MARSBUGS: The Electronic Astrobiology Newsletter Volume 8, Number 47, 10 December 2001. Editors: Dr. David J. Thomas, 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 monthly basis as warranted by the number of articles and announcements. Copyright of this compilation exists with the editors, except for specific articles, in which instance copyright exists with the author/authors. While we cannot copyright our mailing list, our readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing list. The editors do not condone "spamming" of our subscribers. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editors. E-mail subscriptions are free, and may be obtained by contacting either of the editors. Article contributions are welcome, and should be submitted to either of the two editors. Contributions should include a short biographical statement about the author(s) along with the author(s)' correspondence address. Subscribers are advised to make appropriate inquiries before joining societies, ordering goods etc. Back issues and Adobe Acrobat PDF files suitable for printing may be obtained from the official Marsbugs web page at http://welcome.to/marsbugs. The purpose of this newsletter is to provide a channel of information for scientists, educators and other persons interested in exobiology and related fields. This newsletter is not intended to replace peer- reviewed journals, but to supplement them. We, the editors, envision Marsbugs as a medium in which people can informally present ideas for investigation, questions about exobiology, and announcements of upcoming events. Astrobiology is still a relatively young field, and new ideas may come from the most unexpected places. Subjects may include, but are not limited to: exobiology and astrobiology (life on other planets), the search for extraterrestrial intelligence (SETI), ecopoeisis and terraformation, Earth from space, the biology of terrestrial extreme environments, planetary biology, primordial evolution, space physiology, biological life support systems, and human habitation of space and other planets. _____________________________________________________________________ CONTENTS 1) DEEP IMPACT AND THE MASS EXTINCTION OF SPECIES 65 MILLION YEARS AGO: START OF THE CHICXULUB DRILLING PROJECT IN YUCATAN, MEXICO GeoForschungsZentrum Potsdam (GFZ) release 2) A CURVE BALL INTO THE SNOWBALL EARTH HYPOTHESIS? By Kara LeBeau 3) WATER, SEDIMENTS IN ICE-BOUND ANTARCTIC LAKES MAY HARBOR UNIQUE MICROORGANISMS, ECOSYSTEMS National Science Foundation release 01-94 4) WHAT MAKES EUROPA PINK? By Nicola Jones 5) NASA REPORT: SPACE TRAVEL "INHERENTLY HAZARDOUS" TO HUMAN HEALTH By Leonard David 6) HOW WILL WE REACT TO FIRST CONTACT? THE SETI INSTITUTE WANTS YOUR ANSWERS By Douglas Vakoch 7) NASA'S GLOBAL SURVEYOR SEES POSSIBLE CLIMATE CHANGE ON MARS NASA/JPL release 8) ZUBRIN TALKS MARS WITH SPACEDAILY From SpaceDaily 9) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 10) CASSINI WEEKLY SIGNIFICANT EVENTS NASA/JPL release 11) THIS WEEK ON GALILEO NASA/JPL release 12) STARDUST STATUS REPORT NASA/JPL release _____________________________________________________________________ DEEP IMPACT AND THE MASS EXTINCTION OF SPECIES 65 MILLION YEARS AGO: START OF THE CHICXULUB DRILLING PROJECT IN YUCATAN, MEXICO GeoForschungsZentrum Potsdam (GFZ) release 3 December 2001 On December 3, a scientific deep drilling projects started on the Yucatan Peninsula, Mexico into the Chicxulub crater that was formed some 65 million years ago by the impact of an asteroid, which is believed to have caused the extinction of the dinosaurs and other species. In the opening ceremony the governor of the province of Yucatan, Patricio P. Laviada and the President of the Autonomous University of Mexico, Juan R. de la Fuente will participate as well as numerous scientists, engineers, and regional politicians. The German delegation consists of the German ambassador to Mexico, Dr. Wolf-Ruthart Born and Professor Rolf Emmermann, chair of the executive board of the GFZ Potsdam. Professor Emmermann is also the chairman of the International Continental Scientific Drilling Program (ICDP) which sets up the organizational framework of the Chicxulub Project. This drill site named Yaxcopoil-1 (YAX-1) is situated 40 kilometers southwest of the province's capital Merida. It is intended to give insight on the one hand into the size and material properties of the projectile, the amount of released impact energy, the structure of the crater and the physico-chemical processes related to the impact. On the other hand, the research aims at the effects of this catastrophic event on environment and life on Earth. Chicxulub and the Cretaceous-Tertiary boundary About 65 million years ago at the boundary between the Cretaceous (the last geological period of the Mesozoic) and the Tertiary eras, a large asteroid came rushing out of space at a velocity of more than 25 km per second and impacted the Earth at the tip of the Yucatan platform. The enormous amount of energy generated by this impact, equivalent to 10 thousand times the world's nuclear arsenal, ejected into the atmosphere huge quantities of dust particles and gases. The asteroid with a diameter of more than 10 km impacted into a shallow ocean and penetrated the Earth's crust down to a depth of several kilometers. It vaporized, melted and shattered ocean water and the Yucatan target rocks composed of carbonate and sulfate. As a result, a crater some 200 km in diameter formed. Over a short period of time (a few minutes) several hundred billion tons of CO2, SO2 and water vapor released by the vaporized target rock were injected into the Earth atmosphere. An abrupt and global perturbation of the Earth System followed: the climate became unstable, the fine dust suspended in the atmosphere blocked sunlight, decreasing or even stopping photosynthesis. This ecological catastrophe is believed to have caused the famous Cretaceous-Tertiary (KT) boundary mass extinction which saw the demise of the dinosaurs and more than 50% of the Earth fauna and flora on land and in the oceans. The hypothesis that an asteroid or comet impact induced the mass extinction at the KT boundary was first proposed in 1980 by a team from the University of California at Berkeley led by Nobel price laureate physicist Luis Alvarez and his geologist son Walter. Very controversial at first because of its catastrophic aspect, this hypothesis was confirmed in the early 1990's when scientists realized that the impact structure, which lay buried under approximately 1 km of Yucatan platform sediments was in fact the long-sought KT boundary crater predicted by the Alvarez hypothesis. This huge bowl-shaped structure, centered at Puerto Chicxulub near Merida is clearly outlined by gravity and magnetic geophysical anomalies. It had first been identified as a potential impact crater by geophysicists Antonio Camargo-Zanoguera and Glen Penfield while exploring the potential oil reserves of Yucatan for Pemex. The structure had been drilled, although unsuccessfully for oil. In the early nineties, studies of the recovered core samples confirmed that the Chicxulub structure was indeed a huge impact crater. Dating of the impacted lithologies indicated that it was precisely of KT boundary age, coeval with the mass extinction. Exactly how the Chicxulub impact induced the perturbation of the Earth System and the mass extinction of organisms is not yet fully understood. The study of the crater and its internal lithology in the framework of the ICDP scientific deep drilling project will provide answers to this fundamental question. Cratering: an important process in the formation of planets The ICDP deep drilling project in the Chicxulub crater will also help Earth scientists to understand better the mechanisms of crater formation. Cratering is a key process in formation and evolution of the rocky planets. With a diameter of approximately 200 km Chicxulub is one of the largest and best preserved craters on Earth. Chicxulub can thus serve as a proto-typical and accessible large planetary impact structure providing key information as to the formation and early evolution of Earth and both dry (Moon, Mercury) and volatile- rich planets (e.g. Venus). A high-resolution picture of the structure of the magnetic field of the Chicxulub crater can be found at http://www.gfz- potsdam.de/news/foto/chicxulub/. More information is available on the Internet at http://icdp.gfz- potsdam.de. Image caption: 1D- and 3D-images of the magnetic anomalies of the inner Chicxulub crater ring compiled from aeromagnetometry measurements of the GFZ aero-campaign "MEXAGE" (Mexico Aerogeophysical Experiment). The anomalies are sharply bounded within the inner crater. Long- wavelength anomalies are generated by larger melt bodies deeply buried in the crater, short-wavelength anomalies are caused by overlaying breccia. (Graphics: U. Meyer, GFZ Potsdam) Contact: Franz J. Ossing, phone: ++49-0-288-1040, e-mail: ossing@gfz- potsdam.de An additional article on this subject is available at http://www.spacedaily.com/news/deepimpact-01h.html. _____________________________________________________________________ A CURVE BALL INTO THE SNOWBALL EARTH HYPOTHESIS? By Kara LeBeau From SpaceDaily 3 December 2001 The idea that the Earth was encased in ice some 650 million years ago has sparked much scientific debate in recent years. In the ongoing Snowball Earth "fight," scientists continually uncover and report new evidence that supports their respective views. Martin Kennedy, from the University of California, Riverside, has just tossed a curveball into the Snowball Earth theory with new data he reports in the December issue of Geology. The Snowball Earth hypothesis proposes that during several profoundly cold periods of Earth's history that occurred from 750 to 600 million years ago, the ocean was covered by a thick sheet of ice. This would have had a huge impact on early life on Earth, and would have just about wiped it out entirely. Scientists generally agree that ice sheets reached low latitudes on the planet during severe glaciation, but the idea of a completely ice-covered ocean is what's being disputed. Kennedy and his colleagues' most recent research reveals that life in the oceans during the "snowball" event basically went on as usual. This new data is difficult to reconcile with the effects on life an entirely ice-covered ocean would have imposed, and this fundamentally challenges the Snowball hypothesis. This new evidence also supports alternative models, such as Kennedy's post-glacial release of methane from massive Clathrate destabilization that he proposed in last May's issue of Geology. Get the full story at http://www.spacedaily.com/news/iceage-01f.html. _____________________________________________________________________ WATER, SEDIMENTS IN ICE-BOUND ANTARCTIC LAKES MAY HARBOR UNIQUE MICROORGANISMS, ECOSYSTEMS National Science Foundation release 01-94 5 December 2001 Liquid lakes buried thousands of meters below the Antarctic ice sheet are likely the home to unique habitats and creatures that thrive in them. Exploration of those lakes will therefore require extreme care and an international cooperative effort, according to a team of authors writing in the December 6 issue of Nature. The pressure exerted by the continent-wide ice sheet together with heat generated by the Earth from below and the enormous insulating properties of the overlying ice sheet, may mean that liquid water exists in many--if not all--of the lakes. That may mean that they harbor life, according to a team of authors, led by Martin Siegert of Bristol University. Microbiologists funded by the National Science Foundation (NSF), working with ice samples gathered from deep beneath Russia's Vostok Station--that is thought to be refrozen water from Lake Vostok itself--have argued that microbes may survive in extreme cold and darkness under more than 4,000 meters of ice. John Priscu of Montana State University, one of those NSF-funded biologists, is a co-author of the paper. Antarctica is home to more than 70 lakes that lie thousands of meters under the ice sheet. The lakes include one under the South Pole and another, Lake Vostok, deep in the Antarctic interior, that is comparable in size and depth to one of the North American Great Lakes. Given the conditions in the lakes, the authors state, it is reasonable to believe "that subglacial lakes house a variety of microorganisms potentially unique to subglacial Antarctica and, if they are isolated hydrologically, unique to each lake." In the Nature article, Priscu and his colleagues also argue that the sediments at the bottom of Lake Vostok, and in other lakes, may also sustain life. They caution, though, that developing both the technology and the experimental protocols to explore those lakes without contaminating the waters or harming any microbial communities that may exist there will be an extremely complex undertaking that will require "significant multinational cooperation." The United States Antarctic Program, which is managed by NSF and which coordinates almost all U.S. research in Antarctica, already has taken some non-invasive steps to explore Lake Vostok. During the 2000-2001 research season, researchers from the Lamont Doherty Earth Observatory at Columbia University conducted detailed airborne radar mapping of the lake to more thoroughly understand its physical and geographical boundaries. In 1999, two NSF-funded teams, one headed by Priscu and another headed by David Karl of the University of Hawaii, published papers in Science describing evidence that viable microbes lived in the "accreted," or melted and refrozen ice from Lake Vostok. Priscu and his co-authors write in the Nature article that these investigations into the nature of Lake Vostok "have helped to define the next generation of research objectives, and it is likely that several exciting bio-geochemical-physical systems will be documented during the next decade." Recognizing the scientific and technological challenges and opportunities of such an undertaking, NSF's Office of Polar Programs has established an NSF committee to study the possible scientific exploration of the lakes. Karl Erb, who heads the U.S. Antarctic Program, cautioned committee members that future workshops to discuss whether and how to proceed with scientific exploration will need to explore how advanced technologies, including technologies that may as yet not be developed, can enable scientists to achieve their research goals. He noted that the workshops will "bring out the likely interplay between science goals and technology requirements: The goals should define the requirements but the state of the technology may proscribe the goals." He also adds that any scientific exploration of subglacial lakes, including Lake Vostok, should include international and interagency participation. Read about the Vostok research conducted by Priscu and by Karl at http://www.nsf.gov/od/lpa/news/press/99/pr9972.htm. Read a report on an NSF-funded 1998 workshop, "Lake Vostok: A Curiosity or a Focus for Interdisciplinary Study?" at http://www.ldeo.columbia.edu/vostok/. NSF's Office of Polar Programs has established a committee to study the possible scientific exploration of subglacial Antarctic lakes. Read the committee's charge at http://www.nsf.gov/od/opp/antarct/subglclk.htm. The international Scientific Committee on Antarctic Research maintains a site on the exploration of subglacial lakes at http://salegos-scar.montana.edu/. Media contacts: Peter West, phone: 703-292-8070, e-mail: pwest@nsf.gov For available photography and b-roll, contact Dena Headlee, phone: 703-292-8070, e-mail: dheadlee@nsf.gov An additional article on this subject is available at http://www.spacedaily.com/news/life-01zu.html. _____________________________________________________________________ WHAT MAKES EUROPA PINK? By Nicola Jones From New Scientist, http://www.newscientist.com 5 December 2001 Does Europa's rosy glow betray a flourishing colony of bugs? The red tinge of Europa, one of Jupiter's moons, could be caused by frozen bits of bacteria. Their presence would also help explain Europa's mysterious infrared signal. Europa is mostly frozen water, but it absorbs infrared radiation differently to how normal ice does. Researchers think this is because something is binding the water molecules together. Salts of magnesium sulphate frozen within the ice, for example, would make the molecules vibrate at different frequencies. But no one has managed to come up with the perfect mix of salts to explain all of Europa's spectrum. Astrogeophysicist Brad Dalton wondered if something else was bound up with the water molecules. "Just on a lark, I asked a colleague of mine at Yellowstone if he had any IR spectra of extremophile bacteria," he says, and he was shocked by how well they matched Europa's mysterious spectrum. Then he analysed three kinds of bacteria under the same sort of conditions as Europa: its temperature is about -170°C and at 0.01 millibars it has virtually no atmosphere. Preliminary results show that all three species, the ordinary gut bacteria Escherichia coli, and extremophiles Deinococcus radiodurans and Sulfolobus shibatae, are just as good at explaining Europa's IR spectrum as the salts. However Dalton says the two species that thrive under extreme conditions are obviously more likely candidates for life on the icy moon. They also happen to be pink and brown, which would help explain the red patches on the moon's face. Bacteria couldn't survive on Europa's surface, but there might be liquid water inside Europa's icy crust capable of supporting life. "They could be blasted out to the surface in some kind of eruption and flash frozen," says Dalton. He plans to present his results at the Lunar and Planetary Science conference next spring. Glenn Teeter from the Pacific Northwest National Laboratory in Washington State says bacteria aren't the simplest explanation for Europa's spectrum. "It does strike me as a bit far fetched," he says. But it can't be ruled out until we go there to see. From New Scientist issue: 8 December 2001, http://www.newscientist.com. Additional articles on this subject are available at: http://www.spacedaily.com/news/jupiter-europa-01e.html http://www.space.com/scienceastronomy/astronomy/science_briefs-1.html _____________________________________________________________________ NASA REPORT: SPACE TRAVEL "INHERENTLY HAZARDOUS" TO HUMAN HEALTH By Leonard David From Space.com 5 December 2001 According to a new study created for NASA the medical risks--both physical and psychological--of long treks beyond Earth orbit remain daunting and a far greater challenge than the public has been led to believe. After 40 years of rocketing humans skyward, information on stresses to the body due to space travel have not been well collected, nor fully analyzed. Today, not enough is known about the dangers of prolonged travel to enable humans to venture into deep space in a safe and sane manner. However, the new, no-holds-barred study says part of the problem comes from "underreporting" by space travelers about their health woes. Also, there is too much data privacy and confidentiality between astronauts and flight surgeons. Get the full story at http://www.space.com/scienceastronomy/generalscience/space_health_011 205-1.html. _____________________________________________________________________ HOW WILL WE REACT TO FIRST CONTACT? THE SETI INSTITUTE WANTS YOUR ANSWERS By Douglas Vakoch 6 December 2001 When we think of SETI scientists, we often picture astronomers electronically sifting through cosmic noise in search of signals from intelligent life on other planets. And indeed, that’s a very accurate image of most of the scientists involved in SETI programs worldwide... However, ever since the first SETI observations in the 1960s, there have been a handful of scientists studying the possibility of life beyond Earth, even though they have little or no formal training in astronomy, physics, or engineering. Instead, these scientists are social scientists, with backgrounds in fields such as anthropology, political science, and psychology. But how can social scientists make significant contributions to SETI before astronomers and engineers detect signals from other stars? Get the full story at http://www.space.com/searchforlife/seti_social_011206.html. Take the SETI survey at http://www.seti.org/forms/survey/12_01.html. _____________________________________________________________________ NASA'S GLOBAL SURVEYOR SEES POSSIBLE CLIMATE CHANGE ON MARS NASA/JPL release 6 December 2001 The planet Mars we know today is a cold, dry, desert world, but suppose the Martian climate is changing even now, year to year and decade to decade? New observations by NASA's Mars Global Surveyor spacecraft are expanding our understanding of the Martian climate and may indicate the climate is changing significantly even today. This suggests even larger climate changes have occurred during the planet's recent history and may again in its future. The observations were made during a full Martian year, 687 Earth days. If this is so, Mars might someday become warmer and wetter, as some scientists suggest it was during its early history. Papers detailing these observations are published in the December 7, 2001, issue of Science magazine. "If the environment of Mars has really changed by as much and over as short a time-scale as our observation implies, there should be attributes of Mars reflecting these changes that may be measurable by landers," said Dr. Michael Malin, principal investigator for Global Surveyor's camera system at Malin Space Science Systems, San Diego. "If Mars had a higher atmospheric pressure in the not-too-distant past, it is more likely that water was present as a liquid near the surface." Liquid water is required to support known forms of life, and the presence of liquid water on Mars would make it more likely life may once have existed there. "Detecting evidence of climate change and variability on Mars using Mars Global Surveyor data is an important aspect of telling us where to go on the surface this decade," said Dr. James Garvin, lead scientist for Mars exploration, NASA Headquarters, Washington, DC. "Clearly, the polar regions are a good place where we would like to look for hydrothermal vents to see if they exist on Mars." Images from Global Surveyor's camera system show that pits--often referred to as the "Swiss cheese" terrain--at the southern polar ice cap of Mars have dramatically increased in diameter, indicating the material has evaporated rapidly compared to last year. "The amount of change is much larger than any previous change we've seen on Mars, and it is much larger than can be explained by the evaporation of water ice. We have calculated the only material that could have changed this much is carbon dioxide ice, what we know as dry ice," said Malin. "This means the Mars environment we see today may not be what it was a few hundred years ago, and may not be what will exist a few hundred years in the future." A separate observation is providing more detail about the behavior of carbon dioxide in the Martian atmosphere. Carbon dioxide is a "greenhouse gas" believed to warm climates when its atmospheric concentration increases. The spacecraft's laser altimeter and radio tracking system have made precise measurements of the amount and density of carbon dioxide snow in both polar regions. This information gives scientists the first global measurement of the seasonal exchange of carbon dioxide between the atmosphere and surface. Due to the tilt of the planet, Mars has seasons just like Earth. Scientists have long known the most important seasonal change on Mars is the autumn and winter "freezing out" of carbon dioxide from the atmosphere in the form of dry-ice frost and snow. The evaporation of the surface frost in spring and summer returns carbon dioxide to the atmosphere. Over the course of a Martian year, as much as a quarter of the atmosphere freezes out, but until now scientists didn't know precisely where and how much dry-ice frost and snow would pile up on the surface. "We have measured how deep the dry-ice snow got on Mars over the course of a year. We have also measured the corresponding tiny change in the gravity field due to carbon dioxide being transported from one pole to the other with the seasons," said Dr. Maria Zuber, deputy principal investigator of the laser altimeter, at the Massachusetts Institute of Technology, Cambridge, and NASA's Goddard Space Flight Center, Greenbelt, MD. "Snow on Mars is denser than snow on Earth and is really more like ice than snow. Understanding the present carbon dioxide cycle is an essential step towards understanding past Martian climates," Zuber said. JPL manages the Mars Global Surveyor mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena. Images and additional information about these observations can be found at: http://www.jpl.nasa.gov/images/mars http://www.msss.com/mars_images/moc/CO2_Science_rel/ http://www.msss.com/mars_images/moc/CO2_Science_cvr/ http://ltpwww.gsfc.nasa.gov/tharsis/snow_paper.html Extensive digital material is available at http://www.gsfc.nasa.gov/topstory/20011206molaice.html. Contacts: JPL/Mary Hardin, phone: 818-354-0344 Goddard Space Flight Center/Tim Tawney, phone: 301-614-6573 NASA Headquarters/Don Savage, phone: 202-358-1727 _____________________________________________________________________ ZUBRIN TALKS MARS WITH SPACEDAILY From SpaceDaily 9 December 2001 What could you do with six billion dollars? Robert Zubrin thinks you could go to Mars with it. Unless you are the U.S. government, that is: then it would take closer to twenty billion dollars. Dr. Zubrin is the founder and president of Pioneer Astronautics, and a founder of The Mars Society, a group dedicated to expanding the knowledge of Mars and establishing a permanent human presence there. He knows something about space exploration, having been part of it for over sixteen years. He advocates harnessing the pent-up dreams of average citizens to finance Mars exploration. As he puts it, "a hundred million people times a hundred dollars is ten billion dollars." Get the full story at http://www.spacedaily.com/news/oped-01m- overview.html. _____________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.h tml 10 December 2001 Articles about astrobiology, exobiology and terraformation http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s1.html SpaceDaily, 2001. Does Europa's rosy glow betray a flourishing colony of bugs? SpaceDaily and New Scientist. Articles about the biology of extreme environments (on Earth) http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s2.html M. J. Siegert, J. C. Ellis-Evans, M. Tranter, C. Mayer, J-R Petit, A. Salamatin and J. C. Priscu, 2001. Physical, chemical and biological processes in Lake Vostok and other Antarctic subglacial lakes. Nature, 414:603-609. SpaceDaily, 2001. Sediments in ice-bound Antarctic lakes may harbor unique lifeforms. SpaceDaily. Articles about human space exploration and the microgravity environment http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s3.html L. David, 2001. NASA report: space travel "inherently hazardous" to human health. Space.com. SpaceDaily, 2001. Zubrin talks Mars with SpaceDaily. SpaceDaily. Articles about the search for extraterrestrial intelligence (SETI) http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s4.html D. Vakoch, 2001. How will we react to first contact? The SETI Institute wants your answers. Space.com. Articles about evolutionary biology and chemistry http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s5.html K. LeBeau, 2001. A curve ball into the snowball earth hypothesis? SpaceDaily. SpaceDaily, 2001. Chicxulub drilling project could have major impact on extinction studies. SpaceDaily. _____________________________________________________________________ CASSINI WEEKLY SIGNIFICANT EVENTS NASA/JPL release 21-28 November 2001 The most recent spacecraft telemetry was acquired from the Madrid tracking station on Wednesday, October 24. The Cassini spacecraft is in an excellent state of health and is operating normally. Information on the spacecraft's position and speed can be viewed on the "Present Position" web page at http://www.jpl.nasa.gov/cassini/english/where/. The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Wednesday, November 28. The Cassini spacecraft is in an excellent state of health and is operating normally. Recent instrument activities include a Radio and Plasma Wave Science (RPWS) High Frequency Receiver calibration, instruments waking up after the Huygens Probe Relay test, the Ka-Band Exciter and Traveling Wave Tube Amplifier powering on, and all instruments going quiet for the Gravitational Wave Experiment (GWE). Engineering activities taking place onboard the spacecraft this week include a transition to Reaction Wheel Assembly (RWA) control from the Reaction Control Subsystem and an RWA unload in preparation for the GWE. The Cassini Radio Science team began the GWE on November 25. This is the first prime science objective on the Cassini Program, and will run for 40 days, ending on January 4, with two more opportunities later during the cruise phase of the mission. The GWE research scientists will use radio transmissions between Cassini and Earth to search for gravitational waves measurably warping space between the two, using continuous coverage throughout the 40-day experiment to maximize the chances of detecting the extremely weak waves. The multi-day Probe Relay test was completed this week. The tests were required to check out the communications link between the Huygens probe and the Cassini orbiter spacecraft. Using the Goldstone DSS-24 antenna, a series of signals was transmitted to Huygens, via Cassini, to simulate the stream of data that will be sent back by Huygens during its parachute descent through Titan's atmosphere. This test represented a major step towards the validation of the Huygens Recovery Task Force design, testing the nominal mission scenario and several deviations from it. While it will take a few months to fully analyze the data, initial indications show that all objectives were successfully met. A demonstration of uplink and downlink capabilities at the Emergency Control Center (ECC) was conducted last week and test reports indicate that all command, tracking, monitor and telemetry data functions worked successfully. Further testing of the ECC is planned after completion of the GWE. A Project Briefing was held to review the C31 Science Planning Team integrated plan. The Program Manager approved the contents of the plan, and C31 sequence generation will continue into the next phase of the process. Other Science Planning activities included the Saturn, Cross-Discipline, and Ring Target Working Teams meeting last week to finish integrating the Tour segments associated with Orbits 4 through 10. The Imaging Science Subsystem and the Visual and Infrared Mapping Spectrometer (VIMS) teams delivered various software packages to the Multi-mission Image Processing Laboratory (MIPL) Integration and Test organization as a part of MIPL delivery D27. The delivery to Operations will be in February 2002. The delivery includes software to analyze data policing losses, extract background, mirror data, and internal housekeeping measurements from the VIMS Level 1A products, improve validation of observation description files delivered from the Science Teams, build such observation description files in order to easily generate test data, and improve handling of VIMS data when the visible portion arrives before the infrared. The Cassini Project scientist and deputy are attending the American Astronomical Society Division for Planetary Science meeting in New Orleans. A number of Cassini at Jupiter papers have been presented. 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 NASA/JPL release 3-9 December 2001 As playback from the October 15 flyby of Io continues, two engineering activities dot the schedule for Galileo this week. On Wednesday, the spacecraft executes a small 2 degree turn to keep its communications antenna pointed towards Earth, and on Friday, routine maintenance of the propulsion system is performed. A varied week of playback returns data from the Solid State Imaging camera (SSI), the Photopolarimeter Radiometer (PPR), and the Near Infrared Mapping Spectrometer (NIMS) instruments. Pictures expected from SSI this week include views of Io near the terminator captured an hour after the closest approach to the satellite and a global-scale color image taken nearly 12 hours after closest approach. We will also be treated to two views of the tiny inner satellite Amalthea, which will not only show us some of the surface features, but will also be used to improve our knowledge of the precise location of the tiny moon. This will aid the navigators in directing Galileo to fly by Amalthea in November of next year. PPR data will include thermal scans along Io's equator and three thermal and polarimetry maps of the entire visible hemisphere of the satellite. PPR measurements of the dark side of the icy moon Europa and of the atmosphere of Jupiter are also expected this week. NIMS observations slated for playback include two regional maps of the hot spots on Io and a global observation of the temperatures of Jupiter's atmosphere. In addition, the steady collection of real-time data by the Magnetometer, the Dust Detector, and the Extreme Ultraviolet Spectrometer continues throughout the week. For more information on the Galileo spacecraft and its mission to Jupiter, please visit the Galileo home page at one of the following URL's: http://galileo.jpl.nasa.gov http://www.jpl.nasa.gov/galileo _____________________________________________________________________ STARDUST STATUS REPORT NASA/JPL release 7 December 2001 There were two Deep Space Network (DSN) passes during the past week, and all subsystems are normal. Stardust is currently 2.55 AU (237 million miles) from the Sun. The time it takes for a signal to leave Earth and come back is 58 minutes and 15 seconds. The first battery discharges were observed during the two DSN passes. The battery's state of charge typically cycles from 107 to 108 percent. When the state of charge reaches 108 percent, the battery is discharged until the state of charge reaches 107 percent; then the battery is slowly charged back to 108 percent. During the last DSN pass, which lasted four hours and fifteen minutes, the battery's state of charge ended at 102.6 percent. We had predicted that the predicted battery's state of charge at the end of the pass would be approximately 97 percent. This indicates the power subsystem is performing better than predicted, which is very good news. When the spacecraft reaches maximum solar range (2.72 AU, or about 253 million miles from the Sun) in April, the battery's state of charge for a three-hour DSN pass is predicted to be 60 percent. 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 47.