MARSBUGS: The Electronic Astrobiology Newsletter Volume 7, Number 9, 10 March 2000. Editors: Dr. David J. Thomas, Biology and Chemistry 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://www.lyon.edu/webdata/users/dthomas/marsbugs/marsbugs.html. 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) "SAFARI 2000" FIELD CAMPAIGN TO PROBE AFRICAN ECOSYSTEMS, GLOBAL CHANGE NASA release 00-25 2) SPACE BIOTECH REPORT AVAILABLE National Research Council 3) MARTIAN METEORITES REVEAL CLUES TO PROCESSES IN PLANET'S ATMOSPHERE UCSD release 4) MARS GLOBAL SURVEYOR PROVIDES A GEOLOGIST'S SURVEY OF MARS Arizona State University release 5) TIMOTHY FERRIS INTERVIEW ONLINE AT ASTRONOMY MAGAZINE From Astronomy 6) EXTRASOLAR PLANETS: THE SEARCH FOR NEW WORLDS By D. B. Anderson 7) THE DIFFERENCE BETWEEN THE MARTIAN POLES? IT'S THE "CHEESE" JPL release 8) NASA TO HOST 31st LUNAR AND PLANETARY SCIENCE CONFERENCE IN HOUSTON JSC release J00-14 9) VIEW INSIDE MARS REVEALS RAPID COOLING AND BURIED CHANNELS NASA release 00-36 10) NEW GALILEO VIEWS OF IO, EUROPA TO BE AVAILABLE ONLINE JPL image advisory 11) GALILEO SPACECRAFT TO FLY WITH A FRIEND, EARN BONUS MILES JPL release 12) THIS WEEK ON GALILEO JPL releases 13) MARS GLOBAL SURVEYOR STATUS REPORT JPL release 14) NEW MARS GLOBAL SURVEYOR IMAGES By Ron Baalke 15) STARDUST STATUS REPORT JPL release --------------------------------------------------------------------- "SAFARI 2000" FIELD CAMPAIGN TO PROBE AFRICAN ECOSYSTEMS, GLOBAL CHANGE NASA release 00-25 29 February 2000 A caravan of scientists and students begins a 600-mile trek across southern Africa this week as part of a major international experiment to better understand the region's diverse ecosystems and improve NASA's ability to monitor global change around the world. The research caravan is part of a three-year study of southern Africa's ecology, air quality and land use from the ground, air and space. SAFARI 2000, the Southern African Regional Science Initiative, brings together African, U.S. and international scientists in a multidisciplinary research effort aimed at understanding the sustainability of the region's sensitive and pressured ecosystems. NASA's contribution includes images from the Terra, Landsat 7 and SeaWiFS spacecraft, aircraft measurements, measurements from observation towers, ozone-measuring balloons, and collaborative research with African scientists. Dr. Jeffrey Privette of NASA Goddard Space Flight Center's Laboratory for Terrestrial Physics is one of the coordinators of the 30-person caravan, which began its first survey February 28 in Mongu, Zambia, at the peak of the wet season. Researchers will travel to five different ecosystems along a north-south route from Mongu to Tshane, Botswana. This area, dubbed the "Kalahari Transect" for the underlying sandy soil, has been identified as a key global change study area by the International Geosphere-Biosphere Program. At each survey site, participants will stake out a large, square plot over half a mile (1 kilometer) on a side and inventory the type, density and height of all the vegetation. They will also measure the way sunlight is absorbed and reflected by the plants and soil. By comparing this information with spacecraft views of the same area, scientists can precisely match the reflected sunlight the spacecraft instruments see with the type of ground cover that produces it. This "validation" procedure will increase the precision and usefulness of observations made by NASA's Terra spacecraft, which was launched in December 1999. Terra is scheduled to begin its first observations during SAFARI 2000. "The caravan survey will produce the first coordinated measurements of several very different ecosystems, from woodlands in the north to shrubland in the south," says Privette. These data combined with chemical analysis of rainfall and atmospheric particles will shed light on how the nutrient-poor soil in this region can support vegetation. One current hypothesis is that nutrients lofted into the air by extensive fires are blown here by winds and deposited in the soil. A final caravan sets off from Mongu early next year heading east to survey the Miombo Forest region. Ozone in the lower atmosphere also will be monitored during this period with balloon-borne instruments launched several times a week. Dr. Anne Thompson of Goddard's Laboratory for Atmospheres is organizing these "ozonesonde" releases from the South African Weather Bureau station in Pretoria. The measurements will be used to validate spacecraft views of lower-atmosphere ozone produced by NASA's Total Ozone Mapping Spectrometer (TOMS). The largest field activity of SAFARI 2000--a six-week airborne campaign--begins in August at the height of the dry season. NASA's ER-2 aircraft along with aircraft from the University of Washington and the South African Weather Bureau will conduct scientific flights over nine southern African countries to study the circulation and composition of the atmosphere and pollution from biomass burning and industrial emissions. Southern Africa is subject to some of the highest levels of biomass burning in the world. The cumulative SAFARI 2000 observations will benefit monitoring of global change worldwide through its use in validating Terra data, says Dr. Michael D. King, senior project scientist of NASA's Earth Observing System Project Science Office at NASA Goddard. "With SAFARI 2000, we will be able to focus validation of all five Terra scientific instruments with the extensive observations gathered on the ground and in the air. This will help us improve all types of observations Terra will make, from clouds to vegetation types to carbon monoxide." SAFARI 2000 builds on ongoing research by the international community and southern African nations and on a history of international collaboration in the region. The first SAFARI field campaign in 1992 produced insights into biomass burning and the long-range movement of air pollution. SAFARI 2000 pulls together a wider range of scientific disciplines needed to study the functioning of southern African ecosystems and the regional atmosphere. In 1998 President Clinton announced the "Southern Africa Environmental Review" during his trip to Africa in response to the increasing pressures on the environment caused by the rapid growth in population and economic activity in the region. SAFARI 2000 will support this initiative by providing an enhanced understanding of change in the region. NASA's Earth Observing System project, a suite of spacecraft and interdisciplinary science investigations dedicated to advancing our knowledge of global change, is the primary sponsor of U.S. participants. The SAFARI 2000 campaign includes international participation from the Republic of South Africa, Zambia, Botswana and Namibia and also includes potential over-flights of Lesotho, Malawi, Mozambique, Swaziland and Zimbabwe. More information on SAFARI 2000 can be found on the internet at http://safari.gecp.virginia.edu/ --------------------------------------------------------------------- SPACE BIOTECH REPORT AVAILABLE National Research Council 1 March 2000 NASA should involve a broader segment of the scientific community in its biotechnology research program, in order to make the most of the International Space Station as a platform for cutting-edge research in cell biology and protein crystal growth, says a new National Research Council report. The full report is available online at http://books.nap.edu/catalog/9785.html --------------------------------------------------------------------- MARTIAN METEORITES REVEAL CLUES TO PROCESSES IN PLANET'S ATMOSPHERE UCSD release 1 March 2000 Detailed measurements of sulfur isotopes in five martian meteorites have enabled researchers at the University of California, San Diego to determine that the abundant sulfur on the surface of Mars is due largely to chemical reactions in the Red Planet's atmosphere that are similar to those that occur in Earth's atmosphere. Their conclusions, which are detailed in a paper in the March 2 issue of Nature, also suggest that the variations in sulfur isotopes found on ALH84001, the martian meteorite thought by some scientists to contain evidence of ancient martian life, are not due to biological processes. Instead, the UCSD researchers say, the chemical processes that produced the variations in sulfur isotopes on many of the bits of rock that were blasted from the surface of Mars millions of years ago and eventually recovered on Earth appear to be purely inorganic-- that is, non-biologic. "On Earth, if you see a large variation in the sulfur isotope ratio, it generally, though not exclusively, means you've got a biogenic input," said Mark H. Thiemens, professor of chemistry and biochemistry and dean of the Division of Natural Sciences at UCSD. "Organisms are very good at separating isotopes and choosing one over the other. So when you see big changes in isotope ratios, it often means biochemistry." On Earth, such changes are often produced by terrestrial bacteria that derive their energy solely from the conversion of sulfur compounds from one form to another. In so doing, they selectively break the chemical bonds of the lighter isotopes of sulfur, producing large variations in the normal sulfur-isotope ratio. In their laboratory, Thiemens and UCSD researchers James Farquhar, Joel Savarino and Terri L. Jackson sought to find out whether some of this sulfur may have been produced by organisms. They also examined the sulfur in the martian meteorites to find clues to the evolution of the martian atmosphere, a major puzzle for planetary scientists. "Sulfur and a number of other elements are involved in the chemical and physical cycling of elements between oceans, rocks, living organisms and the atmosphere," said Farquhar, the principal author of the study. "We have shown that the sulfur-isotope ratios in martian meteorites have a component that can only be explained by atmospheric chemical reactions. This provides new insights into the origin of sulfur species found at the Viking and Pathfinder landing sites, and into sulfur mobility within the martian surface." "Mars is a nice case study, because it's relatively simple," explained Thiemens. "There's not that much atmosphere, it's photochemical, it couples directly to the surface and it's not complicated by biology or an ocean. Sulfur is a major element and it has a number of isotopes, so it's a very nice probe to understand an entire planetary system." The UCSD researchers' measurements of sulfur isotopes in reduced and oxidized phases, which were supported by the National Aeronautics and Space Administration, are the first from a group of martian meteorites, known as SNC meteorites. Only about a dozen of these rare meteorites have been recovered over the past two centuries. Farquhar and his colleagues examined samples of five meteorites in this group, including a 1.3 billion-old-year martian rock that reputedly killed a dog when it fell to Earth in 1911 near Nakhla, Egypt and a 165-million-year-old chunk of the Red Planet that fell near Shergotty, India in 1865. The UCSD scientists said the isotopic variations in those meteorites, combined with what is known about the martian atmosphere from the Viking landers, are best accounted for by inorganic chemical reactions in the atmosphere, not biological processes. "When you put them all together to account for the data, it fits," said Thiemens. "Biology can't accommodate what we see, but the photochemistry in the martian atmosphere does." The UCSD researchers will also present their results later this month at the Lunar and Planetary Science Conference, scheduled for March 13-17 in Houston. --------------------------------------------------------------------- MARS GLOBAL SURVEYOR PROVIDES A GEOLOGIST'S SURVEY OF MARS Arizona State University release 3 March 2000 Hey, remember Mars Global Surveyor? Though the disappearance of the Mars Polar Lander has received most of the recent space press, there is still a very functional spacecraft orbiting Mars and it has been sending back some very important information--particularly if you are a planetary geologist. In a paper to be published March 3 in the journal Science, Arizona State University geologists Josh Bandfield, Vicky Hamilton, and Philip Christensen report the first results of a major survey being performed by the Mars Global Surveyor's Thermal Emission Spectrometer (TES) of the planet's mineral composition. TES measures the thermal infrared energy (heat) emitted from Mars and records the unique infrared spectra emitted by specific minerals. Scientists then use this data to map the mineral composition of the planet's surface. The instrument captures spectra covering 3 km. patches of the martian surface. With the mapping now about 75% complete, the instrument "has taken about 100 million spectra in about a year," said Christensen, and the planet should be completely mapped within the next four months. "From those spectra we have made a detailed map showing mineral abundance. These are the first mineral maps ever made of Mars," Christensen noted. "As of now, we have looked at the basic composition of the martian surface--it's an overall view. "What we've found is that the surface materials are primarily volcanic. People have suspected that this was the case, but we've finally been able to clearly demonstrate it." There is volcanic rock though, and there is volcanic rock, Christensen points out, and the differences in the rocks' compositions can have very large implications about planetary history. "What's particularly interesting is the surfaces in the southern hemisphere--which tend to be very ancient, heavily cratered surfaces dating back to near when Mars was first formed--are primarily basaltic in composition," said Christensen. "On earth, most of the lavas that are erupted are primarily basaltic. These are the result of slow, non-explosive lava flooding." "The northern hemisphere of Mars is much younger--it may only be a billion years or less in age. Those rocks are still volcanic, but have a different composition--it's a rock called andesite. On earth, these tend to erupt in a very different way in places like the Andes Mountains or Mount St. Helens." "To a geologist, this change in materials says that the interior of Mars has changed. We're still debating what changed and why it occurred, but it's fascinating that the change did occur." Christensen believes that the change is likely to be due to a change in water content deeper in the planet's interior, but it could also be caused by the martian crust getting thicker. "Now it's the geochemists turn to get excited. We're providing them with data to work with and they get to design models to try to explain why this happened." Christensen and his team are likely to have some exciting science of their own to contemplate in the months to come. "This map is a baseline. Now we'll start focusing on the places that are unique and different," he said. "It's like if you sent a survey out to map the west and you discover the Rocky Mountains and the Sierra Nevadas and the great deserts--you do an inventory of what's out there, and then you start focusing on places like Yellowstone, places that are unique and different from every place else. "On Mars, some of those places are going to be really interesting," he said. --------------------------------------------------------------------- TIMOTHY FERRIS INTERVIEW ONLINE AT ASTRONOMY MAGAZINE From Astronomy 3 March 2000 Last fall, acclaimed science writer Timothy Ferris spoke with Astronomy about his PBS film, Life Beyond Earth, which aired on PBS in November [http://www.pbs.org/lifebeyondearth/]. Ferris has written bestsellers that include Galaxies, Coming of Age in the Milky Way, The Mind's Sky, and The Whole Shebang: A State-of- the-Universe(s) Report. A member of Astronomy's editorial board of advisors and a former editor of Rolling Stone, Ferris is author of more than 100 articles, essays, and reviews in such publications as Esquire, Nature, and The New Republic. The full article is online at http://www2.astronomy.com/astro/Magazine/AstIndex/2000/2000Apr/Ferris .html --------------------------------------------------------------------- EXTRASOLAR PLANETS: THE SEARCH FOR NEW WORLDS By D. B. Anderson 6 March 2000 In recent years, headlines have trumpeted the beginning of a new era in humanity's exploration of the universe: "A Parade of New Planets" (Scientific American), "Universal truth: Ours Isn't Only Solar System" (Houston Chronicle), "Three Planets Found Around Sunlike Star" (Astronomy). With more than 20 extrasolar planet or planet candidate discoveries having been announced in the press since 1995 (many discovered by the planet-searching team of Geoff Marcy and Paul Butler of San Francisco State University), it would seem that the detection of planets outside our own solar system has become a commonplace, even routine affair. Such discoveries capture the imagination of the public and the scientific community, in no small part because the thought of planets circling distant stars appeals to our basic human existential yearning for meaning. The full story appeared in the Fall 1999/Number 87 issue of Lunar and Planetary Information Bulletin, and is available as a PDF file (476 KB) at http://cass.jsc.nasa.gov/publications/newsletters/lpib/lpib87/lpib87. pdf --------------------------------------------------------------------- THE DIFFERENCE BETWEEN THE MARTIAN POLES? IT'S THE "CHEESE" JPL release 8 March 2000 New high-resolution images from NASA's Mars Global Surveyor spacecraft comparing the ice caps at the North and South poles show the difference between the two regions is in the 'cheese'. The North polar cap has a relatively flat, pitted surface that resembles cottage cheese, while the South polar cap has larger pits, trough and flat mesas that give it a holey, Swiss cheese appearance. "Looking like pieces of sliced and broken Swiss cheese, the upper layer of the martian South polar residual cap has been eroded, leaving flat-topped mesas into which are set circular depressions," said Dr. Peter Thomas of Cornell University, Ithaca, NY and lead author of the paper. "Nothing like this has ever been seen anywhere on Mars except within the South polar cap, leading to some speculation that these landforms may have something to do with the carbon dioxide thought to be frozen in the South polar region." In a paper to be published March 9, 2000, in the journal Nature, members of the Mars Global Surveyor imaging team have described some of the newly discovered differences in polar terrain. "The unusual shapes of the landforms on the North and South polar caps suggest that these regions have had different climates and histories for thousands or perhaps even millions of years," said Thomas. "We are discovering them for the first time because Mars Global Surveyor is working to provide high-resolution views of the tremendously diverse terrain on Mars over all martian seasons." "These landforms may be telling us what the South polar cap is made of," said Dr. Andrew Ingersoll of the California Institute of Technology in Pasadena and one of the authors of the paper. "The North residual cap--the part that survives the summer--is made of water ice. The South residual cap seems to be made of carbon dioxide or dry ice, but we don't know if this is a veneer a few meters thick or a solid block that extends down 2 or 3 kilometers (1.24 or 1.86 miles). These images may help us decide." The North polar cap is covered mainly by pits, cracks, small bumps and knobs that give it the cottage cheese look. The pits that have developed on the surface are spaced close together relative to the very different depressions in the South polar cap. These pits probably developed slowly over successive spring and summer seasons. "The polar images demonstrate again that understanding Mars' complicated history requires studying many areas in detail, just as understanding the Earth does," Thomas said. The new images can be seen at http://photojournal.nasa.gov/new and http://www.msss.com "If we discovered that both polar caps are mostly water, it would leave a mystery about why there is so little carbon dioxide on Mars. Earth has a lot of carbon dioxide, but creatures living in the ocean have turned it into limestone rocks. Without oceans or life, Mars should have a lot more carbon dioxide on its surface than we seem to be finding," explained Ingersoll. Mars Global Surveyor is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, DC. JPL's industrial partner is Lockheed Martin Astronautics, Denver, which developed and operates the spacecraft. JPL is a division of the California Institute of Technology. --------------------------------------------------------------------- NASA TO HOST 31st LUNAR AND PLANETARY SCIENCE CONFERENCE IN HOUSTON JSC release J00-14 8 March 2000 New evidence that an ocean may once have existed on Mars will be among this year's topics of interest at the 31st annual Lunar and Planetary Science Conference (LPSC), March 13-17, 2000. The conference, which is chaired by Dr. Carl B. Agee of NASA and Dr. David C. Black of the Lunar and Planetary Institute, will be held at the NASA Johnson Space Center and the University of Houston-Clear Lake (UHCL). One highlight of this year's conference will be early results from the Near Earth Asteroid Rendezvous (NEAR) spacecraft, which went into orbit around the asteroid Eros on February 14. As the first spacecraft to orbit an asteroid, the NEAR mission promises to answer fundamental questions about the nature and origin of asteroids in the vicinity of Earth's orbit. These objects are of interest as the primary source of large bodies that collide with Earth, greatly influencing the evolution of the atmosphere and life on our planet. Early information, images and data analysis from this mission will be presented by NEAR team members during a special session of invited talks March 14. Other presentations will focus on * results from the Galileo spacecraft's close fly-bys of Jupiter's volcanic moon Io * new theories about the presence of water on early Mars * latest results from the Mars Global Surveyor's 2-year mapping mission * new views of the moon * the martian surface as seen by Mars Pathfinder and Viking * meteorites from the asteroids, the moon and Mars * astrobiology and the origin(s) of life in the universe * impact craters throughout the solar system Oral presentations are scheduled all day Monday through Thursday, as well as Friday morning in JSC's Gilruth Center. Dr. John Wood, meteorite researcher from the Harvard-Smithsonian Center for Astrophysics, will give the Harold Masursky Lecture at a special session Monday afternoon. His topic will be "Chondrites: Tight- Lipped Witnesses to the Beginning." Poster presentations are scheduled for Tuesday and Thursday evenings from 7:00 PM to 9:30 PM at UHCL's Bayou Building. Additional information about conference events, including registration and text of abstracts, can be found at the Lunar and Planetary Institute web site at http://cass.jsc.nasa.gov. Click on "meetings and conferences." News media should contact Pam Thompson by phone at 281/486-2175 with questions or to schedule interviews with participants, or by e-mail (thompson@lpi.jsc.nasa.gov). --------------------------------------------------------------------- VIEW INSIDE MARS REVEALS RAPID COOLING AND BURIED CHANNELS NASA release 00-36 9 March 2000 Some of Mars' best kept secrets, long buried beneath the surface of the red planet, were recently revealed by instruments on NASA's Mars Global Surveyor spacecraft. New observations of Mars reveal that the planet's flat northern lowlands were an early zone of high heat flow that later may have been the site of rapid water accumulation, according to a view of the martian interior generated using data from Mars Global Surveyor (MGS). Elevation and gravity measurements, which have been used to probe beneath the surface of Mars, indicate a period of rapid cooling early in martian history, and evidence for large, buried channels that could have formed from the flow of enormous volumes of water. This global view of the martian interior was generated from gravity measurements with the Radio Science experiment and elevation measurements from the Mars Orbiter Laser Altimeter (MOLA) instruments. Gravity and topography measurements were combined to reveal the structure of the crust on Mars, which preserves the record of melting of the interior and the heat loss from the planet over time. "The crustal thickness map shows that, as for Earth, Mars has two distinct crustal provinces," explained Dr. Maria Zuber of the Massachusetts Institute of Technology, Cambridge, MA, and lead author of a study to be published in the March 10 issue of Science. Beneath the rough southern highlands and Tharsis volcanic province the crust, estimated at 50 miles thick, thins progressively from the South pole toward the North. In contrast, the northern lowlands and Arabia Terra region of the southern highlands have a crust of uniform thickness, about 22 miles deep. The crustal structure accounts for the elevation of the martian northern lowlands, which controlled the northward flow of water early in martian history, producing a network of valleys and outflow channels. The new gravity- field data suggest that the transport of water continued far into the northern plains. The gravity shows features interpreted as channels buried beneath the northern lowlands emanating from Valles Marineris and the Chryse and Kasei Valles outflow regions. The features are about 125 miles wide and over a thousand miles long, with characteristics that can be explained by water flow on the surface or in a submarine environment, later buried by sediments. The large size of these channels implies that any bodies of water in the northern lowlands could have accumulated rapidly. The now- buried channels may represent the means for filling an early ocean. The gravity and topography also provide information on the cooling of Mars over time, which bears on the early climate and history of water. "The observations suggest that the northern lowlands was a location of high heat loss from the interior early in martian history, probably due to a period of vigorous convection and possibly plate recycling inside of Mars," said Dr. Sean Solomon, Director of the Department of Terrestrial Magnetism of the Carnegie Institution in Washington, DC, and a co-author of the study. The high heat-loss zone corresponds to the part of Mars proposed to have been the site of an ancient ocean. The rapid transport of heat to the surface in this region would have released onto the surface and into the atmosphere gases and water or ice trapped in the interior. The time of rapid interior heat loss may correspond to the period when Mars had a warmer climate, liquid water flowed on the surface, and the planet's surface was shielded from the solar wind by a global magnetic field. During the ongoing Mars Global Surveyor mapping mission the Radio Science and MOLA experiments will continue to collect data on a near- continuous basis through the end of the mission in February 2001. The MOLA instrument was designed and built by the Laser Remote Sensing Branch of the Laboratory for Terrestrial Physics at NASA's Goddard Space Flight Center, Greenbelt, MD. The Radio Science experiment is implemented from the Center for Radio Astronomy of Stanford University, Palo Alto, CA. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, DC, by the Jet Propulsion Laboratory, Pasadena, CA, a division of the California Institute of Technology. Maps of the interior of Mars may be viewed at http://pao.gsfc.nasa.gov/ and http://svs.gsfc.nasa.gov/imagewall/MOLA/mola_images.html Information about the MGS Radio Science investigation can be found at http://nova.stanford.edu/projects/mgs/dmwr.html Information about the MOLA investigation can be found at http://ltpwww.gsfc.nasa.gov/tharsis/mola.html The MGS home page is http://mars.jpl.nasa.gov/mgs/ --------------------------------------------------------------------- NEW GALILEO VIEWS OF IO, EUROPA TO BE AVAILABLE ONLINE JPL image advisory 3 March 2000 Images of two of Jupiter's moons--Io and Europa--taken by NASA's Galileo spacecraft during encounters late last year will be unveiled online Monday, March 6, at 9 AM Pacific Daylight Time at http://photojournal.jpl.nasa.gov/new. These are the same images being released by the University of Arizona, Tucson, and they show volcanic features on Io and the side of Europa that faces Jupiter. Pictures from the more recent, closest-every flyby of Io on February 22 are currently being transmitted to Earth and will be processed and then released in the near future. Galileo has been orbiting Jupiter and its moons since December 1995. After its primary mission ended in December 1997, Galileo successfully completed a two-year extended mission, and it is currently embarking on another extension, called the Galileo Millennium Mission. More information about the Galileo mission is available at http://galileo.jpl.nasa.gov. JPL manages Galileo for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology in Pasadena. --------------------------------------------------------------------- GALILEO SPACECRAFT TO FLY WITH A FRIEND, EARN BONUS MILES JPL release 8 March 2000 NASA plans to renew the solar system passport of the Galileo spacecraft by extending the mission exploring Jupiter and its moons through the end of 2000, when Galileo may embark on a joint scientific expedition with another solar system explorer, the Saturn- bound Cassini spacecraft. "This extended travel ticket enables us to continue studying Jupiter and its fascinating moons," said Jim Erickson, Galileo Project Manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. During this new extension, called the Galileo Millennium Mission, tour planners hope to include three high-priority scientific observations in 2000. Galileo would team with Cassini for simultaneous observations of the Jupiter system and its magnetic environment from two vantage points. Cassini will visit Jupiter's neighborhood in December 2000. Jupiter's powerful gravity will be used to "slingshot" Cassini toward Saturn. Galileo will perform two additional flybys of Jupiter's moon Ganymede, the largest moon in the solar system, on May 20 and December 28. Scientists hope these flybys will tell us more about Ganymede's geologic history, including the highest resolution pictures ever taken of this icy world. Results will be analyzed from the January 3 flyby of Jupiter's moon Europa and the closest-ever flyby of the volcanic moon Io on February 22. That encounter, at an altitude of only 200 kilometers (124 miles), may have been the last tour of that unique environment for years to come. The close-up images will add to Galileo's bulging scrapbook, which already contains about 14,000 pictures beamed back to Earth so far. By April 2001, after the spacecraft transmits to Earth pictures and scientific information stored on its tape recorder during the flybys in 2000, Galileo will have traveled nearly 41/2 billion kilometers (2.8 billion miles). Here on Earth, that mileage would earn a frequent flyer nearly 85,000 free round-trip tickets to Hawaii, an area with volcanoes remarkably similar to those observed by Galileo on Io. "For the first time ever, two spacecraft will simultaneously explore an outer planet," Cassini Project Scientist Dr. Dennis Matson said about the planned Jupiter observation by Cassini and Galileo. "One spacecraft will be inside Jupiter's magnetic envelope, with the other outside where it can observe the powerful solar wind pressing on the envelope. From the two vantage points, we'll watch cause and effect as the wind changes the magnetic properties around Jupiter." "We have a unique opportunity to study this dynamic system with two highly capable spacecraft at the same time," added Galileo Project Scientist Dr. Torrence Johnson. "It's a real bonus for both missions." Galileo's original two-year mission ended in December 1997, and a two-year extension called the Galileo Europa Mission, ended on January 31, 2000. Galileo engineers are fond of saying that the spacecraft has lived well past its warranty. The spacecraft has already endured nearly three times the radiation it was designed to withstand, but repeated exposure to Jupiter's radiation has taken its toll. Galileo was zapped with particularly high doses of radiation during recent flybys of Io, which lies deep within Jupiter's radiation belts. "As Galileo continues operating in Jupiter's harsh radiation environment, it's a challenge for our operations team to keep the spacecraft healthy," Erickson said. "But we like to think of Galileo as the 'little spacecraft that could.'" Galileo mission planners are currently exploring various options for the mission's eventual conclusion, including possible further encounters with Io and another Jovian moon, Callisto. Planners are looking into a possible impact with Io or Jupiter for a mission finale, with other options are also being considered. They are trying to avoid an impact with Europa because recent evidence suggests there may be a liquid ocean beneath its icy crust, raising the possibility that life could exist there. More information on the Galileo mission is available at http://galileo.jpl.nasa.gov. Additional information about the Cassini mission is available at http://www.jpl.nasa.gov/cassini. Galileo was launched aboard the Space Shuttle Atlantis on October 18, 1989, and it entered orbit around Jupiter on December 7, 1995. Cassini was launched on October 15, 1997 and it will arrive at Saturn in 2004. JPL manages the Galileo and Cassini missions for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena. --------------------------------------------------------------------- THIS WEEK ON GALILEO JPL releases 28 February - 5 March 2000 This week, Galileo continues to return data from a historic encounter with Jupiter's volcanic moon Io. The third flyby since October 1999, the spacecraft flew within 198 kilometers (123) miles of Io's surface, the closest yet of the encounters. The data returned this week were stored on Galileo's onboard tape recorder during the flyby. Data playback proceeds uninterrupted during the week, limited only by the amount of time allocated to Galileo on the Deep Space Network's 70-m (230-ft) diameter radio antennas. During data playback, the spacecraft computer retrieves the data stored on the tape recorder, then processes and packages the data, and subsequently transmits the data to Earth. Only one observation is on the playback docket this week. The Fields and Particles instruments continue the return of a 23/4-hour high-resolution recording of the Io torus that was taken starting 31/2 hours prior to the Io flyby. The Fields and Particles instruments are comprised of the Dust Detector, Energetic Particle Detector, Heavy Ion Counter, Magnetometer, Plasma Detector, and Plasma Wave instrument. The observation contains measurements of the plasma, dust, and electric and magnetic fields within the Io torus, and will be used increase the knowledge of the structure and dynamics of the torus region. The torus is a ring-shaped region of intense plasma and radiation activity with its inner edge bounded by Io's orbit. The torus is actively maintained by Jupiter's strong electric and magnetic fields and Io's constant supply of volcanic particles. On a final note, Galileo is operating normally this week after suffering a safing event late last week. The spacecraft safing is believed to have been caused by an erroneous power reset signal, which happens regularly during each encounter. You might remember that new software was installed on Galileo to allow the spacecraft to recover autonomously from this type of anomaly. Unfortunately, the new software must be disabled during tape recorder playback. Galileo suffered two other power reset signals during last week's encounter, and the new software allowed encounter commands to continue executing unhindered, protecting the time-critical data gathering phase. This means that the Galileo team expects that all planned observations of Io were completed successfully. March 6-12, 2000 Galileo spends the week playing back science data that is stored on its onboard tape recorder. The data were acquired when the spacecraft flew past Jupiter's fiery moon Io on February 22, 2000. Observations from seven instruments are returned this week: the Photopolarimeter Radiometer and Galileo's suite of six Fields and Particles instruments. The Fields and Particles instruments are comprised of the Dust Detector, Energetic Particle Detector, Heavy Ion Counter, Magnetometer, Plasma Detector, and Plasma Wave instrument. Data processing and transmission are interrupted three times this week. On Friday, the spacecraft performs a small turn to keep its radio antenna pointed toward Earth. Over the weekend, the Near-Infrared Mapping Spectrometer conducts two separate instrument calibrations. Most of the data returned this week come from the Fields and Particles observations of the plasma, dust, and electric and magnetic fields in the Io torus and in the region near Io. The Io torus is a ring-shaped region of intense plasma and radiation activity that is fed by Io's constant supply of volcanic particles, and shaped by Io's orbit and Jupiter's strong electric and magnetic fields. The information distilled from the Fields and Particles 23/4 hour high resolution recording of the region will be used to increase the knowledge of the structure and dynamics of the torus region and overall Jovian magnetosphere. Toward the end of the week, the Fields and Particles instruments begin returning a high-resolution recording that was taken during the spacecraft's closest 82 minutes to Io. The data will allow scientists to better understand the interaction of Io with the Io torus and the Jovian magnetosphere. Focusing on the surface of Io itself, the Photopolarimeter Radiometer (PPR) returns two observations. The first PPR observation contains temperature measurements of the active Loki hot spot and of surrounding regions in which no volcanism is currently active. The comparison of the different regions will allow scientists to study heat flow on Io's surface. The second PPR observation also contains temperature measurements, but this time of a region known as Daedalus Patera, which is characterized by the presence of sulfur frost. 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 --------------------------------------------------------------------- MARS GLOBAL SURVEYOR STATUS REPORT JPL release 1 March 2000 Launch / Days since Launch = Nov 7, 1996 / 1213 days Start of Mapping / Days since Start of Mapping = April 1, 1999 / 335 days Total Mapping Orbits = 4390 Total Orbits = 6072 Recent events The spacecraft continues to operate nominally in performing the daily recording and transmission of the science data. The mm016 sequence executed successfully from 00-55 (2/24/00) through 00-58 (2/27/00). The mm017 sequence began execution on 00-59 (2/28/00) and will run through completion of 00-61 (3/1/00). The next sequence mm018, scheduled to execute from 00-62 (3/2/00) through 00-64 (3/4/00), has been successfully uplinked to the spacecraft. The first fixed-HGA sequence of the beta supplement mapping phase, mm019, has been generated and will be uplinked Saturday March 4. The mm019 sequence will begin execution on 00-65 and continue through 00- 68 (3/8/00). Included in the mm019 sequence is the first of the monthly off-nadir polar scans for the MOLA instrument, approved by the Program. The first 12 orbits of the mm019 sequence will fly with a -17.1 degree nadir off-point angle for 45 minutes centered about the South Pole and a 14.4 degree nadir off-point angle for 45 minutes centered about the North Pole. For the fixed-HGA mapping operations, the spacecraft will be nadir pointed for 24 hours, recording science data on the solid state recorders, then the spacecraft will be oriented to point the HGA bore-sight at Earth for an eight hour playback period to return the data collected on the recorders. During this eight-hour period, the spacecraft will not be nadir pointed and not collecting science data, with the exception of radio science which will perform atmospheric observations as the spacecraft enters and exits Earth occultation. As reported last week the reason for the fixed-HGA sequences is to provide radio science atmospheric observations near the South Pole as the spacecraft exits Earth occultation, a geometry not supported by the HGA gimbals in the beta supplement operations due to EMI and HGA boom interference constraints. Upon completion of the data playback at the end of the eight-hour Earth pointed period, the spacecraft will be turned back to nadir pointing to begin the next fixed-HG A cycle Spacecraft health All subsystems are reporting nominal health. Three more PDS reset occurred over the last week. The frequency has been increasing over the last two weeks. So far no cause has been found for the recurring resets. The resets appear to have minimal if any impacts to the instruments. We continue to forward all reset data to the PDS software experts at JPL. Uplinks There have been 21 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm017 and mm018 sequences. Total command files radiated to the spacecraft since launch is 4480. Upcoming events The Navigation team has been looking at the ground track walk on a weekly basis to determine if an orbit trim maneuver (OTM) is required. Prior to the start of beta supplement operations, it appeared that an OTM would be needed sometime in March. However, the latest tracking data for the first few weeks of beta supplement operations shows the rate of the ground track walk decreasing and starting to knee over, which if the trend continues will not necessitate an OTM in the near term. With the likelihood of the next OTM diminishing, planning has begun for a focus calibration of the MOC to be performed in the next few weeks. --------------------------------------------------------------------- NEW MARS GLOBAL SURVEYOR IMAGES By Ron Baalke 2 March 2000 The following new images were taken by the Mars Global Surveyor spacecraft: Return to "Giant's Footprint" 3 Decades After Mariner 7 Flyby The images resides on the Mars Global Surveyor web site at http://mars.jpl.nasa.gov/mgs/msss/camera/images/index.html The image captions are appended below. Mars Global Surveyor was launched in November 1996 and has been in Mars orbit since September 1997. It began its primary mapping mission on March 8, 1999. Mars Global Surveyor is the first mission in a long-term program of Mars exploration known as the Mars Surveyor Program that is managed by JPL for NASA's Office of Space Science, Washington, DC. Malin Space Science Systems (MSSS) and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. Mars Global Surveyor Mars Orbiter Camera Return to "Giant's Footprint" 3 Decades After Mariner 7 Flyby MGS MOC Release #MOC2-209, 2 March 2000 As we head into the 21st Century, it seems hard to believe that human beings have been sending spacecraft toward Mars for more than 3 decades already. The first spacecraft to reach Mars was Mariner 4 in 1965. This success was followed by two spacecraft in 1969, Mariners 6 and 7. Now, despite several recent losses in 1999, the wonders and alien beauty of Mars continue to unfold with each day that the Mars Global Surveyor---which arrived in September 1997--continues to radio its data to Earth. Mars exploration was always difficult and each bit of data returned from the planet is a marvel. On August 5, 1969, the Mariner 7 spacecraft flew past Mars at a minimum altitude of about 4200 km. It acquired 14 wide/narrow angle image pairs during the few minutes of the "near encounter" flyby. One of these image pairs, 7N19/7N20, shows the south polar region and contains a feature that at the time was nicknamed "the Giant's Footprint". Shown in the first two pictures, above, the feature consists of two adjoining craters, one about 80 km (50 mi) in diameter and the other about 50 km (31 mi) across near latitude 76°S, longitude 276°W. The oblique geometry of the Mariner 7 image enhances the impression of a footprint. The "Giant's Footprint" was almost missed... as with recent difficulties in exploring Mars, Mariner 7 was not without troubles. The spacecraft in fact suffered a near-catastrophic battery failure just a few days before the encounter--on July 30--that put Mariner 7 sporadically out of contact with Earth for two days. Ground controllers at the Jet Propulsion Laboratory (JPL) recovered the spacecraft, re-planned its imaging sequence based on results from the Mariner 6 flyby on July 31, and salvaged all of the mission's science goals in under a week! In the 1970's, the larger crater in "giant's footprint" was named "Vishniac" in honor of Wolf Vishniac, an American microbiologist of the University of Rochester who was instrumental in the development of methods to search for life on Mars. Vishniac was tragically killed in a fall in Antarctica in 1973 while retrieving a life detection experiment, and the crater was named in honor of this "giant" in the search for life on Mars. More than three decades after the Mariner 7 flyby, Mars Global Surveyor's Mars Orbiter Camera (MOC) acquired a commemorative view of the interior of Vishniac Crater on October 25, 1999. The context image and the 3-meters (9.8 feet)-per-pixel narrow angle view are shown above (in the lower image pair). Mariner 7's 7N20 has a nominal resolution of about 180 meters (591 feet) per pixel, while the MOC high resolution view is about 60 times higher (in actuality, the lower quality of the Mariner 7 images makes the resolution gain even more dramatic). The MOC high resolution view (lower right, above) shows a 1.5 kilometer-wide portion of the floor of Vishniac in the process of defrosting during southern spring. The bright areas are still frost- covered, while the darker areas are either defrosted or composed of darkened or "dirty" frost. The dark patches in the image seem to serve as sources for dark streaks of material that has either been blown across the landscape by wind, or has somehow caused the erosion of frost to create the streaks. Dark streaks follow the local topography, as might the wind that blew across this landscape. This pattern of spots and streaks was quite common on the defrosting south polar cap during the spring that lasted from early August 1999 to late December 1999. All images shown here are illuminated by sunlight from the lower right. Image orientation with north toward the bottom was selected in order to show the "footprint" visible in Mariner 7 image 7N20. The Mariner 7 images were recovered at Malin Space Science Systems from the original 7-track magnetic tapes, archived on CD-ROM by the JPL Data Preservation activity. Image credits: NASA/JPL/Malin Space Science Systems --------------------------------------------------------------------- STARDUST STATUS REPORT JPL release 3 March 2000 There were five Deep Space Network (DSN) tracking passes during the past week. All subsystems onboard the spacecraft are performing normally. Commands were successfully sent and executed to return the spacecraft to All-Stellar mode and to power off the Inertial Measurement Unit (IMU). The flight sequence SC015 command files were transmitted to the spacecraft and began execution last Sunday. The Aerogel Grid collection angle was successfully increased by 4.1 degrees towards the full open position. This was the first bi-weekly update to the collection angle. The update is necessary to ensure the grid remains perpendicular to the interstellar dust flow. For more information on the Stardust mission--the first ever comet sample return mission--please visit the Stardust home page at http://stardust.jpl.nasa.gov. --------------------------------------------------------------------- End Marsbugs Volume 7, Number 9