MARSBUGS: The Electronic Exobiology Newsletter Volume 5, Number 3, 21 February, 1998. Editors: David Thomas, Department of Biological Sciences, University of Idaho, Moscow, ID, 83844-3051, USA, thoma457@uidaho.edu or Marsbugs@aol.com. Julian Hiscox, Division of Molecular Biology, IAH Compton Laboratory, Berkshire, RG20 7NN, UK. Julian.Hiscox@bbsrc.ac.uk or Marsbug@msn.com 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. E-mail subscriptions are free, and may be obtained by contacting either of the editors. 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 may be obtained via anonymous FTP at: ftp.uidaho.edu/pub/mmbb/marsbugs. The purpose of this newsletter is to provide a channel of information for scientists, educators and other persons interested in exobiology and related fields. This newsletter is not intended to replace peer-reviewed journals, but to supplement them. We, the editors, envision MARSBUGS as a medium in which people can informally present ideas for investigation, questions about exobiology, and announcements of upcoming events. Exobiology 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 proper (life on other planets), the search for extraterrestrial intelligence (SETI), ecopoeisis/ terraformation, Earth from space, planetary biology, primordial evolution, space physiology, biological life support systems, and human habitation of space and other planets. ------------------------------------------------------------------ INDEX 1) MARS '98 PAYLOADS INTEGRATED AS SCIENTISTS VIEW FIRST CLOSE-UPS OF STRANGE, LAYERED POLAR TERRAIN JPL release 2) PLANETARY MAPS by Phil Stooke 3) NEUROLAB: NASA'S CONTRIBUTION TO THE "DECADE OF THE BRAIN" From the NASA Ames Life Science Division Homepage 4) MARS GLOBAL SURVEYOR MISSION STATUS JPL release 5) NASA RADAR REVEALS HIDDEN REMAINS AT ANCIENT ANGKOR NASA release 6) CALL FOR PAPERS: JBIS TERRAFORMATION ISSUE by Julian Hiscox ------------------------------------------------------------------ MARS '98 PAYLOADS INTEGRATED AS SCIENTISTS VIEW FIRST CLOSE-UPS OF STRANGE, LAYERED POLAR TERRAIN JPL release 11 February, 1998 Swirling bands of eroded, layered rock, reminiscent of the edges of Alaskan ice sheets, and an array of light and dark mottled patterns blanket the frigid floor of Mars' south pole, where NASA's newly named Mars Polar Lander will touch down in late 1999. The new images of the landing zone for the Mars Polar Lander, taken by the camera aboard NASA's Mars Global Surveyor, confirm that this strange, layered terrain in the south polar region represents a dramatic departure from the now-familiar Martian landscapes observed by the Viking landers and Mars Pathfinder. In December 1999, the next lander in a steady series begun by Pathfinder will set down in this uncharted territory to dig for traces of frozen, subsurface water. "Despite ground fog that obscures part of the surface in these images, we can see much more surface detail than we've ever seen before, which suggests that the 75-degree south latitude landing zone is quite a bit more rugged and geologically diverse than we had previously thought," said Dr. Michael Malin of Malin Space Science Systems, Inc., San Diego, CA. Malin is principal investigator of the Global Surveyor camera and the cameras on the 1998 missions, the Mars Polar Lander and its newly named partner, the Mars Climate Orbiter. In the current images from Mars Global Surveyor, obtained during an aerobraking orbit from about 2,800 kilometers (1,700 miles) above the planet's surface, objects about 15 meters (48 feet) across can be resolved. Once the spacecraft reaches its final mapping orbit early next year, at an average of 378 kilometers (234 miles) above the surface, the camera will be able to resolve ground features as small as 2 to 3 meters (7 to 9 feet) across. This greater clarity will enable views of objects as small as boulders or as subtle as sand dunes. Over the next year, the Global Surveyor images will be used in concert with other spacecraft data such as that obtained by the thermal emission spectrometer to better characterize the geology of Martian south pole. After Global Surveyor has reached its mapping orbit, data from the spacecraft's laser altimeter, which measures the height and roughness of Martian surface features, will be combined with imaging data to aid the final choice of landing sites. "We have a wonderful opportunity in the next year to study this region with data from Mars Global Surveyor, which underscores the true advantage of conducting a continuing program of Mars exploration," said Dr. John McNamee, Mars Surveyor '98 project manager at NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA. "We will be able to characterize the geology of the whole region and find the best spot to land, one that presents a balance between lander safety and scientific interest. This process does not have to be finalized until June 1999, five months after the lander has been launched and six months before it lands." The landing site images are available on the Internet at JPL's Mars web sites: http://mars.jpl.nasa.gov/msp98/news/news12.html or http://www.jpl.nasa.gov/marsnews/ The images are being studied while the 1998 Mars Climate Orbiter and Mars Polar Lander are undergoing key hardware integration and testing at Lockheed Martin Astronautics, Denver, CO. The spacecraft are currently being prepared for transfer to the Lockheed Martin environmental test chambers to ensure that they can survive and operate in the extreme conditions at Mars. At the completion of this testing, the spacecraft will be flown separately to NASA's Kennedy Space Center, FL, for integration with their launch vehicles. The 1998 Mars lander and orbiter missions are designed to learn more about the history of Mars' climate and the behavior of related Martian volatiles, such as water vapor and ground ice. The orbiter, scheduled for launch on Dec. 10, will conduct a two- year primary mission to profile the Martian atmosphere and map its surface. The lander, scheduled for liftoff on Jan. 3, 1999, will carry out a three-month mission to search for traces of subsurface water in this frozen, layered terrain and any evidence of a physical record of climate change. To meet these scientific objectives, the orbiter will carry a rebuilt version of the Pressure Modulated Infrared Radiometer (PMIRR) that was lost with Mars Observer in 1993. This atmospheric sounder will observe the global distribution and time variation of temperature, dust, water vapor and condensates in the Martian atmosphere. PMIRR is a collaboration between JPL, Oxford University and Russia's Space Research Institute. Like Mars Global Surveyor, the Mars Climate Orbiter carries a dual camera system, but this one is contained in an amazingly compact package about the size of a pair of binoculars. The Mars color imager's 0.5-kilogram (1 pound) wide-angle camera will return daily low-resolution global views of the planet's atmosphere and surface, while its medium-angle camera will provide higher resolution (40 meters or 30 feet per pixel) images. The medium-angle camera will build global and regional maps of Mars in multiple colors over the course of the mission. These maps will be used to characterize surface properties and changes in the distribution of dust. The 1998 lander carries three scientific packages: the Mars descent imager, again provided by Malin, which will view the landing site at increasingly higher resolution as the lander descends to the surface of Mars; the atmospheric lidar experiment, provided by the Russia space institute, which will monitor the presence and height of atmospheric hazes, coupled with a miniature microphone furnished by The Planetary Society, Pasadena, CA, to record the sounds of Mars; and the Mars Volatile and Climate Surveyor (MVACS) package, led by principal investigator Dr. David Paige of the University of California, Los Angeles. MVACS includes a surface stereo imager based on the Mars Pathfinder camera, both built at the University of Arizona; a meteorology package, built at JPL; a robotic arm, also built at JPL, to acquire soil samples and close-up images of the surface and subsurface; and the thermal and evolved gas analysis experiment, built at the University of Arizona. JPL will oversee mission operations with the spacecraft team at Lockheed Martin Astronautics and the instrument teams located at their home institutions during the lander and orbiter missions. "MVACS and the other science experiments are tailor-made for the exploration of Mars' south pole," said Dr. Richard Zurek, project scientist at JPL. "The robotic arm, which is reminiscent of the Viking arm and scoop that were used to carry out biology experiments in the mid-1970s, is, in fact, much more versatile. It can reach farther out, dig up to 1 meter (3 feet) below the surface and then place soil samples in a miniature oven, called the evolved gas analysis experiment, where the samples are 'cooked' and analyzed for chemical and gas content." Piggybacking on the Mars Polar Lander are two small, 2-kilogram (4.5-pound) microprobes, provided by NASA's New Millennium validation program. Deployed before landing, they will penetrate and embed themselves beneath the Martian surface to study subsurface materials. A microchip with the electronic signatures of students from all over the world will also be flown on the lander. Signatures may be submitted via the Internet to: http://comet.hq.nasa.gov/mars98/ The Mars Polar Lander and Mars Climate Orbiter are the second set of launches in a long-term NASA program of Mars exploration known as the Mars Surveyor Program. The missions are managed by JPL, Pasadena, CA, for NASA's Office of Space Science, Washington, DC. Lockheed Martin Astronautics, Denver, CO, is NASA's industrial partner in the mission. ------------------------------------------------------------------ PLANETARY MAPS by Phil Stooke "Are there any good maps of Mars?" Of course there are. Useful maps are listed in the planetary map FAQ that follows this posting. Look for these maps and the literally hundreds of sheets of topographic, geological maps and photomosaics from the U.S. Geological Survey at any good university map library. Here is a list of maps of all mapped solar system bodies except Earth--56 as of February 1998. If there are many maps (e.g. Mars) a general-purpose global map is listed, subdivided if necessary: relief maps (usually with placenames), topography (contours), geological maps. If not (e.g. Deimos) the best available map is listed. Some (e.g. Comet Encke) are simple diagrams of possible surface features ('sketch' under map type). A few interesting books are listed at the end. Questions, errors or omissions? Please contact me (Phil Stooke) at: stooke@sscl.uwo.ca. For IAU definitions of North, longitudes, prime meridians etc. see Chapter 5 of PLANETARY MAPPING (see below) and further references in that chapter. References: USGS = U.S. Geological Survey. Order by I-number from USGS Map Sales, Box 25286, Denver, Colorado USA 80225. About $4/sheet (some in list are sets of several sheets). Call Customer Service: (303) 236-7477 for price and ordering details. NASA Tech. Memo. 4395 (Indexes of Maps of Planets and Satellites 1992) by J. Inge and R. Batson is the best guide to sheet maps. Most Apollo-era Moon maps (LAC, LTO) are out of print, but some (plus NASA CD-ROMS) may be found at NSSDC: National Space Science Data Center, Goddard Space Flight Center, Greenbelt, Maryland USA 20771. NSSDC now has a WWW interface into their inventory of available planetary maps (Moon, Mars, and Mercury only): http://nssdc.gsfc.nasa.gov/nmc/map.html Edmund Scientific: 101 E. Gloucester Pike, Barrington, NJ 08007-1380, USA. Virtual Reality Labs: 2341 Ganador Ct., San Luis Obispo, CA 93401, USA. Other maps are in books and journals. Bibliographic data are abbreviated but there should be enough detail to find the item. My maps and digital shape models of small bodies are available on the WWW at: www.geog.uwo.ca/Stooke.html BODY MAP TYPE REFERENCE Sun outline L'Astronomie (Astr. Soc. France) (prior to 1996) Mercury relief USGS maps I-1149,1171,1822 geology USGS maps I-1199,1233,1408,1409,1658,1659,1660, 2015,2148, + NASA ATLAS OF THE SOLAR SYSTEM atlas Davies et al. ATLAS OF MERCURY, NASA SP-423, 1978 globe USGS (out of print- see at Cornell U. or LPI) Venus relief NASA ATLAS OF THE SOLAR SYSTEM (see below) topogr USGS maps I-1324,1562,2041 + GxDR CD-ROM from NSSDC geology USGS map I-2059 (Venera 15/16 data) digital VENUS EXPLORER CD-ROM, Virtual Reality Labs Inc. atlas ATLAS POVERKHNOSTI VENERY, Russia, 1989 globe Sky Publishing (ads in Sky & Telescope) online http://www-pdsimage.jpl.nasa.gov/PDS/public/ magellan/midrcd_query.html Moon relief USGS maps I-1218,1326,2276 topogr NSSDC: LAC maps (earthside), LTO maps (Apollo zone) + Smith et al.,J.GEO.RES.102:1591-1611,1997 (global) geology USGS maps I-703,948,1034,1047,1062,1162, + Wilhelms, USGS Professional Paper 1348, 1987 atlas LUNAR ORBITER PHOTO ATLAS, NASA SP-206, 1971 + A. Rukl, ATLAS OF THE MOON, Hamlyn, 1990 globe Replogle Globes (via Sky Publ., ads in SKY+TEL.) online http://www.nrl.navy.mil/clementine/clib digital CLEM. BASEMAP CD-ROMs (set of 15), from NSSDC Mars relief USGS maps I-1618,2179, Edmund Scientific Mars Map topogr USGS map I-2160 + MDIM CD-ROM, disk 7, from NSSDC geology USGS map I-1802 digital MDIM CD-ROMs, disks 1-6, available from NSSDC + MARS EXPLORER CD-ROM, Virtual Reality Labs Inc. atlas Batson et al., ATLAS OF MARS, NASA SP-438, 1979 globe Sky Publishing (ads in SKY+TELESCOPE) online http://ic-www.arc.nasa.gov/ic/projects/ bayes-group/Atlas/Mars Phobos relief Greeley+Batson, NASA ATLAS SOL.SYST. Cambr.U.Pr. 1996 topogr Thomas, ICARUS, 105:326-344, 1993 (+ photomosaic) globe Max Planck Inst. Phys+Astrophys., 1988 (see at LPI) Deimos outline Thomas, ICARUS, 40: 223-243, 1979 topogr Thomas, ICARUS, 105:326-344, 1993 (+ photomosaic) Jupiter mosaics Smith et al., SCIENCE 206:927-950, 1979 (Voyager) mosaics Hammel+, SCIENCE 267:1288-1296, 1995 (HST, SL9 sites) Amalthea rel,topo Stooke, EARTH,MOON,PLANETS 64:187-197, 1994 Io relief USGS map I-1713 topogr Gaskell+Synnott,GEOPHYS.RES.LET. 15:581-584, 1988 geology USGS map I-2209 digital ftpflag.wr.usgs.gov/pub/outgoing/io_low_simp.raw colour Burns+, SATELLITES, U.Ariz.Pr.,1986, Pl.2 (Voyager) colour ASTRONOMY v.25:p.28, 1997 (Galileo mosaic) Europa relief USGS maps I-1241,1493,1499 geology SATELLITES OF JUPITER,Ch.14, U.Arizona Press, 1982 digital http://wwwflag.wr.usgs.gov/USGSFlag/Space/europa/ europa.html Ganymede relief USGS map I-2331 geology USGS maps I-1934,1966,2289,2328,2388,2497,2534 digital ftpflag.wr.usgs.gov/pub/outgoing/gan_low_simp.raw Callisto relief USGS maps I-1239,2035 geology Schenk, JOURN.GEOPHYS.RES., 100:19023-19040, 1995 Saturn mosaics Sromovsky+, J.GEOPH.RES.88:8650-8666, 1983 (Voyager) mosaics Westphal et al., ICARUS 100:485-498, 1992 (HST) mosaics Godfrey, ICARUS 76:335-356, 1988 (N. Pole) Prometheus rel,topo Stooke, EARTH,MOON,PLANETS, 62: 199-221, 1993 Pandora rel,topo Stooke, EARTH,MOON,PLANETS, 62: 199-221, 1993 Janus rel,topo Stooke+Lumsdon, EARTH,MOON,PLAN. 62:223-237, 1993 Epimetheus rel,topo Stooke, EARTH,MOON,PLANETS, 63: 67-83, 1993 Mimas relief USGS maps I-1489,2155 geology Croft, NASA TECH.MEM. 4300, 95-97, 1991 Enceladus relief USGS maps I-1485,2156 geology Kargel+Pozio, ICARUS 119:385-404, 1996 Tethys relief USGS maps I-1487,2157 geology Moore+Ahern, J.GEOPHYS.RES. 88:A577-A584, 1983 Dione relief USGS maps I-1488,2158 geology Moore, ICARUS, 59:205-220, 1984 Rhea relief USGS maps I-1484,1921 geology Moore et al., J.GEOPHYS.RES. 90:C785-C795, 1985 Titan albedo Smith et al., ICARUS 119:336-349, 1996 Hyperion rel,topo Stooke, EARTH,MOON,PLANETS 74:61-83, 1996 Iapetus relief USGS maps I-1486,2159 geology Croft, NASA TECH.MEM. 4300, 101-103, 1991 Phoebe albedo Thomas et al., J.GEOPHYS.RES. 88:8736-8742, 1983 Uranus magnetic Connerney+,J.GEO.RES.92:15329-15336, 1987 Puck outline Stooke, LUN.PLANET.SCI. XXV, 1349-1350, 1994 Miranda relief USGS map I-1920 topogr Wu, LUNAR PLANET.SCI XVIII, 1110-1111, 1987 geology Croft+Soderblom, URANUS, U.Ariz.Press, 1991 Ariel relief USGS map I-1920 geology Croft+Soderblom, URANUS, U.Ariz.Press, 1991 Umbriel relief USGS map I-1920 geology Croft+Soderblom, URANUS, U.Ariz.Press, 1991 Titania relief USGS map I-1920 geology Croft+Soderblom, URANUS, U.Ariz.Press, 1991 Oberon relief USGS map I-1920 geology Croft+Soderblom, URANUS, U.Ariz.Press, 1991 Neptune mosaics Smith et al., SCIENCE 246:1422-1449, 1989 Larissa relief Stooke, EARTH,MOON,PLANETS, 65:31-54, 1994 Proteus rel,topo Stooke, EARTH,MOON,PLANETS, 65:31-54, 1994 Triton relief USGS maps I-2153,2154,2275 geology Croft et al., NEPTUNE+TRITON, U.Ariz.Press, 1995 Pluto albedo Stern et al., ASTRON. JOURNAL 113:827-843, 1997 Charon albedo Buie et al., ICARUS, 97:211-227, 1992 4 Vesta albedo Binzel et al., ICARUS, 128:95-103, 1997 topogr Thomas et al., SCIENCE, 277:1492-1495, 1997 15 Eunomia sketch Reed et al., ICARUS, 125:446-454, 1997 29 Amphitrite sketch Barucci et al., ASTER.COMET.METEOR.II,89-92, 1986 43 Ariadne sketch Detal et al., ASTRON.ASTROPHYS. 281:269-280, 1994 243 Ida geology Belton et al., SCIENCE, 265:1543-1547, 1994 + Stooke, LPSC XXVIII, 1385-1386, 1997 topogr Thomas et al., ICARUS, 120:20-32, 1996 243(1) Dactyl outline Veverka et al., ICARUS, 120:200-211, 1996 532 Herculina sketch Taylor et al., ICARUS, 69:354-369, 1987 624 Hektor sketch Hartmann+Cruikshank, ICARUS, 36:353-366, 1978 951 Gaspra rel,topo Stooke, EARTH, MOON,PLANETS, 75:53-75, 1997 1620 Geographos outline Stooke, LPSC XXVIII, 1387-1388, 1997 4179 Toutatis relief Hudson+Ostro, SCIENCE, 270:84-86, 1995 outline Stooke, LPSC XXVII, 1283-1284, 1996 4769 Castalia relief Hudson+Ostro, SCIENCE, 263:940-943, 1994 + Stooke, CANADIAN GEOGRAPHER, in press, 1997 topogr Scheeres et al., ICARUS, 121:67-87, 1996 Comet Encke sketch Sekanina, ASTRON. JOURN. 96:1455-1475, 1988 Comet Halley outline Moehlmann+,COMETS,POST-HALLEY ERA, p.764, Kluwer 1991 rel,topo Stooke+Abergel, ASTRON.ASTROPHYS 248:656-668, 1991 + Stooke, LPSC XXVIII, 1387-1388, 1997 Swift-Tuttle sketch Sekanina, ASTRON.J. 86:1741-1773, 1981 Com.Tempel-2 sketch Sekanina, ASTRON.J. 102:350-388, 1991 Interesting books: (no single book has maps of all bodies listed above) NASA ATLAS OF SOLAR SYSTEM, Greeley & Batson (eds), Cambridge U.Press, 1996 ATLAS PLANET ZEMNOI GRUPPA...(atlas of terrestrial planets), Russia, 1992 PLANETARY MAPPING, Greeley & Batson (eds), Cambridge U. Press, 1990 PLANETARY LANDSCAPES, Greeley, Cambridge U. Press, 2nd ed. 1994 MAPPING OF THE MOON, Kopal & Carder, D.Reidel Co., 1974 MARS AND ITS SATELLITES, J. Blunck, Exposition Press, 1982 (ed. 2) ------------------------------------------------------------------ NEUROLAB: NASA'S CONTRIBUTION TO THE "DECADE OF THE BRAIN" From the NASA Ames Life Science Division Homepage Neurolab To recognize the tremendous advances that have been made in the brain and behavioral sciences, the 1990's were designated as the "decade of the Brain" by the U.S. President and Congress. The Neurolab mission, scheduled for launch in early 1998, will be a significant and important contribution to this national research effort. The goals of Neurolab are to study basic research questions in the neurosciences and to increase understanding of the mechanisms responsible for neurological and behavioral changes in space. The 16 day mission will combine biomedical techniques, new combinations of sophisticated measurement and recording devices, and advances in the neurosciences from both Earth- and space-based research into a single integrated suite of investigations. Science The experiments on Neurolab will examine the effects of space flight and microgravity on the functioning of the nervous system. The researchers anticipate significant progress in studies that will elucidate basic links in neural development, signal processing, and sensory motor integration. Working with a variety of organisms, including crickets, fish, mice, rats and humans, Neurolab offers an unparalleled opportunity to make fundamental, and possibly unexpected, discoveries. Experiments on human behavior, perception, and learning are combined on Neurolab to permit a unique and unified approach to these inter-disciplinary areas. New knowledge and new technological developments gained through the Neurolab experiments may have immediate impacts to human health or may open new fields of inquiry. At the same time, these investigations contribute to NASA's Human Exploration and Development of Space enterprise. Partners The Neurolab Program is being carried out by NASA in cooperation with a variety of domestic and international partners. The major domestic partner is the National Institutes of Health; the National Science Foundation and the Office of Naval Research are also partners. International partners are the European Space Agency and the space agencies of Japan, France, Germany, and Canada. The partners are supporting the mission by providing funding for scientists, supplying scientific equipment to be used on the Space Shuttle, and participating in the planning of the mission. Investigators Following a rigorous peer review process conducted by the National Institutes of Health Division of Research Grants, a 10 month integration and definition period, and an additional peer review, 32 scientists were selected for development on the Neurolab mission. The investigators are from the United States, Japan, Germany, France, Canada, Italy, and the Netherlands. Friedhelm J. Baisch, M.D. DLR Institute of Aerospace Medicine Kenneth M. Baldwin, Ph.D. University of California, Irvine Alain Berthoz, Ph.D. CNRS/Collège de France C. Gunnar Bloomqvist, M.D., Ph.D. University of Texas Southwestern Medical Center Otmar Bock, M.D. Physiologisches Institut Deutsche Sporthochschule Barbara Chapman, Ph.D. University of California, Davis Scott T. Brady, Ph.D. University of Texas Southwestern Medical Center Gilles R. Clement, Ph.D. National Center for Scientific Research Bernard Cohen, M.D. Mount Sinai School of Medicine Charles A. Czeisler, M.D., Ph.D. Harvard Medical School/Brigham & Women's Hospital Dwain L. Eckberg, M.D. Medical College of Virginia Charles A. Fuller, Ph.D. University of California, Davis Stephen M. Highstein, M.D., Ph.D. Washington University Gay R. Holstein, Ph.D. Mount Sinai School of Medicine Eberhard, R. Horn, Ph.D. University of Ulm Haig S. Keshishian, Ph.D. Yale University Kenneth S. Kosik Harvard Medical School/Brigham & Women's Bruce L. McNaughton, Ph.D. University of Arizona Richard S. Nowakowski, Ph.D. UMDNJ-Robert Wood Johnson Medical School Charles M. Oman, Ph.D. Massachusetts Institute of Technology Ottavio Pompeiano, M.D. University of Pisa Jaqueline Raymond, Ph.D. University of Montpellier Danny A. Riley, Ph.D. Medical College of Wisconsin David Robertson, M.D. Vanderbilt University School of Medicine Muriel D. Ross, Ph.D. NASA Ames Research Center Tsuyoshi Shimizu, M.D., Ph.D. Fukushima Medical College Tracey J. Shors, Ph.D. Princeton University Kerry Walton, Ph.D. New York University Medical Center John B. West, M.D., Ph.D. University of California, San Diego Michael L. Wiederhold, Ph.D. University of Texas Health Center at San Antonio Bruce G. Jenks, Ph.D. ------------------------------------------------------------------ MARS GLOBAL SURVEYOR MISSION STATUS JPL release 12 February, 1998 Mars Global Surveyor is currently in its 128th orbit around Mars. Aerobraking continues to go normally and is being aided by the relatively calm state of the Martian atmosphere. Atmospheric stability allows the spacecraft to dip lower into the Martian atmosphere, experience more air resistance and lower its orbit at a faster rate. The spacecraft's closest approach to Mars is currently bringing it to within 117 kilometers (about 73 miles) of the surface and has reduced the time it takes to complete one orbit around the red planet to 17 hours. The flight team reported that there have been no additional issues with the slightly damaged attachment structure on one of the spacecraft's two solar panels. Global Surveyor's science instruments are scheduled to be turned off on Wednesday, February 18 and remain off until late March. The payload is being shut off because of Surveyor's much-diminished orbital period, which no longer allows enough time to both send aerobraking commands to the spacecraft and to transmit to Earth the scientific data stored onboard. The flight team has begun commands to rotate the spacecraft twice per orbit so that different parts of Global Surveyor are better exposed to the Sun. Normally, Surveyor spends the majority of its time with its high-gain antenna pointed directly at the Earth. The new commands are necessary to keep the temperatures onboard the laser altimeter from falling below 10 degrees Celsius (50 degrees Fahrenheit). Current analysis suggests that the rotations will be necessary until September. After 462 days in flight, Mars Global Surveyor is currently about 340 million kilometers (211 million miles) from Earth, circling Mars about once every 17 hours. The spacecraft's current elliptical orbit takes it about 117 kilometers (73 miles) above the surface of Mars at the closest point and about 25,000 kilometers (15,500 miles) from the planet at the farthest point in the orbit. At present, one-way light time from Global Surveyor to Earth is 18 minutes, 9 seconds. Real-time orbital information about Mars Global Surveyor is available on the Internet at http://marsnt3.jpl.nasa.gov/mgs/realtime/orbit.html. The information is automatically updated every 30 seconds. ------------------------------------------------------------------ NASA RADAR REVEALS HIDDEN REMAINS AT ANCIENT ANGKOR NASA release 12 February, 1998 New evidence of a prehistoric civilization and remnants of ancient temples in Angkor, Cambodia have been discovered by researchers using highly detailed maps produced with data from an airborne imaging radar instrument created by NASA. Experts say the findings, made possible by the Airborne Synthetic Aperture Radar (AIRSAR) developed by NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA, may revolutionize the way archaeologists view the ancient city's development. Angkor is a vast complex of some 1,000 temples covering more than 160 square kilometers (about 100 square miles) of northern Cambodia. Little is known of the prehistoric occupation of this fertile flood plain, but at its height the city housed an estimated population of 1 million people. The famous temples were built from the 8th to 13th century AD and were accompanied by a massive hydrological system of reservoirs and canals. Today, much of the civilization of Angkor is hidden beneath a dense forest canopy and is inaccessible due to poor roads, land mines and political instability. "The radar data have enabled us to detect a distribution of circular 'prehistoric' mounds and undocumented temples far to the northwest of Angkor," said Dr. Elizabeth Moore, Head of the Department of Art & Archaeology at the School of Oriental and African Studies at the University of London. "The site's topography is highlighted by the radar, focusing our attention on previously neglected features, some at the very heart of the city. "The radar maps not only bring into question traditional concepts of the urban evolution of Angkor, but reveal evidence of temples and earlier civilization either absent or incorrect on modern topographic maps and in early 20th century archaeological reports," she said. "The radar images make apparent many features that are not readily identifiable on the ground," said Dr. Anthony Freeman, a radar scientist at JPL who has collaborated with Moore for the past three years studying the use of radar on the Angkor site. "We can see differences in vegetation structure and some features that are obscured by vegetation cover." In December 1997, Moore surveyed a small mound on the perimeter of the famous 12th century AD temple, Angkor Wat, that Freeman had first noticed in the radar image. "Previous archaeological accounts from 1904 and 1911 note only two temples and make no mention of the distinct circular form of the mound. We found four to six temple remains, including pre-Angkorean structures," Moore said. "This suggests occupation of the 12th century site some 300 years earlier, radically changing accepted chronologies of Angkor." Angkor's beauty is seen its in temples, but the greatness of the Khmer city lies in the multitude of water-related constructions, according to Moore. The Khmer kings nominally dedicated temples to Hindu and Buddhist deities, but the underlying significance was veneration of ancestral spirits, ensuring fertility of the land. Management of water was essential, both for control during the monsoon rains and conservation during the dry season and involved the construction of moats, dikes, canals, tanks, and reservoirs. The largest of these reservoirs, dated to the 12th century AD, is eight kilometers (five miles) long and its function remains a matter of archaeological debate. "These new detailed topographic maps have shown us many more hydrological features and highlighted how they function in the rituals and daily life of the Khmer people," Moore explained. "Using a technique known as radar interferometry, which combines two images to create a three-dimensional topographic map, we can construct a map of the area surrounding Angkor that is more accurate than most maps we have of the United States," said Dr. Scott Hensley, a radar engineer at JPL. "This map lets us see both natural and human-made water management features at the site with great clarity." "Angkor is situated on the edge of the Tonle Sap lake, a unique body of water that doubles in size during the rainy season. These maps give us new insights into the human impact on this ecosystem, from the ancient Khmer to the present day, and are of importance in the study of our changing Earth," Freeman continued. The Angkor radar images were taken in late 1996 as part of the AIRSAR Pacific Rim Deployment and were a follow-up to the 1994 study of Angkor with data collected by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) that flew on NASA's Space Shuttle Endeavour. Like SIR-C/X-SAR, AIRSAR transmits and receives three radar frequencies in both horizontal and vertical polarizations. While both systems use C-band and L-band wavelengths, AIRSAR has the added benefit of P-band, a longer wavelength that can penetrate below the forest canopy. In addition, AIRSAR can be flown in a mode called TOPSAR that allows it to measure topography and create three-dimensional images of the surface. AIRSAR images of the Angkor region will be posted to the Internet at this address: http://www.jpl.nasa.gov/news/ AIRSAR flies on a NASA DC-8 aircraft that is managed at NASA's Dryden Flight Research Center, Edwards, CA. The AIRSAR instrument is managed by JPL, a division of the California Institute of Technology for NASA's Office of Earth Sciences, Washington, DC. This office manages NASA's Earth Science enterprise, an internationally coordinated effort to study natural and human-induced changes in the Earth's land, oceans, atmosphere, ice and life. The AIRSAR flight over Cambodia was funded by the Government of Thailand. Ground verification has been made possible by Vann Molyvann, Minister of State for Culture and Fine Arts, Territorial Management, Urban Planning and Construction; and Dr. Ang Chouléan of the Cambodian Authority for the Protection and Management of Angkor and the Region of Siem Reap. ------------------------------------------------------------------ CALL FOR PAPERS: JBIS TERRAFORMATION ISSUE by Julian Hiscox Martyn Fogg has asked me whether I would like to take over from him as editor of the JBIS terraforming issue, which I am delighted to do. I would therefore like to begin to solicit manuscripts. At the moment the British Interplanetary Society has pencilled in March 1999 for the next terraforming issue. If you are interested in submitting a paper (or know of someone who might) please could you send me an e-mail and include a suggested title and brief abstract. [E-mail addresses can be found at the top of this issue.] ------------------------------------------------------------------ End MARSBUGS Vol. 5, No. 3.