MARSBUGS: The Electronic Astrobiology Newsletter Volume 9, Number 16, 22 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) HOW LIFE ORIGINATED IN SPACE Informnauka (Informscience) Agency release 2) SCIENTISTS DISCOVER ANTIFREEZE IN SPACE, WARMING THEORIES ON HOW AND WHERE LIFE BEGINS National Radio Astronomy Observatory release 3) NASA AMES RECEIVES FIRST PLANT IMAGES FROM SPACE STATION NASA/ARC reclease 02-42AR 4) NEW BIOSATELLITE TO STUDY LIFE IN MARTIAN GRAVITY Mars Society release 5) RIFT VALLEY FEVER By Karen Miller 6) LOOKING FOR LIFE IN ALL THE RIGHT PLACES By Edna DeVore 7) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 8) CASSINI SIGNIFICANT EVENTS NASA/JPL release 9) MARS ODYSSEY THEMIS IMAGES Arizona State University release 10) STARDUST STATUS REPORT NASA/JPL release _____________________________________________________________________ HOW LIFE ORIGINATED IN SPACE Informnauka (Informscience) Agency release, Moscow, Russia 12 April 2002 The eternal question about the origin of life on the Earth has no answer so far. One of the theories assumes that life on the Earth might have originated in space. Russian scientists successfully reproduced the experiment carried out by Nature three and a half billion years ago. Life originated on the Earth more than 3.5 billion years ago. However, the scientists are still disputing over the possible sources of the life origin. The matter is that life on our planet evolved from the molecular level to the level of bacteria organisms within 0.5-1 billion years, this period being very short for such an important evolutionary step. The researchers are still racking the brains over this mystery. One of the popular hypotheses asserts that some germs of life have been brought to the Earth from space. But what exactly could have been brought from space and how could the germs have originated in space? E. A. Kuzicheva and N. B. Gontareva, research assistants from the Institute of Cytology, Russian Academy of Sciences, have confirmed a possibility of abiogenic synthesis of complex organic compounds (monomeric units of nucleic acids) on the surface of comets, asteroids, meteorites and space dust particles in the outer space. Therefore, it is possible that the above monomeric units of nucleic acids could have got to the Earth and thus could have significantly reduced the time period of the evolution process. On the surface of space bodies the scientists have found all kinds of various organic molecules (amino acids, organic acids, sugars etc.) and the components required for their synthesis. Obviously, it is there that organic substances are being synthesized, but the researchers can not be sure of this fact, until the experiments confirm their assumptions. The scientists from St. Petersburg reproduced synthesis of one of the DNA components--5'-adenosine monophosphate (5'-AMP) under the conditions specially designed to simulate the space environment. In order to synthesise 5'-AMP it is required to combine adenosine and inorganic phosphate. On the Earth the reaction goes in the solution, but there are no solvents whatsoever in space, therefore the researchers dried them in the air and got a pellicle. Synthesis requires energy. The major source of energy in the outer space both at present and in the prebiotic period of the Earth history has been the solar ultraviolet radiation of different wavelengths. Therefore, the pellicles were irradiated by a powerful ultraviolet lamp. Naturally, the synthesis was carried out in vacuum, and the researchers used the lunar soil, delivered to the Earth by the 'Moon- 16' station from the Sea of Abundance, as a model of the comet, meteorite, interplanetary or cosmic dust. The soil represented basaltic dust of the dark-gray color, the diameter of its particles being less than 0.2 millimeters. After 7-9 hours of ultraviolet irradiation of the dry pellicles the scientists acquired several compounds, mainly 5'-AMP, one of the DNA/RNA monomers. The energy of radiation does not promote synthesis alone, it also facilitates decomposition of the initial and newly synthesized compounds; the more powerful the radiation is, the more extensively the decomposition goes. However, the lunar soil provided some protection. It has appeared that a small pinch of the lunar soil protects organic substances from the destructive ultraviolet impact--the lunar soil helps to increase the 5'-AMP yield by 2.7 times. The researchers have made a conclusion that the organic compounds' synthesis could have happened in the outer space environment. The synthesis could have taken place on the surface of space bodies at the initial phases of the solar system formation, along with that the chemical evolution (formation and selection of complex molecules) could have started in space. By the time the Earth was formed the chemical evolution might have approached the phase to be followed by the biological evolution. That implies that life on the Earth most probably did not start from the elementary organic molecules' synthesis, but commenced from the polymers formation phase or from a further stage. Hopefully, the above assumptions will help the scientists to deeper penetrate into the mystery of the accelerated development of life on the Earth when the latter was quite a "young" planet. Contacts: E. A. Kuzicheva, N. B. Gontareva Institute of Cytology Russian Academy of Sciences St. Petersburg Phone: 7-812-247-18-29 E-mail: nnnik@dcc.cyt.ras.spb.ru Natalia Reznik Informnauka (Informscience) Agency Phone: 7-095-267-54-18 E-mail: textmaster@informnauka.ru _____________________________________________________________________ SCIENTISTS DISCOVER ANTIFREEZE IN SPACE, WARMING THEORIES ON HOW AND WHERE LIFE BEGINS National Radio Astronomy Observatory release 15 April 2002 Ethylene glycol, the chemical commonly used as automobile antifreeze, was discovered recently in a massive interstellar cloud of dust and gas near the center of the Milky Way Galaxy. Scientists used the National Science Foundation's (NSF) 12-Meter Radio Telescope to detect this organic molecule. "Though we most commonly think of ethylene glycol as antifreeze, it actually is associated with the formation of more complex sugar molecules that are necessary for life," said Jan M. Hollis of NASA Goddard Space Flight Center in Greenbelt, Maryland. "Finding this molecule supports the view that prebiotic chemistry may first get started in interstellar space." Hollis collaborated with Frank J. Lovas of the University of Illinois, Philip R. Jewell of the National Radio Astronomy Observatory (NRAO), and Laurent H. Coudert of the University of Paris at Campus d'Orsay to identify the ethylene glycol molecule. Their results were accepted for publication in the Astrophysical Journal Letters. The scientific team detected ethylene glycol in the molecular cloud called Sagittarius B, located 26,000 light-years from Earth near the center of our Galaxy. Though rarefied by Earth standards, interstellar clouds like this one can enable complex chemical reactions over time scales of hundreds-of-thousands or even millions of years. About 130 different molecules are known to exist in interstellar clouds. Ethylene glycol (a 10-atom molecule made up of carbon, hydrogen, and oxygen) is one of the five largest molecules ever discovered in space. It also is a chemically reduced form of 8-atom glycolaldehyde, the simplest member of the sugar family. This means that ethylene glycol can be produced from glycolaldehyde by the addition of two hydrogen atoms. Both molecules have now been detected in space by this team. "These detections suggest that the production of more complex sugars, like ribose, may be occurring in interstellar clouds," Hollis said. Ribose sugar is required for the backbone structure of RNA; a less complex form, deoxyribose sugar, is required for the backbone structure of DNA. "This discovery further demonstrates how important interstellar chemistry may be to understanding the creation of biological molecules on the early Earth," said Jewell. "Some scientists have even speculated that the Earth could have been 'seeded' with complex molecules from passing comets, which were formed from the condensing gas nebula that produced our Solar System." Astronomers on Earth are able to detect and identify the faint radio emission of molecules in space as they tumble and vibrate within interstellar clouds, emitting radio waves at precise frequencies. These frequencies are unique to each molecule, and provide a "fingerprint" in the electromagnetic spectrum. Signals from other molecules can sometimes fall at nearby frequencies, in effect smudging the ethylene glycol fingerprint. The scientists used four different signals from ethylene glycol to secure its detection. The researchers made their discovery with data taken in May 2000 with the 12-Meter Radio Telescope at Kitt Peak, Arizona, which has been a pioneering instrument in detecting molecules in space. Though operated by NRAO at the time, the Steward Observatory of the University of Arizona now operates this telescope. The research team plans future work on interstellar biomolecules using the new NRAO Robert C. Byrd Green Bank Telescope, which promises to be the most sensitive telescope yet for such work. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. Additional information on this article is available at http://www.aoc.nrao.edu/pr/antifreeze.html. An additional article on this subject is available at http://spaceflightnow.com/news/n0204/16antifreeze/. _____________________________________________________________________ NASA AMES RECEIVES FIRST PLANT IMAGES FROM SPACE STATION NASA/ARC reclease 02-42AR 17 April 2002 Scientists at NASA Ames Research Center have received the first images of plants growing aboard the International Space Station (ISS). They also have acquired the ability to send commands to the orbiting plant-growth system. Astronauts transferred the Biomass Production System to the ISS from the space shuttle Atlantis last week. The Biomass Production System (BPS) is an engineering development unit for a future ISS plant habitat capable of supporting long-term plant growth and botanical experimentation in space. The BPS and science samples will return to Earth on the STS-111 space shuttle mission, currently scheduled for a late May launch. "BPS is a versatile piece of hardware and the team is excited about this first chance to test its capabilities on orbit in support of current and future science experiments," said Dr. Randy Berthold, BPS payload manager at NASA Ames. The BPS is one of several pieces of science hardware being developed by the Space Station Biological Research Project at NASA Ames, in California's Silicon Valley, for use on the space station. "Although the BPS is the third suite of flight hardware NASA Ames has provided to the ISS, this marks the first time Ames has controlled any of the hardware from the ground," Berthold said. A 2001 space shuttle mission carried an autonomous radiation monitoring and recording system to the ISS. Later that year, the Avian Development Facility was carried on a mission to the ISS, although the facility remained on board the space shuttle. Each day, the BPS team sends commands to the unit and retrieves the previous day's data files, seven in all. Pictures of the plants included in these files help the investigators determine how well the plants are developing. Commands also can be sent to the BPS to change the timeline for automated activities that were programmed into the unit preflight. The BPS is a powered hardware system that includes four independent plant-growth chambers, a nutrient delivery system, a temperature/humidity control system, airflow and atmospheric control systems, a video system and a data-processing system. Orbital Technologies Corp., Madison, WI, developed the BPS for NASA. The primary objective of the BPS is the technology validation test, which will determine how well the BPS and its environmental control subsystems support plant growth and development in microgravity. The best subsystems will be used to design and develop a permanent plant research unit capable of supporting the continued growth and development of plant specimens for 90 days or more on orbit. The BPS testing process uses Apogee wheat and Brassica rapa plants. Brassica includes such common vegetables as broccoli, cabbage and cauliflower. The multiple developmental stages (growth, flowering and seedpod production) of Brassica test the ability of the BPS to support the growth of a developmentally complex plant. Dr. Robert Morrow, Orbital Technologies Corp., Madison, WI, is the principal investigator. The BPS also supports the Photosynthesis Experiment and System Testing Operations (PESTO), which studies the growth, photosynthesis, gas exchange and metabolism of Apogee wheat in microgravity. The PESTO principal investigator is Dr. Gary Stutte, Dynamac Corp., Kennedy Space Center, FL. Understanding photosynthesis is a critical component of plant-based atmospheric regeneration systems now under study for possible use in future long-duration space missions. By generating oxygen, removing carbon dioxide and purifying water, living plants could help maintain proper spacecraft atmosphere, and reduce the costs of air and water resupply. This research also will have direct application to future production of crops that the ISS crew could eat, such as lettuce, radishes or onions. BPS testing and research are supported by NASA's Office of Biological and Physical Research, which promotes basic and applied research to support human exploration of space and to take advantage of the space environment as a laboratory. More information is available at http://spaceresearch.nasa.gov/. Information about NASA's Space Station Biological Research Project is available at http://brp.arc.nasa.gov/. Images supporting this release are available at http://amesnews.arc.nasa.gov/releases/2002/02images/bps/bps.html. Contact: Ann Hutchison NASA Ames Research Center, Moffett Field, CA Phone: 650-604-3039 or 650-604-9000 E-mail: ahutchison@mail.arc.nasa.gov _____________________________________________________________________ NEW BIOSATELLITE TO STUDY LIFE IN MARTIAN GRAVITY Mars Society release 17 April 2002 The Mars Society has announced a landmark private space mission that will help researchers understand the long-term effects of living on Mars. MIT(Cambridge, MA), the University of Washington (Seattle, WA), and the University of Queensland (Brisbane, Australia) are leading the project. Mission highlights include: * The first privately developed biosatellite * The first mammalian births in space * The first in-depth study of mammals in a partial-gravity environment * The first student-led launch and recovery of a spacecraft The privately funded, pioneering mission will study the effects of prolonged exposure to Martian gravity on mammals, a vital step on the road to human exploration of Mars. Student teams at three leading universities will design, construct, and launch a satellite with a payload of mice on board. The mice will experience Martian gravity--3/8 that of Earth. While in space, some will give birth to a second generation, who will grow and develop entirely in this new environment. After nearly two months, the craft will return to Earth, where teams of scientists will study the crew and their offspring to obtain the first clues about life and development in reduced gravity. The Translife Mars Gravity Biosatellite, as the mission will be called, will fly the mice aboard a spinning spacecraft that generates artificial gravity identical to that on the surface of Mars. The satellite is scheduled to launch in mid-2005, orbit for about 50 days, and then return the crew safely to Earth. The team is considering a number of launch vehicle options. The mission will conduct basic scientific research necessary before humans can safely explore Mars. Astronauts living in space stations have encountered serious health problems, such as bone loss, due to the weightless environment. The first crew on Mars could experience similar effects, and scientists do not yet know whether Martian gravity is sufficient to prevent these long-term health hazards. The mission's crew of mice will provide the first answers to this important question, and the equally vital question of whether higher life from Earth will ever be able to settle Mars. During the seven- week mission, their offspring will grow from birth to nearly adulthood in Martian gravity. At the end of the flight, the satellite will re-enter the atmosphere, bringing the original crew and their progeny safely back to Earth for scientific study. Three universities will collaborate to develop this complex spacecraft: MIT will manage scientific objectives and the mission payload; the University of Washington will design the carrier spacecraft; and the University of Queensland (Australia) will devise the re-entry and recovery systems. The Mars Gravity Biosatellite is expected to cost nearly $10 million. The students are seeking financial and in-kind support from both public and private sectors to complete the project. An anonymous donor has pledged to match all contributions at 50%. The Mars Society is a private organization that works toward the exploration and settlement of our neighboring planet. It furthers these goals through public outreach to instill the vision of pioneering Mars, supporting aggressive government Mars exploration programs, and conducting exploratory research on a private basis. Before we can explore and settle the planet Mars, we must determine whether mammals can live, function, reproduce, and develop normally in its weak gravity field. This mission's groundbreaking research will provide the first insight into humans' ability to one day travel beyond the Earth and inhabit new worlds. A complete report on the progress of the Translife Mission will be presented at the 5th international Mars Society Convention, August 8- 11, University of Colorado at Boulder. Registration is now open at www.marssociety.org. Read more about the Translife Mars Gravity Biosatellite project at http://www.marsgravity.org/. More information about the Mars Society's Translife Initiative is available at http://www.marssociety.org/translife/. Contacts: Bill Litant, MIT/Project Office Phone: 617-253-1564 E-mail: wlitant@mit.edu Rob Harrill, University of Washington Phone: 206-543-2580 E-mail: rharrill@u.washington.edu Jan King, University of Queensland Phone: +61-7-3365-1120 E-mail: j.king@uq.edu.au Robert Zubrin, Mars Society E-mail: zubrin@aol.com For further information about the Mars Society, visit our web site at www.marssociety.org, or send e-mail to info@marssociety.org. _____________________________________________________________________ RIFT VALLEY FEVER By Karen Miller From NASA Science News 17 April 2002 Scientists are learning that the key to predicting certain epidemics --like Rift Valley fever in Africa or Hanta virus in the U.S.--lies in an unexpected place: the ocean. On the dusty savannahs of eastern Africa, where livestock sustain the economy, about twice a decade an epidemic whips through to decimate the herds. Nearly all of the pregnant animals spontaneously lose their fetuses. Among those already born--the lambs and kids--the mortality rate can reach 90 percent. It's called Rift Valley fever. Humans can be infected as well, either through mosquitoes that carry the disease, or by handling infected tissue. Few die, but the illness can cause serious complications: meningoencephalitis, an inflammation of the brain, and lesions of the retina, which leave victims with at least some permanent loss of vision. During the most recent and devastating outbreak in 1997-98, an embargo banned exports of East African meat for one and a half years. While no easy treatment exists for the disease, Rift Valley fever can be controlled. Animals can be vaccinated; insecticides can be spread into the soil to keep infected mosquitoes from hatching. But the disease's unpredictability has been a sticking point: without knowing when and where the disease will strike, it's hard to know how to use those controls efficiently. But the disease might not be so capricious after all, says Assaf Anyamba of NASA's Goddard Space Flight Center. Anyamba and colleagues at Goddard and at the Walter Reed Army Institute of Research have discovered that outbreaks of Rift Valley fever follow sudden floods triggered by El Niņo and a similar (yet lesser-known) climate disturbance called the "Indian Ocean Dipole." Using weather satellites to track sea surface temperature patterns in the Indian and Pacific oceans, they now believe they have found a way to predict outbreaks up to five months in advance. Sea surface temperatures can predict the likelihood of the disease because tiny variations in these temperatures cause huge shifts in air circulation patterns--shifts that alter rainfall around the globe. El Niņo, for example, happens when a band of warmer-than- average water forms near the Pacific coast of South America. Meanwhile, Pacific waters near Australia and Indonesia become a bit cooler than usual. A similar type of temperature imbalance can occur in the Indian Ocean, with the western part near Africa becoming warmer than the eastern part near Australia. Indeed, researchers liken this "Indian Ocean Dipole" to El Niņo in the Pacific. Both tend to increase rainfall in East Africa. When the two anomalies occur at the same time, buckets pour. "The year 1997 saw the largest El Niņo ever recorded simultaneous with a very large Indian Ocean Dipole (see figure)," says Christina Clark, an atmospheric scientist at the University of Colorado. "East African rainfall was then the highest on record, in many places five times the normal amount." Such floods bring Rift Valley fever because water collects in shallow depressions called "dambos" that punctuate the savannahs, providing mosquito eggs with exactly the nurturing conditions that they need to hatch. Tracking sea surface temperatures isn't enough for disease forecasters, however, because rainy weather isn't necessarily uniform across the region. To pinpoint specific vulnerable areas, forecasters look for the color green. "Where it rains there will be an increase in greenness of vegetation," says Anyamba. Earth-orbiting satellites that scan for verdant areas can spot places within the savannahs where mosquitoes will thrive. The data about both sea surface temperature and vegetation is provided by NOAA's Advanced Very High-Resolution Radiometer (AVHRR)-- a type of visible-light and infrared sensor carried on many polar orbiting weather satellites. "These satellites were not really designed to monitor land surface conditions," says Anyamba. "They were designed to monitor atmospheric conditions--basically, clouds." But Goddard scientist Compton Tucker realized, says Anyamba, that by manipulating the information provided by the AVHRR, he could produce a "greenness index," which measured the condition of the vegetation on the ground. Using sea surface temperatures to predict when East Africa might be vulnerable, and using the greenness index to pinpoint exactly where, researchers can alert health officials to potential danger. "What we can do is provide public health officials with an efficient way of being able to focus their resources, rather than sending teams out all over the place," says Anyamba. The method used to forecast Rift Valley fever could be expanded to predict other types of epidemics. It could be applied in areas that, like East Africa, are usually dry, but sometimes experience heavy rains, and that, like East Africa, have ecosystems that burgeon when precipitation comes. Hanta virus outbreaks in the American southwest could be monitored in this way. The virus is carried by deer mice and can kill people who have been exposed to it. Like Rift Valley fever, says Anyamba, Hanta virus is correlated with rainfall. "The US southwest is really a very dry environment," he says, "and you are likely to see there the same kind of bioclimatic rhythms that you see in East Africa." Right now, says Anyamba, "we're in operational mode [for East Africa]." Every month, he and his colleagues post their findings on the web, so that people in the field can "check the animals, check the people, see whether there's any activity." Things are quiet--for now. But sea temperatures will shift again. And when they do, the work of Anyamba and his colleagues will save lives. Additional information on this article is available at http://science.nasa.gov/headlines/y2002/17apr_rvf.htm?list52260. _____________________________________________________________________ LOOKING FOR LIFE IN ALL THE RIGHT PLACES By Edna DeVore From Space.com 18 April 2002 The SETI Institute's Edna DeVore reports from the second annual NASA Astrobiology Science Conference held at NASA's Ames Research Center, April 7 to 11, 2002. Tuesday, April 9: Hundreds of scientists fill the darkened meeting room while images of the largest and smallest structures in the universe appear before them. Leading experts from diverse scientific disciplines challenge the assembled crowd to explain the origin, evolution, distribution, and future of life on Earth and beyond. Physicists, geologists, chemists, biologists, and astronomers are sharing research, crossing the traditional boundaries of their disciplines to seek answers to three questions. What is the history of life? What is the future of life? Are we alone? This is the burgeoning field of astrobiology and today it's all happening in the historic Hangar 1 at NASA Ames Research Center, the California home of NASA's Astrobiology Institute. Senior scientists, Nobel Prize winners, graduate students, and educators are attending sessions and debating poster papers that ask questions such as "Is the Universe a Bio-Friendly Place?" They begin with the physical conditions for life as we know it, as well as life in extreme environments, and debate what may be inferred from our Earth-bound experiences. Can we detect life elsewhere if it indeed exists? Is there life on Mars? On Europa? On distant planets or moons in the habitable zones surrounding other stars? These questions and the scientific debate will drive the design of robotic explorers in our own solar system, and huge space-based observatories that will seek the signature of life in more distant solar systems. It's all about the application of the study of life (biology) with the explorer's vision of looking beyond Earth (astronomy)--hence, astrobiology. Get the full story at http://www.space.com/searchforlife/seti_devore_astrobio_020418.html. _____________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.h tml 22 April 2002 Astrobiology, exobiology and terraformation articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s1.html E. DeVore, 2002. Looking for life in all the right places. Space.com. Terrestrial extreme environments articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s2.html A. P. Amend and E. L. Shock, 1998. Energetics of amino acid synthesis in hydrothermal ecosystems. Science, 281(5383):1659-1662. Evolutionary biology and chemistry articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s5.html J. Halpern, 2002. Supramolecular chemistry and self-assembly special feature editorial: Reaching across the sciences. Proceedings of the National Academy of Sciences USA, 99(8):4762. F. Hof and J. Rebek, Jr., 2002. Molecules within molecules: Recognition through self-assembly. Proceedings of the National Academy of Sciences USA, 99(8):4775-4777. C. Huber and G. Wachtershauser, 1998. Peptides by activation of amino acids with CO on (Ni,Fe)S surfaces: implications for the origin of life. Science, 281(5377):670-672. J.-M. Lehn, 2002. Toward complex matter: supramolecular chemistry and self-organization. Proceedings of the National Academy of Sciences USA, 99(8):4763-4768. C. P. McKay and W. J. Borucki, 1997. Organic synthesis in experimental impact shocks. Science, 276(5311):390-392. NRAO, 2002. Antifreeze found in space. Spaceflight Now. G. M. Whitesides and M. Boncheva, 2002. Beyond molecules: Self- assembly of mesoscopic and macroscopic components. Proceedings of the National Academy of Sciences USA, 99(8):4769-4774. _____________________________________________________________________ CASSINI SIGNIFICANT EVENTS NASA/JPL release 11-17 April 2002 The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Wednesday, April 17. 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/. The primary activity on board the spacecraft this week was Probe Checkout (PCO) #9. The checkout was completed successfully. However, during the checkout, Goldstone Deep Space Station (DSS) 25 was required to end track and stow its antenna early due to high winds. The resulting telemetry outage caused the loss of PCO #9 real-time data and was expected to continue though the time allotted for PCO recorded data playback. At the request of Huygens Probe Operations Center personnel, with Cassini Program Manager concurrence, and with prior notification given to affected instruments, the Spacecraft Office built a real-time command to inhibit writing of Magnetospheric and Plasma Science (MAPS) data on the Solid State Recorder. This preserved the PCO data for playback at the next scheduled track. About 20 hours of MAPS data was lost. The pass over DSS 45 was then used to playback the PCO data and resume normal C31 activities. Additional instrument and spacecraft activities included the uplink of real-time commands to modify the Radio and Plasma Wave Science Instrument Expanded Block to fine tune resolution of data collected, clearing of the ACS high water marks, an autonomous CDS Solid State Recorder memory load partition repair, a demonstration over DSS 45 of the new Version 26.4 Command System, and uplink of a Privileged Action Program to disable/enable the Solid State Power Switch trip Fault Protection in support of the Probe checkout. Science Planning reported that all Target Working Teams made the delivery for the Science Operations Plan integration activity for orbits 15 through 20. The Instrument Operations Science Data Archive Engineer is conducting a Planetary Data Archive Workshop in conjunction with the Huygens Science Working Team meeting being held this week in Paris, France. After last week's delivery coordination meeting for Cosmic Dust Analyzer flight software, it was identified that V9 may generate invalid packet IDs. Workarounds were discussed and a final decision regarding uplink will be determined by next week. Mission Support and Services Office (MSSO) personnel met with Radio Science and the DSN Network Operations Project Engineer to discuss uplink transfers for the next Superior Conjunction Experiment. During the Gravitational Wave Experiment last December, about a dozen uplink transfers failed, each causing more than 2 hours outage in prime mission science data. The most likely cause identified was the setting DSS waiting too long to initiate tune-out. It was resolved that a briefing message will be sent to the DSN specifying begin tune-out time based on Spacecraft Office telecom analysis. All teams and offices supported the Cassini Monthly Management Review. The Program Manager gave a presentation to the JPL Executive Council on the issue of providing real-time communications during the SOI burn by doing the burn at Earth-line attitude. It is feasible to provide telemetry during all of the burn except for a period where the spacecraft is occulted by the rings, but at a cost in science return and propellant usage. Further studies were requested. MSSO personnel gave a talk and museum tour to attendees of a NASA Administrative Issues Conference held at the Jet Propulsion Laboratory. 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. _____________________________________________________________________ MARS ODYSSEY THEMIS IMAGES Arizona State University release 15-19 April 2002 * Eastern Floor of Holden Crater (Released 15 April 2002) http://themis.la.asu.edu/zoom-20020415a.html * Medusae Fossae Formation (Released 16 April 2002) http://themis.la.asu.edu/zoom-20020416a.html * Holden Crater/Uzboi Valles (Released 17 April 2002) http://themis.la.asu.edu/zoom-20020417a.html * Bosporus Planum (Released 18 April 2002) http://themis.la.asu.edu/zoom-20020418a.html * White Rock (Released 19 April 2002) http://themis.la.asu.edu/zoom-20020419a.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, DC. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen 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) Eastern Floor of Holden Crater (Released 15 April 2002) http://themis.la.asu.edu/zoom-20020415a.html The story With its beautiful symmetry and gullies radially streaming down to the floor, the dominant crater in this image is an impressive focal point. Yet, it is really just a small crater within a much larger one named Holden Crater. Take a look at the context image to the right to see just how much bigger Holden Crater is. Then come back to the image strip that shows the mottled surface of Holden Crater's eastern floor in greater detail, and count how many hills, ridges, channels, and small impact craters can be seen. No perfectly smooth terrain abounds there, that's for sure. The textured terrain of Holden Crater has been particularly intriguing ever since the Mars Orbital Camera on the Mars Global Surveyor spacecraft found evidence of sedimentary rock layers there that might have formed in lakes or shallow seas in Mars' ancient past. This finding suggests that Mars may have been more like Earth long ago, with water on its surface. Holden Crater might even have held a lake long ago. No one knows for sure, but it's an exciting possibility. Why? If water was once on the surface of Mars long enough to form sedimentary materials, maybe it was there long enough for microbial life to have developed too. (Life as we know it just isn't possible without the long-term presence of liquid water.) The question of life on the red planet is certainly tantalizing, but scientists will need to engage in a huge amount of further investigation to begin to know the answer. That's why orbital images of Holden Crater like this one are so important. They continue to help scientists piece together the answers to their fundamental questions about the planet's environment and its potential as a past or present habitat for life. The science Today's THEMIS image covers territory on the eastern floor of Holden Crater, which is located in region of the southern hemisphere called Noachis Terra. Holden Crater is 154 km in diameter and named after American Astronomer Edward Holden (1846-1914). This image shows a mottled surface with channels, hills, ridges and impact craters. The largest crater seen in this image is 5 km in diameter. This crater has gullies and what appears to be horizontal layers in its walls. This image is the 14th image in a series of daily images released by the THEMIS Team. Mars 2001 Odyssey Thermal Emission Imaging System (THEMIS) Medusae Fossae Formation (Released 16 April 2002) http://themis.la.asu.edu/zoom-20020416a.html The story "Yardang!" Now, that may seem like a peculiar-sounding curse word, but nobody would get in trouble for using it. A yardang is one of the very cool-sounding words geologists use to describe long, irregular features like the ones seen in this image. Yardangs are grooved, furrowed ridges that form as the wind erodes away weakly cemented material in the region. Rippling across the surface, yardangs tell the story of how the powerful Martian wind carved the surface into such a gorgeous pattern over time. (Don't miss clicking on the above image to see a detailed view, in which the beauty and almost dance-like symmetry of the waving terrain pops out in highly compelling, three-dimensional texture.) It may be easy to see which way the wind blows in this area, since these streamlined features point in the direction of prevailing winds. But how can geologists understand the various kinds of terrain seen here? First, they have to study the different patterns of erosion, looking closely at how the wind has stripped off certain layers and not others. Want to be a geologist yourself? Start at the bottom of the image and scroll upward, and see how the relatively smooth, higher terrain toward the south gradually becomes more and more eroded. Moving up the image, at first you'll see only a few, isolated regions of parallel ridges and knolls. Go a little farther north with your eyes (toward the center of the image), and you'll see how these linear knobs really get going! Once you get to the top of the image, only patches of these grooved ridges remain, leaving an incredibly smooth, wind-scrubbed surface behind. You know this layer has to be made of pretty hard material, because it seems impervious to further erosion. Geologists studying Mars can compare these Martian yardangs to examples found on Earth, such as those in the Lut desert of Iran. Humans have even been known to use the wind as their inspiration, sculpting the shape of yardangs themselves. The famous sphynx at Giza in Egypt is thought to be a yardang that's been whittled down a little more by ancient human chiselers. The science This THEMIS visible image was acquired near 11N, 159W and shows examples of the remarkable variations that can be seen in the erosion of the Medusae Fossae Formation. This Formation is a soft, easily eroded deposit that extends for nearly 1,000 km along the equator of Mars. In this region, like many others throughout the Medusae Fossae Formation, the surface has been eroded by the wind into a series of linear ridges called yardangs. These ridges generally point in direction of the prevailing winds that carved them, and demonstrate the power of Martian winds to erode the landscape of Mars. The easily eroded nature of the Medusae Fossae Formation suggests that it is composed of weakly cemented particles, and was most likely formed by the deposition of wind-blown dust or volcanic ash. Within this single image it is possible to see differing amounts of erosion and stripping of layers in the Medusae Fossae Formation. Near the bottom (southern) edge of the image a rock layer with a relatively smooth upper surface covers much of the image. Moving upwards (north) in the image this layer becomes more and more eroded. At first there are isolated regions where the smooth unit has been eroded to produce sets of parallel ridges and knobs. Further north these linear knobs increase in number, and only small, isolated patches of the smooth upper surface remain. Finally, at the top of the image, even the ridges have been removed, exposing the remarkably smooth top of hard, resistant layer below. This sequence of layers with differing hardness and resistance to erosion is common on Earth and on Mars, and suggests significant variations in the physical properties, composition, particle size, and/or cementation of these Martian layers. As is common throughout the Medusae Fossae Formation, very few impact craters are visible, indicating that the surface exposed is relatively young, and that the process of erosion may be active today. This image is the 15th image in a series of daily images released by the THEMIS team. Mars 2001 Odyssey Thermal Emission Imaging System (THEMIS) Holden Crater/Uzboi Valles (Released 17 April 2002) http://themis.la.asu.edu/zoom-20020417a.html The story Mars doesn't have a shortage of rugged terrain, and this area is no exception. While things look pretty quiet now, this cratered region was once the scene of some tremendous action. Long ago in Martian history, an incoming meteroid probably smashed into the planet and produced a giant impact crater named Holden Crater, which stretches 88 miles across the Martian surface. The history of the area around Holden Crater doesn't stop there. At some point, a catastrophic flood burst forth on the surface, forming an impressive outflow channel called Uzboi Valles. No one knows exactly how that happened, or whether the water might even have rushed into Holden Crater at some point, forming a long-ago lake. What we do know is that there is a lot of sedimentary material that could have formed in two hypothesized ways: in an ancient lake environment or as volcanic-ash deposits. Scientists are searching for the answers by studying the region where Uzboi Valles meets the crater. You can see the rough edge of Holden Crater running diagonally down in a sharply edged swath (from the top left-hand corner of this image to the center right-hand side). Just below it, running almost smoothly down the right-hand side of the image is an intriguing channel where water may once have flowed. Much of the terrain in the bottom half of the image, in fact, seems to be cut into a swish-swash of dissected sedimentary terrain. Sliced through in such a way, the terrain ends up carrying bunches of small, rounded hills called "hummocks." Earth can boast of its own rolling, hummocky terrain too, such as that found in the ravine-cut Missouri Hills and High Plains areas of South Dakota. The science This image, located near 27.0S and 35.5W, displays the intersection of Holden Crater with Uzboi Valles. This region of Mars contains a number of features that could be related to liquid water on the surface in the Martian past. Holden Crater contains finely layered sedimentary units that have been subsequently dissected. The hummucky terrain in the bottom half of the image is the remnants of this terrain, though the fine layers are not visible in this image at this resolution. The sedimentary units could have formed through deposition of material in a lacustrine type environment. Alternately, these layers could also be volcanic ash deposits. Uzboi Valles, which enters the crater from the southwest, is a catastrophic outflow channel that formed in the Martian past. The streamlined nature of the topographic features at the intersection of the crater with Uzboi Valles record the erosional pattern of flowing liquid water on the surface of Mars during the episodic outflow event. This image is the 16th image in a series of daily images released by the THEMIS team. Mars 2001 Odyssey Thermal Emission Imaging System (THEMIS) Bosporus Planum (Released 18 April 2002) http://themis.la.asu.edu/zoom-20020418a.html The story Splat! Take a look at the lumpy edge of the large crater half (left- hand side of the image) and compare it to the much neater rims of other craters in the region. Why is there such a difference? Scientists believe that when something hit the surface of Mars long ago, ice may have been present in the subsurface and was "regurgitated" upward into the Martian air along wih dirt and rock, "splooshing" outward. When that happened, the mixed-up, ejected material created a wavering, batter-like edge that is not typical for most (ice-free) craters. More ejected material from this same impact radiates much farther out from the crater, giving it a vague, sun- like appearance. Many of the small craters in this image appear much fainter and more subdued than the others. Their ghostly appearance may be due to a lava flow that smoothed out most of the terrain in this image, partially burying them... Or?... Maybe it was a layer of dust that settled in this region to accomplish the same concealed look. And what about that scar-like trek that cuts through the upper third of the image? It's an elongated fault created when a crust-breaking, tectonic force ripped apart the Martian terrain, leaving a long depression on the surface. This feature is called a graben, and we find them on Earth too (think of Death Valley, the lowest dry land in the United States, or the Jordan Dead Sea depression). The graben's rumpled, scar-like appearance is only enhanced by the stitchy-looking sand dunes that run down its sides. This dune pattern shows that the Martian wind probably blew down through the graben canyon to create their ruffled appearance. The wind doesn't have its way everywhere, though. The brighter surface material on the western side of the two diagonally positioned smaller craters is probably a layer of dust that has been shielded from removal by the craters' higher rims. Dark streaks (possibly dark sand) on the opposite side of these craters reveal that the wind has been blowing to no avail in the opposite direction too. So, think that explains everything in this image? Here's a quick geology quiz! Which features happened first? The dunes, the lava plains, the big crater, or the linear depression called a graben? To find out if you're right, check out the last paragraph in "The science" caption. Hint! Whatever happened later has to be on top of whatever came before. The science This THEMIS image is of Bosporus Planum, located in a region of smooth plains that appear to have formed from lava flows. A crater, ~7 km in diameter, on the left edge of the image has produced an ejecta blanket that can be seen radiating from the crater. Lobes of ejecta such as those seen close to the crater rim are not formed at most typical craters and may indicate that there was a ice component in the sub-surface material when the impact occurred. A linear depression trending from the northwest to southeast along the top of the image is about 1 to 2 km wide. This may be a tectonic feature, known as a graben, that forms when a region is under stresses that are pulling it apart. There are numerous small bright dunes or ripples along the margins of the floor of this linear feature that have formed perpendicular to the sides of the graben. This pattern of ripples suggests that the wind was blowing down the graben canyon. Similar small bright dunes can be faintly seen on top of the crater ejecta along ridges (most apparent directly to the east of the crater) and along the southern margin of the interior deposits in the crater. Bright wind streaks are also apparent in this area to the west (right) of several large craters. These streaks likely formed when very small particle size materials (like dust) is deposited on the surface and then protected from removal by the wind shadow produced by the crater's rim. Shorter dark streaks, possible deposits of dark sand, have formed to the east side of the smaller craters. These streaks on opposite sides of craters may indicate that there have been different wind patterns in the area, blowing in opposite directions. Subtle ridges near the south end of the image hint that there may have been other graben that have been nearly filled in. Many of the craters in this image have a subdued, buried appearance and may have been partially filled by lava flows or mantled by dust. A short geologic history of the area in this image can be created using the basic principles of geology, such as the principle of superposition (deposits that lie on top of other materials are younger). The linear depression must have formed after the deposition of the lava plains since it is a feature that would not have been otherwise preserved. Ejecta from the large crater has been deposited inside and over the edges of the linear depression, thus the crater must have formed after the linear depression. Finally, the bright dunes and dust streaks formed last because they have been deposited on top of all of these different features. Mars 2001 Odyssey Thermal Emission Imaging System (THEMIS) White Rock (Released 19 April 2002) http://themis.la.asu.edu/zoom-20020419a.html The story Fingers of hard, white rock seem to jut out like icy daggers across a moody Martian surface, but appearances can be deceiving. These bright, jagged features are neither white, nor icy, nor even hard and rocky! So what are they, and why are they so different from the surrounding terrain? Scientists know that you can't always trust what your eyes see alone. You have to use other kinds of science instruments to measure things that our eyes can't see... things like information about what kinds of minerals make up the landforms. Mars scientists once thought, for instance, that these unusual features might be vast hills of salt, the dried up remains of a long-ago, evaporated lake. Not so, said an instrument on the Mars Global Surveyor spacecraft, which revealed that the bright material is probably made up of volcanic ash or windblown dust instead. And talk about a cyclical "ashes to ashes, dust to dust" story! Particles of this material fell and fell until they built up quite a sedimentary deposit, which was then only eroded away again by the wind over time, leaving the spiky terrain seen today. It looks white, but its apparent brightness arises from the fact that the surrounding material is so dark. Of course, good eyesight always helps in understanding. A camera on Mars Global Surveyor with close-up capabilities revealed that sand dunes are responsible for the smudgy dark material in the bright sediment and around it. But that's not all. The THEMIS camera on the Mars Odyssey spacecraft that took this image reveals that this ashy or dusty deposit once covered a much larger area than it does today. Look yourself for two small dots of white material on the floor of a small crater nearby (center right in this image). They preserve a record that this bright deposit once reached much farther. Since so little of it remains, you can figure that the material probably isn't very hard, and simply blows away. One thing's for sure. No one looking at this image could ever think that Mars is a boring place. With all of its bright and dark contrasts, this picture would be perfect for anyone who loves Ansel Adams and his black-and-white photography. The science "White Rock" is the unofficial name for this unusual landform which was first observed during the Mariner 9 mission in the early 1970's. As later analysis of additional data sets would show, White Rock is neither white nor dense rock. Its apparent brightness arises from the fact that the material surrounding it is so dark. Images from the Mars Global Surveyor MOC camera revealed dark sand dunes surrounding White Rock and on the floor of the troughs within it. Some of these dunes are just apparent in the THEMIS image. Although there was speculation that the material composing White Rock could be salts from an ancient dry lakebed, spectral data from the MGS TES instrument did not support this claim. Instead, the White Rock deposit may be the erosional remnant of a previously more continuous occurrence of air fall sediments, either volcanic ash or windblown dust. The THEMIS image offers new evidence for the idea that the original deposit covered a larger area. Approximately 10 kilometers to the southeast of the main deposit are some tiny knobs of similarly bright material preserved on the floor of a small crater. Given that the eolian erosion of the main White Rock deposit has produced isolated knobs at its edges, it is reasonable to suspect that the more distant outliers are the remnants of a once continuous deposit that stretched at least to this location. The fact that so little remains of the larger deposit suggests that the material is very easily eroded and simply blows away. _____________________________________________________________________ STARDUST STATUS REPORT NASA/JPL release 19 April 2002 There was one Deep Space Network tracking pass in the past week and all subsystems onboard the spacecraft are normal. Stardust passed through aphelion, its furthest point from the Sun, 2.72 AU and is now on its way toward the inner solar system. This is the farthest distance ever reached by a solar-powered spacecraft. Far beyond the orbit of Mars, the sunlight intensity is only 13% of what we see at Earth, resulting in very cold temperatures and diminishing the power the spacecraft's solar cells can generate. However, the battery's charge state has not dropped below 91.6 %. The spacecraft has now successfully traveled 1.5 of its planned 3 loops around the Sun. 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 16.