instruments during the Ganymede flyby portion of the May encounter. SSI returns portions of four observations of Io this week. The first captures the Prometheus plume source and active lava flow. The next observation is of Tohil Mons, one Io's mountains, whose geological structure, origin and history are presently not well known. SSI's next observation is a color mosaic of the Prometheus volcanic region. Finally, SSI returns portions of a 12-frame mosaic covering the Camaxtli Patera hot spot and nearby regions to the west, including the Chaac Patera region. NIMS returns parts of two observations. The first is a mosaic of several different volcanic regions on Io. The second also captures different volcanic regions, but focuses on the Prometheus volcanic vent in particular. 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 REPORT JPL release 15 September 2000 There were two Deep Space Network (DSN) tracking passes during the past week. All subsystems onboard the spacecraft are performing normally. A Medium Gain Antenna (MGA) DSN pass used the Solid State Power Amplifier (SSPA) 1 and did not show a power drop. During the previous two MGA DSN passes (early August) the SSPA 1 exhibited its 3db drop in power output that was observed a year ago. At that time, root cause was thought to be due to trapped charge particles accumulating in on one the floating point gate array (FPGA) chips. The SSPA operation was changed from leaving the SSPA on continuously to power cycling between DSN tracking passes to stop the gain. When this power cycling strategy was adopted the 3 dB power drop ceased. The investigation has been re-opened with an emphasis on SSPA temperature since during the pass on Saturday the SSPA temperature was slightly cooler than the two previous passes. Five Navigation Camera (NAVCAM) images were taken using five different mirrors. Each image had a minimum of three 6th magnitude stars in the field of view. These images will be used to determine any improvements to the NAVCAM performance since the CCD heater test. With the current DSN scheduling, it will take approximately two weeks to transmit the images stored onboard the spacecraft to Earth. Plans are being developed to perform another NAVCAM CCD heater test, which one change that would include turning on the Navigation Mirror heater to raise the overall temperature in the optical path. For more information on the Stardust mission--the first ever comet sample return mission--please visit the Stardust home page at http://stardust.jpl.nasa.gov. --------------------------------------------------------------------- End Marsbugs, Volume 7, Number 35.