MARSBUGS: The Electronic Astrobiology Newsletter Volume 10, Number 15, 14 April 2003. Editor/Publisher: David J. Thomas, Ph.D., Science Division, Lyon College, Batesville, AR 72503-2317, USA. dthomas@lyon.edu Contributing Editor: Julian A. Hiscox, Ph.D., School of Animal and Microbial Sciences, University of Reading, Reading, RG6 6AJ, United Kingdom. J.A.Hiscox@reading.ac.uk Marsbugs is published on a weekly to monthly basis as warranted by the number of articles and announcements. Copyright of this compilation exists with the editors, except for specific articles, in which instance copyright exists with the author/authors. While we cannot effectively copyright our mailing list, our readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing list. The editors do not condone "spamming" of our subscribers. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editors. E-mail subscriptions are free, and may be obtained by contacting either of the editors. Information concerning the scope of this newsletter, subscription formats and availability of back-issues is available from the Marsbugs web page at http://welcome.to/marsbugs or http://www.lyon.edu/webdata/users/dthomas/marsbugs/. ________________________________________________________________________ CONTENTS 1) MARS GULLIES COULD HARBOR MARTIAN BIOLOGY By Leonard David 2) NASA SCIENTISTS TO DRILL FOR NEW, EXOTIC LIFE NEAR ACIDIC SPANISH RIVER NASA/ARC release 03-24AR 3) RUSSIA TO CONFINE SIX COSMONAUTS FOR 17 MONTHS IN MARS EXPERIMENT From Agence France-Press and SpaceDaily 4) CALL FOR PAPERS: SIXTH INTERNATIONAL MARS SOCIETY CONVENTION Mars Society release 5) HITCHHIKERS MAY HAVE THUMBED A RIDE TO MARS By Leslie Mullen 6) NASA NEEDS NEW VISION FOR HUMAN SPACEFLIGHT, ASTEROID PROTECTION, EXPERTS SAY By Robert Roy Britt 7) ACROSS GENERATIONS: SETI LOOKS TO THE FUTURE By Douglas Vakoch 8) MARS MYSTERIES REVEALED IN TWO PUBLIC LECTURES NASA release 2003-050 9) NASA ROVERS SLATED TO EXAMINE TWO INTRIGUING SITES ON MARS NASA/JPL release 2003-051 10) PROJECT PHOENIX: SETI PREPARES TO OBSERVE AT ARECIBO By Peter Backus 11) LIFE'S WORKING DEFINITION: DOES IT WORK? From Astrobiology Magazine 12) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 13) CONTINUING COVERAGE OF THE COLUMBIA DISASTER By David J. Thomas 14) CASSINI SIGNIFICANT EVENTS NASA/JPL release 15) GALILEO MILLENNIUM MISSION STATUS NASA/JPL release 2003-049 16) MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 17) STARDUST STATUS REPORT NASA/JPL release ________________________________________________________________________ MARS GULLIES COULD HARBOR MARTIAN BIOLOGY By Leonard David From Space.com 7 April 2003 Over the decades, a flotilla of Mars spacecraft have relayed back to Earth freeze-frame portraits of a cold, dry, dusty and desolate planet. But Mars experts are becoming progressively more surprised as they observe a world in constant change. Evidence is mounting that the red planet bares witness to very young, water-related features. Mars has undergone episodic climate cycles that have caused dramatic changes to its surface. Some of these climate swings may have been fairly recent as measured in geologic time. For one, new spacecraft imagery shows apparent signs of water seeping into what look to be young, freshly cut gullies and gaps in the martian surface. Given that water is the elixir of life, could Mars biology cuddle up to such wild and wet features, not just in the long ago, but even today? Read the full article at http://www.space.com/scienceastronomy/mars_experiments_030407.html. ________________________________________________________________________ NASA SCIENTISTS TO DRILL FOR NEW, EXOTIC LIFE NEAR ACIDIC SPANISH RIVER NASA/ARC release 03-24AR 8 April 2003 NASA scientists will visit Spain April 10 through 12 to search for drilling sites where later this fall they plan to look for exotic life forms that may live underground near the Rio Tinto, a river in southwestern Spain. During the Mars Analog Research and Technology Experiment (MARTE), scientists and engineers from NASA, U.S. universities and the Spanish Centro De Astrobiología (Center for Astrobiology) hope to show how robot systems could look for life below Mars' surface. Bacteria may dwell beneath the surface, eating minerals derived from subsurface rocks that contain iron and sulfur. Similar bacteria are in the very acidic Rio Tinto, and these microbes may play a role in producing acid in the river. Located in a region that legend claims was part of King Solomon's mines, the Rio Tinto looks like deep, red wine, because iron is dissolved in the highly acidic river water. "The Rio Tinto area is an important analog to searching for life in liquid water, deep beneath the subsurface of Mars," said Carol Stoker, principal investigator of the three-year project and a scientist at NASA Ames Research Center in California's Silicon Valley. "Beginning next fall, we plan to start drilling to explore for life in subsurface waters that are the source of the Rio Tinto," she said. The team plans to explore the area using a drill and science instruments designed for use in a Mars mission. Scientists at NASA facilities in the United States and at the Centro de Astrobiología in Madrid will remotely operate a robotic drill and life-detection instruments, and will interpret the results, all via satellite, to simulate the operation of a mission to search for life on Mars. At the same time, scientists at the drill site will conduct traditional core sample drilling and analysis to understand subsurface life forms at the site and to check the accuracy of the remote-control efforts to identify life forms, organic compounds and minerals. "From a planetary exploration, technological point of view the project could have a large impact, since a drilling system and many instruments and equipment developed specifically from the project are going to be tested outside a laboratory, (in) uncontrolled environmental conditions like high temperature, humidity, transport vibration, etc.," said Javier Gómez-Elvira, lead engineer for robotics for the Centro de Astrobiología. Because the science team will remotely operate all equipment and instruments including, the drill, many 'lessons learned' could result that could be used for a real Mars mission, Gómez-Elvira explained. The subsurface is the key environment for searching for life on other planets, according to MARTE scientists. "Life needs liquid water and a source of energy," Stoker said. "On Earth, most common life forms are at the surface where sunlight provides the energy, but liquid water occurs rarely at the martian surface, if at all. Liquid water is expected in the subsurface of Mars. So, NASA plans to use robotic drilling to search for subsurface life. That is why we are testing the life search strategy in the Rio Tinto, where subsurface water and chemical energy are expected to support life." Stoker added. Scientists say evidence suggests the chemistry of the Rio Tinto and its biology may be the result of an underground biologically based chemical reactor fueled by organisms that do not need oxygen gas to survive. MARTE scientists propose that such a system may exist in the subsurface of the Rio Tinto area, according to Ricardo Amils Pibernat, a biologist at the Centro de Astrobiología and a specialist on the biology of the Rio Tinto. If found, this type of life would represent an entirely new subsurface life system, he said. One of the largest deposits of sulfide minerals in the world is in the Rio Tinto region. Similar mineral deposits may well be found on Mars, according to the scientists. "There is a critical and immediate need for technology maturation for drilling that can be done during a field experiment on Earth to simulate a Mars mission," Stoker said. "It is crucial to prepare for Mars exploration by understanding the relevant terrestrial environments where life persists," she added. Searching for life in the subsurface of another planet will not only require drilling, but sample extraction and handling, as well as new technologies to identify biomarker compounds and search for living organisms, according to Stoker and her colleagues. "A biomarker compound is like a signature left by life," she explained. During the Rio Tinto campaign, the drill and the robotic system will bring cores of underground rock to the surface. There, a suite of remotely operated science instruments that simulate a Mars mission payload will analyze samples and search for signs of life or biomarkers. The Signs of Life Detector (SOLID) instrument, developed at the Centro de Astrobiología, will search for life in the samples using new technology derived from molecular biology. This instrument can detect not just whole organisms, but macromolecules or other life byproducts, said Gómez-Elvira. "In addition to looking for evidence of subsurface life, we hope MARTE inspires students to pursue careers in science and engineering," Stoker said. "Because of the location in Spain, we're hoping this experiment will be of particular interest to Hispanic students." The NASA team also will meet with Spanish scientists in Madrid April 14 through 15 at the Centro De Astrobiología. The Astrobiology Science and Technology for Exploring Planets program at NASA Headquarters, Washington, is funding the project. Publication-size images are available at http://amesnews.arc.nasa.gov/releases/2003/03images/tinto/tinto.html. Broadcast-quality sound files of interviews suitable for radio broadcast are at http://amesnews.arc.nasa.gov/audio/tinto/tintoaudio.html. Contacts: John Bluck NASA Ames Research Center, Moffett Field, CA Phone: 650-604-5026 or 650-604-9000 E-mail: John.G.Bluck@nasa.gov Juan Baustista Rodriguez Instituto Nacional de Tecnica Aeroespacial (INTA), Spain Phone: 34 91 520 1938 An additional article on this subject is available at http://www.astrobio.net/news/article424.html. ________________________________________________________________________ RUSSIA TO CONFINE SIX COSMONAUTS FOR 17 MONTHS IN MARS EXPERIMENT From Agence France-Press and SpaceDaily 8 April 2003 Russia is to confine six cosmonauts in an imitation spacecraft for nearly a year and a half to prepare for a possible manned flight to Mars in 2018, and foreign cosmonauts could be invited to join in, a top medical official said Tuesday. The experiment will be designed to simulate conditions that could be encountered during a return journey to the red planet that under preparation, Dmitry Malashenkov of the Institute of Biological and Medical Problems told AFP. "The experiment to be carried out at the institute will involve six people spending 500 days in an enclosed space inside the ground module of a space station where certain conditions of a Mars flight will be simulated," he said. Read the full article at http://www.spacedaily.com/2003/030408154101.1oko823r.html. ________________________________________________________________________ CALL FOR PAPERS: SIXTH INTERNATIONAL MARS SOCIETY CONVENTION Mars Society release 8 April 2003 August 14-17, 2003 Hilton Hotel, Eugene, Oregon The Mars Society was founded to further the exploration and settlement of the Red Planet. The International Mars Society convention presents a unique opportunity for those interested in Mars to come together and discuss the technology, science, social implications, philosophy and a multitude of other aspects of Mars exploration. Highlights of the convention will include the report from the fourth field season of the Devon Island Flashline Mars Arctic Research Station, the second season of the Mars Desert Research Station, the building of the EuroMARS in Iceland, status reports from the Translife Mars Gravity Biosatellite Mission and Analog Rover teams, panels and debates concerning key issues bearing on Mars exploration and settlement, and keynote addresses from many prominent leaders of the effort to get humans to Mars. Prior conventions have drawn thousands of participants from all over the world and received extensive press coverage in many leading international media. This year's conference should be the most exciting event to date. Conference sessions 1. The Search for Life on Mars 2. Findings from Global Surveyor and Odyssey 3. Plans for the Mars Missions of 2003 and 2005 4. The Cross Contamination Threat-myth or reality? 5. Concepts for Future Robotic Mars missions 6. Piloted Missions to Mars 7. Advanced Propulsion 8. Launch Vehicles for Mars Exploration 9. Long Range Mobility on Mars 10. Life Support technology 11. Biomedical and Human Factors Issues in Mars Exploration 12. Options for Producing Power on Mars 13. Methods of Martian Construction 14. In Situ Resource Utilization 15. Water on Mars--Accessing the Hydrosphere 16. Concepts for a Permanent Mars Base 17. Colonizing Mars 18. Terraforming--Creating an Ecology for Mars 19. Analog Studies Relating to Mars Exploration 20. The Flashline Mars Arctic Research Station 21. The Mars Desert Research Station 22. The Mars Analog Rover project 23. The Translife Mars Gravity Mission 24. The Value of Mars Exploration to the Earth 25. Public Policy and Mars Exploration 26. Concepts for Privately Funded Mars Missions 27. International Cooperation in Mars Exploration 28. Law and Governance for Mars 29. Social Systems for Mars 30. The Significance of the Martian Frontier 31. Philosophical Implications of Mars Exploration. 32. Mars and Education 33. Mars and the Arts 34. Outreach Strategy for the Mars Society 35. Proposed Projects for the Mars Society 36. Open Mike Martian Literature Reading & Gallery Call for papers Presentations for the convention are invited dealing with all matters (science, engineering, politics, economics, public policy, etc.) associated with the exploration and settlement of Mars. Abstracts of no more than 300 words should be sent by June 30, 2003 to: The Mars Society, P.O. Box 273, Indian Hills 80454, or via email to msabstracts@aol.com (e-mail submission preferred). Conference Registration Fees: $150 for MS members if paid before June 30th, 2003, $240 for non-members. After June 30: $190 for members, $280 for non-members. Students and Seniors: $35 for members, $80 for non- members. Registration is now open online at www.marssociety.org. ________________________________________________________________________ HITCHHIKERS MAY HAVE THUMBED A RIDE TO MARS By Leslie Mullen From Astrobiology Magazine 9 April 2003 A new Mars exploration mission is due to launch this summer, and scientists will be eagerly awaiting results from experiments conducted on the planet's surface. These results may indicate--at long last--the possibility for life on the Red Planet. But new research published in the BioMed Central Microbiology journal suggests that any life we might discover could have an earthly origin. According to Ronald Crawford and colleagues from the University of Idaho, conditions on Mars may harbor a form of bacteria known as endospores. These dormant bacteria could have been inadvertently transported to Mars, hitchhiking on previous spacecraft sent from bacteria-rich Earth. Some bacteria form endospores when they find themselves in a jeopardous situation--facing such dangers as extreme temperatures, disinfectants, radiation, or drying. Bacterial endospores can remain in this dormant state for thousands of years, and they can even survive the harsh vacuum of space. Scientists have suggested that if there is life on Mars, it will be below the surface layer of soil. The soil on Mars is believed to be rich in superoxidizing chemicals that can destroy life, and the surface of the planet is exposed to high levels of damaging UV radiation. Crawford and his colleagues investigated whether endospores of Bacillus subtilis could survive in a simulated martian environment. They created an analogy of martian soil by mixing dry sand containing endospores with ferrate. Ferrates are iron-enriched soils, and they are considered to be the strongest of the oxidizing soils that make the surface of Mars self-sterilizing. To replicate the conditions of the martian surface, the soil was kept under a carbon dioxide atmosphere and cooled to -20 degrees C (-4°F). The soil was exposed to high levels of ultraviolet (UV) light for six weeks. Subsequent analysis of the soil showed that endospores were still alive below a depth of 5 millimeters. The scientists also exposed their soils to liquid water. Although all the water on Mars appears to be frozen, many scientists have suggested that the ice may have melted during brief episodes in the past. Ferrates are highly reactive in water, where they alter into a less toxic soil. The scientists found that endospores were not killed by ferrate when liquid water also was present. If life arrived on Mars by traveling on Earth-sent spacecrafts, that could compromise efforts to determine the past and present history of life on Mars. Researchers would not be sure whether any endospores found on Mars were native to the planet, or if they originated from Earth. "The United Sates and other space faring nations are required by treaty to protect Mars and other non-earthly planetary systems from contamination by earthly microorganisms," the authors write. "(Our work suggests) that environmentally robust endospores, if delivered to Mars on spacecraft, could survive for very extended periods of time in the cold, dry, preserving environment of Mars, despite the presence of strong oxidants in the soil." Christopher McKay, planetary scientist with the Space Science Division of NASA Ames Research Center, says the experiment results make sense. "Many types of bacteria from Earth could survive in dormant form in the martian soil, where even a thin layer of soil over them would protect them from UV," says McKay. "At some point in the future we may want to go to Mars and retrieve all the old spacecraft that have landed or crashed there, and clean up the bacterial mess." What's next? The experiment did not duplicate the martian atmosphere exactly, because the scientists did not have a vacuum chamber. They hope to acquire more sophisticated equipment for future tests. The Mars 2003 mission, consisting of two identical rovers, will launch in mid-2003 and arrive at Mars in January 2004. The rovers are designed to cover roughly 100 meters each martian day, and they will be equipped with many scientific instruments to gather data. The rovers will help determine if life ever arose on Mars, characterize the planetary climate and geology, and pave the way for future human exploration. Read the original article at http://www.astrobio.net/news/article423.html. Read the BMC Microbiology paper at http://www.biomedcentral.com/content/pdf/1471-2180-3-4.pdf. ________________________________________________________________________ NASA NEEDS NEW VISION FOR HUMAN SPACEFLIGHT, ASTEROID PROTECTION, EXPERTS SAY By Robert Roy Britt From Space.com 9 April 2003 A group of 30 scientists has formally urged NASA to use the International Space Station (ISS) as part of an expanded program of human and robotic missions to learn more about asteroids and how to deflect one that might one day threaten Earth. The suggested effort would lead to human missions to asteroids, a stepping stone for a crewed trip to Mars. In a letter to NASA, asteroid experts and other researchers inside and outside the space agency suggest it seek to emerge from the Shuttle Columbia tragedy with a fresh vision for integrating human and robotic space exploration. That vision should incorporate the space station in an effort to investigate asteroid compositions and to understand how innovative propulsion systems might be used to visit them or even to nudge an incoming asteroid off course. Learning how to destroy an asteroid might also be a goal. The letter was signed by two former astronauts and 28 astronomers and scientists at universities and space industry companies, as well as institutions closely tied to or largely funded by NASA. Read the full article at http://www.space.com/scienceastronomy/asteroid_iss_030409.html. ________________________________________________________________________ ACROSS GENERATIONS: SETI LOOKS TO THE FUTURE By Douglas Vakoch From Space.com 10 April 2003 The timescales of interstellar communication can be measured in two ways. First, we can compute them by the objective ticking of timepieces. Measuring time by a clock has the virtue of being objective and quantifiable, whether using a beloved old windup pocket watch or the latest atomic clock, accurate to one second in 20 million years. Measured in this way, a roundtrip exchange with another civilization is guaranteed to take a minimum of eight years-and that's in the unlikely event that the star nearest our solar system is inhabited. More realistically, such an exchange could take centuries or millennia. But as we search for signals from extraterrestrials, perhaps bearing tutorials in mathematics, perhaps with encoded messages describing alien analogues of music or art, objective time is not enough. Just as crucial to sustaining a search that may take decades or centuries is an appreciation of our subjective experience of time. The metronome may offer a precise measure of time, but its pace has its origins in the beating of the heart. And for humans, the best of hearts stop long before a laboratory-grade cesium clock. Read the full article at http://www.space.com/searchforlife/seti_vakoch_future_030410.html. ________________________________________________________________________ MARS MYSTERIES REVEALED IN TWO PUBLIC LECTURES NASA release 2003-050 10 April 2003 Two free public programs in Pasadena next week offer an overview of the historic Mars Global Surveyor mission. Dr. Terry Martin, planetary scientist and member of the Mars Global Surveyor science team, will discuss and display imagery, charts and scientific findings as he chronicles the adventures of the one spacecraft that has returned more data about Mars than all other missions combined. The first lecture will be held on Thursday evening, April 17, at NASA's Jet Propulsion Laboratory, and the second on Friday evening, April 18, at Pasadena City College. Mars Global Surveyor has been orbiting the red planet since September 12, 1997. The mission has examined the entire martian surface and provided a wealth of information about the planet's atmosphere and interior. Evaluation of landing sites for two Mars Exploration Rovers, due to launch in the next three months, has relied heavily on mineral mapping, detailed imagery and topographic measurements made by Global Surveyor. "There are at least five kinds of new global maps of Mars in hand now, thanks to Global Surveyor," said Martin. "We are finding places on the planet both fascinating and beautiful." Both lectures begin at 7:00 PM. Seating is on a first-come, first- served basis. The lecture at JPL, located at 4800 Oak Grove Drive, Pasadena, off the Oak Grove Drive exit of the 210 (Foothill) Freeway, will be held in the von Karman Auditorium. The Friday lecture will be in Pasadena City College's Vosloh Forum, 1570 East Colorado Blvd. For more information, call 354-0112. The lecture at JPL will be webcast live and available for later viewing at http://www.jpl.nasa.gov/events/lectures/apr03.html. Contact: D. C. Agle Jet Propulsion Laboratory, Pasadena, CA Phone: 818-393-9011 ________________________________________________________________________ NASA ROVERS SLATED TO EXAMINE TWO INTRIGUING SITES ON MARS NASA/JPL release 2003-051 11 April 2003 NASA has chosen two scientifically compelling landing sites for twin robotic rovers to explore on the surface of Mars early next year. The two sites are a giant crater that appears to have once held a lake, and a broad outcropping of a mineral that usually forms in the presence of liquid water. Each Mars Exploration Rover will examine its landing site for geological evidence of past liquid water activity and past environmental conditions hospitable to life. "Landing on Mars is very difficult, and it's harder on some parts of the planet than others," said Dr. Ed Weiler, NASA associate administrator for space science in Washington, DC. "In choosing where to go, we need to balance science value with engineering safety considerations at the landing sites. The sites we have chosen provide such balance." The first rover, scheduled for launch May 30, will be targeted to land at Gusev Crater, 15 degrees south of Mars' equator. The second, scheduled to launch June 25, will be targeted to land at Meridiani Planum, an area with deposits of an iron oxide mineral (gray hematite) about two degrees south of the equator and halfway around the planet from Gusev. Which rover is targeted to a specific site is still considered tentative, while further analyses and simulations are conducted. NASA can change the order as late as approximately one month after the launch of the first rover. The first mission will parachute to an airbag- cushioned landing on January 4, 2004, and the second on January 25, 2004. "A tremendous amount of effort has gone into evaluating possible landing sites in the past two years, to maximize the probability of mission success," said Peter Theisinger, Mars Exploration Rover project manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. Images and measurements from two NASA spacecraft orbiting Mars provided scientists and engineers evaluating potential landing sites with details of candidate site topography, composition, rockiness and geological context. "Meridiani and Gusev both show powerful evidence of past liquid water, but in very different ways," said Dr. Steve Squyres, principal investigator for the rovers' science toolkit and a geologist at Cornell University, Ithaca, NY. "Meridiani has a chemical signature of past water. Gray hematite is usually, but not always, produced in an environment where there is liquid water. At Gusev, you've got a big hole in the ground with a dry riverbed going right into it. There had to have been a lake in Gusev Crater at some point. They are fabulous sites, and they complement each other because they're so different." Mars Exploration Rover site selection began with identifying all areas on Mars that fit a set of engineering-driven requirements, said JPL's Dr. Matt Golombek, co-chair of a landing-site steering committee. To qualify, candidate sites had to be near the equator, low in elevation, not too steep, not too rocky and not too dusty, among other criteria; 155 potential sites were studied. A series of public meetings evaluated the merits of potential landing sites. More than 100 Mars scientists participated in the meetings. "These two landing sites have been studied more than anywhere else on Mars. Both sites have specific scientific hypotheses that can be tested using the instruments on board each rover. It should be a very busy and exciting time after landing for the scientists analyzing the wealth of new data from the ground," said Dr. Cathy Weitz, Mars Exploration Rover program scientist at NASA Headquarters. "Clearly there is tremendous interest in the science community in what these missions can accomplish and eagerness to help see that the rovers go to the best possible sites," said the National Air and Space Museum's Dr. John Grant, the steering committee's other co-chair. Once they reach their landing sites, each rover's prime mission will last at least 90 martian days (92 Earth days). The rovers are solar- powered, and in approximately 90 days, dust accumulating on the solar arrays likely will be diminishing the power supply. The twin Mars Exploration Rover spacecraft are at NASA's Kennedy Space Center, FL, in preparation for launch. JPL built the rovers and manages the project for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology in Pasadena. Information about the Mars Exploration Project is available online at http://mars.jpl.nasa.gov/mer/. For more information about NASA on the Internet, visit http://www.nasa.gov. Contacts: Guy Webster Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-6278 Donald Savage NASA Headquarters, Washington, DC Phone: 202-358-1547 Additional articles on this subject are available at: http://www.astrobio.net/news/article426.html http://www.nytimes.com/2003/04/13/science/13MARS.html?tntemail0 http://www.space.com/missionlaunches/mer_landsites_030411.html http://www.spacedaily.com/news/mars2003-03d.html http://spaceflightnow.com/news/n0304/11mersites/ ________________________________________________________________________ PROJECT PHOENIX: SETI PREPARES TO OBSERVE AT ARECIBO By Peter Backus From Space.com 14 April 2003 Sunday, April 6, 2003 Arecibo Observatory, Puerto Rico It's a quiet Sunday morning at Arecibo. As I sit by a window in the cafeteria enjoying my first cup of café con leche, I look out at a small tropical garden with showy red flowers. Beneath one of the flowers a small lizard hunts. He is motionless, his cold reptile eyes fixed on his prey. For the humans, life is a little more relaxed on weekends at the observatory. Most of the Arecibo personnel are at home, enjoying time with their families. Project Phoenix observing starts a week from tomorrow, so we can slow down a bit, too. Suddenly, the lizard is half a body length further along the branch. I could swear that the move was instantaneous--a quantum movement. Schroedinger's lizard? Perhaps I need another café con leche before starting work. So, if observing doesn't start for a week what do we work on? Read the full story at http://www.space.com/searchforlife/seti_arecibo_prep_030414.html. ________________________________________________________________________ LIFE'S WORKING DEFINITION: DOES IT WORK? From Astrobiology Magazine 14 April 2003 Is it alive? How to define "life" is a sweeping question that affects whole branches of biology, biochemistry, genetics, and ultimately the search for life elsewhere in the universe. Comparing the semantic task to the ancient Hindu story of identifying an elephant by having each of six blind men touch only the tail, the trunk, or the leg, what answer a biologist might give can differ dramatically from the answer given by a theoretical physicist. However, some initial agreement is possible. Living things tend to be complex and highly organized. They have the ability to take in energy from the environment and transform it for growth and reproduction. Organisms tend toward homeostasis: an equilibrium of parameters that define their internal environment. Living creatures respond, and their stimulation fosters a reaction-like motion, recoil, and in advanced forms, learning. Life is reproductive, as some kind of copying is needed for evolution to take hold through a population's mutation and natural selection. To grow and develop, living creatures need foremost to be consumers, since growth includes changing biomass, creating new individuals, and the shedding of waste. To qualify as a living thing, a creature must meet some variation for all these criteria. For example, a crystal can grow, reach equilibrium, and even move in response to stimuli, but lacks what commonly would be thought of as a biological nervous system. While a "bright line" definition is needed, the borderline cases give life's definition a distinctly gray and fuzzy quality. In hopes of restricting the working definition at least terrestrially, all known organisms seem to share a carbon-based chemistry, depend on water, and leave behind fossils with carbon or sulfur isotopes that point to present or past metabolism. If these tendencies make for a rich set of characteristics, they have been criticized as ignoring the history of life itself. Terrestrially, life is classified among four biological families: archaea, bacteria, eukaryotes, and viruses. Archaea are the recently defined branch that often survives in extreme environments as single cells, and they share traits with both bacteria and eukaryotes. Bacteria, often referred to as prokaryotes, generally lack chlorophyll (except for cyanobacteria) and a cell nucleus, and they ferment and respire to produce energy. The eukaryotes include all organisms whose cells have a nucleus--so humans and all other animals are eukaryotes, as are plants, protists, and fungi. The final grouping includes the viruses, which don't have cells at all, but fragments of DNA and RNA that parasitically reproduce when they infect a compatible host cell [for this reason, not all biologists consider viruses to be truly alive]. These classifications clarify the grand puzzle of existing life, but do little to provide a final definition. Defining life takes on a more bewitching character when extended beyond the Earth's biosphere. The recent addition of extremophiles (archaea) to the tree of life underscores the notion that life is defined by what we know, what we have seen before, and often what we have succeeded in domesticating to a laboratory Petri dish. Astrobiology Magazine sought out expert opinion on this important question from Dr. Carol Cleland, who teaches philosophy at Colorado University in Boulder and is a member of NASA's Astrobiology Institute. While on sabbatical in Madrid, Spain, at the Centro de Astrobiologia (CSIC-INTA), she shared her thoughts on the power of definitions to shape science and philosophy. Interview with Carol Cleland Q: What is your opinion of attempts to define of "life?" I argue that it is a mistake to try to define "life." Such efforts reflect fundamental misunderstandings about the nature and power of definitions. Definitions tell us about the meanings of words in our language, as opposed to telling us about the nature of the world. In the case of life, scientists are interested in the nature of life; they are not interested in what the word "life" happens to mean in our language. What we really need to focus on is coming up with an adequately general theory of living systems, as opposed to a definition of "life." But in order to formulate a general theory of living systems, one needs more than a single example of life. As revealed by its remarkable biochemical and microbiological similarities, life on Earth has a common origin. Despite its amazing morphological diversity, terrestrial life represents only a single case. The key to formulating a general theory of living systems is to explore alternative possibilities for life. I am interested in formulating a strategy for searching for extraterrestrial life that allows one to push the boundaries of our Earth-centric concepts of life. Q: In the category of what is "alive," would you exclude what you call the "borderline" cases--viruses, self-replicating proteins, or even non- traditional objects that have some information content, reproduce, consume, and die (like computer programs, forest fires, etc.)? This is a complex question. Language is vague, and all terms face borderline cases. Is an unmarried twelve-year-old boy a "bachelor?" How about an eighteen year old? How many hairs does it take to turn a "bald" man into a man who is "not bald"--20 or 100 or 1,000 hairs? The fact that there are borderline cases--that we can't come up with a precise cut-off--doesn't mean there isn't a difference between a bachelor and a married man, or a bald man and a man who is not bald. These difficulties don't represent profound difficulties; they merely represent the fact that language has a certain degree of flexibility. So I don't think that entities like viruses provide very interesting challenges to definitions of "life." On the other hand, I don't think that defining "life" is a very useful activity for scientists to pursue since it is not going to tell us what we really want to know, which is "what is life." A scientific theory of life (which is not the same as a definition of life) would be able to answer these questions in a satisfying way. As an analogy, the medieval alchemists classified many different kinds of substances as water, including nitric acid (which was called "aqua fortis"). They did this because nitric acid exhibited many of the sensible properties of water, and perhaps most importantly, it was a good solvent. It wasn't until the advent of molecular theory that scientists could understand why nitric acid, which has many of the properties of water, is nonetheless not water. Molecular theory clearly and convincingly explains why this is the case: water is H2O--two hydrogen atoms and one oxygen atom. Nitric acid has a different molecular composition. A good theory of life would do the same for the cases that you mention, such as computer programs. Merely defining "life" in such a way that it incorporates one's favorite non-traditional "living" entity does not at all advance this project. Q: What is your favored theory for how life could have arisen on Earth-- clay crystals, RNA world, membranes, or some other option? It seems to me that all theories of the origin of life face two major hurdles. The biggest one is explaining the origin of the complex cooperative schema worked out between proteins and nucleic acids--the controlled production of self-replicating catalytic systems of biomolecules. All of the popular accounts of the origin of life strike me as side stepping this issue. Instead, they focus on the other hurdle: producing amino acids and nucleotides, and getting them to polymerize into proteins and nucleic acids (typically, RNA). But it seems to me that none of them have provided us with a very satisfying story about how this happened. All the scenarios that have been proposed for producing RNA under plausible natural conditions lack experimental demonstration, and this includes the RNA world, clay crystals, and vesicle accounts. No one has been able to synthesize RNA without the help of protein catalysts or nucleic acid templates, and on top of this problem, there is the fragility of the RNA molecule to contend with. But I still think that the more serious problem is the next stage of the process, the coordinating of proteins and RNA through a genetic code into a self-replicating catalytic system of molecules. The probability of this happening by chance (given a random mixture of proteins and RNA) seems astronomically low. Yet most researchers seem to assume that if they can make sense of the independent production of proteins and RNA under natural primordial conditions, the coordination will somehow take care of itself. I suppose that if I had to pick a favorite theory, it would be Freeman Dyson's double origin theory, which postulates an initial protein world that eventually produced an RNA world as a by-product of an increasingly sophisticated metabolism. The RNA world, which starts out as an obligatory parasite of the protein world, eventually produces the cooperative schema, and hence life as we know it today. I like the fact that this account attempts to deal with the origin of the cooperative schema. Q: Do you think there could have been multiple origins of life, or that life could have come to Earth from somewhere else? Life arising more than once from nonliving materials could occur elsewhere than Earth, but it could also have occurred on Earth. It is possible that extraterrestrial life exists and that all life nonetheless has a common ancestor. Scientists now believe that microbes can survive interplanetary journeys ensconced in meteors produced by asteroid impacts on planetary bodies containing life. In other words, we could all be the descendants of martians--or martians, if they happen to exist, could share a common ancestor with us! In short, the mere discovery of extraterrestrial life doesn't guarantee that life had more than one origin. Q: As one of the great mysteries and challenges in science, do you think we can determine the origin of life through experimentation? I hope so! But until we have an adequate theory of life to drive the formulation of the right experiments, it will be difficult to tell. I suppose it is always possible that life is not a natural category, and thus no universal theory of life can be formulated. But I doubt it. It is also possible that life on Earth is the product of a very complex historical process that involves too many contingencies to be readily accessible to definitive experimental investigations. An adequately general theory of life would make this clear, however. Besides, historical research is quite capable of obtaining empirical evidence that can resolve historical questions of this sort-evidence that is just as convincing as that provided by classical experimental research! So even if we can't produce life in the lab from nonliving materials, it doesn't follow that we will never know how life originated on Earth. What's next? The European Space Agency will launch a Mars mission in early summer 2003. Current plans are for its lander, Beagle 2, to perform biological experiments designed to search for evidence of life on Mars. As an example of how the definition of life can directly shape exploratory science, the scientific payload on Beagle 2 will investigate the common features thought to indicate life. For instance, Beagle 2 will look for the presence of water, the existence of carbonate minerals, the occurrence of organic residues, and any isotopic fractionation between organic and inorganic phases. Each of these will provide clues to the likelihood of life on Mars when matched against the prevailing environmental conditions, such as temperature, pressure, wind speed, UV flux, oxidation potential, and dust environment. Read the original article at http://www.astrobio.net/news/article428.html. ________________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.html 14 April 2003 Astrobiology, exobiology and terraformation articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_articles1. html Astrobiology Magazine, 2003. Life's working definition: does it work? Astrobiology Magazine. L. David, 2003. Mars gullies could harbor martian biology. Space.com. L. David, 2003. NASA selects Mars Rover landing sites. Space.com. Terrestrial extreme environments articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_articles2. html NASA Ames Research Center, 2003. Life under a Spanish red river. Astrobiology Magazine. Human space exploration and microgravity effects articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_articles3. html Agence France-Presse, 2003. Russia to confine six cosmonauts for 17 months in Mars experiment. SpaceDaily. R. R. Britt, 2003. NASA needs new vision for human spaceflight, asteroid protection, experts say. Space.com. Search for extraterrestrial intelligence (SETI) articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_articles4. html P. Backus, 2003. Project Phoenix: SETI prepares to observe at Arecibo. Space.com. D. Vakoch, 2003. Across generations: SETI looks to the future. Space.com. Planetary protection articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_articles6. html R. L. Crawford, A. Paszczynski and L. Allenbach, 2003. Potassium ferrate [Fe(VI)] does not mediate self-sterilization of a surrogate Mars soil. BMC Microbiology, 3:4. L. Mullen, 2003. Hitchhikers may have thumbed a ride to Mars. Astrobiology Magazine. ________________________________________________________________________ CONTINUING COVERAGE OF THE COLUMBIA DISASTER By David J. Thomas 14 April 2003 The investigation of the Columbia tragedy continues to make headlines in both space and general media. I have included (below) a non-exhaustive list of links to recent articles on the subject. http://www.cnn.com/2003/TECH/space/04/09/sprj.colu.shuttle.investigation .ap/index.html http://www.space.com/missionlaunches/sts107_caib_030407.html http://www.space.com/missionlaunches/sts107_mystery_030407.html http://www.space.com/missionlaunches/sts107_caib_030408.html 1ttp://www.space.com/missionlaunches/sts107_report_030409.html http://www.space.com/missionlaunches/sts107_collins_030411.html http://www.space.com/missionlaunches/sts107_discovery_030414.html http://spaceflightnow.com/shuttle/sts107/030408privileged/ http://spaceflightnow.com/shuttle/sts107/030408shedding/ ________________________________________________________________________ CASSINI SIGNIFICANT EVENTS NASA/JPL release 3-9 April 2003 The most recent spacecraft telemetry was acquired from the Canberra tracking station on Wednesday, April 9. The Cassini spacecraft is in an excellent state of health and is operating normally. Information on the present position and speed of the Cassini spacecraft may be found on the "Present Position" web page located at http://saturn.jpl.nasa.gov/operations/present-position.cfm. Command and Data Subsystem (CDS) Flight Software (FSW) checkout activities continued this week with an Instrument Expanded Block (IEB) load to the SSR library region. This procedure uplinks and stores IEBs in the new Version 9.0 Library region. The Library Region is a new sub- partition on the SSR that allows instruments or subsystems to store frequently used commands on the SSR for an extended length of time. When needed, a single command will load this data from the Library region to the instrument for execution. This procedure loaded and verified that Instrument IEBs were loaded into the Library region successfully. After the IEB load, the CDS Command Loss Timer threshold value was set to 2 days, and a High Gain Antenna (HGA) response checkout was performed. The purpose of this procedure was to demonstrate that the new System Fault Protection algorithm called the HGA Response will change the uplink data rate to 250 bps, and the downlink telemetry mode to RTE-1896, as well as the proper execution of the SAFE, OTHER response. This procedure was clean and successful, thanks to all the support from Systems, Attitude Control Subsystem (ACS), System Fault Protection, Telecom and others. Following the HGA checkout, the ACS High Water Marks were cleared, CDS Background Sequence #2 uplinked, CDS Command Loss Timer threshold returned to the nominal 11 day value, and a Probe Solid State Recorder dual record demo was begun. This will be the first in-flight demonstration of the Probe Relay telemetry mode with dual SSRs. A simulation procedure review meeting was held for C37 as part of the sequence development process. Testing in the Integrated Test Laboratory for the C37 background sequence and Trajectory Correction Maneuver 19 began this week and continues to the weekend. A wrap-up meeting was held for Science Operations Plan (SOP) implementation for tour sequences S15/S16. The sequences will now be archived until June of 2005 when SOP Update, and the Science and Sequence Update Process will begin. The S17/S18 preliminary port#3 inputs have been delivered. A data volume problem occurring on two days was identified, and later resolved at the weekly Tour Process meeting. The C38 Science Planning Team process kicked off this week. Development of this sequence will use a compressed five week schedule, and completes in early May. SOP Update Verification and Validation (V&V) using S14 continued this week. Cassini Information Management System (CIMS) change requests were published to identify changes the teams need to make to their CIMS requests. Mission Sequence Subsystem developers provided user support for D9.0 PDT and SEQ_CONVERT during the on-going V&V exercise. Mission Planning presented the results of the extended mission planning and budget task. Budget and workforce estimates were delivered along with a final implementation schedule. System Engineering is leading preparation for the Approach Science/Tour Operations Readiness Review to be held in October of this year. A requirements and capabilities table organized by Operations Concept has been generated and is being reviewed by the Teams/Offices. In last weeks Significant Events report, an incorrect ULR was listed for the Kids' section of the Cassini web site. The correct URL is http://saturn.jpl.nasa.gov/kids/index.cfm University of Hawaii astronomers formally announced the discovery of the first new satellite of Saturn in three years at the International Astronomical Union on April 8, 2003. The satellite has a distant retrograde orbit, and is about 8 km in diameter. For more information go to http://www.ifa.hawaii.edu/~sheppard/satellites/sat2003.html 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. ________________________________________________________________________ GALILEO MILLENNIUM MISSION STATUS NASA/JPL release 2003-049 9 April 2003 NASA's Galileo spacecraft serendipitously discovered seven to nine space rocks near Jupiter's inner moon Amalthea when Galileo flew past that moon five months ago. Galileo detected the objects as bright flashes seen by its star scanner, an onboard telescope used to determine the spacecraft's orientation by sighting stars. Information from the star scanner was recorded onto Galileo's tape recorder during the flyby and transmitted to Earth in subsequent months. Experts at NASA's Jet Propulsion Laboratory, Pasadena, Calif., are analyzing the data to estimate the sizes of the objects, which may be anywhere from gravel to stadium-size rocks. JPL engineers Paul Fieseler and Shadan Ardalan reported the findings to the International Astronomical Union. The star tracker saw nine flashes during the flyby, but two may be duplicate sightings. "It is likely that these bodies have either been gravitationally captured into an orbit near Amalthea or have been split off of the moon as a result of past collisions," Fieseler said. The Amalthea encounter was Galileo's last flyby of a jovian moon. After more than seven years in orbit around Jupiter, the spacecraft has nearly depleted its supply of propellant needed for pointing its antenna toward Earth and controlling its flight path. While still controllable, it has been put on a course for impact into Jupiter next September. The maneuver prevents the risk of Galileo drifting to an unwanted impact with the moon Europa, where it has discovered evidence of a subsurface ocean that is of interest as a possible habitat for extraterrestrial life. Additional information about Galileo and the discoveries is available at http://galileo.jpl.nasa.gov. JPL, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, DC. Contact: Guy Webster Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-6278 Additional articles on this subject are available at: http://www.cnn.com/2003/TECH/space/04/05/jupiter.moons.ap/index.html http://www.ifa.hawaii.edu/~sheppard/satellites/jup2003.html http://www.spacedaily.com/news/galileo-03c.html http://spaceflightnow.com/news/n0304/09galileo/ ________________________________________________________________________ MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 7-11 April 2003 Surface Erosion and Flow (Released 7 April 2003 http://themis.la.asu.edu/zoom-20030407a.html Olympica Fossae (Released 8 April 2003) http://themis.la.asu.edu/zoom-20030408a.html Chipped Paint Crater (Released 9 April 2003) http://themis.la.asu.edu/zoom-20030409a.html Ismenia Fossae: Craters or Pits? (Released 10 April 2003) http://themis.la.asu.edu/zoom-20030410a.html Ridges (Released 11 April 2003) http://themis.la.asu.edu/zoom-20030411a.html All of the THEMIS images are archived at http://themis.la.asu.edu/latest.html. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, DC. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. ________________________________________________________________________ STARDUST STATUS REPORT NASA/JPL release 14 April 2003 As the Stardust spacecraft passed into a "solar conjunction period" on April 3, and there is currently no communication between the spacecraft and the Stardust team here on terra firma. Solar conjunction period is the interval that the Sun obscures the line of sight between Earth and the spacecraft, making it virtually impossible to transmit radio signals between the two. The last data relayed from the spacecraft prior to conjunction indicated that the spacecraft was healthy and all subsystems continue to operate normally. The Stardust team is confident that will remain the case when they reestablish communications sometime after the end of solar conjunction on April 18. Information on the present position and orbits of the Stardust spacecraft and comet Wild 2 may be found on the "Where Is Stardust Right Now?" web page located at http://stardust.jpl.nasa.gov/mission/scnow.html. The Stardust team held a science workshop on April 3 and 4 at Cal Tech. Issues covered ran the gamut from the expected dust environment around Comet Wild 2 to the media plan for encounter. The Pasadena Art Center recently made a three-dimensional image of the brain. While artistic interpretations of the gray matter are somewhat unusual enough what warrants its inclusion here is the media in which it was depicted. The Art Center created this work of art utilizing an etching/laser process in aerogel provided by the Stardust Technology Transfer team. The image can be seen on the cover of Nature Neuroscience and at http://www.nature.com/nrn. 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 10, Number 15.