MARSBUGS: The Electronic Astrobiology Newsletter Volume 8, Number 4, 29 January 2001. Editors: Dr. David J. Thomas, Math and Science Division, Lyon College, Batesville, AR 72503-2317, USA. dthomas@lyon.edu Dr. Julian A. Hiscox, School of Animal and Microbial Sciences, University of Reading, Reading, RG6 6AJ, United Kingdom. J.A.Hiscox@reading.ac.uk Marsbugs is published on a weekly to quarterly basis as warranted by the number of articles and announcements. Copyright of this compilation exists with the editors, except for specific articles, in which instance copyright exists with the author/authors. While we cannot copyright our mailing list, our readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing list. The editors do not condone “spamming” of our subscribers. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editors. E-mail subscriptions are free, and may be obtained by contacting either of the editors. Article contributions are welcome, and should be submitted to either of the two editors. Contributions should include a short biographical statement about the author(s) along with the author(s)’ correspondence address. Subscribers are advised to make appropriate inquiries before joining societies, ordering goods etc. Back issues and Adobe Acrobat PDF files suitable for printing may be obtained from the official Marsbugs web page at http://welcome.to/marsbugs. The purpose of this newsletter is to provide a channel of information for scientists, educators and other persons interested in exobiology and related fields. This newsletter is not intended to replace peer- reviewed journals, but to supplement them. We, the editors, envision Marsbugs as a medium in which people can informally present ideas for investigation, questions about exobiology, and announcements of upcoming events. Astrobiology is still a relatively young field, and new ideas may come from the most unexpected places. Subjects may include, but are not limited to: exobiology and astrobiology (life on other planets), the search for extraterrestrial intelligence (SETI), ecopoeisis and terraformation, Earth from space, planetary biology, primordial evolution, space physiology, biological life support systems, and human habitation of space and other planets. --------------------------------------------------------------------- CONTENTS 1) NEW OPTICAL SETI TELESCOPE Planetary Society release 2) ISO DETECTS BENZENE IN SPACE From ESA Science News 3) OTHER EARTHS: ARE THEY OUT THERE? By John G. Watson 4) LAYERS OF MARS By Patrick L. Barry and Tony Phillips 5) MARS 2003: TWIN ROVER MISSION FACES TECHNICAL OBSTACLES By Leonard David 6) MARS MAGMAS ONCE CONTAINED A LOT OF WATER, RESEARCHERS FROM MIT AND U. OF TENNESSEE REPORT Massachusetts Institute of Technology release 7) STUDY SUGGESTS VENUS COULD HAVE BEEN WET PLANET Washington University in St. Louis release 8) THE RIGHT PLACES TO LOOK FOR ALIEN LIFE By Ken Croswell 9) HIGH SCHOOL STUDENTS TO PLAN COMMUNITY ON MARS NASA/JSC release J01-04 10) SETI—WHAT TO DO IF A SIGNAL ARRIVES By Seth Shostak 11) GREENING OF THE RED PLANET NASA Astrobiology Institute 12) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 13) CASSINI WEEKLY SIGNIFICANT EVENTS JPL releases 14) THIS WEEK ON GALILEO JPL release 15) ISS STATUS REPORT NASA/JSC release 16) MARS GLOBAL SURVEYOR MISSION STATUS JPL release 17) STARDUST STATUS REPORTS JPL releases --------------------------------------------------------------------- NEW OPTICAL SETI TELESCOPE Planetary Society release December 2000 If alien civilizations are beaming laser messages across the galaxy, The Planetary Society is about to increase the odds of finding them when it opens its new Optical SETI Telescope in Harvard, Massachusetts early in 2002. Designed to scan the sky for pulsed laser signals, the all-sky Optical SETI Survey will use a 1.8 meter (72 inch) diameter optical telescope dedicated exclusively to SETI. When completed, the new telescope will be the largest in the eastern United States. Professor Paul Horowitz of Harvard University is the project leader. “Using only ‘Earth 2001’ technology, we could now generate a beamed laser pulse that appears 5000 times brighter than our sun, as seen by a distant civilization in the direction of its slender beam,” said Horowitz. “In other words, interstellar laser communication is altogether practicable. The new Optical SETI Telescope will allow us to search the entire northern sky for such signs of intelligent life elsewhere in the galaxy.” Horowitz and his team have designed and ordered a custom telescope and broken ground on construction of an observatory in which to house it in Harvard, Massachusetts. Once operational, the new optical SETI observatory will search for brief pulses of light, covering the entire northern sky once every 200 clear nights. Its special camera will stare at a stripe of sky with an array of 1024 ultrafast detectors, seeking flashes of light as short as a billionth of a second. The Planetary Society is funding the project with a $350,000 grant, raised through contributions from its members. David Brown, a member of the Society’s New Millennium Committee, is providing half the funds through a matching gift challenge to Society members. This project will be the twelfth SETI project sponsored by the Society since the organization began in 1980. It is the latest in a long history of Society-supported SETI projects—all with private funds— which include several radio telescope searches and the internationally popular SETI@home project. Over 2.6 million SETI@home users have joined the quest for extraterrestrial intelligence, using their home computers to help process SETI data. Professor Horowitz has worked on SETI projects with The Planetary Society for nearly two decades now. These include BETA, a radio telescope search in Harvard, Massachusetts; META in Argentina; and a search for laser communication from 13,000 selected stars. Searching for continuous-wave laser SETI signals was first suggested by Robert Schwartz and Nobel Prize winner Charles Townes in 1961. A few years later, Monte Ross showed the substantial benefits of very short laser pulses for interstellar communications. Early optical SETI observations were made by Viktor Shvartsman, Albert Betz and Stuart Kingsley. More information Visit http://planetary.org and http://www.oseti.org. Carl Sagan, Bruce Murray and Louis Friedman founded The Planetary Society in 1980 to advance the exploration of the solar system and to continue the search for extraterrestrial life. With 100,000 members in over 140 countries, the Society is the largest space interest group in the world. Contacts: Contact Susan Lendroth at 626-793-5100 ext 214 or by e-mail at susan.lendroth@planetary.org. The Planetary Society 65 N. Catalina Ave. Pasadena, CA 91106-2301 Phone: 626-793-5100 Fax: 626-793-5528 E-mail: tps@planetary.org http://planetary.org Additional articles on this subject are available at: http://www.astronomy.com/Content/Dynamic/Articles/000/000/000/280chcl h.asp http://news.bbc.co.uk/hi/english/sci/tech/newsid_1131000/1131230.stm http://www.cnn.com/2001/TECH/space/01/22/telescope.alien/index.html http://www.cosmiverse.com/space01230103.html --------------------------------------------------------------------- ISO DETECTS BENZENE IN SPACE From ESA Science News http://sci.esa.int 22 January 2001 Life as we know it is based on the ability of the carbon atom to form ring-shaped molecules. But rings of carbon are not exclusive to Earth, as experts in space chemistry now know. A Spanish team of astronomers that observed with ESA’s Infrared Space Observatory (ISO) report this week the first detection in interstellar space of benzene, the ring molecule par excellence. They think stars produce benzene at a specific stage of evolution, and that it is an essential chemical step towards the synthesis of more complex organic molecules whose true nature is still unclear—although their fingerprints are very conspicuous in the universe. In industry, benzene is obtained from petroleum and has many uses. Benzene is made of six atoms of carbon chained together to form a ring, plus six atoms of hydrogen, one per carbon. This structure was discovered in 1865 by the German chemist August Kekule—who would later say a dream inspired him. Chemists know today that benzene- type molecules make a whole family of compounds, called “aromatic” hydrocarbons because of their smell (they are basic constituents, for instance, of perfumes and candles). Astronomers also expected to find these ringed molecules in space, where long strings of carbon atoms have been detected. Moreover, it had been postulated that certain compounds of yet unknown nature, that are known to be very abundant in space, are actually aromatic hydrocarbons. These compounds have left their chemical fingerprint, the so-called “Unidentified Infrared Bands” or “UIBs”, in many places in the Universe, and although the labs have not yet been able to confirm their nature for certain, many astronomers already call them “Polycyclic Aromatic Hydrocarbons”, or PAHs. Where to look for the “ringed molecules”? Around carbon-rich old stars, thought the astronomers. When stars of intermediate mass—up to about three solar masses—become old, and reach the “red giant” phase, they begin to release huge amounts of gas and dust into their environment; because carbon is produced by the nuclear reactions in the core of the star, many carbonaceous compounds are present in the dust expelled by the red giant star. The team, led by José Cernicharo (Instituto de Estructura de la Materia, CSIC), chose a typical red giant star to start the search. But it did not work: the star did have carbon-based molecules, such as acetylene, but not ringed molecules. It did not have any UIBs either. So the astronomers turned to an even older star, a “protoplanetary nebula”—a star that is about to “die” via becoming a “white dwarf” star surrounded by a beautiful cloud of glowing dust and gas. They focused on the protoplanetary nebula CRL618 (See image taken by the ESA/NASA Hubble Space Telescope). “We knew that, in a protoplanetary nebula, the dust ejected in the previous red-giant stage is bathed in powerful ultraviolet radiation coming from the central star, which also emits high velocity winds. The radiation and the winds break up the carbonaceous compounds in the dust and trigger new reactions. We thought benzene could be formed in this way, a process that we could call polymerization of acetylene in evolved stars”, explains Cernicharo. This time the idea was correct. As published in the 10 January issue of The Astrophysical Journal, they have found benzene in the surroundings of the CRL618 protoplanetary nebula. The authors think that there could be a few molecules of benzene per cubic centimeter, a value considered to be high, although the estimated density of molecules of all kinds in the area observed is ten million per cubic centimeter. A “missing link” The team thinks that this molecule is the “missing link” between the simple carbon molecules observed in red giants, made of no more than eight carbon atoms, and the complex molecules responsible for UIBs, known to be made of hundreds of carbon atoms. This theory therefore implies that the UIBs are indeed due to aromatic hydrocarbons, a possibility that, according to the authors, becomes stronger after the first confirmed detection of an aromatic molecule in space. The “missing-link” idea is based on observations of objects at each stage of evolution. UIBs have been detected around stars that are already “dead”, the “planetary nebula”, but not in the previous evolutionary stage of protoplanetary nebula—such as CRL618, where benzene has been found. The transformation from protoplanetary to planetary nebula lasts for no longer than a thousand years, a quick process in astronomical terms—as an example, the central star of CRL618 was still a red giant only a few centuries ago, and will become a “fully formed” planetary nebula in a few thousand years. As Cernicharo says, “the molecules causing the UIBs must form in the relatively short period from protoplanetary nebula to planetary nebulae. It seems that carbon-rich protoplanetary nebula are the best organic chemistry factories in space”. About ISO The European Space Agency’s infrared space telescope, ISO, operated from November 1995 till May 1998, almost a year longer than expected. As an unprecedented observatory for infrared astronomy, able to examine cool and hidden places in the Universe, ISO successfully made nearly 30,000 scientific observations. For more information José Cernicharo Instituto de Estructura de la Materia, CSIC, Madrid cerni@astro.iem.csic.es +34 91 590 1611 Martin F. Kessler, ISO Project Scientist ESA Villfranca Satellite Tracking Station, Spain +34-91-8131253 Martin.Kessler@esa.int ESA Science Communication Service: +31-71-5653223 Useful links for this story ESA Science home page http://sci.esa.int/ ISO home page http://sci.esa.int/home/iso/index.cfm ISO Science web site http://www.iso.vilspa.esa.es/ “The infrared revolution” http://sci2.esa.int/specialevents/infrared/index.html ISO finds the precursors of the complex organic molecules in space http://sci.esa.int/content/news/index.cfm?aid=18&cid=599&oid=12850 Stellar cocoon CRL 618 http://spdext.estec.esa.nl/hubble/gallery/new_searchresult.cfm?ooid=2 4530&imgid=10322&ftitle=&instruments=ANY&cosmicobjects=288&startz=9 Image captions [Image 1] http://sci.esa.int/content/searchimage/searchresult.cfm?aid=18&cid=12 &oid=25880&ooid=24530 Stellar cocoon CRL 618. This image comes from the large archive of scientific observations performed with the Hubble Space Telescope. Currently more than 250,000 scientific Hubble observations are contained in this highly valuable archive and more are added all the time. In this image singly ionised sulphur is shown in red, green represents neutral hydrogen, the blue-green colour comes from neutral oxygen and blue light is continuum light seen through a so-called Strömgren y filter. The full extent of the nebula is 12 arcseconds from tip to tip. The original Hubble observations were obtained in 1998 by Susan R. Trammell from University of North Carolina, and were turned into a color image by the Hubble European Space Agency Information Centre at European Southern Observatory, Munich and A.G.G.M. Tielens from the Kapteyn Astronomical Institute in the Netherlands. [Image 2] http://sci.esa.int/content/searchimage/searchresult.cfm?aid=18&cid=12 &oid=25880&ooid=25900 Benzene structure. --------------------------------------------------------------------- OTHER EARTHS: ARE THEY OUT THERE? By John G. Watson From Space.com 23 January 2001 Was the formation of our lovably habitable Earth a freak accident or commonplace occurrence throughout the universe? Certainly there are planets out there—more than 50 have been discovered in recent years— but most of the ones we know about so far are huge monsters ridiculously close to their suns, hardly ideal conditions for life. NASA has just chosen the Kepler mission, which will use a space telescope, specially designed to search for habitable planets, to unravel the mystery. This mission is one of the three candidates for NASA’s Discovery Program missions. Get the full story at http://www.space.com/scienceastronomy/solarsystem/other_earths_kepler _010122.html. --------------------------------------------------------------------- LAYERS OF MARS By Patrick L. Barry and Tony Phillips From NASA Science News 23 January 2001 Layered terrains on Mars discovered just last year by NASA’s Mars Global Surveyor spacecraft bear a striking resemblance to sedimentary deposits here on Earth that form under water. Liquid water is scarce on Mars nowadays, but it might have been common four billion years ago. If these martian layers turn out to have a watery origin, as some scientists suspect, they could hold the key to the mysterious history of water (and maybe even life) on the Red Planet. Studying Mars’s sedimentary deposits, if that’s what they are, could tell scientists if water existed on Mars long enough for primitive life to begin. Indeed, the layered rocks themselves may be the best places to go fossil hunting. “One of the reasons that we get so excited about the layers is that they could imply water was there for a while,” said Ken Nealson, director of the Center for Life Detection at NASA’s Jet Propulsion Laboratory. Large sedimentary deposits on Earth often take millions of years to accumulate. As tiny bits of sand or dust sink under water they settle in layers. Pressed upon by their own weight and that of the water above them, the layers grow steadily thicker and harder with the passage of time. The color and texture of each layer depends on the chemistry of the water and the make-up of the sediments when they settled. If the martian deposits settled in similar fashion out of long-gone ancient lakes, it could mean that the lakes were around long enough for microbial life to arise—a process that took roughly 500 million years on Earth. Sedimentary deposits are places where our planet’s fossil record is stored, so they are probably good places to hunt for fossils on Mars, too, added Nealson. Unfortunately, single-celled microbes—the most likely forms of life on ancient Mars—rarely fossilize. Their small, soft bodies usually decompose before fossilization can occur. “It’s unusual (to find fossils of bacteria), but if you get enough stuff being deposited, you usually get some circumstances where you’d find them,” said Thor Hansen, professor and chair of the geology department at Western Washington University. For now, the challenge facing scientists is to determine whether the sedimentary deposits seen on Mars are in fact the remnants of ancient lakebeds or seafloors. “You have to be careful. Just because there are some layers, that doesn’t prove there was an ocean basin and sediments deposited there,” Nealson said. “You can look around on our planet and see a lot of examples of things that form layers—everywhere from the geyserite deposits in Yellowstone to layers of variation that come from forest fires or volcanoes... there are all sorts of things.” Clues in the rocks themselves will help scientists determine whether the layered features on Mars were deposited by water or by some other agent. Wind is a primary contender. Mars today has only a tenuous atmosphere, less than 1% as thick as Earth’s, but if the martian air had been much denser billions of years ago winds might have carried dust grains aloft and deposited them in places where the wind speed dropped. As these deposits became buried, pressure from the covering material’s weight would begin the transformation to sedimentary rock. Because wind can carry only very small dust particles, while water can transport larger ones, geologists would expect wind-laid sedimentary rocks to contain relatively small grains. Measuring the sizes of grains in the martian deposits will provide important clues about their origin. Some of these data will be gathered by upcoming missions to Mars. In December 2003, the European Space Agency’s Beagle 2 lander is scheduled to land at Isidis Planitia, an area of the martian surface near 10 degrees North latitude. This landing site was not among the sedimentary regions discovered by NASA’s Mars Global Surveyor, but researchers believe the site is a sedimentary basin that may harbor the telltale signs of water or possibly of ancient life. Beagle 2 will carry instruments that can bore into rocks and burrow into the soil to gather samples. These samples will then be analyzed for the presence of water, carbonates and complex organic molecules, which are considered indicators of past life. The spacecraft will also wield a microscope camera with an 8-micron resolution that could provide data on grain sizes in the sedimentary rocks. “The stereo cameras, which have a close-up lens, and the Beagle 2 microscope may be able to tell (whether the deposits were water-laid or wind-laid) from rock and deposit morphology, i.e., structure,” said Mark Sims, project manager for Beagle 2. A pair of NASA rovers is also slated to land on Mars in 2004. The Mars Exploration Rovers will carry scientific instruments similar to the ones on Beagle 2, but they will have an added advantage: they can drive toward desirable locations for sample-taking. With both NASA and the ESA heading for the Red Planet, a solution to the mystery of martian layers might be just a few years away. For more information on this story see http://science.nasa.gov/headlines/y2001/ast23jan_1.htm. --------------------------------------------------------------------- MARS 2003: TWIN ROVER MISSION FACES TECHNICAL OBSTACLES By Leonard David From Space.com 24 January 2001 NASA’s bid to toss two powerful rovers toward Mars in 2003 has run into a suite of technical and operational worries. Space engineers face a critical review of work-in-progress next week. That report card emerging from a January 31-February 1 review will gauge the overall health of the project. Some senior officials close to the effort favor an unpopular and now minority view of dropping one rover to relieve schedule pressures. Other Mars spacecraft experts see trouble down the road in operating two Mars rovers at once. Furthermore, how to utilize an already over subscribed Deep Space Network of radio dishes to work a rover duo appears loaded with headaches. Get the full story at http://www.space.com/missionlaunches/missions/mars2003_snags_010124.h tml. --------------------------------------------------------------------- MARS MAGMAS ONCE CONTAINED A LOT OF WATER, RESEARCHERS FROM MIT AND U. OF TENNESSEE REPORT Massachusetts Institute of Technology release 24 January 2001 Evidence from a martian volcanic rock indicates that Mars magmas contained significant amounts of water before eruption on the planet’s surface, researchers from the Massachusetts Institute of Technology, the University of Tennessee and other institutions report in the January 25 issue of Nature. Scientists say that channels on Mars’s surface may have been carved by flowing water and an ancient ocean may have existed there, but little is known about the source of the water. One possible source is volcanic degassing, in which water vapor is produced by magma spewing from volcanoes, but the martian rocks that have reached Earth as meteorites have notoriously low water content. This study shows that before the molten rock that crystallized to form martian meteorites was erupted on the surface of the planet, it contained as much as 2 percent dissolved water. When magma reaches the planet’s surface, the solubility of water in the molten liquid decreases and the water forms vapor bubbles and escapes as gas. The process is similar to the release of gas bubbles that occurs when you open a can of soda. Although this doesn’t explain how water got into Mars in the first place, it does show that water on the red planet once cycled through the deep interior as well as existed on the surface, as similar processes have cycled water through the Earth’s interior throughout geologic history. A visitor from Mars Timothy L. Grove, professor of Earth, Atmospheric and Planetary Sciences at MIT, and University of Tennessee geologist Harry Y. McSween Jr. analyzed the Mars meteorite Shergotty to provide an estimate of the water that was present in Mars magmas prior to their eruption on the surface. Shergotty, a meteorite weighing around 5 kilograms was discovered in India in 1865. It is one of a handful of proven Mars meteorites that landed on Earth. It is relatively young— around 175 million years old—and may have originated in the volcanic Tharsis region of the red planet. Its measured water content is only around 130-350 parts per million. But by exploring the amount of water that would be necessary for its pyroxenes—its earliest crystallizing minerals—to form, the researchers have determined that at one time, Shergotty magma contained around 2 percent water. They also have detected the presence of elements that indicate the growth of the pyroxenes at high water contents. This has important implications for the origin of the water that was present on the surface of the planet during the past. This new information points to erupting volcanos as a possible mechanism for getting water to Mars’s surface. Squeezing hydrogen into rocks In the interior of Mars, hot magma is generated at great depth. It then ascends into the shallower, colder outer portions of the martian interior, where it encounters cooler rock that contains hydrogen- bearing minerals. These minerals decompose when heated by the magma and the hydrogen is released and dissolves in the magma. The magma continues its ascent to the surface of the planet. When it reaches very shallow, near-surface conditions in the crust, the magma erupts and its water is released in the form of vapor. The magma holds the water-creating hydrogen as the rock circulates underneath the crust. It undergoes changes as it moves from areas of enormous heat and pressure to cooler areas nearer the surface. When it finally erupts through a volcano, the magma releases its water in the form of vapor. Grove recreates Mars and moon rocks in his laboratory for these studies. By subjecting synthetic rocks to conditions of high temperature and pressure, he can tell how much water was contained in magma at the time that its crystals were formed. “What my experiment can do is estimate how much water was involved in the process that led to the formation of Mars meteorites. The only way you can reproduce the unique chemical composition of these minerals is to have water present,” he said. Other authors on the Nature paper include McSween’s graduate student, Rachel C. F. Lentz; Lee R. Riciputi of the chemical and analytical sciences division of Oak Ridge National Laboratory; Jeffrey G. Ryan, a geologist at the University of South Florida; and Jesse C. Dann and Astrid H. Holzheid of MIT’s Department of Earth, Atmospheric and Planetary Sciences. This work was partly supported by NASA. Contact: Deborah Halber, MIT News Office 617-258-9276, dhalber@mit.edu Additional articles on this subject are available at: http://www.astronomy.com/Content/Dynamic/Articles/000/000/000/283bazt r.asp http://news.bbc.co.uk/hi/english/sci/tech/newsid_1135000/1135028.stm http://www.msnbc.com/news/520954.asp http://www.nature.com/nature/links/010125/010125-2.html http://www.space.com/scienceastronomy/solarsystem/wet_mars_010124.htm l http://www.spacedaily.com/news/mars-water-science-01c.html http://spaceflightnow.com/news/n0101/25venusmars/ --------------------------------------------------------------------- STUDY SUGGESTS VENUS COULD HAVE BEEN WET PLANET Washington University in St. Louis release 24 January 2001 Researchers at Washington University in St. Louis, studying hydrous mineral decomposition rates at extreme temperatures, have concluded that hot and dry Venus may have been a wet planet in the past, like Earth and ancient Mars. The new evidence suggesting a wetter Venusian history comes from a series of experiments documenting the chemical stability of tremolite for several billion years at temperatures similar to that of Venus’ surface, about 740 Kelvin or roughly 870 degrees Fahrenheit (F). Tremolite is a mineral that forms in the presence of water. If tremolite or some other hydrous mineral can be detected on the surface of Venus, then it can be concluded that Earth’s once-wet neighbor lost its water over time, putting to rest an enduring question in planetary science. Graduate student Natasha M. Johnson and Professor Bruce Fegley, Jr., Ph.D., of the Planetary Chemistry Laboratory in Earth and Planetary Sciences at Washington University, reported their findings in the paper “Water on Venus: New Insights from Tremolite Decomposition,” Icarus, 146:301-306, July, 2000. “Ours is the first study that investigates hydrous mineral decomposition rates with applications to Venus,” says Johnson. “We have shown that tremolite can withstand extreme temperatures and remain intact for billions of years. If we can go to Venus and find tremolite, or some other hydrous mineral, then we would have proof that Venus had water in its past.” Indirect evidence that Venus had water in the past is found in its high deuterium/hydrogen (D/H) ratios. If the high D/H ratios are the result of lighter hydrogen (deuterium is a heavier form of hydrogen) escaping Venus’ atmosphere to space, then it is possible that Venus had water in the past. But the D/H ratio of Venus varies relative to that of Earth, and comets and meteorites can also have high D/H ratios, so other types of evidence of water are needed. Johnson and Fegley’s research on the decomposition rate of tremolite shows that the evidence is in the rocks. “We want to know if it is worth our time to go to Venus and look for minerals that have water in them,” says Johnson. “When you go backpacking, you want to know where you are going and what you need to carry. These experiments are laying the foundation, and saying, “Hey, should we, or should we not, bring a parka?” Should we be looking for hydrous minerals on Venus or is it a waste of time?” Johnson and Fegley conducted over 200 experiments, heating samples of tremolite in laboratory furnaces at temperatures of up to 1240 Kelvin (about 1770 degrees Fahrenheit) for as long as 20 months, periodically weighing them to document the amount and rate of decomposition. Tremolite, an amphibole, and other hydrous minerals contain OH (hydroxyl groups as part of a lattice holding these minerals together. Amphiboles are formed when lava and magma interact with water. In the case of tremolite, it is a metamorphic mineral generally found in dolomitic-type limestone. Amphiboles are thermodynamically unstable and according to theory should decompose rather quickly at high temperatures. But Johnson and Fegley’s experiments indicate that tremolite is much more stable than previously thought, and would take about 4 billion years to decompose by half in conditions similar to Venus’ surface. “Diamonds are a good analogy for what is happening with tremolite,” says Johnson. “Diamonds are unstable at the surface of the Earth; graphite is the stable form. But you don’t see diamonds popping into little chunks of graphite on people’s fingers.” If tremolite and other amphiboles formed on Venus at some time in the past, they should be detectable using infrared reflectance spectroscopy and other current technology. The researchers also are measuring decomposition properties of other hydrous minerals. Surprisingly little is known about these minerals with the exception of those with commercial purposes like asbestos and other insulators. “This research could give us some idea about the formation of our solar system, and has applications on Earth for investigating metamorphic regimes or subduction zones,” says Johnson. Contact: Tony Fitzpatrick, tony_fitzpatrick@aismail.wustl.edu, 314-935-5272 An additional article on this subject is available at http://spaceflightnow.com/news/n0101/25venusmars/. --------------------------------------------------------------------- THE RIGHT PLACES TO LOOK FOR ALIEN LIFE By Ken Croswell From New Scientist http://www.newscientist.com 24 January 2001 If you want to find extraterrestrial intelligence, you’re going to have to look in the right place. In our Galaxy alone there are more than 100 billion stars, so you might expect to find a profusion of alien abodes. But which suns do you point your telescope at? Bright, yellow stars like our own Sun have always seemed the obvious place to start. In the past few years, though, researchers have begun to wonder if they’ve been neglecting a whole class of likely targets: red dwarfs. Smaller, cooler and fainter than the Sun, red dwarfs give out just a feeble red glow. More than a dozen of these puny stars reside within as many light years of Earth, yet they’re so faint that not a single one is visible to the unaided eye. It was always thought that any planet orbiting a red dwarf would be an extremely unlikely place to find life. But it now looks as though these dim red suns could harbor most of the Galaxy’s life-bearing worlds. This is great news for anyone hoping to find hospitable planets outside the Solar System. While stars like the Sun are relatively rare, four out of five stars in our Galaxy are red dwarfs. “We all want to find habitable planets out there,” says Laurance Doyle, an astronomer at the SETI Institute in Mountain View, California. “The fact that we can now rule in 80 per cent of the stars is a positive note for almost everybody.” For decades, the arguments against finding life around red dwarfs have seemed secure. These stars owe their dimness to a misfortune of birth—when they formed they only acquired between 8 and 60 per cent as much mass as the Sun. As a result, their cores are cool and the nuclear reactions take place at a slow rate, providing little energy. The nearest red dwarf—Proxima Centauri, which is 4 light years from Earth—emits less visible light in a century than the Sun does in a week. No problem, you may say. The Earth is hospitable to life because it lies at just the right distance from the Sun. So although red dwarfs may be fainter than the Sun, an alien planet orbiting one could still have a balmy climate if it huddled close enough to its star. For a red dwarf with one-hundredth of the Sun’s brightness, for instance, a planet would be at a suitable temperature if it circled ten times closer to its parent star than the Earth does to the Sun. Such a planet would not, however, be just like the Earth. Although it would enjoy terrestrial temperatures, its proximity to the star would come at a price. A planet in such a tight orbit would become tidally locked to its star, just as our own Moon is locked to Earth. One side would perpetually face the star, while the other faced away. The Moon’s Earth-facing side suffers little more than the occasional visiting astronaut, but the day side of a red dwarf planet would fry. Worse, the night side would be so frigid that you would expect the gases in the atmosphere to freeze, and snow onto the dark surface, where they would remain locked up forever. Only if the atmosphere was sufficiently thick would a planet be spared such a fate. Researchers calculated that gases circulating in the atmosphere would then be able to transport heat from the planet’s day side to its night side, warming the night air so that it wouldn’t freeze out. Until recently, though, most researchers believed that to do this the atmosphere would have to be so thick that it would prevent the sun’s rays from reaching the surface. And that would rule out photosynthesis on the planet, a serious blow for the development of life as we know it. No wonder, then, that those looking for life have pointed their telescopes elsewhere. But in the 1990s, Robert Haberle and Manoj Joshi of NASA’s Ames Research Center in Moffett Field, California, found something unexpected. They simulated the atmosphere of a red dwarf planet, and calculated that even a thin atmosphere would do the trick. If the planet had only 15 per cent as much air as the Earth, they said, that would still ferry enough heat around to the dark side to keep the atmosphere from freezing out. “When I first heard that the atmosphere wasn’t going to freeze out, I found it tremendously exciting,” says Martin Heath of Greenwich Community College in London. But there was still a problem with the water cycle. Even in some of Joshi and Haberle’s models, there remained freezing conditions on the planet’s dark side. Heath was worried that even if the gases didn’t freeze, the planet’s water might still migrate from the day side to the night side, killing off any prospects of life. Then in 1997, Heath began to wonder whether deep ocean basins might solve the problem. With deep enough seas, even though the surface of the ocean might freeze on the planet’s dark side, you could still have a liquid layer beneath, kept from freezing by the planet’s geothermal heat. This would allow liquid water to flow back to the day side. Perpetual light Although it now looks as if a planet orbiting a red dwarf can offer oceans, atmospheres and a mild climate, such a world would still differ greatly from Earth. It would have no seasons, because the tidal pull of the star would prevent its spin axis from tilting. And one side would be in perpetual light, while the other was in perpetual darkness. The hottest part of a red dwarf planet would be just one spot on the equator—the center of the day side, where the sun is overhead. On a habitable planet, the temperature at the hot spot might soar to 40° or 50°C (see Diagram [not available]). Moving away from this spot, temperatures would drop, falling towards freezing near the dividing line between the day and night sides. On the night side there would be an ice cap covering the coldest part, directly opposite the hot spot. “The daylight hemisphere is going to be where the action is,” says Heath. “For one thing, it’s going to be pretty cold on the dark side. We know that there are organisms that can sit in water pockets in the ice and carry out photosynthesis, but they can’t do that if there’s no light getting there.” Wherever you were on the planet’s day side, the red dwarf sun would never set. Instead it would hover perpetually at the same place in the sky. Plants and trees might orient themselves towards it as they grew. But because the sun is stationary some regions would never see direct sunlight. A region in the shadow of a mountain, for example, would be forever in shade, preventing photosynthesis there. And even for the regions in sunlight, photosynthesis might be difficult. Red dwarfs are so cool that they emit most of their energy at infrared wavelengths, giving off relatively little at the visible wavelengths that support life on Earth. As if all this weren’t enough, red dwarfs subject their planets to other challenges. They often display spots far larger than those seen on the Sun. These “starspots” can cause the star to dim by up to 40 per cent for several months at a time. Would this be enough to precipitate the big freeze? Joshi thinks not, as long as the planet wasn’t at the extreme edge of the star’s comfort zone. Plants might cope with starspots by changing their color, absorbing more light when their sun dims. At other times, red dwarfs brighten dramatically, spewing large flares that can more than double the star’s brightness in a matter of minutes. Such flares might damage life, but they might also help it evolve, by increasing the mutation rate. In any case, the number of flares often decreases as a red dwarf ages, and many old red dwarfs don’t flare at all. One clear advantage that red dwarfs have over Sun-like stars is their longevity. Although they were born with less fuel than the Sun, they burn it so frugally that some will survive for more than 1000 billion years. In contrast, the Sun will die within a mere 8 billion years. It has taken terrestrial intelligence 4.6 billion years to evolve since the Solar System formed, but life on Earth may be atypical. If intelligence generally requires more time to emerge, then planets orbiting red dwarfs may be ideal. So do red dwarfs really have suitable rocky planets like the Earth for life to occupy? We already know that they can have larger planets, more akin to Jupiter. Astronomers have found two Jupiter- sized worlds circling a nearby red dwarf called Gliese 876, which lies just 15 light years from Earth. These particular planets are unlikely to harbor life, however, since Jupiter-sized planets—at least in our Solar System—consist mostly of hydrogen and helium. Even chance Still, it’s perfectly possible that red dwarfs could have smaller planets too. Doyle and his team think they may have detected Earth- sized worlds around another star, CM Draconis. This “star” is actually a binary system composed of red dwarfs orbiting each other. The plane of this orbit is edge-on to the Earth, so the stars eclipse each other every 30 hours. If it has planets, they too should lie in this plane, meaning they will cross the stars’ faces and block out some of their light. And because the stars are so small, even a planet with just three times the Earth’s diameter would dim the light noticeably. But does CM Draconis have such planets? “I think it’s about 50:50,” says Doyle. His team published a paper last year reporting two possible candidates, but they still have nothing definite. “The candidates we have need to be observed more,” says Doyle. Even if such planets exist, researchers admit that many questions remain about whether red dwarfs can support life. “It’s very early days,” says Heath. “What we’ve shown is that there is a case to be answered. That’s a very different thing from demonstrating that there is actually life on a planet around a red dwarf star.” But they are cautiously optimistic. “Our approach to this whole subject has gotten more catholic over the years rather than more selective,” says SETI pioneer Jill Tarter, who is searching for signs of life around all stars within 16 light years of the Sun, most of which are red dwarfs. “Those are our next-door neighbors, and we really ought to look down the street before we try and hike across the country,” she adds. When it comes to SETI surveys of more distant systems, however, Tarter still prefers Sun-like stars. “If you’d asked me a few years ago,” says David Soderblom of the Space Telescope Science Institute in Baltimore, Maryland, “I would have said that red dwarfs have a very low probability of having life- bearing planets. But given what we’ve seen here on Earth and the rather hostile conditions under which life can flourish, I would say it’s pretty good odds.” And there is good reason to believe that the first extraterrestrial civilization that we find will differ greatly from our own. Ten years ago, when astronomers knew no planets beyond the Solar System, they believed that other solar systems would resemble our own. Then, in 1991, they accidentally discovered the first extrasolar planets, circling not a living star like the Sun but a type of dead star known as a pulsar. And in 1995, when they found the first extrasolar planet around a Sun-like star, it took them completely by surprise. In our Solar System, giant planets like Jupiter and Saturn orbit far out from the Sun. But this giant was astonishingly close to its star, and astronomers have since found many others like it. Which leads to an intriguing thought. Any planets that circle red dwarfs may have given rise to astronomers as parochial as those on Earth. These alien observers may have concluded that only red dwarfs can support life, blessed as they are with stable planets where suns never set and seasons never disrupt the climate. Indeed, their SETI programs may ignore Sun-like stars altogether. After all, they might argue, any temperate planet orbiting such a star would lie so far out that it would rotate freely, subjecting life to a relentless cycle of light and dark. Any tilt of the axis would cause severe summers and winters, and changes in axial tilt might induce ice ages, with mighty glaciers smothering much of the globe. How on Earth could life possibly arise on such a hostile world? Ken Croswell is an astronomer living in Berkeley, California, and is the author of Magnificent Universe (Simon & Schuster, 1999). Further reading: “Habitability of Planets Around Red Dwarf Stars” by Martin Heath, Laurance Doyle, Manoj Joshi and Robert Haberle, Origins of Life and Evolution of the Biosphere, 29:405 (1999). “Simulations of the Atmospheres of Synchronously Rotating Terrestrial Planets Orbiting M Dwarfs: Conditions for Atmospheric Collapse and the Implications for Habitability” by Manoj Joshi, Robert Haberle and R. Reynolds, Icarus, 129:450 (1997). New Scientist issue: 27 January 2001 UK Contact: Claire Bowles, claire.bowles@rbi.co.uk, 44-207-331-2751 US Contact: New Scientist Washington office, newscidc@idt.net, 202-452-1178 --------------------------------------------------------------------- HIGH SCHOOL STUDENTS TO PLAN COMMUNITY ON MARS NASA/JSC release J01-04 24 January 2001 While living at Johnson Space Center the weekend of February 2-4, Houston area high school students will use their imagination and knowledge to design complete details of a human settlement on Mars in the year 2045. About 140 students from Houston and Southeast Texas will participate in the Third Annual JSC Mars Settlement Design Competition, a program designed to introduce students to the technical, communication and teamwork skills they will need when they join industry. Organized into four “company” teams, the students gain the experience of working as members of an aerospace industry proposal team. They will work against a deadline to design, develop and present a 50-page proposal of their concept of a human community on Mars to a team of NASA and industry judges. Teams will be mentored and coached by executives from NASA, Boeing and other aerospace companies who volunteer their time to guide the students’ efforts. Using technologies and materials expected to be available in 2045, the teams must plan a community that would support several thousand residents. All aspects that would be necessary to actually complete the project must be considered in their proposal. These include design, construction materials, logistics including transport vehicles, power allocation, robotics systems, life support, a cost estimate and a schedule. At the conclusion of the weekend, the teams will present their proposals to a panel of expert judges who will hold them to an exacting standard. Once presentations are complete and while the judges make their final decision, the students will tour JSC for a behind-the-scenes look at the Mission Control Center and the next- generation X-38 spacecraft currently under development. The Mars Settlement Design Competition is one of the key events of NASA’s month-long outreach effort in support of National Engineers Week. The competition is hosted and sponsored by NASA Johnson Space Center, The Boeing Company, the Clear Creek Independent School District and the American Institute of Aeronautics and Astronautics. Additional information is available at the competition web site (http://marsbase.jsc.nasa.gov). --------------------------------------------------------------------- SETI—WHAT TO DO IF A SIGNAL ARRIVES By Seth Shostak From Space.com 25 January 2001 Looking for aliens can be cold and lonely work, just ask Agent Mulder. Better yet, ask Frank Drake. Four decades ago, when Drake was the only SETI scientist on the planet, he would single-handedly tune the receiver on his radio telescope in the chilly West Virginia mornings. He was prepared for discomfort. But he was less prepared for success. In 1960, Drake was hoping to eavesdrop on radio signals that might be coming from either of two Sun-like stars, Tau Ceti and Epsilon Eridani. These stellar neighbors are about a dozen light- years from Earth, and Drake was inspecting them with an 85-foot (26- meter) diameter antenna. Then it happened. Tau Ceti had just eased below the horizon, so Drake swung the telescope toward Epsilon Eridani. To his surprise, the loudspeaker began to bray with a loud “wham.” Drake was surprised. “Could it be this easy?” he thought. And then he pondered, “what do I do next?” Get the full story at http://www.space.com/searchforlife/seti_signal_010125.html?Enews=y. --------------------------------------------------------------------- GREENING OF THE RED PLANET NASA Astrobiology Institute From NASA Science News 26 January 2001 Although Mars may once have been warm and wet, the Red Planet today is a frozen wasteland. Most scientists agree, it’s highly unlikely that any living creature—even a microbe—could survive for long on the surface of Mars. When the first humans travel there to explore the Red Planet up close, they will have to grow their food in airtight, heated greenhouses. The martian atmosphere is far too cold and dry for edible plants to grow in the open air. But if humans ever hope to establish long-term colonies on their planetary neighbor, they will no doubt want to find a way to farm outdoors. Imre Friedmann has an idea of how they might take the first step. Friedmann is a microbiologist who recently joined the NASA Astrobiology Institute team at NASA’s Ames Research Center. Friedmann was one of the invited speakers at a NASA-sponsored conference, “The Physics and Biology of Making Mars Habitable,” held at Ames in October 2000. His talk focused on an organism that could be used to begin the process of converting the martian surface into arable soil. A layer of ground-up rock and fine dust, known as regolith, covers Mars. To convert regolith into soil, it will be necessary to add organic matter, much as organic farmers on Earth fertilize their soil by adding compost to it. On Earth, compost is made up primarily of decayed vegetable matter. Microorganisms play an important role in breaking down dead plants, recycling their nutrients back into the soil so that living plants can reuse them. But on Mars, says Friedmann, where there is no vegetation to decay, the dead bodies of the microorganisms themselves will provide the organic matter needed to build up the soil. The trick is finding the right microbe. “Among the organisms that are known today,” says Friedmann, “Chroococcidiopsis is most suitable” for the task. Chroococcidiopsis is one of the most primitive cyanobacteria known. What makes it such a good candidate is its ability to survive in a wide range of extreme environments that are hostile to most other forms of life. Chroococcidiopsis has been found growing in hot springs, in hypersaline (high-salt) habitats, in a number of hot, arid deserts throughout the world, and in the frigid Ross Desert in Antarctica. “Chroococcidiopsis is the constantly appearing organism in nearly all extreme environments,” Friedmann points out, “at least extreme dry, extreme cold, and extremely salty environments. This is the one which always comes up.” Moreover, where Chroococcidiopsis survives, it is often the only living thing that does. But it gladly gives up its dominance when conditions enable other, more complex forms of life to thrive. For clues on how to farm Chroococcidiopsis on Mars, Friedmann looks to its growth habits in arid regions on Earth. In desert environments, Chroococcidiopsis grows either inside porous rocks, or just underground, on the lower surfaces of translucent pebbles. The pebbles provide an ideal microenvironment for Chroococcidiopsis in two ways. First, they trap moisture underneath them. Experiments have shown that small amounts of moisture can cling to the undersurfaces of rocks for weeks after their above-ground surfaces have dried out. Second, because the pebbles are translucent, they allow just enough light to reach the organisms to sustain growth. Friedmann envisions large farms where the bacteria are cultured on the underside of strips of glass that are treated to achieve the proper light-transmission characteristics. Mars today, however, is too cold for this technique to work effectively. Before even as hardy a microbe as Chroococcidiopsis could be farmed on Mars, the planet would have to be warmed up considerably, to just below the freezing point. Friedmann... admits that his ideas about growing Chroococcidiopsis are, at this point, merely a thought experiment. “I don’t think any of us alive today will see this happen,” he muses. When the time does come to make Mars a more habitable place, “the technology will be so different that everything we plan today... will be ridiculously outdated.” Friedmann fully expects that genetic engineering will eventually develop designer organisms to do the job. Even if Chroococcidiopsis is ultimately used as the basis, it will be a vastly improved version of today’s microbe. For more information on this story, see http://science.nasa.gov/headlines/y2001/ast26jan_1.htm. --------------------------------------------------------------------- NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.h tml 29 January 2000 Articles about astrobiology, exobiology and terraformation http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s1.html P. L. Barry and T. Phillips, 2001. Layers of Mars. NASA Science News. J. F. McGowan III, 2000. Oil and natural gas on Mars, in Instruments, Methods, and Missions for Astrobiology III, Richard B. Hoover, Editor. Proceedings of SPIE, 4137:63-74. NASA Astrobiology Institute, 2001. Greening of Mars. NASA Science News. Articles about human space exploration and the microgravity environment http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s3.html W. F. Crouch, 2001. Catastrophes and human evolution. SpaceDaily. --------------------------------------------------------------------- CASSINI WEEKLY SIGNIFICANT EVENTS JPL releases 11-17 January 2001 The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Wednesday, January 17. The Cassini spacecraft is in an excellent state of health and is operating normally. The speed of the spacecraft can be viewed on the “Present Position” web page at http://www.jpl.nasa.gov/cassini/english/where/. Phase E of the Jupiter subphase continues this week. Activities included atmospheric cyclic observations, Ganymede eclipse observations, Ultraviolet Imaging Spectrometer (UVIS) Io torus observations, Europa observations, and a UVIS/Hubble Space Telescope aurora observation. Uplinked commands included the C24 Background Sequence, Radio and Plasma Wave Science (RPWS) High Frequency Receiver Calibration Immediate/Delayed Action Program, reaction wheel momentum unload, and Imaging Science Subsystem (ISS) Instrument Expanded Block load. On Sunday January 14th, the Cruise 24 sequence began execution. Activities included Narrow Angle Camera (NAC) observations of the Io torus, Visual and Infrared Mapping Spectrometer (VIMS) ring spectral observations, ISS 1X2 Movie, RPWS periodic engineering maintenance, and start of Cosmic Dust Analyzer dust stream collection. Other activities included uplink of the MIMI memory readout, clearing of the RPWS write protect bit and AACS clear high watermark. RPWS personnel report additional bow shock crossings. It appears Cassini crossed the bow shock (outbound) on day 12 at approximately 14:20. Weak Langmuir waves were observed afterwards at a frequency of about 9 kHz (1 cm^-3). Instrument personnel have determined that there was an inbound shock at 2:10 on day 014 followed by an outbound shock at 5:28 on day 015. The solar wind density after the day 015 shock was about 0.8 cm^-3. The Cassini Instrument Operations (IO) Team and the Multi Mission Image Processing Laboratory have produced and delivered 19,107 ISS images—12,715 from the NAC and 6292 from the Wide Angle Camera—and 3,618 VIMS cubes since Jupiter encounter began. The Huygens Recovery Task Force met at the European Space Technology Center (ESTEC) in Noordwijk, the Netherlands on January 10. The team began by assessing several different options for improving the probe link performance. These options included improved ground processing and error correction, changes in both the probe and orbiter flight software, and changes in the trajectory. Follow-on meetings will be held at JPL during the week of January 15. IO hosted the Events Kernel Working Group kick-off meeting, with participation by Navigation Ancillary Information Facility (NAIF) personnel and remote site Operations Technical Leads (OTL). System Engineering continues to coordinate update of the Tour Operations Concepts. At this week’s Cassini Design Team meeting, three of the downlink science concepts were discussed and open items identified. A Delivery Coordination Meeting was held for Command Data Base D7E. This is a new command database, which will become active with the delivery of Mission Sequence Subsystem D7.4 on 1/26/01. Equipment inventories are being reviewed in preparation for input to the publication of the Lab wide, NASA directed “Information Technology Security Plan.” This plan is to be completed with Headquarters approval by the end of fiscal 2001. Discussions have begun with the scientific journal, Icarus, regarding publishing a series of Cassini articles over the next ten years. 18-24 January 2001 The most recent spacecraft telemetry was acquired from the Madrid tracking station on Wednesday, January 24. The Cassini spacecraft is in an excellent state of health and is operating normally. Science activities included Cosmic Dust Analyzer (CDA) dust stream collection, Ultraviolet Imaging Spectrometer (UVIS) / Hubble Space Telescope auroral observations, Imaging Science Subsystem (ISS) atmosphere observations, Cassini Plasma Spectrometer (CAPS) housekeeping memory readout, and Radio and Plasma Wave Science (RPWS) calibrations. Engineering activities included Command & Data Subsystem (CDS) SSR automatic repair for both SSR A and B, Reaction Wheel Assembly (RWA) momentum unload, Attitude and Articulation Control Subsystem (AACS) Clear High Water Marks, and clearing of CDS error logs. The Probe Relay Test mini-sequence and CAPS Power On mini-sequence for C24 were released this week. All populated Spacecraft Activity Sequence Files for C25 have been received from the core members of the Sequence Virtual Team (SVT). The inputs have been merged in order to build an integrated sequence. A Project briefing was held this week for Cruise 26. The plan for this sequence has now been approved for implementation. The Cassini Instrument Operations (IO) Team and the Multi Mission Image Processing Laboratory have produced and delivered 20,740 ISS images—14,076 from the NAC and 6,664 from the Wide Angle Camera—and 4,689 Visual and Infrared Mapping Spectrometer (VIMS) cubes since Jupiter encounter began. JPL was the site of the January Cassini Project Science Group (PSG) meeting. Plenary sessions, working groups, tutorials and “Brown Bag Lunch” science presentations were held this week and will continue into next week. Concurrent with the PSG, Instrument Operations coordinated training for over 20 classes and 60 team members allowing newer Cassini team members to obtain training as well as allowing an opportunity for enrichment for existing staff. Cassini Mission Assurance recently sponsored a Risk Management Training Workshop. This workshop was conducted to familiarize the Flight Team with the Cassini Risk Management Process. During an interactive session, inputs were gathered and incorporated into the process. Brainstorming activity during the workshop has initiated the process to document and collect potential risks to the Cassini Program. Results include a draft Risk Management Plan and an initial risk list. Follow-up sessions will be scheduled in the near future. A Delivery Coordination Meeting was held for Cassini Information Management System (CIMS) 1.0. The software has been approved for use and operations installation will begin soon. Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, CA, manages the Cassini mission for NASA’s Office of Space Science, Washington, DC. --------------------------------------------------------------------- THIS WEEK ON GALILEO JPL release 22-28 January 2001 This week, Galileo nears the end of a 14-week-long collaboration with the Cassini spacecraft to study the influence of the solar wind on the Jovian magnetosphere. Galileo is in week 13 of its contribution to this study, which was initiated in late October, 2000. Galileo performs one engineering activity this week. On Wednesday, the spacecraft executes standard maintenance on its onboard tape recorder. Galileo’s tape recorder is a reel-to-reel mechanical type and these regular maintenance activities are performed to keep the tape recorder in good operating shape. Galileo’s contribution to the study of the solar wind’s influence on the Jovian magnetosphere comes in the form of a low-resolution survey being performed by the Fields and Particles instruments. This suite of six instruments is comprised of the Dust Detector, Energetic Particle Detector, Heavy Ion Counter, Magnetometer, Plasma Detector, and Plasma Wave instrument. During the past 13 weeks, Galileo has flown from the solar wind, into the Jovian magnetosphere, and now back out into the solar wind. Cassini, on the other hand, was generally expected to remain outside the magnetosphere until after its flyby of Jupiter, when it would fly along the boundary region of the magnetosphere and solar wind as it left the vicinity of Jupiter. Measurements now indicate that Cassini entered the bow shock region on December 27, three days prior to its closest approach to Jupiter. Cassini has since crossed into and out of the magnetosphere multiple times as the solar wind “blew” stronger and then weaker. The solar wind is a stream of charged particles and gas that emanate from the Sun. Because the solar wind waxes and wanes with changes in the Sun, it exerts varying amounts of pressure on the Jovian magnetosphere. The magnetosphere responds by shrinking when the solar wind pressure is high, and ballooning outward when it is low. Currently, Galileo is in the solar wind, while Cassini is moving through the magnetotail, or vast “downstream” portion to the magnetosphere that extends as far outward as Saturn. Thus, Galileo will measure variations in the solar wind while Cassini observes the response of the downstream parts of Jupiter’s magnetosphere. This series of joint observations is expected to provide new insights into how the solar wind affects the magnetospheres of Jupiter and other planets, including Earth. For more information on the Galileo spacecraft and its mission to Jupiter, please visit the Galileo home page at one of the following URL’s: http://galileo.jpl.nasa.gov http://www.jpl.nasa.gov/galileo --------------------------------------------------------------------- ISS STATUS REPORT NASA/JSC release 25 January 2001 Nearing the end of their third month in space, the three-member Expedition 1 crew spent a smooth but busy week aboard the International Space Station, practicing emergency procedures, performing routine maintenance and inspections, and preparing for the continued expansion of the station with the launch of the Space Shuttle Atlantis next month. With some additional testing of solid rocket booster cables successfully completed, Atlantis is now planned to be moved back to its Kennedy Space Center launch pad on Friday. Launch of the shuttle on mission STS-98 is now planned for about 6:11 PM EST February 7. Atlantis will bring the first station laboratory, the United States-developed Destiny module, to the orbiting complex. Station Commander Bill Shepherd, Flight Engineer Sergei Krikalev and Pilot Yuri Gidzenko practiced emergency procedures aboard the station this week, dealing with a simulated leak aboard the complex and performing the preparations that would be needed if the station were evacuated. Such practice sessions may be performed regularly by station crews to ensure emergency procedures remain up to date and the crew’s skills remain sharp. Station flight controllers regularly simulate such activities on the ground for similar reasons. Also this week, the station crew worked with updating and expanding the station’s Inventory Management System, a software package that tracks the amount and location of supplies and equipment aboard the outpost. The crew is continuing to add to the system supplies brought to the station in December by Shuttle mission STS-97, and they are expanding it to prepare for the arrival of the Destiny lab and its equipment. The three space fliers also continued their daily regimen of exercise and performed several routine housekeeping-type activities—changing filters, inspecting equipment and checking station systems. Next week, plans for the crew and flight controllers may include a test of station procedures that will be used for the docking of the Space Shuttle Atlantis. Orbiting the Earth at an average altitude of 230 statute miles, the International Space Station is operating in excellent condition. The next Expedition One status report will be issued on Wednesday, January 31, or as developments warrant. --------------------------------------------------------------------- MARS GLOBAL SURVEYOR MISSION STATUS JPL release 25 January 2001 Engineers operating NASA’s highly successful Mars Global Surveyor spacecraft, which concludes its primary mission at the red planet next week, report that one of the spacecraft’s reaction wheels, which helps stabilize the spacecraft’s orientation, has turned itself off. The spacecraft correctly responded by switching to a backup reaction wheel, allowing Global Surveyor to continue its mapping mission without interruption. The mission proceeds as planned, and the spacecraft is operating normally. Engineering data from the spacecraft indicate that an electrical short led to the automatic shutdown of the X-axis reaction wheel on January 18. Spacecraft orientation is stabilized by the rotation of three such wheels (X, Y and Z) during normal operations. Subsequent attempts to restart the X-axis reaction wheel on January 24 lead mission engineers to believe that a short circuit caused the reaction wheel subsystem’s 7 amp fuse to become permanently open, permanently disabling the reaction wheel. Should another wheel fail, the spacecraft would use its attitude control thrusters to maintain proper orientation much like the previous Mariner and Viking Orbiters. On January 31, Mars Global Surveyor will conclude its mapping mission phase having accomplished all of the planned science objectives during a full Mars year (687 days). Over the next 14 months, continued operation of the science instruments will provide observations of potential future landing sites, make inter-annual seasonal comparisons and obtain measurements of targets selected by guest observers. Following this period, operations personnel at JPL in Pasadena, CA, and Lockheed Martin Astronautics in Denver, CO, expect to coax the aging spacecraft to perform telemetry relay during the landing of the Mars Exploration Rovers in January of 2004. The Global Surveyor mission is managed by JPL for NASA’s Office of Space Science, Washington, DC. Lockheed Martin Astronautics developed and operates the spacecraft. JPL is a division of the California Institute of Technology. An additional article on this subject is available at http://spaceflightnow.com/news/n0101/27mgswheel/. --------------------------------------------------------------------- STARDUST STATUS REPORTS JPL releases 19 January 2001 There were numerous Deep Space Network (DSN) tracking passes in the past week and all subsystems are performing normally. Stardust came within 6008 km of Earth’s surface to obtain a gravity assist. This enlarged its orbit relative to the Sun so that it will now intercept the orbit of Comet Wild 2 in 2004. No DSN coverage was possible around closest flyby, as the spacecraft was below the elevation limits of the DSN antennas. Images of the Stardust spacecraft, streaking across the heavens as it approached Earth, were taken in the United States, Australia, Hungary and Mexico. The images can be seen on the Stardust home page (http://stardust.jpl.nasa.gov). Seventeen hours after Earth flyby, as the spacecraft flew above the Moon, Stardust took twenty-five images. Twenty-one images were taken of the moon, while the remaining four were zero exposure bias images to determine the background noise. These images were taken to provide calibration data of the Navigation Camera (NAVCAM) performance. All filters were used and the moon was placed in different locations in the CCD field of view. The lunar image sequence was executed perfectly. The images were a combination of compressed (8 bits/pixel) and uncompressed (16 bits/pixel) images. The spacecraft turned to the proper attitude and the mirror was correctly positioned to capture the moon in all planned images. The exposures were correct, using about half of the 4096 gray levels in the uncompressed images. Finally, all images were received on the ground and are now being analyzed. The best news is that the spatial resolution of the camera has been improved significantly due to the two heating sequences. Features as small as a few pixels are visible in the image, which is over 500 pixels across. Stardust could resolve features as small as tens of meters on a 1-km (0.62-mile) comet, an order of magnitude better than the Giotto images of Comet Halley. There is still room for improvement to sharpen the images even more and to reduce scattered light with additional camera and mirror heating. This will be reviewed in the next few months. JPL Media Relations provided a news release about the successful flyby and lunar images with a lunar image available on the Stardust web site. 26 January 2001 There were numerous Deep Space Network (DSN) passes in the past week, and all subsystems are performing normally. Since the successful completion of the Earth Gravity Assist (EGA) and receipt of the navigation camera moon images, the team’s activities are returning to normal. They are focusing on analysis by navigation and science teams, and the spacecraft team is working on several flight software patches. Planning is underway for TCM-6, the EGA cleanup maneuver, scheduled for February 14. Preliminary estimates are for a 0.7 meters/second burn. Stardust continues to have daily contacts to provide tracking data for the TCM-6 design. The weekly contact cruise mode will resume the week of 26 March. Ed Hirst, the Stardust Mission Planner, did a live interview about Stardust on the Telemundo Spanish language channel on January 22. For more information on the Stardust mission—the first ever comet sample return mission—please visit the Stardust home page at http://stardust.jpl.nasa.gov. --------------------------------------------------------------------- End Marsbugs, Volume 8, Number 4.