MARSBUGS: The Electronic Astrobiology Newsletter Volume 6, Number 34, 22 October 1999. Editors: Dr. David J. Thomas, Biology and Chemistry Division, Lyon College, Batesville, AR 72503-2317, USA. Dthomas@lyon.edu or marsbugs@aol.com 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 out of 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) NASA UNVEILS NEW, MOST ACCURATE MAP OF ANTARCTIC CONTINENT NASA release 99-122 2) MARS CLIMATE ORBITER INVESTIGATION BOARD ISSUES FIRST STATEMENT NASA release 99-123 3) LA NIÑA CONDITIONS LIKELY TO PREVAIL THIS FALL AND WINTER JPL image advisory 4) ESA PARABOLIC FLIGHTS TO PREPARE FOR THE INTERNATIONAL SPACE STATION ESA release 42-99 5) THIS WEEK ON GALILEO JPL release 6) MARS POLAR LANDER MISSION STATUS JPL release 7) NEW MARS GLOBAL SURVEYOR IMAGE By Ron Baalke ---------------------------------------------------------------- NASA UNVEILS NEW, MOST ACCURATE MAP OF ANTARCTIC CONTINENT NASA release 99-122 18 October 1999 For 18 days during the Southern Hemisphere spring of 1997, a NASA-launched Canadian satellite called RADARSAT collected pieces of a puzzle that will help scientists study the most remote and inaccessible part of the Earth--Antarctica. Scientists now have the puzzle pieces put together, forming the first high-resolution radar map of the mysterious frozen continent. With detail to the point of picking out a research bungalow on an iceberg, the new map has both answered scientists' questions about the icy continent, and left them scratching their heads about what to make of strange and fascinating features never seen before. "This map is truly a new window on the Antarctic continent, providing new beginnings in our Earth science studies there," said Dr. Ghassem Asrar, Associate Administrator for Earth Science, NASA Headquarters, Washington, DC. The new map was produced as part of NASA's Antarctic Mapping Project. The most amazing features scientists now see are twisted patterns of ice draining from the ice sheet into the ocean. "We were surprised to see a complex network of ice streams reaching deep into the heart of East Antarctica," said Kenneth Jezek, a glaciologist from the Byrd Polar Research Center at Ohio State University. Ice streams are vast rivers of ice that flow up to 100 times faster than the ice they channel through, with speeds up to 3000 feet per year. "There are some extraordinary ice streams in East Antarctica that extend almost 500 miles--nearly the distance along the Mississippi River from New Orleans to Cairo, Illinois," Jezek said. Ice streams form the most energetic parts of the Antarctic ice sheet, and scientists believe that they are quite susceptible to environmental change. Ice streams also transport most of the snow that falls on the continent's interior and dump it into the ocean. "We've recently used RADARSAT and other satellite data to estimate that one ice stream system sends over 19 cubic miles of ice to the sea every year--an amount equivalent to burying Washington, DC, in 1700 feet of ice every 12 months," said Jezek. Antarctica looks pure, white and mostly featureless to the low- resolution satellites that previously mapped the frozen landscape. With the new RADARSAT map, however, the continent comes alive. Blocks of broken sea ice line the coast and sedimentary rock protrudes from the rocky walls of Antarctica's Dry Valleys. The vast, perplexing Antarctic Ice Sheet flows and twists into the sea, volcanoes poke through the ice sheet and ice streams flow like rivers into the Southern Ocean. Even the tracks of wayward snow tractors on their way to inland stations are visible. "We have a new view of the entire southern continent. It shows us something about an extraordinary part of our world and how humans may be changing it--on both local and global scales," said Jezek. Jezek and his colleagues have been working to complete the enormous map since the Canadian Space Agency began the mission with a complex in-orbit rotation of the satellite. Researchers chose RADARSAT because its radar collects data day and night, through cloudy weather or clear. Such capability enabled the mapping to be completed in just 18 days, compared to the last satellite map of Antarctica which required images from five different satellites spanning a 13-year period from 1980 to 1994. Even at that time, parts of the continent remained obscured by cloud cover. The map also depends on accurate ground measurements by scientists from many of the nations that study Antarctica. "The entire mission was conducted in a true spirit of international cooperation, and that is why it succeeded," said Verne Kaupp, NASA's Alaska SAR Facility Director and Chief Scientist. RADARSAT-1 is owned and operated by the Canadian Space Agency (CSA). Its data is distributed and marketed by RADARSAT International, a Canadian company licensed by the CSA. "We at the Canadian Space Agency are very pleased to make this significant contribution to the international science community," said Dr. Rolf Mamem, Director General, CSA Space Operations Branch. "We are looking forward to the exploitation of these data for the benefit of all." The Antarctic Mapping Mission is only one part of NASA's study of the frozen continent. NASA's study of the Antarctic is part of the Agency's Earth Science Enterprise, a dedicated effort to better understand how natural and human-induced changes affect our Earth's environmental system. RADARSAT images of Antarctica are available on the internet at http://svs.gsfc.nasa.gov/imagewall/antarctica.html. ---------------------------------------------------------------- MARS CLIMATE ORBITER INVESTIGATION BOARD ISSUES FIRST STATEMENT NASA release 99-123 20 October 1999 Members of the NASA review board investigating the loss of Mars Climate Orbiter began meeting this week at the Jet Propulsion Laboratory (JPL), Pasadena, CA, and today issued the following statement. "We want to understand what was the root cause of this failure," said board chairman Art Stephenson, director of NASA's Marshall Space Flight Center, Huntsville, AL. "Based on that understanding, we will recommend actions the JPL/Lockheed Martin team might take regarding the Mars Polar Lander spacecraft, scheduled to land on Mars on December 3." During the first two days of discussions, the board has heard detailed reports from the mission team, including the spacecraft team and the navigation team. The board was also briefed by a JPL internal review board that was formed to find the technical cause of the loss of the orbiter as it attempted to enter orbit around Mars on September 23. The board will deliver an initial report to NASA in early November addressing recommendations related to Mars Polar Lander. Its final report, due February 1, 2000, will address root cause, lessons learned and recommendations for NASA process improvement to reduce the probability of similar incidents in the future. Mars Climate Orbiter was one of a series of missions in a long- term program of Mars exploration managed by JPL for NASA's Office of Space Science, Washington, DC. JPL's industrial partner is Lockheed Martin Astronautics, Denver, CO. JPL is a division of the California Institute of Technology, Pasadena, CA. ---------------------------------------------------------------- LA NIÑA CONDITIONS LIKELY TO PREVAIL THIS FALL AND WINTER JPL image advisory 20 October 1999 A repeat of last year's mild La Niña conditions--with a stormy winter in the Pacific Northwest and a dry winter in the southwestern United States--will be the likely outcome of sea- surface heights observed by NASA's TOPEX/Poseidon satellite, scientists say. TOPEX/Poseidon has detected lower than normal sea-surface heights in the eastern North Pacific and unusually high sea- surface heights in the western and mid-latitude Pacific. The height of the sea surface over a given area is an indicator of ocean temperature and other factors that influence climate. The latest measurements, taken during a 10-day data cycle October 5-15, are available at http://www.jpl.nasa.gov/elnino. Sea-surface height is shown relative to normal (green) and reveals cooler water (blue and purple) measuring about 14 centimeters (6 inches) lower in the eastern North Pacific, from the Gulf of Alaska to central Alaska, and along the equator. The cooling trend sets the stage for another La Niña this winter. A mirror image of that oceanic profile prevails in the western and mid-latitude Pacific Ocean, where higher than normal sea-surface heights (red and white) are currently about 20 centimeters or 8 inches. Unusually warm temperatures (shown in red and white) have persisted and topped last year's temperatures, said Dr. William Patzert, an oceanographer at NASA's Jet Propulsion Laboratory, Pasadena, CA. "These unbalanced conditions will undoubtedly exert a very strong influence on climate over North America this fall and winter," Patzert said. "Our profile of high sea-surface heights and warm temperatures in the western Pacific Ocean contrasts with low sea-surface heights and cool conditions in the eastern and equatorial Pacific. Those conditions will have a powerful impact on the weather system delivering jet streams out of the North Pacific." Conditions are ripe for a stormy, wet winter in the Pacific Northwest and a dry, relatively rainless winter in Southern California and the Southwest, the data show. "Clearly, these unusual conditions, which have persisted for 2 1/2 years, will not be returning to normal any time soon," Patzert said. "This climate imbalance is big and we're definitely going through a decade of wild climatic behavior. But when we look back at the climate record over the past century, we've seen behavior like this before." The TOPEX/Poseidon satellite's measurements have provided scientists with a detailed view of the 1997-1999 El Niño/La Niña climate pattern by measuring the changing sea-surface height with unprecedented precision. The Jet Propulsion Laboratory manages the U.S./French TOPEX/Poseidon mission for NASA's Office of Earth Sciences, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. ---------------------------------------------------------------- ESA PARABOLIC FLIGHTS TO PREPARE FOR THE INTERNATIONAL SPACE STATION ESA release 42-99 21 October 1999 On 25 October, a specially adapted Airbus A-300 will take off from Bordeaux-Mérignac airport in France on the first of a week- long (25-29 October) campaign of parabolic flights designed to carry out experiments in weightlessness and to test instruments and equipment before they embark on a real space flight. These campaigns observe how technical systems and biological, chemical and physical processes function in the absence of gravity and this one, the 27th organized by the European Space Agency (ESA), will focus mainly on how the human respiratory system works and how new materials can be produced. During a parabolic flight the aircraft performs a nose-up maneuver to put it into a steep climb. This creates a centrifugal force of 1.8 g (1.8 times the force of gravity on the ground) for about 20 seconds. Then the pilot reduces engine thrust to almost zero, injecting the aircraft into a parabola. The plane continues to climb till it reaches the apex of the parabola, then it starts descending. This condition lasts for about 25 seconds, during which the passengers and all unstrapped equipment in the cabin float in the weightlessness resulting from the free fall of the aircraft. When the angle below the horizontal reaches 45°, the pilot accelerates again and pulls up the aircraft to come back to a steady horizontal flight. These maneuvers are repeated 30 times per flight. During the weightlessness periods, the 28 scientists on this flight--from research institutes in six European countries and the U.S.*--will carry out their work: measuring blood pressure under various conditions, monitoring a newly developed instrument or heating metals in a purpose-built furnace, in order to confirm a hypothesis, test instruments or replicate results obtained during an earlier space flight. The 26 previous campaigns that ESA has conducted since 1984 have produced a total of 2650 parabolas and almost 15 hours of weightlessness, the equivalent of flying around the Earth (in low Earth orbit) nearly 10 times. A total of 360 experiments have been carried out. With Europe and its international partners now building the International Space Station, where research will be carried on for the next 15 years, parabolic flights are crucial to the preparation of experiments, equipment and astronauts and allow scientists to have their experiments tested before they are actually flown on a space mission. Over the coming four years, ESA will run two parabolic campaigns a year. Scientists are regularly invited to submit experiment proposals for review and selection by peers. Scientists whose experiments are selected have the possibility to participate in an ESA parabolic flight campaign. In each of its future campaigns, ESA will also include experiments proposed by students to encourage the scientists of tomorrow to learn all about experimentation in weightlessness and the extensive research opportunities the International Space Station is going to offer. Further information on ESA parabolic flights can be found at ESA's special parabolic flight internet pages at http://www.estec.esa.int/spaceflight/parabolic. You may also contact: Vladimir Pletser ESA/ESTEC, Microgravity Payloads Division Directorate of Manned Spaceflight and Microgravity Tel: + 31 71 565 33 16 Fax: +31 71 565 3141 Franco Bonacina ESA Public Relations Tel + 33 1 5369 7155 Fax. + 33 1 5369 7690 For further information on ESA visit our web site at http://www.esa.int. *Experiments and scientists involved in the 27th ESA parabolic flight campaign: 1. "Gravity and lung function, first use of ARMS in microgravity", D. Linnarsson (Karolinska Institute, Stockholm, S), M. Paiva (University of Brussels, B) and G. K. Prisk (University of California, San Diego, USA). Focuses on the quantitative relationship between lung geometry, gas diffusion and convective gas transport. 2. "Does weightlessness induce peripheral vasodilatation ?", P. Norsk and R. Videbaek (DAMEC, Copenhagen, DK). To test hypothesis on the dilatation of the heart and the peripheral vascular system that could be caused by weightlessness. Both experiments make use of ESA's "Advanced Respiratory Monitoring System" built by Innovision (DK) and Alcatel Space (CH) which is to be flown on the Shuttle in January 2001. 3. "Respiratory mechanics under 0 g", P. Vaïda (University of Bordeaux 2, F) and G. Miserocchi (University of Milan, I) to study pulmonary mechanics. 4. "Otolithic control of the cardiovascular system during parabolic flights", P. Denise, H. Normand (University of Caen, F) and P. Arbeille (University of Tours, F). To test the hypothesis that otolithic receptors, part of the inner ear balance system, affect the cardiovascular system. 5. "In vivo monitoring of the mechanical environment of fractures in microgravity", M. Hinsenkamp and F. Burny (University of Brussels, B). Will measure mechanical constraints in healing bones on subjects having recently fractured tibia. 6. "The effects of a change in gravity on the dynamics of prehension and the kinematics of the upper limb during cyclic arm movements with a hand-held load", J. L. Thonnard, N. Heglund and P. Willems (University of Louvain-La-Neuve, B). Will measure the grip force and total load force of test subjects. 7. "The effect of short-duration microgravity on leukocyte early signal transduction events and cytoskeleton dynamics", J. Hatton, J. P. Breittmayer (Hôpital Archet, Nice, F) and B. Hashemi (National Space Biomedical Research Institute, Houston, USA). Leukocytes are white blood corpuscles found in suspension in human blood plasma. This experiment will help explain the mechanisms of leukocyte sensitivity to gravity. 8. Investigations of metallic foam production under microgravity conditions", S. Odenbach (ZARM, University of Bremen, D) and J. Banhart (IFAM, Bremen, D)". Will study metallic foams, new materials with interesting properties of high firmness and low weight with potential applications in lighter car shock absorbers, for instance. 9. "Thermal analysis of pure silicon and aluminum-silicon alloys by mirror furnace experiments", H. Fredriksson (Royal Institute of Technology, Stockholm, S). Will investigate samples of pure silicon and aluminum-silicon alloys using a special furnace developed by the Swedish Space Corporation and flown several times on previous ESA campaigns. 10. "Critical velocities in open capillary flow (choking)", M. E. Dreyer, U. Rosendahl and H. J. Rath (ZARM, University of Bremen, D). This fluid physics experiment aims at determining the maximum flow rate that can be established in a capillary channel. 11. "Completion of fault arc investigations at cable bundles under weightlessness conditions", Prof. König, J. Hanson and F. Hörtz (Darmstadt University of Technology, D). This technological investigation looks at the characteristics of insulated cables after exposure to the thermal effect of different electrical power in microgravity. ---------------------------------------------------------------- THIS WEEK ON GALILEO JPL release 18-24 October, 1999 Galileo continues to process and return to Earth science information acquired during its historic flyby of Io a couple of weekends ago. The data are stored on the spacecraft's onboard tape recorder. In the process of playback, the spacecraft's main computer reads the tape, processes and packages the data and sends them to Earth to be received by NASA's Deep Space Network antennas. Galileo's playback is interrupted twice this week. On Tuesday, the spacecraft performs regular maintenance on its propulsion system. On Friday, a standard calibration is performed on the Near-Infrared Mapping Spectrometer. Flight engineers continue to investigate the computer memory anomaly that caused the spacecraft to enter into safe mode just hours prior to the Io flyby. Jupiter's intense radiation belts, through which the spacecraft flew, caused an error in the memory of Galileo's onboard computer, causing the spacecraft to enter safe mode. However, flight controllers were able to scramble and restore most functions in time for the flyby. All of the recorded science that was planned for the Io encounter was safely stored on the tape recorder except for a 5 hour Fields and Particles observation of the Io torus and some stand-alone Photopolarimeter Radiometer (PPR) observations. The Fields and Particles recording was lost as the spacecraft was in the process of being recovered from safe mode by ground controllers. The PPR observations were deleted as they would have accessed the faulty area of memory and caused the spacecraft to enter safe mode again. Investigations have now identified the affected area of memory, and have determined that it is safe to play back observations performed by the Solid-State Imaging camera (SSI). However, the affected area lies in a part of memory used to record three types of data (PPR and two types from the Near-Infrared Mapping Spectrometer). The investigation has shown that there is a single bit in memory that is permanently damaged. Efforts are now being focused on developing software changes to not use the affected bit. The Near-Infrared Mapping Spectrometer (NIMS) returns most data in the first half of the week. The second half of the week is devoted to returning observations made by the SSI. Small amounts of ride-along data recorded by the PPR during several SSI observations are also included on this week's schedule. The Fields and Particles instruments also return a small snippet of data. The data come from the instruments' 65-minute high resolution recording of the magnetospheric environment (plasma, dust, and electric and magnetic fields) surrounding Io. The data will assist scientists with studies of the Io ionosphere and its interaction with the Jovian magnetosphere. This week's NIMS observations contain information on several different regions of Io's surface. All of the observations were taken while the features were on Io's day side, allowing NIMS to provide scientists with data describing the composition of the surface. The data consist of spectral signatures of the surface, which contain information on the absorption and emission of light by the surface materials. These spectra allow scientists to identify these materials by their unique signatures. In addition, the NIMS data is expected to reveal the presence of thermal emissions due to active volcanic flows and other volcanic features. This will tell scientists which targets were actively erupting or had recently erupted at the time the observations were obtained. The first NIMS observation captures a look at Dorian Mons, a mountain-like feature whose geological structure, origin and history are presently unknown. Greenish colored deposits characterize the area. Next returned is a scan of the Amirani, Skythia, and Gish Bar regions, followed by a look at a region of Io's surface near the sun terminator (or line dividing the night from day). The region also contains the Hi'iaka caldera. In hopes of catching a volcanic plume in action, the next observation captured the Pillan hot spot while it was situated on Io's limb as seen from the spacecraft. If Pillan was active during the observation, its plume would be observed against the dark sky above the limb. In a similar observation, the NIMS also looked at the plume of the Pele volcano. The geometry of the observation was such that the plume, again, if present, will be on Io's limb, but this time with Jupiter's disk in the background. The NIMS then returns a couple of regional scans of Io's surface. The playback schedule then cycles back up to the beginning of the observation sequence, in order to return SSI observations. First, the NIMS returns two observations capturing the Loki and Pele volcanic regions while on Io's night side. Taken in darkness, the observations were designed to search for thermal emissions from the volcanic calderas. The first SSI data consist of high-resolution images of the Pele region. The images are taken with Pele in darkness in the hope of catching hot glowing lava near Pele's volcanic vent. Capturing daybreak on Io, the next observation consists of high- resolution images of the Pillan volcanic region, taken with oblique viewing geometry, but good low-sun illumination. The next series of SSI observations are taken in full sunlight. The first captures the Colchis Montes region. Next is the return of images of the Zamama volcanic vent, followed by the Prometheus volcanic vent and associated lava flows. A comparison of clear and green filter images of Prometheus are expected to reveal unresolved lava and allow scientists to determine surface temperatures. SSI then returns another set of images of Colchis Montes, with a wider, lower resolution look that should provide a context for the higher resolution images. An observation of Tohil Mons, and a return to Prometheus follow this. Tohil Mons and Colchis Montes, like Dorian Mons, are mountains, whose geological structure, origin, and history are presently unknown. The Prometheus images are in full color, and will be combined with the previous set of images to provide stereo coverage of the region. The NIMS also returns spectral scans of Prometheus at this point in the playback schedule. SSI then returns a second observation of the Zamama volcanic vent, providing coverage of a wider region, again as context for the higher resolution observations performed earlier. The next observation contains a look at Dorian Mons, which as mentioned earlier, is characterized by greenish colored deposits. Finally, SSI returns moderate resolution images of the Amirani, Skythia, and Gish Bar regions. On a final note, Monday, October 18, is Galileo's 10-year anniversary of launch. Carried into orbit by Space Shuttle Atlantis (STS-34), Galileo was propelled out of Earth orbit by an Inertial Upper Stage booster rocket. It arrived at Jupiter in December 1995. En route to Jupiter, Galileo flew past Venus once and Earth twice, using gravity assists to give the spacecraft enough energy to get to Jupiter. Galileo obtained the first close-up images of an asteroid (Gaspra). Flying by the asteroid Ida, Galileo also discovered the first known moon of an asteroid (Dactyl). Galileo gave us our only direct views of the crash of Comet Shoemaker-Levy 9 into Jupiter's atmosphere. Upon arrival, Galileo's probe penetrated Jupiter's atmosphere and returned a Jovian weather report on temperature, pressure, composition, winds and lightning. Since then, the orbiter has flown past Jupiter's Galilean moons a total of 25 times: Callisto (7), Ganymede (4), Europa (12) and Io (2). During its tour of the Jovian system, Galileo has made discoveries that include extreme high temperatures at Io's volcanoes, indications that there may be liquid water inside Europa, an internal magnetic field for Ganymede, and has even raised the possibility of liquid water inside Callisto. Since launch, the spacecraft has traveled a total of 5,539 million kilometers (3,442 million miles) and returned over 3.8 gigabits of data. For more information on the Galileo spacecraft and its mission to Jupiter, please visit the Galileo home page at http://galileo.jpl.nasa.gov or http://www.jpl.nasa.gov/galileo. ---------------------------------------------------------------- MARS POLAR LANDER MISSION STATUS JPL release 20 October 1999 Flight controllers for NASA's Mars Polar Lander have decided to postpone the next thruster firing used to fine-tune the spacecraft's flight path until October 30. This delay allows mission engineers to continue their evaluation of all spacecraft systems and operational procedures after the loss of Mars Climate Orbiter. The thruster maneuver was previously scheduled for today. The spacecraft is healthy and the team is continuing to test and train for the early surface phase of the mission. Mars Polar Lander is currently 18.8 million kilometers (11.7 million miles) from Mars, approaching the planet at a speed of 4.8 kilometers per second (10,740 miles per hour) relative to the planet. ---------------------------------------------------------------- NEW MARS GLOBAL SURVEYOR IMAGE By Ron Baalke October 18, 1999 The following new image taken by the Mars Global Surveyor spacecraft is now available. The Terrain of Margaritifer Chaos The image resides on the Mars Global Surveyor web site at http://mars.jpl.nasa.gov/mgs/msss/camera/images/index.html The image caption is 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 The Terrain of Margaritifer Chaos MGS MOC Release #MOC2-185, 18 October 1999 The jumbled and broken terrain in the picture on the left is known as chaotic terrain. Chaotic terrain was first observed in Mariner 6 and 7 images of Mars more than 30 years ago, and is thought to result from collapse after material--perhaps water or ice--was removed from the subsurface by events such as the formation of giant flood channels. The region shown here is named "Margaritifer Chaos". The left picture is a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) red wide-angle camera context frame that covers an area 115 km (71 miles) across. The small white box is centered at 10.3°S, 21.4°W and indicates the location of the high-resolution view on the right. The high- resolution view (right) covers a small portion of the Margaritifer Chaos at 1.8 meters (6 feet) per pixel. The area shown is 3 km (1.9 miles) across. Uplands are lumpy with small bright outcrops of bedrock. Lowlands or valleys in the chaotic terrain have floors covered by light-toned windblown d rifts. This image is typical of the very highest-resolution views of the equatorial latitudes of Mars. Both pictures are illuminated from the left/upper left, north is toward the top. Image credit: NASA/JPL/Malin Space Science Systems. ---------------------------------------------------------------- End Marsbugs Vol. 6, No. 34