Marsbugs: The Electronic Astrobiology Newsletter Volume 10, Number 36, 15 September 2003. Editor/Publisher: David J. Thomas, Ph.D., Science Division, Lyon College, Batesville, Arkansas 72503-2317, USA. dthomas@lyon.edu 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 editor, except for specific articles, in which instance copyright exists with the author/authors. The editor does not condone "spamming" of subscribers. Readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing lists. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editor. E-mail subscriptions are free, and may be obtained by contacting the editor. Information concerning the scope of this newsletter, subscription formats and availability of back-issues is available from the Marsbugs web page at http://www.lyon.edu/projects/marsbugs/. ________________________________________________________________________ CONTENTS 1) MARS UNDERGROUND: DIGGING DEEP FOR LIFE By Leonard David 2) NEW SPACE SONG RELEASED Mars Society release 3) MIT RESEARCHERS REASSESS ASTEROID HAZARDS Massachusetts Institute of Technology release 4) ASTEROID SCARES: WHY THEY WON'T END By Robert Roy Britt 5) DISCOVERING NEW WORLDS By Edna DeVore 6) NASA RELEASES NEAR-EARTH OBJECT SEARCH REPORT NASA/JPL release 7) THE FUTURE OF MARS: PLANS FOR NASA'S NEXT DECADE OF RED PLANET PROBING By Leonard David 8) BRIDGING THE GAP: A DISCUSSION WITH FREEMAN DYSON, PART III From The Planetary Society and Astrobiology Magazine 9) URGENT CALL TO ACTION By Chuck Fuller 10) NASA REPORT: EXPAND SEARCH TO INCLUDE SMALL ASTEROIDS By Robert Roy Britt 11) BARRIERS TO SPACE: AND WHY THEY SHOULD BE OVERCOME By Douglas Vakoch 12) IS THIS WHAT KILLED THE DINOSAURS? Cardiff University release 13) NASA WANTS YOU TO BE A SOLAR SYSTEM AMBASSADOR NASA/JPL release 2003-123 14) STUDENT TRAVEL GRANTS AVAILABLE NASA Academy release 15) OPTICAL DETECTION OF ANOMALOUS NITROGEN IN COMETS, VLT OPENS NEW WINDOW TOWARDS OUR ORIGINS ESO release 25/03 16) HISTORIC GALILEO MISSION NEARS END NASA release 03-291 17) EARLY MARS WAS FROZEN BUT HABITABLE, PART I From Astrobiology Magazine 18) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 19) CASSINI SIGNIFICANT EVENTS NASA/JPL release 20) MARS GLOBAL SURVEYOR IMAGES NASA/JPL/MSSS release 21) MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 22) STARDUST STATUS REPORT NASA/JPL release ________________________________________________________________________ MARS UNDERGROUND: DIGGING DEEP FOR LIFE By Leonard David From Space.com 5 September 2003 Martian biology is likely alive and well on the red planet, but tucked away in caves or dwelling underground, sustained by pockets of water. That prospect has spurred scientists to look for exotic life forms here on Earth, far from the maddening crowd of topside biota that covers our planet. This quizzical quarry for life is helping devise the strategies, the tools, and the procedures for unearthing the biological leftovers from an ancient Mars, or hardy microbes that might exist on that distant world today. Experts on the search for underground martian biology took part in the Sixth International Mars Society Conference, held here August 14-17. Read the full article at http://www.space.com/scienceastronomy/mars_caves_030905.html. ________________________________________________________________________ NEW SPACE SONG RELEASED Mars Society release 5 September 2003 A powerful new song expressing the drive for the human exploration of space has been released. The song, entitled "Others Standing By" is by Kristoph Klover: author and Lead Vocals, Keyboard and Slide Guitar with John Land: Bass, Curt Moore: Drums and Mark Ungar: Electric Guitar. The song includes the stirring refrain: "Why would you go there they say There's nothing up there anyway We could use the money here Don't they know that life's too dear? Dreamers never ask why. spend their money in the sky. We'll send the best from Earth To find out what it's worth. We'll send the best from Earth, To find out what its worth." The song will appear as part of a collection of songs celebrating space, entitled, To Touch the Stars, which will be released by Prometheus Music this Christmas. (For more information on the CD, see http://www.prometheus-music.com/space.html) Prometheus Music and Kristoph Klover have kindly provided this advance MP3 copy of "Others Standing By." They give full permission for anyone to download, share, and play it anywhere, including in radio broadcasts. The Mars Society thanks them, and urges radio broadcasters to pick it up and play it. It's an anthem that the country could use right now. You can download the song at http://www.prometheus-music.com/others.html. To find out more about the Mars Society, visit our web site at www.marssociety.org. ________________________________________________________________________ MIT RESEARCHERS REASSESS ASTEROID HAZARDS Massachusetts Institute of Technology release 5 September 2003 Of the approximately 1,000 near-Earth asteroids larger than 1 kilometer in diameter, one strikes the Earth on average once every 600,000 years, MIT Lincoln Laboratory researcher J. Scott Stuart reported today (September 5) at the 35th annual meeting of the American Astronomical Society Division for Planetary Sciences. By combining discovery statistics with new observations of the surfaces of near-Earth asteroids (NEAs), Stuart also determined that impacts similar to the Tunguska event-in which an asteroid destroyed more than 2,000 square kilometers of forest in a remote part of Siberia in 1908- are much less frequent than previously thought. Events of this magnitude occur, on average, once every 2,000 to 3,000 years. Near-Earth asteroids are small solar system objects whose orbits around the sun may bring them close to Earth. While all currently known NEAs are in safe orbits that will not cause them to collide with the Earth in the foreseeable future, many NEAs remain undetected and could be on a collision course with Earth, Stuart said. The Lincoln Near-Earth Asteroid Research (LINEAR) Project has been scanning the skies to discover and catalog NEAs and to provide advance warning of any that are bound for Earth. Since March 1998, LINEAR, whose principal investigator is Lincoln Lab associate division head Grant H. Stokes, has found 70 percent of all near-Earth asteroids discovered worldwide and is a major contributor to the NASA goal of cataloguing 90 percent of NEAs larger than 1 kilometer (0.6 miles) in diameter 2008. The amount of damage that would be caused by an asteroid depends on its size. Impacts of asteroids bigger than 1 kilometer are thought to be capable of causing long-term climate damage on a global scale. The NEA in the Tunguska event was relatively small, with a diameter of 50 to 75 meters (150-250 feet). The energy of the impact was about 40 megaton, or more than 600 times the energy of the Hiroshima bomb. Even if impacts of large NEAs occur only once every 600,000 years, this does not mean that they occur at regularly spaced intervals. This figure comes from looking at time spans of millions of years. Likewise, events similar to the Tunguska impact are not evenly spaced. Over long time spans, we might expect such events to occur every 2,000 to 3,000 years on average, Stuart said. Reflecting sunlight When NEAs are first discovered, the only data available are their locations in the solar system and their brightness. To estimate their diameters, astronomers assumed that NEAs reflect about 11 percent of the sunlight that hits them. Through new observations and modeling of the reflective properties of the NEAs, MIT researchers have found that on average, NEAs actually reflect about 14 percent of the sunlight that hits them. This means that NEAs are slightly smaller than previously assumed, so the number of NEAs that are larger than 1 kilometer is somewhat lower than previously estimated. To determine the percentage of sunlight that is reflected from NEAs, MIT researchers used results from the Small Main-belt Asteroid Spectroscopic Survey (SMASS), a multi-wavelength observing program that studies the surface properties of NEAs and other asteroids. This program comprises visible spectroscopy, near-infrared spectroscopy and thermal infrared flux measurements. The visible spectroscopy is collected at Kitt Peak National Observatory and Palomar Observatory, and on the Magellan I Telescope at Las Campanas Observatory. Near-infrared spectroscopy is collected at the NASA Infrared Telescope Facility. The W.M. Keck Observatory is used to obtain thermal flux measurements to estimate reflectivity. SMASS is directed by MIT's Richard P. Binzel, professor of earth, atmospheric and planetary sciences (EAPS), and operates in collaboration with the University of Hawaii, the Space Science Institute in Boulder, Colo., and the Deutschen Zentrum für Luft- und Raumfahrt in Berlin and others. Moon impacts MIT researchers also calculated the rate at which NEAs collide with the moon to produce craters. Lunar maria--dark areas that can be seen with the naked eye--have been accumulating craters from NEA impacts since their formation more than 3 billion years ago. The rate of crater formation expected from the NEAs matches the observable counts of craters from the lunar maria. Because current NEA population matches the crater counts from the lunar maria, the NEA population has been roughly in equilibrium for billions of years. In other words, new asteroids are introduced into near-Earth space at around the same rate that old NEAs are destroyed by collisions with the planets and the sun or are ejected from the solar system. Stuart, a member of the LINEAR project team, is an EAPS alumnus of MIT. The LINEAR project is jointly sponsored by NASA and the U.S. Air Force. Read the original news release at http://web.mit.edu/newsoffice/nr/2003/asteroids.html. Contact: Deborah Halber MIT News Office Phone: 617-253-2700 E-mail: newsoffice@mit.edu An additional article on this subject is available at http://www.spacedaily.com/news/deepimpact-03m.html. ________________________________________________________________________ ASTEROID SCARES: WHY THEY WON'T END By Robert Roy Britt From Space.com 9 September 2003 Kevin Yates could not foresee the global media circus and public anxiety he would fuel last week with a routine Web posting about a potentially dangerous asteroid. Nor could he know that days later a handful researchers would suggest ditching the four-year-old Torino Scale, which rates asteroid hazards like the Richter Scale ranks earthquakes and was designed to improve communication between astronomers and the public. In a telephone interview yesterday, the Torino Scale's creator stands by its value, and SPACE.com has learned that the ranking system has already undergone a revision, taking into account earlier criticisms, as part of a forthcoming book. The media firestorm is just the latest in a long series of foibles involving asteroid researchers and journalists. It began September 3. Read the full article at http://www.space.com/scienceastronomy/asteroid_scares_030909.html. ________________________________________________________________________ DISCOVERING NEW WORLDS By Edna DeVore, Director of Education and Public Outreach, SETI Institute From Astrobiology Magazine 9 September 2003 Most people think of the local bus or tram service when transit is mentioned. But talk to an astronomer, and you'll hear an entirely different definition. Astronomically, we observe transits when a planet crosses the face of the Sun, or an extrasolar planet crosses the face of its parent star. When the planet passes through our line of sight (LOS) to the Sun, we see the transit progress as a small, dark dot moving against the brilliance of the Sun. From our point of view on Earth, both Mercury and Venus can transit the Sun when the LOS is right. This is not a frequent event. During the 21st century, Mercury will transit the Sun only 14 times even though its orbit carries it past the Earth about every 115 days. That means that out of almost 3200 possible line-ups between Earth-Mercury-Sun in this century, only 14 times does Mercury lie along our LOS to the Sun resulting in a transit. Venus is farther from the Sun than Mercury, and the opportunity to see a transit of Venus is much rarer. In fact, over the next two centuries, there will be only four transits of Venus across the Sun: June 8, 2004, June 6, 2012, December 11, 2117 and December 8, 2125. The remainder of the time, Venus and Mercury are above or below the Sun as they pass between the Earth and Sun. Why are astronomers interested in transits? They are both historical and cutting-edge research tools. Since the days of Copernicus, astronomers have been able to estimate the distances of the planets from the Sun in terms of the astronomical unit (AU), the average distance between the Earth and the Sun. It's a matter of geometry. But, the problem was that they could not measure the length of the AU accurately. In 1716, Edmond Halley of comet fame figured out how to use a transit of Venus to measure the Sun's distance. In 1761 and 1769 astronomers observed the transits of Venus, and got a first accurate measurement of the Sun-Earth distance. Subsequent expeditions repeated the observations, but Venus is tricky. It has an atmosphere, and the timing of the beginning and end of the transit was not as precise as needed as a consequence of Venus "fading" rather than abruptly disappearing from the orb of the Sun. In modern times, radar reflections were used to measure the distance from Earth to Venus, and from that the AU was determined with precision. Transit observations are also cutting edge research tools. Since 1995, more than 100 extrasolar planets have been discovered by measuring the subtle shift in the spectrum of a star as it wobbles back and forth as the star-planet dance around their common center of gravity. This observed Doppler shift offers evidence of planets we cannot see in the glare of their star's light. From these data, we can describe the orbital characteristics and something about the planet: from near circular to wildly elliptical. But we can only estimate the minimum mass for the planet, because we do not know the tilt of the orbital plane. If the planet transits the star, the uncertainty of the tilt is removed and we can then calculate the mass as well as the radius. Of the 100 plus systems so far discovered, one, HD209548, has been observed in transit by both professionals and amateurs. It has been observed by all manner of telescopes, from amateurs using modest off-the-shelf telescopes and low- end CCD cameras, to major ground-based observatories with custom high- grade cameras, and the Hubble Space Telescope. Working class star On Labor Day, September 1, professional and amateur astronomers gathered together in Monterey, California for a workshop on observing transits as a part of the Division of Planetary Sciences' annual conference. HD209458 was the "star" of the show, to be sure, but the hunt is on for others. The workshop centered on the challenge of measuring starlight with high precision, the art and science of photometry. To see a transit of HD209458, a Jupiter-size planet that whips around its sun in just 3.5 days, you have to measure the light from the star to one part in 100, or "1% photometry". Several people present had attempted or actually accomplished these measurements with professional or amateur equipment. Dr. Tim Castellano, NASA Ames Research Center, led the workshop, and is a key person on TransitSearch, a project that seeks to enlist students, teachers, and amateur astronomers is searching for the next transiting extrasolar planet. The project runs a web site that offers training, instructions, and targets of opportunity. Tim is there to help you through the teething pains of learning the nuances of doing precision photometry. The group is working down the list of the known extrasolar planet discoveries, seeking evidence of transits to refine our knowledge of these jovian-size worlds. What's next? Transit observations are at the heart of a current NASA Discovery mission named Kepler, after the astronomer who discovered the laws of planetary motion now named for him. The Kepler Mission is being designed and developed by scientists and engineers at NASA Ames Research Center, Jet Propulsion Laboratories, and Ball Aerospace Technology Corporation with a host of universities and research organizations, including SETI Institute, working in close collaboration with the team. When launched in 2007, the Kepler satellite will view more than 100 square degrees of the sky (500 times the area of the Moon) to continuously measure the brightness of 100,000 stars for at least four years. Kepler will seek evidence of planets by searching for the subtle drop in brightness as a planet transits its parent star. It is looking at lots of stars to assure that some planets will be seen in transit- they will be on our LOS to the star. In space, the Kepler Mission can achieve 100 times better photometric precision than Earth-based telescopes looking through the atmosphere, and this will allow the team to search for much smaller planets, like Earth. The Earth is 100 times smaller in area than Jupiter. By observing for at least four years, Kepler has the opportunity to discover and confirm through detection of repeated transits that there are Earth-size planets in Earth-like orbits around other suns. The Kepler Mission may be the discoverer of worlds like our own. Observing transits once offered us the tools to measure our own solar system, and now, transits are at the heart of a cutting-edge NASA Mission seeking planets that could host life elsewhere in our galaxy. Read the original article at http://www.astrobio.net/news/article587.html. ________________________________________________________________________ NASA RELEASES NEAR-EARTH OBJECT SEARCH REPORT NASA/JPL release http://neo.jpl.nasa.gov/neo/report.html 10 September 2003 NASA has released a technical report on potential future search efforts for near-Earth objects after a year of analysis by scientists working on this issue. This Science Definition Team was chartered to study what should be done to find near-Earth objects less than 1 kilometer in size. While impacts by these smaller objects would not be expected to cause global devastation, impacts on land and the tsunamis resulting from ocean impacts could still cause massive regional damage and still pose a significant long-term hazard. In 1998 NASA commenced its part of the "Spaceguard" effort, with the goal of discovering and tracking over 90% of the near-Earth objects larger than one kilometer by the end of 2008. An Earth impact by one of these relatively large objects would be expected to have global consequences and, over time scales of a few million years, they present the greatest impact hazard to Earth. Approximately 60% of the estimated 1,000 to 1,200 large near-Earth objects have already been discovered, about 45% since NASA efforts started, and each of the five NASA- supported search facilities continue to improve their performance, so there has been good progress toward eliminating the risk of any large, undetected impactor. To understand the next steps to discovering the population of potentially hazardous asteroids and comets whose orbits can bring them into the Earth's neighborhood, NASA turned to this Science Definition Team of 12 scientists. The Team, chaired by Dr. Grant Stokes of the MIT Lincoln Laboratory, was asked to study the feasibility of extending the search effort to the far more numerous, perhaps hundreds of thousands, of near-Earth objects whose diameters are less than one kilometer. NASA considers the Science Definition Team's findings to be preliminary, and a much more in-depth program definition, refining objectives and estimating costs, would need to be conducted prior to any decision to continue Spaceguard projects beyond the current effort to 2008. The complete Science Definition Team report is available at http://neo.jpl.nasa.gov/neo/report030825.pdf. An additional article on this subject is available at http://www.astrobio.net/news/article593.html. ________________________________________________________________________ THE FUTURE OF MARS: PLANS FOR NASA'S NEXT DECADE OF RED PLANET PROBING By Leonard David From Space.com 10 September 2003 NASA is formulating a Mars exploration plan for the next decade, receiving advice from all quarters, from outside academic circles to internal NASA working groups, as well as from the White House. And if all goes according to plan, Mars will speak for itself, giving up surface and subsurface secrets as ever-more capable spacecraft--like the two rovers currently en route--survey that mysterious world. How to respond to the expected fast-paced rush of new discoveries, enough so that outgoing missions can take advantage of just-in findings, is a challenge. One scenario has been advocated by the Committee on Planetary and Lunar Exploration (COMPLEX)--a study arm of the National Research Council. It calls for a legion of robotic return-sample craft that are needed to truly unravel the history of Mars and reveal whether life existed in the planet's past or is present today. The National Research Council of the National Academies--a prestigious group that advises the government on scientific and technical matters, has issued the new COMPLEX report: Assessment of Mars Science and Mission Priorities. Beginning in 2011, the COMPLEX study states, the first in a series of perhaps ten automated Mars return-sample missions would be launched to dot the red planet. This robotic search and seize campaign of hauling back to Earth Mars specimens might stretch out for three or four decades, to as much as a century. Read the full article at http://www.space.com/businesstechnology/technology/mars_future_030910.ht ml. ________________________________________________________________________ BRIDGING THE GAP: A DISCUSSION WITH FREEMAN DYSON, PART III From The Planetary Society and Astrobiology Magazine 10 September 2003 Going to another star is a terribly powerful idea, just as going to the Moon was originally. At some point in human history, there will be a leap across the great void not just to the nearest star but to any star that might be interesting to explore. Renowned physicist, educator, and author Freeman Dyson joined Planetary Society Chairman of the Board Bruce Murray and Executive Director Louis Friedman at Society headquarters for an informal discussion about interstellar flight. Their discussion dovetails to a proposal for sailing on solar wind. Nearly 400 years ago astronomer Johannes Kepler observed comet tails blown by a solar breeze and suggested that vessels might likewise navigate through space using appropriately fashioned sails. It is now widely recognized that sunlight does indeed produce a force which moves comet tails and a large, reflective sail could be a practical means of propelling a spacecraft. In fact, one concept explored by NASA centers is to develop an interstellar probe pushed along by sunlight reflected from an ultra-thin sail. Nearly half a kilometer wide, the delicate solar sail would be unfurled in space. Continuous pressure from sunlight would ultimately accelerate the craft to speeds about five times higher than possible with conventional rockets--without requiring any fuel. In collaboration with the Planetary Society, Cosmos Studios, has funded the first solar sail, which had its initial trial launch from an intercontinental ballistic missile [ICBM] on a Russian submarine in the Barents Sea. The launch unfortunately had a third-stage separation failure, which was a problem of the ICBM rather than the spacecraft. They are launching again. Solar sailing is a kind of technology which enables probes to move through space ten times faster than even the Voyager spacecraft,--38,000 miles an hour. To go ten times faster than that begins to get to a potentially practical rapid transit system for our local neighborhood in space, but also even to go to other stars. Lou: So, what is your appraisal of the Cosmos 1 solar sail mission? Freeman: I think it's great that somebody finally started on this technology. The main thing is not to raise expectations too high. It's important to get your feet wet and find out what the problems are. You're certainly doing that. Lou: The vision of Cosmos 1 has been the fact that the technology, as we've been discussing, allows us to think about traveling to the stars, but it's also technology that allows us think about traveling back and forth through the solar system. Freeman: Oh, very much so. In fact, that, to me, is the most interesting part of solar sailing. It could become very cheap if the sails were produced in large quantity, and then solar sailing would be essentially open to everybody. Bruce: We could park the sails in high Earth orbit, for example. Freeman: Then you'd have your own little sailboat and go wherever you wanted. Lou: What's your biggest technological uncertainty about sailing? Freeman: I would say it's all a matter of operations. The physics is easy the problem is, how do you operate the system, where do you want to go, and what do you do when you get there? Bruce: Freeman, in your book, Disturbing the Universe, you had a section on solar sailing. Looking back at that, what would you say differently about solar sailing or space travel or whatever? Freeman: I don't remember what I said, but clearly progress has gone much slower than I expected. Yours is really the first serious effort, and that's a pity. NASA has been systematically opposed to any advanced technology right from the start. That more or less remains true today. Bruce: Are you optimistic that America's, and therefore NASA's, interest will be renewed in moving beyond Earth orbit? Freeman: Maybe you have to get NASA out of the way first. Bruce: That's our strategy. If we can demonstrate a solar sail, even a primitive one, especially on a Russian nuclear submarine launch, NASA will be shamed into it. Also, the Europeans are beginning to look very seriously at the technology. That's The Planetary Society's job: to induce change, just as with the Mars rovers, when we got NASA seriously interested by demonstrating what you could do with them. Freeman: Well, I would say that the initiative has to come from outside NASA. Certainly it'll happen one day, although it's taken much longer than I expected. Lou: I guess that brings us back to the somewhat discouraging view about the possibility of interstellar flight being hundreds of years in the future. So much will happen between then and now. What will happen in genetic engineering or human evolution? What will happen in robotic technology? To me, these things are fairly unimaginable. So, trying to superimpose these unimaginable developments on the imaginable evolution of a solar sail vehicle is where I lose it. If we were looking at only a hundred years of change, I'd feel a little better about grabbing on to it. Bruce: I have one last point. We've been thinking about humans migrating, and adapting in some form, to other worlds in this solar system at least. There's an alternative possibility: to stay here and send only sensors and surrogates elsewhere. I'm wondering, in the 30 to 40 years since you first began fantasizing about some of these things, how do you feel about this alternative vision? Freeman: Well, I detest it. It's quite possible that if we decide to go that way, I will become a rebel and go off in my little spaceship and leave everybody else behind. So, I hope we'll all be rebels when the time comes. Lou: So, you won't be satisfied sitting in some room with a hologram of data pouring in? Freeman: No. I will have lost any freedom that I may have had. It's a matter of taste, of course, but I hope there will always be people who rebel against that kind of thing. Bruce: But it's so much easier to live here than elsewhere. Lou: None of us, to quote John F. Kennedy, is "doing this because it's easy, but because it's difficult." Read the original article at http://www.astrobio.net/news/article588.html. ________________________________________________________________________ URGENT CALL TO ACTION By Chuck Fuller American Society for Gravitational and Space Biology release 10 September 2003 Following the release of the Columbia Accident Investigation Board (CAIB) Report, we are entering a period of renewed national dialogue on the need for human spaceflight. An important part of this discussion will be the scientific rationale, including the quality and value of space and gravitational biology research performed by humans in space. To engage in this national dialogue, I urge you to communicate your opinions on these topics--the importance of space biology research and the need for humans to perform it, particularly on the International Space Station--to Congress, the Administration and the media, both nationally and locally. The need to send a strong message on this national investment is particularly urgent. Congressional hearings will begin soon, so I encourage you to send your responses to your Representative and Senators in the next few days. Further, I encourage each of you to participate because we are a relatively small community and require active membership participation to be heard! To identify your Representative and Senators or to obtain their contact information, visit http://www.house.gov/ and www.senate.gov. In addition to communicating with Congress, I would suggest writing to President Bush's science advisor: Dr. John H. Marburger, III, Director, Office of Science and Technology Policy, Executive Office of the President, Washington, DC 20502; OSTP Fax: 202-456-6021. (Since mail to the Federal Government is still extremely slow, it would be most effective to fax copies of your letter.) I would also suggest you CC your communications to Sean O'Keefe, Mary Kicza and Terri Lomax of NASA, whose respective fax numbers are 202-358-2810, 202-358-4174, and 202- 358-4168. Contact: Chuck Fuller, President, ASGSB E-mail: cafuller@ucdavis.edu. ________________________________________________________________________ NASA REPORT: EXPAND SEARCH TO INCLUDE SMALL ASTEROIDS By Robert Roy Britt From Space.com 10 September 2003 A panel of experts working at NASA's request has recommended a bold new search for potentially dangerous asteroids, including smaller objects that could cause regional damage in an Earth impact. The price tag: at least $236 million. The recommendation for a search effort far more expensive than the existing asteroid detection program, appears to have strong support among asteroid experts. NASA already leads the way in hunting for large Near Earth Objects (NEOs) that could cause global destruction. That effort, mandated by Congress, will be in the mop-up phase by 2008. NASA spends about $3.5 million per year on the program. Critics have long charged that NASA and other government agencies around the world are not doing enough to look for smaller NEOs, those less than 0.62 miles (1 kilometer) in diameter. Though the smaller rocks would only have regional consequences, there are more of them so the chances of an impact are higher, the critics reason. But the smaller rocks are harder and more costly to find. Read the full article at http://www.space.com/scienceastronomy/asteroid_search_030910.html. ________________________________________________________________________ BARRIERS TO SPACE: AND WHY THEY SHOULD BE OVERCOME By Douglas Vakoch From Space.com 11 September 2003 "It's extremely difficult to live and work in space," says psychologist Albert Harrison, who compares a stint onboard the International Space Station to "being in a cramped house with trash piling up." While the wobbly legs of an astronaut just returned to Earth may be the most obvious side-effect of a year-long space mission, simply getting along with other astronauts for months at a time may be even harder. According to Harrison, author of Spacefaring: The Human Dimension, "One of the things that the Russians have done with tremendous skill and daring is to build a record of increasingly long space flights. Our own astronauts gained experience on Skylab and later on Mir and the ISS." As a result, "the people that go up into space have been able to get along with one another. They work out patterns of mutual existence, living under conditions where they're cramped together." In orbit 240 miles above the Earth's surface, astronauts who tire of being in close quarters have "very little opportunity to get away." And in their celestial home away from home, there's little room for solitude. Long gone are the days of the Mercury space capsules, with room for only one astronaut on missions measured in hours. But like their predecessors, Harrison says, today's "astronauts still have the 'Right Stuff,' it's just that it's redefined a little bit." Read the full article at http://www.space.com/searchforlife/seti_vakoch_nasa_030911.html. ________________________________________________________________________ IS THIS WHAT KILLED THE DINOSAURS? Cardiff University release 11 September 2003 The extinction of the dinosaurs--thought to be caused by an asteroid impact some 65 million years ago--was more likely to have been caused by a "mantle plume"--a huge volcanic eruption from deep within the earth's mantle, the region between the crust and the core of the earth. This hypothesis, already supported by a significant body of geologists and palaeontologists, is strengthened by new evidence being presented at an international conference organized by Cardiff University. Research by an American earth scientist, Professor Gerta Keller and her team, suggests that a similar eruption under the Indian Ocean several million years before the extinction of the dinosaurs had a similarly devastating impact on the environment. However, at this earlier time there is no evidence of any asteroid impact. Her findings are based on analysis of microfossil assemblages, which were found inside cores that had been drilled deep into sediments on the ocean floor. The eruptions that were responsible for these two extinction events were as a result of mantle plumes--a phenomenon caused by rising hot mantle from deep within the earth. Likened to the actions of a lava lamp, the mantle's heat causes it to rise and mushroom out; it then flattens causing the mantle to melt and erupt magma over the earth's surface and across an area of some 1,000 kilometers diameter. These eruptions last between one and two million years and more than one million cubic kilometers of lava can be erupted in that time. Today, we can witness seven huge remnants of such mantle plume activity. These are also known as "hotspots" and are responsible for the volcanic activity on Iceland, the islands of Hawaii, Easter, Reunion, Tristan and Louisville as well as volcanism in the Afar region of Ethiopia. "Mantle plumes are literally a hot topic for debate," said conference organizer Dr. Andrew Kerr of Cardiff University's School of Earth, Ocean and Planetary Sciences. "They are a catalyst for the formation of ocean basins and fundamentally reshaping the earth's surfaces. The massive outpouring of lava, ashes, and gas can have significant effects on climate, which destabilizes the environment and have the potential to dictate the course of evolution. It is likely that were it not for mantle plumes, mammals would not have become predominant, and humankind would not be here today. "This conference is an opportunity to address these issues and validity of the links between mantle plumes with the evolution of life by bringing together geophysicists, petrologists and palaeontologists." The conference is organized by Cardiff University's School of Earth, Ocean and Planetary Sciences and takes place at the University and the National Museum and Galleries of Wales in Cardiff. Read the original news release at http://www.cardiff.ac.uk/news/03- 04/030911.html. An additional article on this subject is available at http://www.spacedaily.com/news/life-03zr.html. ________________________________________________________________________ NASA WANTS YOU TO BE A SOLAR SYSTEM AMBASSADOR NASA/JPL release 2003-123 11 September 2003 With hopes to further expand the successful Solar System Ambassador program, NASA's Jet Propulsion Laboratory, Pasadena, CA, is recruiting more volunteers to be Solar System Ambassadors in 2004. Applications are being accepted through September 30. "Ideal candidates are ambitious people who are enthusiastic about space exploration and active in their communities," said Kay Ferrari, national coordinator for the Solar System Ambassador program based at JPL. "Solar System Ambassadors come from all walks of life and aren't necessarily from any particular field of study." John Beasley, an air traffic controller and first-year ambassador from Miami, FL, has held interactive and informative presentations on NASA programs at a local IMAX theater and several elementary schools. "For a long time, I was looking for an avenue by which I could bring people NASA and show how its accomplishments in the manned and unmanned programs help those of us on Earth," Beasley said. "The Solar System Ambassador program provides that avenue." "One of the most important things on my agenda is to educate people on the benefits we enjoy here on Earth due to the space program and therefore why we need to continue supporting the program," said ambassador Melodee Knopp, an educator and coordinator for the Mobile Space Station simulation at the Southeast Kansas Education Service Center, Greenbush, KS. JPL coordinates the Solar System Ambassadors Program, consisting of more than 294 volunteer ambassadors who have committed to organizing at least four public outreach activities a year. JPL provides them with educational materials and training sessions, including contacts with mission scientists. "I've brought the solar system into the classroom and made students excited about learning science and technology," said Kathy Chock, a veteran ambassador and educator from Honolulu, Hawaii. Chock has exposed her students to exhibit boards, hands-on activities, discussion and video clips from missions such as Stardust, which aims to collect and return samples from a comet, and Galileo, which is orbiting Jupiter. Gilberto Monarez, a Solar System Ambassador in El Paso, Texas, translates similar materials and activities into Spanish so his students can share in the excitement. "I really enjoy the expressions the students give me after they realize that space is there for everybody," Monarez said. "You can even feel the excitement of their minds thinking of the planets and the universe moving. The kids get so excited they even pretend to be comets, planets or astronauts." "One of my favorite things about being a Solar System Ambassador is talking to senior citizens," said Cindy Psick, a solar system ambassador from Washington who has hosted at least 12 events since last year on subjects involving amateur astronomy, Mars exploration and the Deep Space Network, ground-based antennas that communicate with spacecraft. "They've seen the space program from the beginning and can deeply appreciate what it took to get this far. They get so excited about the missions. It brings out the kid in them." JPL ambassadors are based in all 50 states and Puerto Rico, serving widespread public interest about robotic missions throughout the solar system. Around 300 volunteers will serve as Solar System Ambassadors in 2004, Ferrari said. "Being a Solar System Ambassador gives me a chance to accomplish something I could not otherwise do: tell people about their space program and their universe. No finer opportunity exists to accomplish this," said Greg Redfern, a Solar System Ambassador from Fairfax, Va., who is fascinated with space rocks. "I highly recommend being a Solar System Ambassador to anyone who wants to give his or her time on behalf of NASA, JPL and the public." More information about the Solar System Ambassadors Program and how to apply is available at http://www.jpl.nasa.gov/ambassador, or contact the coordinator, Kay Ferrari, at ambassadors@jpl.nasa.gov or 818-354-7581. JPL is a division of the California Institute of Technology, Pasadena, CA. Contact: Charli Schuler Jet Propulsion Laboratory, Pasadena, CA Phone: 818-393-5467 An additional article on this subject is available at http://www.spacedaily.com/news/nasa-03c.html. ________________________________________________________________________ STUDENT TRAVEL GRANTS AVAILABLE NASA Academy release 11 September 2003 The Gerald A. Soffen Memorial Fund is pleased to announce the 2003 Travel Grant application opportunity for undergraduate and graduate students pursuing studies in fields of space science and engineering. The Travel Grants, in the amount of $500, enable student recipients to attend professional meetings to present their research. The 2003 Travel Grant application deadline is November 15, 2003. Jerry Soffen, a biologist by training, led a distinguished career in NASA, including serving as the Project Scientist for Viking and as an architect for the NASA Astrobiology Institute. The Travel Grant continues Jerry's dedication to educating and involving future generations in space science and engineering pursuits. Application materials and instructions are located on the Soffen Fund web site (www.nasa- academy.org/soffen). Questions regarding the application or application process may be sent to travelgrant@nasa-academy.org. ________________________________________________________________________ OPTICAL DETECTION OF ANOMALOUS NITROGEN IN COMETS, VLT OPENS NEW WINDOW TOWARDS OUR ORIGINS ESO release 25/03 12 September 2003 Summary A team of European astronomers [1] has used the UVES spectrograph on the 8.2-m VLT KUEYEN telescope to perform a uniquely detailed study of Comet LINEAR (C/2000 WM1). This is the first time that this powerful instrument has been employed to obtain high-resolution spectra of a comet. At the time of the observations in mid-March 2002, Comet LINEAR was about 180 million km from the Sun, moving outwards after its perihelion passage in January. As comets are believed to carry "pristine" material - left-overs from the formation of the solar system, about 4,600 million years ago - studies of these objects are important to obtain clues about the origins of the solar system and the Earth in particular. The high quality of the data obtained of this moving 9th-magnitude object has permitted a determination of the cometary abundance of various elements and their isotopes [2]. Of particular interest is the unambiguous detection and measurement of the nitrogen-15 isotope. The only other comet in which this isotope has been observed is famous Comet Hale-Bopp--this was during the passage in 1997, when it was much brighter than Comet LINEAR. Most interestingly, Comet LINEAR and Comet Hale-Bopp display the same isotopic abundance ratio, about 1 nitrogen-15 atom for each 140 nitrogen-14 atoms (14N/15N = 140 ± 30). That is about half of the terrestrial value (272). It is also very different from the result obtained by means of radio measurements of Comet Hale-Bopp (14N/15N = 330 ± 75). Optical and radio measurements concern different molecules (CN and HCN, respectively), and this isotopic anomaly must be explained by some differentiation mechanism. The astronomers conclude that part of the cometary nitrogen is trapped in macromolecules attached to dust particles. The successful entry of UVES into cometary research now opens eagerly awaited opportunities for similar observations in other, comparatively faint comets. These studies will provide crucial information about the detailed composition of a much larger number of comets than hitherto possible and hence, more information about the primordial matter from which the solar system formed. A better understanding of the origins of the cometary material (in particular the HCN and CN molecules [3]) and the connection with heavier organic molecules is highly desirable. This is especially so in view of the probable role of comets in bringing to the young Earth materials essential for the subsequent formation of life on our planet. Cometary material Knowledge of the abundance of the stable isotopes [2] of the light elements in different solar system objects provides critical clues to the origin and early evolution of these objects and of the system as a whole. In order to gain the best possible insight into the origins and formation of the niche in which we live, it is therefore important to determine such isotopic abundance ratios in as many members of the solar family as possible. This is particularly true for comets, believed to be carriers of well-preserved specimens of the pristine material from which the solar system was made, some 4,600 million years ago. However, the detailed study of cometary material is a difficult task. Measurements of isotopic ratios is an especially daunting undertaking, mainly because of the extreme weakness of the spectral signatures (emissions) of the less abundant species like carbon-13, nitrogen-15, etc. Measurements of microwave emission from those atoms suffer from additional, inherent uncertainties connected to the much stronger emission of the more abundant species. Measurements in the optical spectral region thus take on particular importance in this context. However, it is exceedingly difficult to procure the high-quality, high- resolution spectra needed to show the very faint emissions of the rare species. So far, they were only possible when a very bright comet happened to pass by, perhaps once a decade, thereby significantly limiting such studies. And there has always been some doubt whether the brightest comets are also truly representative of this class of objects. Observations of fainter, more typical comets had to await the advent of powerful instruments and telescopes. First UVES spectrum of a comet Observations of Comet LINEAR (C/2000 WM1) were carried out with the UV- Visual Echelle Spectrograph (UVES) mounted on the 8.2-m VLT KUEYEN telescope at the ESO Paranal Observatory (Chile) on four occasions during March 2002. At that time, the comet had moved past its perihelion and was by far the faintest comet for which such a detailed spectral analysis had ever been attempted. A number of 25-min exposures were secured, resulting in a total observing time of about 4 hours. The final spectrum covers the entire visual region (330 - 670 nm) and is one of the most detailed and information-rich cometary spectra ever obtained. PR Photo 28b/03 displays a small part of this spectrum. These observations are the first high resolution spectra of a comet taken with the VLT. Identification of nitrogen-15 At the time of the VLT observations, the comet was of 9th magnitude, i.e., about 15 times fainter than what can be perceived with the unaided eye. The distance from the Sun was about 180 million km; the distance from the Earth was 186 million km. The observations included calibration spectra of sunlight reflected from the lunar surface; they were used to "subtract" the solar signatures in the comet's spectrum, caused by reflection of sunlight from the dust particles around the comet. As expected, in addition to emission from "normal" CN-molecules (12C14N), the UVES data also show emission lines of the 13C14N-molecule that contains the rare isotope carbon-13. The derived 12C/13C isotopic ratio is 115 ± 20, quite similar to the "standard" solar system value of 89. However, there is also a series of weak features that are positioned exactly at the theoretical wavelengths of emission lines from 12C15N- molecules, cf. PR Photo 28c/03. The excellent fit that is evident in this diagram proves beyond any doubt the presence of nitrogen-15 in Comet LINEAR and allows a quite accurate determination of the isotopic ratio. The "anomalous" nitrogen isotope ratio in comets In 1997, the same group of astronomers obtained spectra of the (at that time) much brighter Comet Hale-Bopp with the 2.6-m NOT telescope (Roque de los Muchachos Observatory, La Palma, Canary Islands, Spain) in order to investigate the isotopic ratio of carbon-12 to carbon-13. Claude Arpigny remembers: "Interestingly, our spectra of Hale-Bopp showed a number of weak and unidentified emission lines. We later realized that they were positioned close to the theoretical wavelengths of some lines from the 12C15N-molecule. This was a pleasant surprise, as lines from that molecular species were previously believed to be so faint that they would not be observable." He continues: "This identification is now fully confirmed with the UVES observations of Comet LINEAR. Our detections in these two comets are the first ever of those emission lines in comets". The estimates of the 14N/15N isotopic ratios are very similar, 140 ± 35 for Hale-Bopp and 140 ± 30 for LINEAR. These ratios are remarkably low and different from the terrestrial value of 272. This means that these comets have comparatively more nitrogen-15 than has the Earth. No measurement has yet been made of the abundance of nitrogen-15 in the Sun. So which of the values corresponds to the composition of the material from which the solar system was made? Different origins? To date, only four cometary values of the 14N/15N isotopic ratio have been reported: two in the radio wavelength range and the two now measured by means of optical spectra. The radio measurements concern the HCN-molecule (hydrocyanic acid) in Comet Hale-Bopp, a "parent" molecule for the CN-molecules present in comets. Contrary to the optical measurements, the radio values (about 330 ± 75) are compatible with the terrestrial value (272). But radio measurements of carbon and nitrogen isotopic ratios are only possible on extraordinarily bright comets like Hale-Bopp, and even then, the achievable accuracy is very limited. This emphasizes the importance of performing this kind of research by means of optical observations. The origin of the isotopic discrepancy between different CN parents is likely due to fractionation mechanisms in the forming presolar nebula, e.g. when oxygen- and carbon-bearing molecules in high-density nebulae stick to cold (10K) dust grains. Macromolecules in space The astronomers think that the new results indicate that the HCN- molecule cannot be the only "parent" of the CN-molecule; the latter must also be produced by some as yet unknown parent(s) in which the nitrogen- 15 isotope is even more abundant. In this connection, it is very interesting that an "excess" of nitrogen- 15 is also known to exist in interplanetary dust particles (IDPs), captured by high-flying aircraft in the Earth's atmosphere. They represent the oldest material in the solar system that can be subjected to detailed laboratory analysis. Many of these particles are thought to originate from passing comets - this possibility is obviously supported by the new measurements. The nitrogen-15 carriers in IDPs have not been securely identified but are possibly organic macromolecules or polycyclic aromatic hydrocarbons (PAHs). It is thus possible that the additional parent(s) of cometary CN may belong to this ensemble of organic substances. Whatever the case, the longstanding question of nitrogen and its isotopic ratio(s) in the solar system, whether present and primordial, is notoriously enigmatic in several respects. However, the present results demonstrate that a detailed study of comets may deliver very useful clues. The team has now been granted more observing time with UVES and KUEYEN in order to pursue this important study by observing more comets. More information The results described in this ESO press release are presented in a research report published today in the Science journal ("Anomalous Nitrogen Isotope Ratio in Comets", by Claude Arpigny and co-authors). The Liège University is also issuing a press release (in French) on this occasion. Notes [1]: The team consists of Claude Arpigny, Jean Manfroid and Damien Hutsemékers (Institut d'Astrophysique et de Géophysique de l'Université de Liège (IAGL), Belgium), Emmanuël Jehin (ESO-Chile), Rita Schulz (ESA/RSSD, Noordwijk, The Netherlands), Joachim A. Stüwe (Leiden Observatory, The Netherlands), Jean-Marc Zucconi (Observatoire de Besançon, France) and Ilya Ilyin (University of Oulu, Finland). [2]: Different isotopes of the same elements have different numbers of neutrons in their nuclei. For instance, carbon-12 nuclei contain six protons and six neutrons (i.e., 12 particles in all) - this is the most abundant carbon isotope; carbon-13 contains six protons and seven neutrons. Nitrogen-14 - the most abundant isotope of this element - has seven protons and seven neutrons; nitrogen-15 has seven protons and eight neutrons. [3]: In chemical terms, CN is referred to as a "radical". Contacts: Claude Arpigny Institut d'Astrophysique et de Géophysique Université de Liège Belgium Phone: +32 (0)4 366 97 12 E-mail: arpigny@astro.ulg.ac.be Emmanuël Jehin ESO Santiago de Chile Phone: +56 2 463 30 65 E-mail: ejehin@eso.org Read the original news release at http://www.eso.org/outreach/press- rel/pr-2003/pr-25-03.html. An additional article on this subject is available at http://www.spacedaily.com/news/comet-03g.html. ________________________________________________________________________ HISTORIC GALILEO MISSION NEARS END NASA release 03-291 12 September 2003 Following eight years of capturing dramatic images and surprising science from Jupiter and its moons, NASA's Galileo mission draws to a close September 21 with a plunge into Jupiter's atmosphere. NASA has scheduled a Space Science Update (SSU) at 2:00 PM EDT, Wednesday, September 17, in the James E. Webb Auditorium at NASA headquarters, 300 E Street SW, Washington, DC. Panelists will discuss the historic mission, engineering challenges, science highlights and plans for Galileo's impact with Jupiter's atmosphere. The SSU will be carried live on NASA Television with two-way question- and-answer capability from participating agency centers. NASA TV is broadcast on AMC-9, transponder 9C, C- Band, located at 85 degrees west longitude. The frequency is 3880 MHz. Polarization is vertical, and audio is monaural at 6.80 MHz. Audio of the SSU is available on voice circuit from the Kennedy Space Center at 321-867-1220. SSU participants: * Dr. Colleen Hartman, director, Solar System Exploration Division, NASA Headquarters. * Dr. Claudia Alexander, Galileo project manager, NASA Jet Propulsion Laboratory (JPL), Pasadena, CA. * Dr. Michael J. S. Belton, Team Leader, Galileo Solid State Imaging Team, Emeritus Astronomer, National Optical Astronomy Observatories, Tucson, AZ. * Dr. Don Williams, principal investigator, Galileo heavy ion counter, The Johns Hopkins University, Applied Physics Laboratory, Laurel, MD. * Jim Erickson, Mars Exploration Rover Mission Manager and former Galileo project manager, JPL. The spacecraft was put on a collision course with Jupiter's atmosphere to eliminate any chance of impact of the moon Europa, which Galileo discovered is likely to have a subsurface ocean. The team expects the spacecraft to transmit a few hours of science measurements in real time, leading up to impact on Sunday, September 21. The maneuver is necessary, since onboard propellant is nearly depleted. Without propellant, the spacecraft would not be able to point its antenna toward Earth nor adjust its flight path, so controlling the spacecraft would no longer be possible. From 4:00 to 5:00 PM EDT, September 21, JPL will provide live commentary from the mission control room and footage of the countdown clock as Galileo nears its final moments. The televised special will feature two panels. One will include former project managers, and the other former project scientists. Live satellite interview opportunities with project personnel are available Friday, September 19. To book a time, please contact Jack Dawson at: 818/354-0040. Launched by the Space Shuttle Atlantis in 1989, the mission produced a string of discoveries while circling Jupiter, the solar system's largest planet, 34 times. Galileo was the first spacecraft to directly measure Jupiter's atmosphere with a probe and the first to conduct long-term observations of the Jovian system from orbit. Galileo found evidence of subsurface liquid layers of salt water on Jupiter's moons Europa, Ganymede and Callisto, and it detected extraordinary levels of volcanic activity on Io. Galileo was the first spacecraft to fly by an asteroid and the first to discover the moon of an asteroid. Galileo's prime mission ended six years ago after two years orbiting Jupiter. NASA extended the mission three times to take advantage of Galileo's unique science capabilities. The September 17 SSU and September 21 end of mission events will be Web cast live at http://www.jpl.nasa.gov/webcast/galileo/. Additional information about the mission and Galileo's discoveries is available at http://galileo.jpl.nasa.gov. For information about NASA on the Internet, visit http://www.nasa.gov Contacts: Donald Savage Headquarters, Washington, DC Phone: 202-358-1547 Carolina Martinez Jet Propulsion Laboratory, Pasadena, CA Phone: 818/354-9382 An additional article on this subject is available at http://www.spacedaily.com/news/galileo-03d.html. ________________________________________________________________________ EARLY MARS WAS FROZEN BUT HABITABLE, PART I From Astrobiology Magazine 15 September 2003 Early Mars was cold--very cold, says Chris McKay, a planetary scientist at the NASA Ames Research Center. But that doesn't mean it was incapable of supporting life. McKay has extensively studied life in some of the harshest environments in the world: the Antarctic dry valleys, the Arctic, and the Atacama Desert. At a meeting of the American Astronomical Society's Division of Planetary Sciences, held in September 2003 in Monterey, CA, McKay gave a plenary talk in which he discussed the evidence for a cold, but wet, early Mars. McKay compared these early martian conditions to Antarctica's modern-day dry valleys. And he laid out a strategy for searching for evidence of the organisms that may have inhabited Mars during its first billion years. His talk is presented here in two parts; this is part one. I think the most important reason to search for life on Mars is the possibility of finding a second genesis of life. And I say "possibility," because life on Earth and Mars may share a common origin. It's not certain that, just because there's life on Mars, it represents a second genesis. But a second genesis is what we're interested in. We're interested in it because it would allow us to do comparative biochemistry, just as we're interested in comparative planetology. As you know, it's very difficult to study objects when you only have one example. Imagine how limited our knowledge of the universe would be if we only had one to study. In addition to comparative biochemistry, if we found a second genesis on Mars, if we discovered that life had two independent starts here in our solar system, we would know right away that life is common in the universe. So it would have a practical scientific implication as well as a deeper philosophical implication. Of course, searching for life is also important in the planetary environmental sense. It gives us information about the early martian environment. And it certainly gives us information relevant to understanding the origin of life on Earth. But I think these are secondary objectives. The search for life on Mars began with the Viking landers. The Viking missions had two separate approaches to searching for life. One was the three biology experiments. They sought to detect life directly. And then we had the GCMS (gas chromatograph-mass spectrometer), which sought to detect what we now would say are signs of life. There's an important distinction here, between trying to detect an actual living organism and trying to detect some indication, some sign that life is present. Well, looking back now, with 20-20 hindsight, how would we assess the Viking approach? The Viking biology experiments detected life by doing incubation: taking a sample, putting it in three chambers, seeing if anything would grow. But that presupposes that you have knowledge of the conditions and nutrients needed for growth. We now know that that's actually a bad approach to searching for life We now know that we couldn't do the Viking experiments successfully even here on Earth. For example, 90 percent of terrestrial soil bacteria cannot be grown in culture. If you took the Viking experiments out into your back yard, they would fail to detect 90 percent of the organisms in the soil. It would detect the other 10 percent, so you'd get a positive signal. But anything that fails to detect 90 percent is probably not a good approach. As a result, it's not surprising that the Viking biology experiments gave ambiguous answers. And it's also not surprising that in the astrobiology community now there is no longer a focus on culturing, trying to grow organisms, as a way of detecting life, because we don't know the conditions and nutrients needed for them to grow. And if we can't make it work for 90 percent of organisms on Earth, we're not going to make it work on Mars and Europa, where we know even less. So the Viking biology experiments' approach is not an approach we want to follow. But the GCMS approach is a much more powerful approach, where what we look for are more robust signs of life that require us to know less about the organisms we want to detect. There is good evidence for water on Mars. In images taken from orbit we see good evidence that at least some of Mars' fluvial features were carved by water. But I want to make the point that on early Mars, when Mars was wet, it wasn't warm, it was cold. And I think this is an important point that we're starting to come around to as a community. I'd say there are several lines of evidence that argue that Mars was cold when it was wet. One, most importantly, is the evidence of very low erosion. Erosion on Mars is low even compared to places on Earth where erosion is at its minimum, such as the Antarctic dry valleys. Also, the sporadic distribution of the valley features we see in images of Mars is a powerful argument that Mars is not Earth-like in the sense of having a warm, Earth-like climate with average annual temperatures of 15 degrees Celsius (59 degrees Fahrenheit). There's also some weaker evidence suggesting it was cold. One is the climate modelers have difficult getting Mars's surface temperatures near or above zero--but that's a sort of a theoretical data point. Another line of evidence is that no massive surface carbonates have been detected by remote sensing. The fact that they're not detectable by remote sensing doesn't mean they're not there, but still this is consistent with Mars being very cold. Well, cold is very interesting. I want to talk a little bit about the environments on Earth that are the most Mars-like, in the sense of being cold, and look at the evidence for life in those environments. And I would argue that the most relevant environment is the dry valleys of Antarctica. This is the largest ice-free region in Antarctica. The average temperature is minus 20°C (minus 4°F). Summertime temperatures are higher. Precipitation is equivalent to one or two centimeters per year of moisture. And the pressures are well above the triple point of water. [The triple point of water is a combination of temperature and pressure that enables water to exist in all three states: solid (ice), liquid and gas (water vapor). When atmospheric pressure is too low, as on the surface of Mars today, water cannot exist in liquid form, regardless of the temperature.] In the Antarctic dry valleys it never rains, only snows, and yet there are large rivers and lakes, such as Lake Vanda and the Onyx River, the largest river in Antarctica. Typically the Onyx River flows a couple months a year. When the temperatures in the summer get above freezing, the glaciers melt and that water forms the Onyx River, which collects in the lake. What's interesting about this environment, is that because it's so dry, it's dead. There's nothing growing on the surface soil. Precipitation is too slight. It evaporates, blows away. This is one of the most lifeless places on Earth. But in the water in Lake Vanda, underneath the ice, there are thick mats of algae and bacteria. So here in this Mars-like environment, where the average temperatures are minus 20°C (minus 4°F), there's still a hydrological cycle, based on snow, glaciers, melt and accumulation in ice-covered lakes. And it hosts a rich community of microorganisms, similar to what you would expect on the early Earth and would hope to find on Mars. On Earth, the hydrological cycle averages a [little over one] meter (39 inches) a year at a temperature of plus 15°C (59°F). On Mars, you could guess that if the average temperature were, say, minus 35°C (minus 31°F), you'd get a hydrological cycle orders of magnitude lower than Earth's. That's similar to what we see in the dry valleys, where the temperature is minus 20 and the hydrological cycle is about 1 to 2 centimeters a year. The point in making this analogy is that cold can still be wet. Very cold can still be wet--and can still be alive. You can see this on Earth. We have this bias for warm places because we're warm creatures and most of Earth is warm. In fact, Earth is on the warm edge of the habitable zone. But warm is not really a requirement for life. Life would do perfectly well in cold water. So a very cold Mars in not uninteresting biologically. It could be very interesting biologically. And we can quantify that. Models of the martian atmosphere show that ice-covered lakes could have existed for perhaps a billion years of its early history, even as the average temperature got quite cold. So we don't have to say that early Mars was 0 degrees C (32 degrees F) to be interesting biologically. I think you could easily see that--and I'm talking just the surface, not even discussing the subsurface-- temperatures could get quite low, minus 40 C (minus 40 F), and there could still have been a significant hydrological cycle that could support ice-covered lakes. So Mars was cold when the valley features that we see now were formed. Temperatures could have been as low as minus 35 C (minus 31 F) and Mars could still have had enough water activity to create the features that we see. And these features could have been habitats for life. Read the original article at http://www.astrobio.net/news/article594.html. ________________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/projects/marsbugs/astrobiology/astrobiology.html 15 September 2003 Astrobiology and planetary engineering articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles1.html C. P. McKay, 2003. Early Mars was frozen but habitable, part I. Astrobiology Magazine. L. David, 2003. The future of Mars: plans for NASA's next decade of red planet probing. Space.com. L. David, 2003. Mars underground: digging deep for life. Space.com. Human space exploration articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles3.html Planetary Society, 2003. Bridging the gap: a discussion with Freeman Dyson, part III. Astrobiology Magazine. D. Vakoch, 2003. Barriers to space: and why they should be overcome. Space.com. Evolution (biological, chemical and cosmological) articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles5.html Cardiff University, 2003. Did earth blow up the dinosaurs? Spacedaily. Planetary protection articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles6.html R. R. Britt, 2003. Asteroid scares: why they won't end. Space.com. R. R. Britt, 2003. NASA report: expand search to include small asteroids. Space.com. Massachusetts Institute of Technology, 2003. MIT reassess asteroid hazards. SpaceDaily. NASA, 2003. Spaceguard: five years and counting. Astrobiology Magazine. Extrasolar planets articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles7.html E. DeVore, 2003. Discovering new worlds. Astrobiology Magazine. Astrobiology and extreme environments book list http://www.lyon.edu/projects/marsbugs/astrobiology/astrobiology_books.ht ml R. Zubrin, 2003. Leaving Earth: Space Stations, Rival Superpowers, and the Quest for Interplanetary Travel. National Academies Press, Washington, DC. ________________________________________________________________________ CASSINI SIGNIFICANT EVENTS NASA/JPL release 4-10 September 2003 The most recent spacecraft telemetry was acquired from the Canberra tracking station on Wednesday, September 10. 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. On-board activities this week included a Composite InfraRed Spectrometer radiator test, reaction wheel assembly friction test, transition to and from reaction wheel control and thrusters in support of Trajectory Correction Maneuver (TCM) 19a, and execution of TCM19a. TCM19a executed properly. A maneuver wrap-up meeting is scheduled for next week. Until then, the Spacecraft Operations Office has released some preliminary statistics: the burn began execution at 253T20:00:00 spacecraft event time, with a duration of 197.88 seconds and a delta V of 0.122 m/s. A Sub-Sequence Generation Sequence Change Request approval meeting was held as part of the development process for the C40 background sequence. Merged Preliminary Sequence Integration and Validation integrated sequence products have been released for review. At a scoping meeting held this week, project management approved a proposed plan for the C43 sequence. A few issues remain open, one of which is the need for 70 meter antenna coverage to support the Probe relay sequence demonstration and data playback in February of 2004. This is a highly contested time due to Mars Exploration Rover activities. The appropriate requests have been submitted to the DSN and the issue is being worked. All teams and offices are currently working on presentations for the Operations Readiness Review to be held in October. System Engineering, Uplink Operations, Instrument Operations, and Navigation have presented drafts and are in the process of incorporating comments. A delivery coordination meeting was held for the Assisted Load Format Tool version 9.2. The software has been approved. A Software Requirements Certification Review delivery meeting for the Magnetospheric Imaging Instrument (MIMI) v7.0.0 flight software (FSW) build was held mid-August. The FSW was accepted for delivery to the project software library and approved for processing to uplink as part of C39 sequence activities. Approval of the FSW for operations was tentatively approved, with full approval to be given with successful closure of three action items. All have now been completed and the FSW build is fully approved for operations uplink. This FSW is scheduled to be sent to the spacecraft September 11. Mission Assurance supported a JPL/Aerospace Corporation Risk Management Workshop this week. The group has been working to develop a coordinated Risk Management Process, including the creation of a "story book" of common threads and lessons learned. The products produced by this group will be presented at next spring's System Engineering and Risk Management Symposium, sponsored by the Aerospace Corporation. The Hubble telescope has recently taken some excellent images of Saturn. To whet your appetite for what is coming next year, go to the following URLS: http://space.com/scienceastronomy/hubble_saturn_030909.html http://hubblesite.org/newscenter/archive/2003/23/ 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. ________________________________________________________________________ MARS GLOBAL SURVEYOR IMAGES NASA/JPL/MSSS release 4-10 September 2003 The following new images taken by the Mars Orbiter Camera (MOC) on the Mars Global Surveyor spacecraft are now available. South Polar Polygons (Released 04 September 2003) http://www.msss.com/mars_images/moc/2003/09/04/index.html Dune and Dust Devil Streak (Released 05 September 2003) http://www.msss.com/mars_images/moc/2003/09/05/index.html Layers in East Candor (Released 06 September 2003) http://www.msss.com/mars_images/moc/2003/09/06/index.html Brazos Valles Dunes (Released 07 September 2003) http://www.msss.com/mars_images/moc/2003/09/07/index.html Arabia's Auqakuh Vallis (Released 08 September 2003) http://www.msss.com/mars_images/moc/2003/09/08/index.html North Polar Dune Patterns (Released 09 September 2003) http://www.msss.com/mars_images/moc/2003/09/09/index.html Oblique Olympus Mons (Released 10 September 2003) http://www.msss.com/mars_images/moc/2003/09/10/index.html All of the Mars Global Surveyor images are archived at http://www.msss.com/mars_images/moc/index.html. Mars Global Surveyor was launched in November 1996 and has been in Mars orbit since September 1997. It began its primary mapping mission on March 8, 1999. Mars Global Surveyor is the first mission in a long-term program of Mars exploration known as the Mars Surveyor Program that is managed by JPL for NASA's Office of Space Science, Washington, DC. Malin Space Science Systems (MSSS) and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. ________________________________________________________________________ MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 8-12 September 2003 Central Peak (Released 8 September 2003) http://themis.la.asu.edu/zoom-20030908a.html Spallanzani's Neighbor (Released 9 September 2003) http://themis.la.asu.edu/zoom-20030909a.html Noctis Labyrinthus (Released 10 September 2003) http://themis.la.asu.edu/zoom-20030910a.html Arkhangelsky Crater (Released 12 September 2003) http://themis.la.asu.edu/zoom-20030912a.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 12 September 2003 There was one Deep Space Network (DSN) tracking pass in the past week. Telemetry relayed from the spacecraft indicates it is healthy and all subsystems continue to operate normally. The start of the formal Spacecraft Test Lab (STL) testing of the Comet Wild 2 encounter sequence has begun. 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 Mission Design Manager participated with the Genesis project in the annual landing planning and review meeting at the Utah Test and Training Range (UTTR). Since Genesis will land in one year, Stardust is working closely with Genesis to gain flight experience and capitalize on their lessons learned. The Stardust Camera Science Lead made a presentation to the Caltech Alumni Association on Stardust at the invitation of the Caltech Associates Office. The Spacecraft Systems Engineer and DSN Lead briefed the station personnel at Canberra on the Comet Wild 2 encounter and also made presentation on STARDUST at the Canberra Questacon Museum and the Sydney Powerhouse Museum, drawing hundreds of participants. 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 36.