MARSBUGS: The Electronic Astrobiology Newsletter Volume 9, Number 17, 29 April 2002. 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. Information concerning the scope of this newsletter, subscription formats and availability of back-issues is available from the Marsbugs web page at http://welcome.to/marsbugs or http://www.lyon.edu/webdata/users/dthomas/marsbugs/marsbugs.html. _____________________________________________________________________ CONTENTS 1) UW STUDENTS PICKED TO HELP SEND MICE INTO SPACE By Rob Harrill 2) NEW EVIDENCE FOR ORGANIC COMPOUNDS IN DEEP SPACE From SpaceDaily 3) NASA AMES ASTROBIOLOGY EXPLORER TELESCOPE CHOSEN FOR FEASIBILITY STUDY NASA/ARC relase 02-46AR 4) FABRICATION OF EUROMARS BEGINS! Mars Society release 5) CHINA HATCHES ROCKET-BORNE EGGS INTO "SPACE CHICKENS" From SpaceDaily 6) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 7) CASSINI SIGNIFICANT EVENTS NASA/JPL release 8) THE NEXT FOUR WEEKS ON GALILEO NASA/JPL release 9) MARS ODYSSEY THEMIS IMAGES NASA/JPL/Arizona State University release 10) STARDUST STATUS REPORT NASA/JPL release _____________________________________________________________________ UW STUDENTS PICKED TO HELP SEND MICE INTO SPACE By Rob Harrill University of Washington release 17 April 2002 Students from the University of Washington have won a place on a team that plans to launch mice into space, seeking answers to the little- explored question of how Martian gravity affects mammals. The UW aeronautics and astronautics students will work with fellow students from the Massachusetts Institute of Technology and the University of Queensland in Australia to build the Translife Mars Gravity Biosatellite, a spacecraft capable of carrying the mice in orbit for nearly two months under simulated Martian gravity, then landing them safely back on Earth. The mission will feature several firsts, including the first birth of mammals in space. The Mars Society, a private organization that promotes the exploration and settlement of Mars, officially announced the team today, after having hosted a competition to determine the best concept for a spacecraft to undertake the endeavor. The UW contingent will build the biosatellite's carrier module, which will provide the power, propulsion, navigation, artificial gravity and other elements necessary to sustain the entire spacecraft during the mission. MIT and Queensland will be responsible for the re-entry module, which will house the mice. "From a student perspective, this sort of project is priceless," said Adam Bruckner, chairman of the UW Department of Aeronautics and Astronautics. The UW team worked for three months in a senior-level space systems design course under the direction of lecturer Bogdan Udrea to come up with a winning design. "It's one thing to learn about spacecraft from a book, but it's a completely different experience to design and build something that will actually go into space." It's not the first such undertaking for the department, Bruckner added. "Our students have had previous experience with the Dawgstar project," a small self-propelled nanosatellite scheduled to be launched from the Space Shuttle next year, he said. The Translife Mission will seek answers to a critical question involving the human exploration of Mars: can people live, function and develop normally in Martian gravity? Mars' gravity is three- eighths that of Earth's, and scientists don't know whether that is sufficient to avoid serious health effects, such as bone loss and muscle deterioration, that astronauts have encountered while living in the weightless environments of space stations. The Mars Gravity Biosatellite's crew will boldly go where no mice have gone before: during the 50-day flight, some crewmembers will give birth--the first mammalian births in space. The offspring will develop in simulated Martian gravity for the duration of the mission. At the end of the flight, the spacecraft will re-enter the atmosphere and return the mice safely to Earth for further study. Other mission firsts include: The first private launch and recovery of a spacecraft carrying mammals, the first launch and recovery by students of a satellite, and the first study of living organisms in a partial-gravity environment. While circling the Earth, the spacecraft's carrier module will spin, using centrifugal force to simulate gravity on Mars. The carrier module must also establish and maintain a precise orbit, provide power and support to sustain the mouse habitat and communicate with mission control, all complex challenges that the UW students are addressing. Project participants are evaluating options for a launch vehicle. Students are also seeking both private and public funding to finance the cost of the mission, which, with trials and testing, could total as much as $10 million. An anonymous donor has pledged to match contributions at 50 percent. Contacts: Rob Harrill University of Washington Seattle, Washington Phone: 206-543-2580 E-mail: rharrill@u.washington.edu Adam Bruckner Phone: 206-543-6143 E-mail: bruckner@aa.washington.edu Bogdan Udrea Phone: 206 543-4719 E-mail: udrea@aa.washington.edu Brian Bloudek Phone: 206-355-0783 E-mail: bloudek@aa.washington.edu Bill Litant Massachusetts Institute of Technology Phone: 617-253-1564 E-mail: wlitant@mit.edu Jan King University of Queensland Phone: +61 7 3365 1120 E-mail: j.king@uq.edu.au For more information on the project, check the Web at http://www.marsgravity.org/. More information about the Mars Society's Translife Initiative is available at http://www.marssociety.org/translife/. IMAGE CAPTION: [http://www.washington.edu/newsroom/news/images/micesatlr.jpg] The Translife Mars Gravity Biosatellite, as shown in this artist's conception, will carry mice into space under simulated Martian gravity to study how partial-gravity environments affect mammals. Scientists say such information is necessary to prepare for the human exploration of Mars. _____________________________________________________________________ NEW EVIDENCE FOR ORGANIC COMPOUNDS IN DEEP SPACE From SpaceDaily 22 April 2002 The mysterious spectral bands in the infrared of interstellar gas clouds in deep space originate from organic compounds. Research by the Nijmegen physicist Hans Piest confirms this. He has provided new experimental evidence for this almost 30-year-old problem in astronomy. Each molecule has specific wavelengths at which it can either absorb or emit light. This forms the fingerprint of a substance. With this fingerprint, astronomers can demonstrate the presence of a substance in a distant star or cloud. In a wide range of lines of sight, in the almost empty interstellar space, bright infrared emission is observed, the spectrum of which has become commonly known as the "Unidentified Infrared Bands". The most widely accepted hypothesis is that complex organic compounds cause the bands. Put more precisely it is thought to be a mixture of various polyaromatic hydrocarbons, each containing about fifty carbon atoms. Nobody had yet succeeded in measuring the spectrum of these complex molecules under conditions comparable to the cold gas situation in deep space where these spectra are found... ...Hans Piest found a way of measuring the spectrum indirectly. For this he made use of a special laser from the Institute for Plasma Physics (FOM) in Rijnhuizen. Get the full story at http://www.spacedaily.com/news/stellar- chemistry-02a.html. _____________________________________________________________________ NASA AMES ASTROBIOLOGY EXPLORER TELESCOPE CHOSEN FOR FEASIBILITY STUDY NASA/ARC relase 02-46AR 23 April 2002 A mission proposal from NASA Ames Research Center to measure the pre- biological chemical building blocks of life in deep space has been selected as a next-mission candidate under NASA'S Explorer Program--a roster of low-cost, focused next-generation spacecraft. The Astrobiology Explorer, known as ABE, has a hydrogen ice-chilled telescope that will search for interstellar organic compounds, such as carbon-containing ices, dust and molecules, throughout the universe. If chosen, the $180 million mission will fly as early as 2007. The ABE spacecraft will be put into an orbit around the sun, gradually drifting 14 million miles away from Earth during its 18- month mission lifetime. "This is the next step," said Ames principal investigator Dr. Scott Sandford. "We need an infrared telescope in space because we can't measure signals at these wavelengths using even the largest ground- based telescopes." The ABE telescope must be chilled and put into space in order to detect the very weak signals it seeks, which would otherwise be lost in the flood of infrared radiation produced by the Earth's own warmth. "It's as if we were trying to detect the light from a candle that is held in front of a searchlight," Sandford added. "Chilling the telescope and putting it in space is like turning off the searchlight." The telescope and its instruments will measure light at wavelengths in the infrared spectrum, which are wavelengths about 10 times longer than what the human eye can see, and that we experience as heat. ABE's primary goal is to understand the molecular chemistry that occurs in space, and to identify the molecules that are found in different space environments. ABE observations also will provide new insights into the physical nature of young stars, comets, galaxies and other objects in the universe. ABE's science team will look for the spectral signatures of complex organic molecules and the simpler molecules from which they are formed, such as water, ammonia and methanol. In recent laboratory simulations of cold, space-like conditions, Sandford and other Ames scientists found that organic molecules, including those necessary for life, such as ketones and complex hydrocarbons, can be produced in deep interstellar space. One advantage ABE will have over previous infrared space observatories, the researchers say, is its large, sensitive infrared light detectors. These Ames-developed devices will allow researchers to collect millions of pixels of information at once, much more than previously. "ABE will have three instruments called spectrometers, which will slice up the light collected by the telescope," said Ames' Dr. Tom Greene, ABE's mission architect. "The detectors in these spectrometers will sense the unique infrared signatures of many atoms, molecules and dust grains." Sylvia Cox and other Ames personnel will serve as members of the ABE team. The team will partner with Ball Aerospace and Technologies Corp., which will build the instrument and spacecraft. A group of 18 scientists from Ames, as well as other U.S. and international institutes, also will work on ABE. NASA will select two of the Explorer mission proposals by early 2003 for full development as Medium-class Explorer flights. The Explorer program is managed by NASA's Goddard Space Flight Center, Greenbelt, MD, for the Office of Space Science, Washington, DC. More information about ABE is available at http://www.astrochem.org/abe.html. More information about the Explorer program and the other selected proposals is available at http://fpd.gsfc.nasa.gov/410/index.html. Contact: Kathleen Burton NASA Ames Research Center, Moffett Field, CA Phone: 650-604-1731 or 604-9000 E-mail: kburton@mail.arc.nasa.gov An additional article on this subject is available at http://www.spacedaily.com/news/telescopes-02e.html. _____________________________________________________________________ FABRICATION OF EUROMARS BEGINS! Mars Society release 24 April 2002 The fabrication of the European Mars Analog Research Station (EuroMARS) has begun in earnest. The work, led by Project Architect Frank Schubert and funded by Starchaser Industries and the United Association of Plumbers and Pipefitters (UA), is being done on the premises of the Rio Grande company in Denver, Colorado. Fabrication is expected to be complete by the end of May 2002, after which the station will be put on display in a major public exhibit in the United States. It will then be shipped to Europe for deployment in the field in the Spring of 2003. Several sites are being considered for the EuroMARS, with Iceland as the current leading candidate. Deployed there, the EuroMARS will provide an opportunity for European and other researchers to engage in a substantial program of Mars exploration operations research, complementing the work the Mars Society will continue to do at its Flashline Mars Arctic Research Station on Devon Island and the Mars Desert Research Station in southern Utah. The Mars Society plans to follow the building of the EuroMARS with a fourth station located in the Australian desert, which is the site of the discovery of the oldest known fossils of microscopic life on Earth. A photograph of the EuroMARS in the process of fabrication can be viewed on the Mars Society web site at www.marssociety.org. More photos will be posted as construction proceeds. To find out more about the Mars Society, visit our web site at www.marssociety.org or contact info@marssociety.org. _____________________________________________________________________ CHINA HATCHES ROCKET-BORNE EGGS INTO "SPACE CHICKENS" From SpaceDaily 24 April 2002 Three chicken eggs that travelled 108 times around the earth aboard China's Shenzhou III space capsule have hatched to become the country's first ever "space chickens", state press said Wednesday. The chickens, two males and one female, hatched Tuesday from among nine eggs that made the seven-day space flight that ended on April 1, the Beijing Daily reported. Get the full story at http://spacedaily.com/news/020424081403.02gvyhpd.html. _____________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.h tml 29 April 2002 Human space exploration and microgravity effects articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s3.html Agence France-Presse, 2002. China hatches rocket-borne eggs into "space chickens". SpaceDaily. Evolutionary biology and chemistry articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s5.html SpaceDaily, 2002. New evidence for organic compounds in deep space. SpaceDaily. SpaceDaily, 2002. Ames astrobiology explorer scope chosen for feasibility study. SpaceDaily. _____________________________________________________________________ CASSINI SIGNIFICANT EVENTS NASA/JPL release 18-24 April 2002 The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Tuesday, April 23. The Cassini spacecraft is in an excellent state of health and is operating normally. Information on the present position and speed of the Cassini spacecraft may be found on the "Present Position" web page located at http://saturn.jpl.nasa.gov/cassini/english/where/. Magnetospheric and Plasma Science data collection has resumed following last week's Probe checkout. Quiet cruise activities continued with minimal onboard activities being performed. The Satellite Orbiter Science Team (SOST) and Project Science Group-- Satellite Surfaces Working Group met to make a decision on the Enceladus flybys in Orbits 3, 4, and 11. A plan was developed and SOST will request a change to the flyby altitude for the non-targeted Enceladus flyby on Orbit 3 with the understanding that this may be very difficult for the Project to accommodate. A Planetary Data System (PDS) archive workshop was held this week at the Huygens Science Working Team meeting in Paris, France. The meeting was attended by Huygens team Principal and Co-Investigators, Interdisciplinary Scientists, and Cassini and PDS archive representatives. The workshop was an introduction to the work involved in archiving with the PDS, and contained examples of Cassini orbiter work and demonstrations of Galileo and Pathfinder imaging CDs. Huygens team members responded positively to the presentation of proposed roles and responsibilities, which included help in generating instrument description files based on the European Space Agency SP-1177 document. Additional progress was made in archiving for the Visual and Infrared Mapping Spectrometer (VIMS), Ultraviolet Imaging Spectrograph (UVIS), and Cosmic Dust Analyzer (CDA). JPL Imaging node representatives traveled to Tucson to meet with the VIMS team to discuss archiving. Samples of UVIS data products were sent to the PDS Atmospheres node for review, and the iterative process for reviewing label contents and file structures has begun. Small Bodies PDS Node and CDA personnel met to further define data products. CDA has identified EKernel and Ckernel data to archive. Instrument Operations reported that the Events Kernel System Design document D-22965 was distributed last week. In addition, unit and system testing of E-Kernel software components has begun. Testing is going well, and development is on schedule. Uplink Office (ULO) personnel presented a tutorial on the use of the Solid State Recorder Management Tool to users from the Spacecraft Operations Office, Mission Planning, and Science Planning. Work on Mission Sequence Subsystem (MSS) D8.0.1 began this week. This patch delivery is intended to release the Science Opportunity Analyzer and SSR Management tools, synchronize the versions of the Inertial Vector Propagator/Kinematic Prediction Tool in use by the Pointing Design Tool (PDT) and ACS operations, and address miscellaneous clean-up of items in PDT, APGEN, SEG and SEQGEN that are needed for the Science Operations Plan development process. ULO chaired a meeting where plans for the development of the Automated Sequence Process (ASP) were discussed and agreed upon. A preliminary version of ASP is scheduled for delivery in late September '02. The software will perform basic processing of a command request, but not include automated notification. Prototype development work is underway, with preliminary requirements to be finished and final coding started in late April '02. ULO began work on a presentation outlining a long-term plan for the Cassini Information Management System (CIMS) through the end of its development. The purpose is to inform users of the functionality available at critical milestones, and provide a forum to discuss processes currently under construction that CIMS will be required to support. 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. _____________________________________________________________________ THE NEXT FOUR WEEKS ON GALILEO NASA/JPL release 22 April - 19 May 2002 The pace with which Galileo is receding from Jupiter is slowing now, as the spacecraft stretches out towards its most distant point in the orbit, which it will reach in early June. During these four weeks, the distance from the spacecraft to Jupiter increases from 320 to 342 Jupiter radii (22.9 million to 24.5 million kilometers or 14.2 million to 15.2 million miles). Diagnostic work continues as we attempt to resolve an anomaly seen in the on-board tape recorder during the routine maintenance activity on April 12. Since the playback of all of the data from the January Io flyby is now complete, we can keep the recorder in an inactive state without losing science data. A deliberate approach to understanding and solving the problem is called for. The important point is to have a fully functional tape recorder in time to support the November flyby of the small inner moon, Amalthea. Routine hardware maintenance activities for the spacecraft this month include one exercise of the propulsion thruster system on May 10. Also included is another exercise of the tape recorder on May 12. If the ongoing diagnostic work indicates that the exercise is unadvisable, that activity can be cancelled pending resolution of the problem. On Saturday, May 4, the spacecraft will turn in place by just over 4 degrees to keep the communications antenna pointed towards Earth. With the spacecraft well outside the magnetosphere of Jupiter on the sunward side of the planet, continuous data collection by the Magnetometer, the Dust Detector, and the Extreme Ultraviolet Spectrometer instruments provides scientists with information about the interplanetary medium. 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 ODYSSEY THEMIS IMAGES NASA/JPL/Arizona State University release 22-26 April 2002 * Alba Patera (Released 22 April 2002) http://themis.la.asu.edu/zoom-20020422a.html * Eastern Floor of Holden Crater (Released 15 April 2002) http://themis.la.asu.edu/zoom-200204.html * Cerberus (Released 24 April 2002) http://themis.la.asu.edu/zoom-20020424a.html * Knobby terrain in Northern Arabia Terra (Released 25 April 2002) http://themis.la.asu.edu/zoom-20020425a.html * Noctis Labyrinthus (Released 26 April 2002) http://themis.la.asu.edu/zoom-20020426a.html All of the THEMIS images are archived at http://themis.la.asu.edu/latest.html. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. Dr. Philip Christensen leads the THEMIS investigation at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. Mars 2001 Odyssey Thermal Emission Imaging System (THEMIS) Alba Patera (Released 22 April 2002) http://themis.la.asu.edu/zoom-20020422a.html The science This image, centered near 46.5 N and 119.3 W (240.7 E), is on the northwestern flank of a large, broad shield volcano called Alba Patera. This region of Mars has a number of unique valley features that at first glance look dendritic much in the same pattern that rivers and tributaries form on Earth. A closer look reveals that the valleys are quite discontinuous and must form through a different process than surface runoff of liquid water that is common on Earth. A number of processes might have taken place at some point in the Martian past to form these features. Some of the broad valley features bear some resemblance to karst topography, where material is removed underground by melting or dissolving in groundwater causing the collapse of the surface above it. The long narrow valleys resemble surfaces where groundwater sapping has occurred. Sapping happens when groundwater reaches the surface and causes headward erosion, forming long valleys with fewer tributaries than is seen with valleys formed by surface water runoff. The volcano itself might have been a source of heat and energy, which played a role in producing surfaces that indicate an active groundwater system. The story Fluid, oozing lava poured somewhat lazily over this area long ago. It happened perhaps thousands of times, over hundreds of thousands of Martian years, creating the nearly smooth, plaster-of-Paris-looking terrain seen today. (Small craters also dent the area, though they may deceive you and look like raised bumps instead. That's just a trick of the eye and the lighting--tilt your head to your left shoulder, and you should see the craters pit the surface as expected.) The lava flows came from a Martian "shield" volcano named Alba Patera. Shield volcanoes get their name from their appearance: from above, they look like large battle shields lying face up to the sky as if a giant, geological warrior had lain them down. Perhaps one did--if you think of a volcano as a "geologic warrior," that is. These volcanoes aren't too fierce, however. Because of the gentle layering of lava over time, they don't stand tall and angry against the horizon, but instead have relatively gentle slopes and are spread out over large areas. (On Earth, the Hawaiian Islands are examples of shield volcanoes, but you can't see much of their expanse, since they rise almost three miles from the ocean floor before popping out above the water's surface.) What's most interesting in this picture are all of the branching features that lightly texture the terrain. The patterns may look like those caused by rivers here on Earth, but geologists say that no surface streams on Mars were responsible. That's no disappointment, however, to those who'd like to find water on Mars, because there are still intriguing water-related possibilities here. Some of the broad valley features in this image look like karsts, a terrain found on Earth in Karst, a limestone area on the Adriatic Sea in modern-day Croatia, and in other world regions including France, China, the American Midwest, Kentucky, and Florida. Karst terrain on Earth is barren land with all kinds of caves, sinkholes, and underground rivers that excavate the subsurface, causing the surface above it to collapse. So, perhaps it's like that in this region on Mars as well. Future Martian spelunkers should be excited, because most caves on Earth are in karst areas. Other suggestions of water here are some long, narrow valleys that resemble Earth surfaces where groundwater has sapped away the terrain. Sapping occurs when groundwater erodes slopes, creating valleys. Water action can be concentrated at valley heads, leading to what is called their "headward growth." That may be what has happened here on Alba Patera as well. All of these features suggest the action of liquid water, but Mars is so cold, you might wonder if any water would have to be as frozen as the world it is on. Well... that depends! Remember that this area is part of a volcano, and volcanoes can put out enough heat and energy below the surface to keep water warm enough to flow--if not now, then at least in the past when the volcano was more active. Mars 2001 Odyssey Thermal Emission Imaging System (THEMIS) A Cloudy Day on Mars (Released 23 April 2002) http://themis.la.asu.edu/zoom-20020423a.html The science This image, centered near 49.7 N and 43.0 W (317.0 E), displays splotchy water ice clouds that obscure the surface. Most of Mars was in a relatively clear period when this image was acquired, which is why many of the other THEMIS images acquired during the same period do not have obvious signs of atmospheric dust or water ice clouds. This image is far enough north to catch the edge of the north polar hood that develops during the northern winter. This is a cap of water ice and CO2 ice clouds that form over the Martian north pole. Mars has a number of interesting atmospheric phenomena that THEMIS will be able to view in addition to water ice clouds, including dust devils, dust storms, and tracking atmospheric temperatures with the infrared camera. The story Anyone who's been on an airplane in a storm knows how clouds on Earth can block the view below. The thin water ice clouds on Mars might make things slightly blurry, but at least we can still see the surface. While the surface features may not be as clear in this image, it's actually kind of fascinating to see clouds at work, because we can get a sense of how the north pole on Mars influences the weather and the climate. In this image, the north pole is responsible for the presence of the clouds. Made of water ice and carbon dioxide, these clouds "mist out" in a atmospheric "hood" that caps the surface during the northern Martian winter, hiding it from full view of eager observers here on Earth. Mars 2001 Odyssey Thermal Emission Imaging System (THEMIS) Cerberus (Released 24 April 2002) http://themis.la.asu.edu/zoom-20020424a.html The science The Cerberus feature is a relatively dark region at the southeastern edge of the huge Elysium Mons volcanic complex. It was visible to early astronomers of Mars because it was a distinctive dark spot on a large bright region of the planet. Today we recognize that the Cerberus region encompasses a range of geologic terrains from relatively young and smooth lava flows to the very rugged, ancient eroded landscape seen in this THEMIS image. The Cerberus feature has also proven to be ephemeral. Compared to just 20 years ago when the Viking orbiter instruments viewed the planet, the Cerberus feature has shrunk down from its original length of roughly 1000 kilometers to just a few isolated dark splotches of just a few 100 kilometers. This is testament to the active eolian environment on Mars where global dust storms can lift and then later deposit significant amounts of dust, brightening formerly dark surfaces. The THEMIS image occurs in a portion of Cerberus that remains relatively dark and dust-free although in the bottommost portion of the image are faint, criss-crossing lines that likely are dust devil tracks. The abundant dune-like features covering many of the low, smooth surfaces are similar to those found in many places across the planet. They are evidence of the interaction of wind and movable particles at the surface but not necessarily in today's environment. In many other places on Mars they are clearly inactive; relicts of a different climate. The story Hellhound of Greek mythology, Cerberus was the three-headed, dragon- tailed dog that stood guard at the opening to the underworld. This rough-and-tumble Mars terrain looks just as fierce and foreboding. At the edge of the huge Elysium Mons volcano complex, the Cerberus area appeared as a dark spot to early Mars astronomers in an otherwise bright region of the planet. If this dark area seems somewhat hellish to your imagination too, you'll be glad to know that the Martian wind has been brightening up the area. Just twenty years ago, the Viking orbiters reached Mars for the first long-term studies of Mars up close. The Cerberus feature was then almost 600 miles long, but has now been vanquished down to few small splotches about 60 miles long. Call that a triumph of lightness upon the surface, but don't think that the force bringing back the light is gentle and kind. The Martian wind can kick up a fierce global dust storm that lifts up the bright Martian dust into the air and then blankets the surface with the brighter material as it settles down again. The ancient, eroded terrain in this image is still rather dark and dust free, so you might say it's one area where a mythical Cerberus still guards its shrinking territory. The wind teases it, however, by kicking up small, whirling dust devils that leave long, dark, scratchy tracks upon the land. Fields of dunes wrinkle the surface in places as well, but they may be permanently cemented upon the surface now, no longer able to blow and drift as they did in their younger days. Mars 2001 Odyssey Thermal Emission Imaging System (THEMIS) Knobby terrain in Northern Arabia Terra (Released 25 April 2002) http://themis.la.asu.edu/zoom-20020425a.html The science This THEMIS visible image shows a region in northern Arabia Terra near 44 N, 322 W (38 E). Knobby or "scabby" plains units that mantle and modify a pre-existing cratered surface dominate the unusual landscape in this region. Several large (5-8 km diameter) impact craters seen in the upper left of the image have been extensively modified since their initial formation. The rims of these craters can still be seen, but a layer of material has buried the ejecta deposits and the surrounding plains. This mantling layer has itself been modified to produce a pitted, knobby surface. Circular depressions of all sizes, presumably the remnants of impact craters, are filled with smooth deposits. In some places this smooth material has covered large regions; an example can be seen in the lower right portion of this image. In many cases the impact craters have been extensively modified prior to their being filled. This modification indicates an erosion process that has removed material from the walls to produce shapes that vary from circular with crisp rims, to circular with no rims, to oblong and elliptical forms, and finally to irregular shapes whose initial circular outline can barely be detected. The slope of the channel at the top of the image has an unusual deposit of material that occurs preferentially on the cold, north-facing slope. Similar deposits are seen frequently at mid- northern and southern latitudes on Mars, and have a characteristic, rounded boundary that typically occurs at approximately the same distance below the ridge crest. It has been suggested that these deposits once draped the entire surface and have since been removed from all but the cold north-facing slopes. The presence and removal of ground ice may play an important role in the formation of this layer, as well as the knobby terrain and unusual features seen in this image. This image is the 22nd image in a series of daily images released by the THEMIS Team. The story There's no way that these impact craters are in their original, pristine shape. Check out their strange deformities and register the geological gross-out factor of all the "scabs" upon the land. You can still see the rims of craters in this savaged land, but an aggressive layer of material once spread out across it, burying the ejected material and all the surrounding plains. This cloaking layer didn't win the battle of dominance, however, as it too has been battered over time, producing the pitted, knobby surface seen today. Only a few smooth deposits in the area are spared from the scabby, scarred look of the long barraged (see lower right portion of the image). Circular depressions, the probable remains of impact craters, are filled with this smooth material. Some were already well eroded prior to being filled, with material removed from their walls used to sculpt the varying shapes. The dark, shadowed channel at the top of this image has an unusual deposit of material on its cold, north-facing slope. Since this material is found elsewhere on Mars, at approximately the same distance below the ridge crest, could it have draped the entire surface of Mars long ago? Why has it been lost from all but the northern slopes? Could ice in the ground play a role in forming and preserving this layer? And did it craft the knobby terrain and other strange features in this area? These are the kinds of questions geologists are asking. As this image proves, the more you discover, the more questions you have. That's what keeps exploration so exciting. Mars 2001 Odyssey Thermal Emission Imaging System (THEMIS) Noctis Labyrinthus (Released 26 April 2002 http://themis.la.asu.edu/zoom-20020426a.html The science This image shows a portion of Noctis Labyrinthus, a large valley system at the western end of the Valles Marineris canyon system. Noctis Labyrinthus is notable for its unusual pattern of intersecting valleys, which give the region a maze-like appearance when viewed from above. The walls of these valleys are very high (~5 km) and quite steep, with slopes approaching 35°. Dust covers most of this region, leading to its rather uniform appearance. At the tops of the ridgelines, small dark streaks can be observed trailing downslope; these streaks suggest that the sediments covering this area occasionally become unstable and slide. Ridges of resistant material also can be observed in the highest terrains. In the lower half of the image, a small linear feature appears to cut across the generally NE/SW-trending slopes. This feature is not continuous, indicating that geologic activity has disrupted it since its formation. The northeastern termination of the feature is on a mesa, where it is joined by a less pronounced but similar feature that trends NE/SW. These small features may have originated in several ways: they may be ridges formed by compression, they may be small fault scarps, or they may represent the edges of ancient lava flows that have been disrupted by the formation of the valley system. The story The smoothly sculpted surface in this close-up image belies the bizarre and twisted Martian landscape of which it is a part (seen at a larger scale in the context image). Labyrinths have long been in the human imagination, and it's no wonder that this area conjured up for early viewers all of the legends of antiquity, of a land where a Minotaur hides and a conquering hero needs a spool of thread to guide him through an inner maze. As writer Jorge Luis Borges might say, this Martian region is a real- life example of a geological "garden of forking paths," a dangerous- seeming place where "the paths of the labyrinth converge." Noctis Labyrinthus, as it's called, is an area of sprawling, intersecting valleys on Mars, and like a Borgesian story, holds within it elusive truths about the passage of time and a multi-layered landscape of possibility. At the western end of Valles Marineris, the largest canyon in the solar system, Noctis Labyrinthus holds the secrets to long-term geologic change in the area. It would be easy to lose oneself on a wandering path through the terrain. The walls of this Martian valley maze rise swiftly and steeply to their three-mile heights, and a layer of long-settled dust deceives the eye, making everything look the same. (Well, almost everything. Look closely, and some of realities of the labyrinth are revealed.) From the tops of ridgelines, small, dark streaks trail down the sides, leaving scant but clear evidence of the sediment that once slid downslope. A long, jagged slash cuts the land (lower third of the image), but is broken in the middle by some unknown geologic force that moved the land through it, "erasing it" sometime later. And then the mysteries: what are the features seen in this image and how did they come to be? Ridges formed by compression? Small cliff lines ("scarps") caused by faults? Or perhaps the edges of ancient lava flows, disrupted by the formation of the valley system? Whatever they are, they represent well the strange and misleading passageways of legend and lore, where the way to the truth of the matter and back again is hard to find. _____________________________________________________________________ STARDUST STATUS REPORT NASA/JPL release 26 April 2002 This past week, there were no Deep Space Network (DSN) tracking passes with the Stardust spacecraft. The Comet Wild 2 Encounter Fault Tree kickoff meeting was held to determine potential faults that would prevent a successful encounter. During the next two months these faults will be analyzed for creditability and criticality, and the team will assess how to mitigate their impact. The Stardust Project, Mission and Flight System Managers participated in the 2-day NASA Discovery Program Workshop. A wide range of issues were covered including lessons learned shared with projects preparing to launch, ITAR, the phasing out of Delta II launch vehicles, project accounting and reporting practices and open discussions between the Program and Project Offices. The Stardust Outreach team provided Stardust Project status and led training activities for NASA Solar System Educators in the area of interactions with the news media. 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 9, Number 17.