Marsbugs: The Electronic Astrobiology Newsletter Volume 11, Number 24, 8 June 2004 Editor/Publisher: David J. Thomas, Ph.D., Science Division, Lyon College, Batesville, Arkansas 72503-2317, USA. dthomas@lyon.edu 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 editor, except for specific articles, in which instance copyright exists with the author/authors. Opinions expressed in this newsletter are those of the authors, and are not necessarily endorsed by the editor or by Lyon College. E-mail subscriptions are free, and may be obtained by contacting the editor. Information concerning the scope of this newsletter, subscription formats and availability of back-issues is available at http://www.lyon.edu/projects/marsbugs. The editor does not condone "spamming" of subscribers. Readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing lists. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editor. __________________________________________________________________________ Articles and News 1) DARK ENERGY TIED TO HUMAN ORIGINS By Robert Roy Britt 2) NASA RESEARCHERS CUSTOMIZE "LAB-ON-A-CHIP" TECHNOLOGY TO HELP PROTECT FUTURE SPACE EXPLORERS AND DETECT LIFE FORMS ON MARS NASA/MSFC release 04-156 3) CAUGHT IN THE ACT Harvard-Smithsonian Center for Astrophysics release 04-23 4) NEW MOON SHOT NOT SO COSTLY From United Press International and SpaceDaily 5) ROCKS TELL TALE OF WARM EARLY ATMOSPHERE--CONTINENTS PLAYED ROLE IN DECAY, RENEWAL OF ANCIENT GREENHOUSE By Dawn Levy 6) METEORITE CRASH TURNED EARTH INSIDE OUT: NEW RESEARCH PAINTS A PICTURE OF WHAT HAPPENED BILLIONS OF YEARS AGO WHEN A DEVASTATING METEORITE CRASHED INTO THE EARTH By Karen Kelly 7) EARLIEST BILATERAL FOSSIL DISCOVERED By Leslie Mullen 8) FLESHING OUT MARTIAN PROTEINS: INTERVIEW WITH RICHARD MATHIES From Astrobiology Magazine Announcements 9) SQUYRES TO ADDRESS MARS SOCIETY CONVENTION Mars Society release 10) SPACE ENTHUSIASTS, CASSINI SCIENTISTS INVITE PUBLIC TO UA ON JUNE 19 By Lori Stiles 11) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas Mission Reports 12) CASSINI-HUYGENS UPDATES NASA/JPL releases 13) MARS EXPLORATION ROVERS UPDATES NASA/JPL releases 14) MARS GLOBAL SURVEYOR IMAGES NASA/JPL/MSSS release 15) MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 16) ROSETTA: MOVING TOWARDS CRUISE PHASE ESA release __________________________________________________________________________ DARK ENERGY TIED TO HUMAN ORIGINS By Robert Roy Britt From Space.com 31 May 2004 Among the most elusive and important questions in science are whether we're alone and what the heck that strange stuff is that's pushing the universe apart. Neither is likely to be answered anytime soon, yet each occupies many great minds and together they drive billions of dollars in research spending every year. Now wouldn't it be really weird if these two seemingly unrelated questions were intimately linked? Strange but possibly true, says Mario Livio, a theorist at the Space Telescope Science Institute (STScI). Read the full article at http://www.space.com/scienceastronomy/mystery_monday_040531.html. __________________________________________________________________________ NASA RESEARCHERS CUSTOMIZE "LAB-ON-A-CHIP" TECHNOLOGY TO HELP PROTECT FUTURE SPACE EXPLORERS AND DETECT LIFE FORMS ON MARS NASA/MSFC release 04-156 1 June 2004 Imagine a huge laboratory filled with people and equipment shrinking to fit on a small chip--the size of a dime. Scientists on Earth use labs on chips for medical tests and other research. Marshall Center scientists are customizing these chips for use in space. One day they may be used in devices to detect contaminates, and rovers may use them to identify life on Mars. With a microscope and computer monitor, researchers at NASA's Marshall Space Flight Center in Huntsville, AL, watch fluorescent bacteria flow through tiny, fluid highways on a dime-sized lab on a chip. Lab-on-a-chip technology allows chemical and biological processes--previously conducted on large pieces of laboratory equipment--to be performed on a small glass plate with fluid channels, known to scientists as microfluidic capillaries. "We are studying how lab-on-a-chip technology can be used for new tools to detect bacteria and life forms on Earth and other planets and for protecting astronauts by monitoring crew health and detecting microbes and contaminants in spacecraft," explains Dr. Helen Cole, project manager for the Lab-on-a-Chip Applications Development program. The chips are made with the same micro-fabrication technique used to print circuits on computer chips. Chemicals and fluid samples can be mixed, diluted, separated, and controlled using channels or electrical circuits embedded in the chip. On Earth, some basic lab-on-a-chip technology approaches are being used for commercial, medical diagnostic applications, such as an in-office test for strep throat, or modern in-home pregnancy tests. These applications conduct a test and yield results in a short time, with a hand-held portable device containing a simple chip design. "NASA requires complex lab-on-a-chip technology, so scientists can conduct multiple chemical and biological assays or perform many processes on a single chip," says Cole. "Current commercial devices are not designed to work in space, so we are developing a set of unique chips along with a corresponding miniaturized controller and analysis unit." NASA researchers are developing complex, portable microarray diagnostic chips to test for all the genes and DNA responsible for determining the traits of a particular organism, detect specific types of organisms, or use biosensor-like probes such as antibodies to detect molecules of interest. By applying this technology in laboratories and in the field where organisms live in extreme environments on Earth, astrobiologists can compare Earth-life with that which may be found on other planets. "The micro array chip system developed to go to Mars will be lightweight, portable and capable of detecting organic molecules," says Dr. Lisa Monaco, the project scientist for the Lab-on-a-Chip Applications Development program. "This instrumentation can easily be adapted for monitoring crew health and their environment." Since the chips are small, a large number of them can be carried on a Mars rover to search for life or on carried on long-duration human exploration missions for monitoring microbes inside lunar or martian habitats. "We need customized microarray chips to find and characterize life at remote places on Earth, Mars, and other places in the solar system," says Dr. Andrew Steele, a scientist at the Carnegie Institution of Washington, a private research organization. Steele, the principal investigator for the Modular Assays for Solar System Exploration (MASSE) project, is working with Marshall scientists and engineers to develop the technology and instruments needed to analyze samples quickly and produce images of samples. "When astrobiologists study life in extreme environments--whether it lives deep in the ocean, in Antarctica, or on Mars--they need a handheld device or something that can fit on a small robot," Steele explains. "We also need to be able to analyze the tests as quickly as possible within periods from 1 to 24 hours. Marshall is one of just a few places in the world developing these specific technologies for space and exploration applications and has unique experience in miniaturizing these instruments and designing them for the harsh space environment." The Marshall Center team is collaborating with scientists at other NASA centers and at universities to design chips for many applications, such as studying how fluidic systems work in spacecraft and identifying microbes in self-contained life support systems. To make customized chips for these various applications, NASA has an agreement with the U.S. Army's Microdevices and Microfabrication Laboratory at Redstone Arsenal in Huntsville. The lab-on-a-chip research is funded by NASA's Biological and Physical Research Enterprise through the Marshall Center's Microgravity Science and Applications Division. More information about space research is available on the Internet at http://spaceresearch.nasa.gov/. Read the original news release at http://www.msfc.nasa.gov/news/news/releases/2004/04-156.html. An additional article on this subject is available at http://www.spacedaily.com/news/chip-tech-04k.html. __________________________________________________________________________ CAUGHT IN THE ACT Harvard-Smithsonian Center for Astrophysics release 04-23 2 June 2004 How old is too old? Pro football players tend to peak in their late 20s, and few continue their careers beyond the age of 35. For young stars, the peak age for planet formation is around 1 to 3 million years. By 10 million years old, their resources are exhausted and they retire to a life on the stellar "main sequence." Using telescopes on the ground and in space, a team of astronomers led by Lee W. Hartmann and Aurora Sicilia-Aguilar (Harvard-Smithsonian Center for Astrophysics) is studying Sun-like stars in their waning formative years, within clusters older than previously explored. They seek to refine our understanding of planet formation by studying dusty protoplanetary disks around such stars. Their results, presented today at the 204th meeting of the American Astronomical Society in Denver, Colorado, better define the time span during which planets might form. "While the planets that may be forming cannot be detected directly," said Sicilia-Aguilar, "we can see changes in the circumstellar dusty accretion disks caused as the planets sweep up and accumulate mass. The data also has shown dramatic differences between stars of 3 and 10 million years of age: the younger stars frequently have dusty disks capable of forming planets, while such disks are essentially absent in the older population." The team used data from the Smithsonian Institution's Whipple Observatory telescopes, the WIYN telescope at Kitt Peak National Observatory, and from the Spitzer Space Telescope (the latter made available as part of the Guaranteed Time Program of Infrared Array Camera PI Giovanni Fazio), to make these findings. "We are trying to understand the evolution of protoplanetary disks around stars not too different from the Sun," said team leader Lee W. Hartmann. "Many stars about 1 million years old have disks, but by 10 million years, almost none have disks. We are trying to find stars at an in-between age and 'catch them in the act' of forming planets." Circumstellar dust disks enshroud young stars, and astronomers understand this to be a common feature of stellar evolution and of possible planetary system formation. The initial protoplanetary disks contain the gas and dust that provide the raw materials for the formation of later planetary systems. "After stars form planets in their disks and clear out most of the material--either by accretion onto the star, accretion onto planets, or ejection--small amounts of dust can remain in so-called 'debris disks.' Most or all of this debris dust is thought to be continuously generated by the collision of small bodies, much like the zodiacal light in our solar system," said Hartmann. The team is presenting the first identification of low mass stars in the young clusters Trumpler 37 and NGC 7160. (These clusters are loose associations of stars that have formed together in the comparatively recent past.) "The cluster members confirm the age estimates of 1 to 5 million years for Tr37 and 10 million years for NGC 7160," said Sicilia-Aguilar. "We do find active accretion in some of the stars in Tr37. The average accretion rate is equivalent to swallowing up 10 Jupiter masses in a million years. This is consistent with models of viscous disk evolution. In comparison, we have detected no signs of active accretion so far in the older cluster NGC 7160, suggesting that disk accretion ends within 10 million years. This probably coincides with the major phase of giant planet formation." Trumpler 37 is of more immediate interest, said Hartmann, because we hope to find stars with Jupiter-size planets that are still accumulating material from the disks, so the disks are not completely cleared out yet. However, there may be a few objects in the 10 million-year-old cluster NGC 7160 that are also still forming their giant planets. Not all disks evolve at the same rate. "Thus we expect eventually to find out more about the frequency of debris disks, and the rate at which the dust in such disks is removed, by studying the 10-million-year-old cluster NGC 7160 and comparing it to Trumpler 37," said Hartmann. In addition to Sicilia-Aguilar and Hartmann, team members include Cesar Briceno (Centro de Investigaciones de Astronomia), James Muzerolle (University of Arizona), and Nuria Calvet (Smithsonian Astrophysical Observatory). This work was supported by NASA grant NAG5-9670. Headquartered in Cambridge, MA, the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe. A high-resolution image to accompany this release is available online at http://www.cfa.harvard.edu/press/pr0423image.html. Contacts: David Aguilar, Director of Public Affairs Harvard-Smithsonian Center for Astrophysics Phone: 617-495-7462 Fax: 617-495-7468 E-mail: daguilar@cfa.harvard.edu Christine Pulliam Public Affairs Specialist Harvard-Smithsonian Center for Astrophysics Phone: 617-495-7463 Fax: 617-495-7016 E-mail: cpulliam@cfa.harvard.edu Read the original news release at http://cfa- www.harvard.edu/press/pr0423.html. Additional articles on this subject are available at: http://spaceflightnow.com/news/n0406/03dustdisk/ http://www.universetoday.com/am/publish/catching_stars_act_forming_planets .html __________________________________________________________________________ NEW MOON SHOT NOT SO COSTLY From United Press International and SpaceDaily 2 June 2004 NASA's plan to fulfill President George W. Bush's space exploration effort suggests the agency will have to spend about $64 billion over the next 15 years to send U.S. astronauts back to the moon. Although the price tag-- projected in fiscal year 2003 dollars--excludes several elements of the Bush space plan, it is far less than the hundreds of billions critics of the proposal have suggested it would cost. The estimate is based on National Aeronautics and Space Administration budget data compiled in an analysis completed May 10 by the Congressional Research Service. A copy of the analysis, which has been seen by only a few members of Congress, was obtained by United Press International. Read the full article athttp://www.spacedaily.com/news/spacetravel- 04zf.html. __________________________________________________________________________ ROCKS TELL TALE OF WARM EARLY ATMOSPHERE--CONTINENTS PLAYED ROLE IN DECAY, RENEWAL OF ANCIENT GREENHOUSE By Dawn Levy Stanford University release 2 June 2004 If a time machine could take us back 4.6 billion years to the Earth's birth, we'd see our sun shining 20 to 25 percent less brightly than today. Without an earthly greenhouse to trap the sun's energy and warm the atmosphere, our world would be a spinning ball of ice. Life may never have evolved. But life did evolve, so greenhouse gases must have been around to warm the Earth. Evidence from the geologic record indicates an abundance of the greenhouse gas carbon dioxide. Methane probably was present as well, but that greenhouse gas doesn't leave enough of a geologic footprint to detect with certainty. Molecular oxygen wasn't around, indicate rocks from the era, which contain iron carbonate instead of iron oxide. Stone fingerprints of flowing streams, liquid oceans and minerals formed from evaporation confirm that 3 billion years ago, Earth was warm enough for liquid water. Now, the geologic record revealed in some of Earth's oldest rocks is telling a surprising tale of collapse of that greenhouse--and its subsequent regeneration. But even more surprising, say the Stanford scientists who report these findings in the May 25 issue of the journal, Geology, is the critical role that rocks played in the evolution of the early atmosphere. "This is really the first time we've tried to put together a picture of how the early atmosphere, early climate and early continental evolution went hand in hand," said Donald R. Lowe, a professor of geological and environmental science who wrote the paper with Michael M. Tice, a graduate student investigating early life. NASA's Exobiology Program funded their work. "In the geologic past, climate and atmosphere were really profoundly influenced by development of continents." The record in the rocks To piece together geologic clues about what the early atmosphere was like and how it evolved, Lowe, a field geologist, has spent virtually every summer since 1977 in South Africa or Western Australia collecting rocks that are, literally, older than the hills. Some of the Earth's oldest rocks, they are about 3.2 to 3.5 billion years old. "The further back you go, generally, the harder it is to find a faithful record, rocks that haven't been twisted and squeezed and metamorphosed and otherwise altered," Lowe says. "We're looking back just about as far as the sedimentary record goes." After measuring and mapping rocks, Lowe brings samples back to Stanford to cut into sections so thin that their features can be revealed under a microscope. Collaborators participate in geochemical and isotopic analyses and computer modeling that further reveal the rocks' histories. The geologic record tells a story in which continents removed the greenhouse gas carbon dioxide from an early atmosphere that may have been as hot as 70 degrees Celsius (158°F). At this time the Earth was mostly ocean. It was too hot to have any polar ice caps. Lowe hypothesizes that rain combined with atmospheric carbon dioxide to make carbonic acid, which weathered jutting mountains of newly formed continental crust. Carbonic acid dissociated to form hydrogen ions, which found their way into the structures of weathering minerals, and bicarbonate, which was carried down rivers and streams to be deposited as limestone and other minerals in ocean sediments. Over time, great slabs of oceanic crust were pulled down, or subducted, into the Earth's mantle. The carbon that was locked into this crust was essentially lost, tied up for the 60 million years or so that it took the minerals to get recycled back to the surface or outgassed through volcanoes. The hot early atmosphere probably contained methane too, Lowe says. As carbon dioxide levels fell due to weathering, at some point, levels of carbon dioxide and methane became about equal, he conjectures. This caused the methane to aerosolize into fine particles, creating a haze akin to that which today is present in the atmosphere of Saturn's moon Titan. This "Titan Effect" occurred on Earth 2.7 to 2.8 billion years ago. The Titan Effect removed methane from the atmosphere and the haze filtered out light; both caused further cooling, perhaps a temperature drop of 40 to 50 degrees Celsius. Eventually, about 3 billion years ago, the greenhouse just collapsed, Lowe and Tice theorize, and the Earth's first glaciation may have occurred 2.9 billion years ago. The rise after the fall Here the rocks reveal an odd twist in the story -- eventual regeneration of the greenhouse. Recall that 3 billion years ago, Earth was essentially Waterworld. There weren't any plants or animals to affect the atmosphere. Even algae hadn't evolved yet. Primitive photosynthetic microbes were around and may have played a role in the generation of methane and minor usage of carbon dioxide. As long as rapid continental weathering continued, carbonate was deposited on the oceanic crust and subducted into what Lowe calls "a big storage facility... that kept most of the carbon dioxide out of the atmosphere." But as carbon dioxide was removed from the atmosphere and incorporated into rock, weathering slowed down--there was less carbonic acid to erode mountains and the mountains were becoming lower. But volcanoes were still spewing into the atmosphere large amounts of carbon from recycled oceanic crust. "So eventually the carbon dioxide level climbs again," Lowe says. "It may never return to its full glorious 70 degrees Centigrade level, but it probably climbed to make the Earth warm again." This summer, Lowe and Tice will collect samples that will allow them to determine the temperature of this time interval, about 2.6 to 2.7 billion years ago, to get a better idea of how hot Earth got. New continents formed and weathered, again taking carbon dioxide out of the atmosphere. About 3 billion years ago, maybe 10 or 15 percent of the Earth's present area in continental crust had formed. By 2.5 billion years ago, an enormous amount of new continental crust had formed--about 50 to 60 percent of the present area of continental crust. During this second cycle, weathering of the larger amount of rock caused even greater atmospheric cooling, spurring a profound glaciation about 2.3 to 2.4 billion years ago. Over the past few million years we have been oscillating back and forth between glacial and interglacial epochs, Lowe says. We are in an interglacial period right now. It's a transition--and scientists are still trying to understand the magnitude of global climate change caused by humans in recent history compared to that caused by natural processes over the ages. "We're disturbing the system at rates that greatly exceed those that have characterized climatic changes in the past," Lowe said. "Nonetheless, virtually all of the experiments, virtually all of the variations and all of the climate changes that we're trying to understand today have happened before. Nature's done most of these experiments already. If we can analyze ancient climates, atmospheric compositions and the interplay among the crust, atmosphere, life and climate in the geologic past, we can take some first steps at understanding what is happening today and likely to happen tomorrow." Read the original news release at http://news- service.stanford.edu/news/2004/june2/lowegeo-62.html. Additional articles on this subject are available at: http://www.astrobio.net/news/article1004.html http://www.spacedaily.com/news/climate-04zj.html. __________________________________________________________________________ METEORITE CRASH TURNED EARTH INSIDE OUT: NEW RESEARCH PAINTS A PICTURE OF WHAT HAPPENED BILLIONS OF YEARS AGO WHEN A DEVASTATING METEORITE CRASHED INTO THE EARTH By Karen Kelly University of Toronto release 3 June 2004 A devastating meteorite collision caused part of the Earth's crust to flip inside out billions of years ago and left a dusting of a rare metal scattered on the top of the crater, says new U of T research. The study, published in the June 3 issue of Nature, examines the devastating effects of meteorite impacts on the Earth's evolution. Researchers from the University of Toronto and the Geological Survey of Canada studied the remains of a 250-kilometre wide crater in Sudbury, Ontario, known as the Sudbury Igneous Complex, caused by a collision with a Mount Everest-sized meteorite 1.8 billion years ago. They discovered that the meteorite burrowed deep into the Earth's upper crust - which measures an average of 35 kilometers thick - and caused the upper crust to be buried under several kilometers of melted rock derived from the lower crust. The dynamics of meteorite impacts remain a source of debate among researchers and, until now, there has been little hard evidence to prove a meteorite could pierce through the Earth's upper crust and alter its Compositional makeup. "It had not really been appreciated that large impacts would selectively move material from the bottom of the crust up to the top," says lead researcher James Mungall, a U of T geology professor. "This has been suggested for the Moon at times in the past but ours is the first observational evidence that this process has operated on Earth." In the study, Mungall, his graduate student Jacob Hanley and Geological Survey researcher Doreen Ames concluded Sudbury Igneous Complex is predominantly derived from shock-melted lower crust rather than the average of the whole crust as has been previously supposed. The researchers discovered a subtle but significant enrichment of iridium, an extremely rare metal found mainly in the Earth's mantle and in meteorites. Due to the low magnesium and nickel content found in the samples they concluded that the iridium came from the meteorite itself rather than the Earth's mantle. The discovery of the iridium allowed the researchers to paint a picture of what happened billions of years ago, when a meteorite collided with the earth at a velocity exceeding 40 kilometers per second and caused a shock melting of 27,000 cubic kilometers of the crust. "The impact punched a hole to the very base of the crust and the meteorite itself was probably vaporized," says Mungall. This collision, he says, caused a plume of iridium-enriched vaporized rock to surge up and recondense on top of the impact site. Simultaneously, the cavity collapsed within minutes or hours to form a multi-ring basin 200 to 300 kilometers in diameter and one to six kilometers deep. "Picture a drop falling into a cup of milk, thus producing a bowl-shaped depression for a moment before the milk outside rushes back in to fill the hole," says Mungall. "Now imagine that the falling drop of milk is a rock 10 kilometers in diameter, and the resulting depression is 30 to 40 kilometers deep." The Sudbury Basin is the second oldest very large impact crater site in the world but is one of the most accessible and well preserved. The oldest one, South Africa's two-billion year-old Vredefort Crater, has eroded over time and only the basement remains. Another impact site, the Chicxulub Crater in Yucatan Peninsula, believed to be responsible for the extinction of the dinosaurs, lies buried under beds of limestone. The study was funded in part by the Geoscience Laboratories of the Ontario Geological Survey and the Geological Survey of Canada. Contact: James Mungall, Department of Geology Phone: 416-978-2975 E-mail: mungall@geology.utoronto.ca Read the original news release at http://www.news.utoronto.ca/bin6/040603- 92.asp. An additional article on this subject is available at http://www.spacedaily.com/news/deepimpact-04i.html. __________________________________________________________________________ EARLIEST BILATERAL FOSSIL DISCOVERED By Leslie Mullen From Astrobiology Magazine 5 June 2004 Scientists have reported that bilateral animals appeared 600 million years ago, about 50 million years before the Cambrian Explosion. Before the Cambrian 550 million years ago, most life on Earth was composed of bacteria and single-celled animals. But then something happened to cause an "explosion" of complex multi-cellular body forms. Scientists have long been puzzled about why this burst of diversity occurred. Some have suggested that a sudden rise in oxygen allowed larger and more complex life forms to appear and develop. Others have suggested that animal complexity started long before the Cambrian, and that we had only failed to find fossil evidence of it. Reporting in the journal, Science, Jun-Yuan Chen of Nanjing Institute of Geology and Paleontology in China, David Bottjer of the University of Southern California, and colleagues described 10 bilateral fossils they discovered in the Doushantuo Formation in China. The fossils are the first evidence of bilateral animals--body plans that have a left and right side, a top and bottom, and a mouth and anus. Early animals like sponges and cnidarians have radial symmetry--rounded body plans that, when cut in half from any direction, are always two mirror images. "This discovery helps us to learn more about the murky origins of bilaterian animals, which are most of what we see on Earth. You and I would have to go scuba diving to see cnidarians and sponges," Bottjer said in the Science Magazine release. Before this discovery, the earliest bilateral fossils were mollusk-like Kimberella, Ediacaran fossils that appeared about 20 to 30 million years before the Cambrian. "These fauna were soft, a lot of them were just big flat sheets with compartments," according to Bottjer. "There were probably some bilaterians around. We just don't have much of a record. Then you go back farther in time and we don't have any record of any of these Ediacaran animals. That's where our fossils come in," he told Science. The Doushantuo Formation in China's Guizhou Province is a phosphorite rock formation that developed in a shallow sea 580 to 600 million years ago. These rocks are already famous for having yielded the oldest known multi- celled embryos. The scientists cut thousands of thin slices from the rock and examined them under a microscope. In addition to the bilateral animal fossils, the scientists found sponges, cnidarians, eggs and embryos. These soft bodies were preserved due to the phosphate, which, thanks to special conditions, quickly worked its way into the cellular structures. The bilateral animal fossils measure only a few hundred microns across--they would look like a mere speck to the naked eye, measuring about the same width of two to four human hairs. Pits located near the front end of the body may have been sensory organs. The miniscule animal probably moved through the water by flexing its body. The specimens probably looked like little helmets [banner image left]. The researchers named the animal Vernanimalcula guizhouena, meaning "small spring animal from Guizhou." The rocks formed after the "winter" of the Earth's final Snowball Earth episode, when glaciers are believed to have covered the planet. Some paleontologists are doubtful about whether the fossils really are bilateral life forms, or even if they are fossils at all. But if the features are bilateral fossils, they may point to a trend in pre-Cambrian animal development. If Vernanimalcula were swimming around 600 million years ago, then the Cambrian Explosion may be a reflection of increases in body size rather than in animal complexity. The Vernanimalcula fossils suggest that "maybe complex animals were around beforehand, and it was just the ability to grow large that caused the Cambrian Explosion," Bottjer said in the Science release. Read the original article at http://www.astrobio.net/news/article1005.html. __________________________________________________________________________ FLESHING OUT MARTIAN PROTEINS: INTERVIEW WITH RICHARD MATHIES From Astrobiology Magazine 7 June 2004 Imagine having a modern biology lab on another planet. Then imagine putting that lab on a tiny silicon chip. That portable concept--when applied to detecting the building blocks of life, amino acids--is being investigated for future Mars missions. Biophysicist Richard Mathies and his colleagues hope to proof-test such a method's exquisite sensitivity by looking at samples from the closest terrestrial analogs to what might eventually be encountered on Mars later this decade. One such place is one of the driest places on Earth, the Atacama Desert in Chile, which Mathies' team will investigate later this year. The project will develop an instrument that would probe Mars dust for evidence of life-based amino acids. A NASA Astrobiology Science and Technology for Exploring Planets (ASTEP) grant has been awarded to Mathies, along with Professor Bada at the Scripps Institution of Oceanography and Dr. Grunthaner at JPL, to develop what they call their Microfabricated Organic Analyzer [MOA] for In Situ Exploration of Mars and Other Solar Bodies. This new instrument [MOA] will then be coupled to a previously developed device called the Mars Organic Detector [MOD], which will acquire and prepare a martian soil sample for biological testing. The MOD itself is already considered a mature platform. The unit applies heat to a soil sample then purifies and concentrates any organics (called polycyclic aromatic hydrocarbons [PAH], organic amines and amino acids)-- the traditional stuff of protein building blocks. "Right now, we are able to detect parts per trillion of amino acids in a gram of soil, which is thousands of times better than Viking," Bada said. The second step then looks for a fluorescent signal based on the travel times of the amino acids down a thin capillary. Different amino acids--there are 20 different kinds used by humans--travel down the tube at different rates, which allows partial identification of those present. But their design looks not only for this chemical signature of amino acids, since it tests for another critical characteristic of life-based amino acids. Biologically derived amino acids on earth are homochiral and they're all left handed. Amino acids can be made by physical processes in space--they're often found in meteorites--but they're about equally left- and right-handed. If amino acids on Mars have a preference for left- handed over right-handed amino acids, or vice versa, they could only have come from some life form on the planet, Mathies said. When married together, these remote, robotic laboratories support the suite of next-generation experiments to look for evidence of life on Mars. Bada said, "When I started thinking about tests for chirality and first talked to Rich [Mathies], we had conceptual ideas, but nothing that was actually functioning. He has taken it to the point where we have an honest-to-God portable instrument." With its much greater sensitivity compared to other biological tests that were first tried on the 1977 Viking mission, the new instruments are anticipated for flight aboard NASA's roving, robotic Mars Science Laboratory mission and/or the European Space Agency's ExoMars mission, both scheduled for launch in 2009. Astrobiology Magazine had the opportunity to talk with Professor Richard Mathies about his research group's interest in the Mars Exploration Project. Astrobiology Magazine (AM): The project is founded on the hypothesis that extraterrestrial life would be based on amino acid polymers, and that the evidence for such biology is remotely accessible by heating dirt. Did the 1977 Mars Viking experiments not have the required sensitivity to make a determination of whether a signal was coming from an organic source? Richard Mathies (RM): The Viking GCMS experiment did not have sufficient sensitivity to detect even high levels of organic molecules like amino acids, and the release experiments were based on the remote possibility of the presence of bacterial cells that were alive and could grow under the available conditions. We feel that the presence of amino acids and measuring homochirality--a prevalence of one type of handedness over another--would be absolute proof of extinct or extant life. That's why we focused on this type of experiment. If we go to Mars and find amino acids but don't measure their chirality, we're going to feel very foolish. Our instrument can do it. AM: It was concluded in 1977 that Mars' soil was strongly oxidizing, and that this might complicate interpretation. When a soil sample is heated, can the evolved carbon dioxide just become masked by oxidizing soil conditions or is there another inherent flaw that limits the interpretation of adding nutrients or heat to soil as a biological test? RM: The pyrolysis conditions cause the conversion of amino acids to amines (especially abundant glycine to methyl amine) but these products are buried under the intense carbon dioxide [CO2] and water [H2O] peaks in the mass spectrometer traces making the amines undetectable. This makes the [Viking's] GCMS experiment about one thousand times less sensitive for amino acid detection than the apparatus we are developing [1]. AM: The ill-fated European Beagle 2 lander was planning to measure carbon isotopes on Mars as a function of temperature. Are there problems you might foresee with interpreting carbon isotopes alone that testing directly for amino acids clears up? RM: The determination of the source of isotopic ratio signatures is difficult because it is hard to unambiguously attribute a change in isotopic ratio to a biological source. First off, the changes are often small. Second, you have to compare the observed ratio to an inorganic standard to identify a biological induced change. On earth this is done with reference to the ratios in carbonates. It is not known what standard to use for this comparison on Mars to establish the nonbiotic control. Our search for amino acids and their chiral ratios is much more interpretable. The prototypes our group is developing for the organic tests would first measure microscopic quantities of amino acids using fluorescent labeling and capillary electrophoresis (CE) to determine mass and charge, then check for homochirality. AM: Can you describe what false positives might arise from the first step of just measuring amino acids alone vs. their biological origin (as left- handed chiral) in the second step? RM: False positives might arise from space craft residues or propellants. These signals should go down as the rover moves away from the landing area or takes samples farther from the craft or deeper into the soil bed. It is also possible that we might see amines or ammonia that result from decomposition of organic molecules and amino acids. While this might interfere with amino acid detection this result alone would be very interesting in that it indicates that organic compounds are present on Mars. AM: There has been recent discussion that sulfur isotopic fractionation might be a clear biological differentiator, particularly given the high sulfate concentrations found at the Opportunity site. Are there disadvantages to that isotope test for remote in situ work compared to building the portable lab your group is designing? RM: Studies of sulfur isotopes have the same problems as carbon isotopes and in addition the changes introduced by biological processes are likely to be smaller because of the larger mass of sulfur. AM: You mentioned the failure of Viking-style experiments to detect life at Chile's Atacama desert site. Are there plans to run the electrophoresis tests in situ there as one terrestrial calibration point? RM: The Viking-type GCMS (Gas Chromatograph/Mass Spectometer) was not run in Atacama but would be unlikely to work well there because of the intense carbon dioxide (CO2) emission from carbonates. We do plan to run the MOD system coupled to the CE (electrophoresis) analyzer (the whole thing is called MOA) sometime this year in the Atacama. AM: Are there additional plans to calibrate against any of the meteorites, like Murchison, where amino acids were detected? RM: Yes, we have run the lab based electrophoresis (CE) system and MOD (Mars Organic Detector) on meteorites including Murchison and we observe what appears to be terrestrial contamination on the surface transitioning to racemic mixtures of amino acids in the interior. Such studies will continue to establish the ground truth. AM: There is new evidence from Opportunity to indicate the soil may be acidic, or have very low pH. If the soil turns out to be strongly acidic, does that affect either the evaluation of its biological prospects or the electrophoresis tests themselves? RM: The sublimation in MOD (Mars Organic Detector) which is the first stage of our analysis should eliminate all polar contaminants and salt that would be likely to make a capillary electrophoresis analysis of amino acid composition and chirality difficult. AM: Before running a test, you have to get a sample. How do you presently imagine sample collection being most productive, as either subsurface, surface or another method for site sampling? RM: The sample collection is not under our control and will be a main subsystem of the lander for all experiments. We hope to have the ability to sample from the surface followed by samples from deeper under the surface crust. Samples from the surface, which is highly oxidizing, are likely to be low in organics. Samples from deeper under the surface will have higher concentrations of organics. This is the pattern we have seen in the Atacama which is the best available Mars analog site and this experience will be used to guide our sampling methods. What's next? Next on Mathies' agenda is a field trip to Chile and an investigation as to whether amino acid "handedness" can be detected in situ. The reason Chile's Atacama Desert is so dry and virtually sterile is because it is blocked from moisture on both sides by the Andes mountains and by coastal mountains. At 3,000 feet, the Atacama is 15 million years old and 50 times more arid than California's Death Valley. In February, Grunthaner and UC Berkeley graduate student Alison Skelley traveled to the Atacama Desert of Chile to see if the amino acid detector- -called the Mars Organic Detector, or MOD--could find amino acids in the driest region of the planet. The MOD easily succeeded. However, because the second half of the experiment--the "lab-on-a-chip" that tests for amino acid handedness--had not yet been married to the MOD, the researchers brought the samples back to UC Berkeley for that part of the test. Skelley has now successfully finished these field experiments demonstrating the compatibility of the lab-on-a-chip system with the MOD. "If you can't detect life in the Yungay region of the Atacama Desert," Mathies said, referring to the desert region in Chile where the crew stayed and conducted some of their tests," you have no business going to Mars". [1] Glavin, Schubert, Botta, Kminek and Bada, 2001, Earth and Planetary Science Letters, 185:1-5 for more details. __________________________________________________________________________ SQUYRES TO ADDRESS MARS SOCIETY CONVENTION Mars Society release 7 June 2004 Dr. Steven Squyres, the Principal Investigator for the Mars Exploration Rover (MER) mission, will give a plenary address to the opening session of the 7th International Mars Society Convention, August 19. The MER mission has uncovered evidence strongly supporting the previous existence of substantial bodies of liquid water on the martian surface--environments which conceivably could have once hosted life. In his talk, Squyres will present the new discoveries of the MER mission and discuss their implications for future robotic and human Mars exploration. The 7th International Mars Society Convention will run August 19-22, 2004 at the Palmer House Hilton, Chicago, IL. In addition to Squyres' opening plenary, there will be over a hundred other talks covering subjects ranging from current robotic missions to future human exploration and settlement of Mars. Other prominent speakers include filmmaker James Cameron, who will present footage of his summer 2003 combined human- telerobot expedition to explore extremophile life forms living in hydrothermal vents 3000 ft below the Atlantic. If you are interested in presenting as well, please send an abstract of no more than 300 words to msabstracts@aol.com no later than June 30, 2004. For further information about the Mars Society, visit our web site at www.marssociety.org, or contact info@marssociety.org. __________________________________________________________________________ SPACE ENTHUSIASTS, CASSINI SCIENTISTS INVITE PUBLIC TO UA ON JUNE 19 By Lori Stiles University of Arizona release 7 June 2004 After a 7-year, 2.2-billion-mile looping voyage across the solar system, the international Cassini mission reaches Saturn on June 30. Cassini promises to run rings around earlier spacecraft-Saturn encounters. One of the biggest planetary spacecraft ever built, Cassini won't just fly by Saturn. It will be the first spacecraft to orbit Saturn, sending data from 12 orbiter experiments back for at least the next four years. In December, Cassini will launch a European-built probe called Huygens toward Saturn's largest moon, Titan. The probe carries 6 experiments for studying Titan, a truly mysterious world that some scientists have worked half their careers to see. The University of Arizona Lunar and Planetary Laboratory (LPL) plays a larger role in the Cassini-Huygens mission than any university in the world. LPL scientists plan Cassini's observations for 45 orbiter flybys of Titan, and will process hundreds of Cassini images in the UA's Planetary Research Imaging Lab. An LPL scientist heads the imaging- spectrometer experiment that will photograph Saturn, its moons and rings at different wavelengths, from the visible to the infrared. Another LPL scientist leads the experiment that will produce the only views from the Huygens probe during its 2-hour, 15-minute fall to Titanıs surface. Several other LPL scientists are on other mission teams that will guide operations and interpret discoveries from the prolonged, exploratory tour of the solar systemıs most beautiful planet. A newly formed group is organizing four events in 2004 to make sure people age 4 on up don't miss this first-ever tour of Saturn and Titan. The first event, "Saturn: The REAL Lord of the Rings," will be Saturday, June 19, from 5:00 PM to 10:00 PM in the Kuiper Space Sciences Building, 1629 East University Blvd., and the adjacent Flandrau Science Center on the UA campus. LPL Director Michael Drake will emcee keynote science talks at 6:30 PM in Room 308 of the Kuiper building. Speakers include: * Professor Robert H. Brown, who leads Cassini's Visual and Infrared Mapping Spectrometer (VIMS) team. VIMS will identify the chemical make-up of the surfaces, atmospheres and rings of Saturn and its moons by measuring colors of visible light and infrared energy emission. Brown's team includes U.S., French, and German scientists who will be in Tucson analyzing first results from Cassini's June 11 flyby of Saturn's outpost moon, Phoebe. Phoebe is likely either an asteroid or a Kuiper Belt object, Brown said. If it's the latter, Cassini will be the first spacecraft ever to fly by a Kuiper Belt object, giving us the first glimpse of what those frigid bodies at the edge of the solar system look like, Brown noted. * Professor Jonathan I. Lunine, one of three interdisciplinary scientists for Cassini's Huygens probe. Lunine began planning the Cassini mission as a graduate student. He titled his feature article on the mission, published in the June 2004 Scientific American, "Saturn at Last!" Lunine is one of the most widely interviewed Cassini scientists when the subject is Titan, Saturn's largest moon. Titan, Lunine says, is "our best chance to study organic chemistry in a planetary environment that has remained lifeless over billions of years. With a thick, nitrogen-rich atmosphere and possibly hydrocarbon seas, Titan may harbor organic compounds important in the chain of chemistry that led to life on Earth." * Research Professor Martin G. Tomasko, who leads the Descent Imager/Spectral Radiometer (DISR) experiment on the Huygens probe. DISR will take pictures as the probe spins through its more than 2 hour, 15 minute descent through Titan's atmosphere. His team hopes to get 20 complete panoramic views, starting at 150 km above the surface. Just before landing, DISR turns on a 20-watt lamp so the instrument's spectrometers get data about the surface. Throughout its fall, DISR will analyze sunlight reflected from the surface of Titan and sunlight absorbed and scattered in Titan's thick, plastic-smog filled atmosphere. Tomasko's team tested an identical DISR model in helicopter flights over southern Arizona's Picacho Peak, then made a movie of those panoramic views, to prepare for the real thing next January 14. Youngsters, as well as adults, will have plenty to do starting at 5:00 PM, before the science talks. In addition to filling up on cake and punch, courtesy of LPL, they can: * Visit educational displays, where volunteers will answer questions, and pick up free educational handouts on the 3rd floor Atrium in the Kuiper Space Sciences Building. * Take part in hands-on activities hosted by UA's Science and Mathematics Education Center and Pima Community College students. Those who will supervise the fun workshops, suitable for ages 4 through 14, suggest coming to the Atrium at 5 to sign up for the activities that start at 5:45. * Join a free star party from 6:00 to 10:00 PM on the mall lawn in front of Flandrau and the Kuiper building. Flandrau telescope operators and members of the Tucson Amateur Astronomy Association will have several telescopes aimed at the best sky sights right now Jupiter and the Galilean moons, Mars (from 6:00 to 8:00 PM), and the razor-thin crescent moon. Saturn can't be seen from Earth right now, but Flandrau will be showing the new "Ring World" planetarium show, an animated version of Cassini's Saturn tour (entry fee charged). Visitors can park free all day on June 19 in the Cherry Ave. garage (southeast corner of Cherry Ave. and University Blvd.) or in any regular UA parking lot, including metered and "service vehicle only" spaces. Note that handicapped spaces are reserved for those designated users and that parking in the fenced NOAO lot north of Flandrau is prohibited. Maps, directions, and more information are on the web at http://www.lpl.arizona.edu/pop. Saturn event organizers include staff from the Lunar and Planetary Laboratory, Flandrau Science Center, the Tucson-based Planetary Science Institute, and the UA. Group members, who have formed the Public Outreach Program (POP), are organizing a second program, "Titan: World of Mystery," to be held Saturday, July 10. They will organize October and November programs that will feature different Cassini scientists and present the latest Cassini images and discoveries. All programs also are NASA-JPL Solar System Ambassadors-sponsored events. The Cassini-Huygens mission is a cooperative project between NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Office of Space Science, Washington, DC. Contact: Lori Stiles, UA News Services Phone: 520-621-1877 __________________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/projects/marsbugs/astrobiology/ 8 June 2004 Astrobiology and planetary engineering articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles1.html Astrobiology Magazine, 2004. Fleshing out martian proteins: interview with Richard Mathies. Astrobiology Magazine. NASA Marshall Space Flight Center, 2004. "Lab-on-a-chip" could protect astronauts and detect new life. SpaceDaily. B. P. Weiss, S. S. Kim, J. L. Kirschvink, R. E. Kopp, M. Sankaran, A. Kobayashi and A. Komeili, 2004. Magnetic tests for magnetosome chains in martian meteorite ALH84001. Proceedings of the National Academy of Sciences USA, 101(22):8281-8284. Human space flight articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles3.html United Press International, 2004. New moon shot not so costly. SpaceDaily. Evolution (biological, chemical and cosmological) articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles5.html L. Becker, R. J. Poreda, A. R. Basu, K. O. Pope, T. M. Harrison, C. Nicholson and R. Iasky, 2004. Bedout: a possible end-Permian impact crater offshore of Northwestern Australia. Science, 304(5676):1469-1476. R. R. Britt, 2004. Dark energy tied to human origins. Space.com. K. Kelly, 2004. The inside-out Earth? Astrobiology Magazine. K. Kelly, 2004. Meteorite turned Earth inside out. SpaceDaily. D. Levy, 2004. Continents played key role in collapse and regeneration of Earth's early greenhouse. SpaceDaily. D. Levy, 2004. Titanic primordial pull: how the Earth got hot. Astrobiology Magazine. L. Mullen, 2004. Earliest bilateral fossil discovered. Astrobiology Magazine. Extrasolar planets articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles7.html Harvard-Smithsonian Center for Astrophysics, 2004. Catching stars in the act of forming planets. Universe Today. Astrobiology and extreme environments book list http://www.lyon.edu/projects/marsbugs/astrobiology/astrobiology_books.html National Research Council, 2004. Stepping-Stones to the Future of Space Exploration: A Workshop Report. National Academies Press, Washington, DC. __________________________________________________________________________ CASSINI-HUYGENS UPDATES NASA/JPL releases Cassini Significant Events NASA/JPL release, 27 May - 2 June 2004 The most recent spacecraft telemetry was acquired from the Canberra tracking station on Wednesday, June 2. 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/operations/present-position.cfm. This week's key activity was the successful execution of Trajectory Correction Maneuver #20 (TCM). This maneuver was particularly significant in that it used the propulsion system in exactly the same mode that it will be used for SOI. A "quick look" immediately after the maneuver showed the burn duration was 362 seconds, giving a delta-V of 34.7 meters per second. This was well within expected tolerances. The low gain antenna 2 (LGA-2) was used while the spacecraft was off Earth-point to provide a signal to the radio science receiver to track the spacecraft during the burn. This was a mini-dress rehearsal for Saturn Orbit Insertion (SOI) where the same technique will be used. The observed Doppler shift due to the burn was almost identical to the pre-burn predict. This was the first use of LGA-2 since prior to Earth flyby. An excellent article appeared on CBS News "Space Place" on May 27 detailing this maneuver and its significance to the Cassini Program. For more information please link to http://www.spaceflightnow.com/cassini/040527burn.html. After execution of TCM-20 and a rest over the Memorial Day holiday, the Spacecraft Operations Office oversaw the uplink of the SOI Critical Sequence Load to the SSR. This load will control on board activities during the SOI period. The upload went nominally. On-board instrument activities this week included calibration of the Radio and Plasma Wave Subsystem antenna in preparation for the Phoebe encounter on June 11. The Imaging Science Subsystem (ISS) observed a full rotation of Saturn in three methane and nearby continuum filters for cloud and haze sounding and visible polarizers for cloud and haze properties. As part of sequence development for S02, Uplink Operations released the Final Sequence Integration and Validation SEG products for review and comment. The kickoff meeting for the S04 Science Operations Plan Update process was held this week. A Science Adaptation Panel meeting was canceled since there were no significant changes to the DSN station requests. A Tour Process meeting was held Wednesday to discuss a candidate trajectory that the Navigation Team developed last Friday. This trajectory solves many of the timing problems that exist in the science plan when using the reference trajectory that was released in May. An initial plan has been developed on how the science planning effort should proceed over the next couple of months. In the last week, 1240 ISS images were obtained and were distributed along with 838 Visual and Infrared Mapping Spectrometer (VIMS) cubes. The total number of ISS images acquired since the start of Approach Science is now 8818, and the number of VIMS cubes is 2050. Mission Planning released the Cassini Saturn arrival mission description document. This provides a high-level profile of arrival activities including Phoebe and SOI. The document is available on the Cassini internal web site. Mission Sequence Subsystem delivered the Mac OS/ X and Linux client-server versions of the Pointing Design tool (PDT). These versions of PDT are functionally identical to the D10.3.1 version delivered for Solaris 9 in mid May. During spring 2004, Saturn Observation Campaign members--200 in the United States and 100 in other countries--conducted nearly 200 observing events featuring Saturn and Cassini. JPL/Cassini Outreach has released a Cassini-Huygens Mission Status Report, May 28, 2004. The report covers TCM-20, the upcoming Phoebe fly by, Saturn Orbit Insertion in late June, and the release of the Huygens Probe. For more information please link to http://www.jpl.nasa.gov. Cassini appeared in an article in Scientific American this month. For more information see their web site at http://www.sciam.com/issue.cfm. Cassini-Huygens Will Unlock Saturn's Secrets NASA/JPL release 2004-141, 3 June 2004 The international Cassini-Huygens mission is poised to begin an extensive tour of Saturn, its majestic rings and 31 known moons. After a nearly seven-year journey, Cassini is scheduled to enter orbit around Saturn at 7:30 PM PDT (10:30 PM EDT) June 30, 2004. "The Saturn system represents an unsurpassed laboratory, where we can look for answers to many fundamental questions about the physics, chemistry and evolution of the planets and the conditions that give rise to life," said Dr. Ed Weiler, associate administrator for space science at NASA Headquarters, Washington, DC. Launched October 15, 1997, on a journey covering 3.5 billion kilometers (2.2 billion miles), Cassini is the most highly instrumented and scientifically capable planetary spacecraft ever flown. It has 12 instruments on the Cassini orbiter and six more on the Huygens probe. The mission represents the best technical efforts of 260 scientists from the United States and 17 European nations. The cost of the Cassini mission is approximately $3 billion. The Cassini-Huygens mission is a four-year study of Saturn. The 18 highly sophisticated science instruments will study Saturn's rings, icy satellites, magnetosphere and Titan, the planet's largest moon. For the critical Saturn orbit insertion maneuver, the spacecraft will fire its main engine for 96 minutes. The maneuver will reduce Cassini's speed and allow it to be captured into orbit as a satellite of Saturn. Cassini will pass through a gap between two of Saturn's rings, called the F and G rings. Cassini will swing close to the planet and begin the first of 76 orbits around the Saturn system. During Cassini's four-year mission, it will execute 52 close encounters with seven of Saturn's 31 known moons. There are risks involved with orbit insertion, but mission planners have prepared for them. There is a backup engine in case the main engine fails. The region of passage through the ring plane was searched for hazards with the best Earth- and space-based telescopes. Particles too small to be seen from Earth could be fatal to the spacecraft, so Cassini will be turned to use its high-gain antenna as a shield against small objects. Saturn is the sixth planet from the sun. It is the second largest planet in our solar system, after Jupiter. The planet and its ring system serve as a miniature model for the disc of gas and dust surrounding the early Sun that formed the planets. Detailed knowledge of the dynamics of interactions among Saturn's elaborate rings and numerous moons will provide valuable data for understanding how each of the solar system's planets evolved. The study of Titan, Saturn's largest moon, is one of the major goals of the mission. Titan may preserve, in deep-freeze, many of the chemical compounds that preceded life on Earth. Cassini will execute 45 flybys of Titan, coming as close as approximately 950 kilometers (590 miles) above the surface. This will permit high-resolution mapping of the moon's surface with an imaging radar instrument, which can see through the opaque haze of Titan's upper atmosphere. "Titan is like a time machine taking us to the past to see what Earth might have been like," said Dr. Dennis Matson, Cassini project scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "The hazy moon may hold clues to how the primitive Earth evolved into a life-bearing planet." On December 25, 2004 (December 24 in U.S. time zones) Cassini will release the wok-shaped Huygens probe on its journey toward Titan. Huygens will be the first probe to descend to the surface of a moon of another planet. It will also make the most distant descent by a robotic probe ever attempted on another object in the solar system. On January 14, 2005, after a 20- day ballistic freefall, Huygens will enter Titan's atmosphere. It will deploy parachutes and begin 2.5 hours of intensive scientific observations. The Huygens probe will transmit data to the Cassini spacecraft, which will relay the information back to Earth. JPL designed, developed and assembled the Cassini orbiter. The European Space Agency managed the development of Huygens and is in charge of operations of the probe from its control center in Darmstadt, Germany. The Italian Space Agency provided the high-gain antenna, much of the radio system and elements of several of Cassini's science instruments. JPL manages the overall program for NASA's Office of Space Science, Washington, DC. 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. For information about the Cassini-Huygens mission to Saturn and Titan on the Internet visit http://www.nasa.gov/cassini or http://www.esa.int/Cassini- Huygens. Contacts: Carolina Martinez Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-9382 Don Savage NASA Headquarters, Washington, DC Phone: 202-358-1727 Additional articles on this subject are available at: http://www.astrobio.net/news/article1002.html http://www.astrobio.net/news/article1007.html http://www.space.com/missionlaunches/cassini_update_040603.html http://www.spacedaily.com/news/cassini-04m.html http://www.spacedaily.com/news/cassini-04l.html http://www.spacedaily.com/news/cassini-04n.html http://spaceflightnow.com/cassini/040603saturncolor.html http://spaceflightnow.com/cassini/soitimeline.html http://www.universetoday.com/am/publish/getting_closer_to_saturn.html http://www.universetoday.com/am/publish/cassini_ready_saturn_tour.html http://www.universetoday.com/am/publish/cassini_orbital_entry_spot.html __________________________________________________________________________ MARS EXPLORATION ROVERS UPDATES NASA/JPL releases Rovers Examining Hills and Crater in Bonus-Time Mission NASA/JPL release 2004-140, 2 June 2004 More than a month into bonus time after a successful primary mission on Mars, NASA's Spirit rover has sighted possibly layered rock in hills just ahead, while twin Opportunity has extended its arm to pockmarked stones on a crater rim to gather clues of a watery past. Both robotic geologists of the Mars Exploration Rover Project remain healthy. Engineers at NASA's Jet Propulsion Laboratory, Pasadena, CA, quickly restored Spirit from two unexpected computer reboots in May triggered by low-probability software glitches. "We had bad luck to hit two very unlikely scenarios just eight days apart, but in both cases the software team was able to figure out the problem within a day," said Joe Snyder, a Lockheed Martin software engineer on JPL's rover team. Spirit has driven more than 2.9 kilometers (1.8 miles) since arriving at Mars five months ago, more than three-fourths of that since completing its three-month primary mission. It now has only about 400 meters (440 yards) to go--possibly less than a week of driving--before reaching the base of a range of hills informally named "Columbia Hills," which scientists identified in January as a desirable but potentially unreachable destination for the rover. "This is the first time we've ever had a close look at hills on Mars," said Dr. James Rice of Arizona State University, Tempe, a member of the rovers' science team. In 1997, hills called "Twin Peaks" tantalized scientists from only about one kilometer (1,100 yards) away from the Mars Pathfinder landing site. "We could only observe Twin Peaks from a distance and wonder about them, but now with a more capable rover we can get to Columbia Hills," Rice said. He spoke at a press briefing today at JPL. Rocks in Columbia Hills may provide insight both into both how hills form on Mars and whether the ancient environment at this part of Mars was wet. Images Spirit has taken as it nears the hills already show boulders and potential rock outcrops. "These rocks are much older than what we've been driving across," Rice said. "We could find a lot of geological history locked in them. They may be some of the oldest material ever seen on Mars." On the rim of stadium-sized "Endurance Crater," halfway around Mars from Spirit, Opportunity has been using its microscopic imager to examine the texture of rocks, adding information about a past lake or sea environment that also left its mark in the smaller crater, "Eagle," where Opportunity landed. "We're looking at rocks that have very interesting surface textures," said science-team member Dr. Wendy Calvin of the University of Nevada, Reno. "These rocks appear to be from the same geological layer as the outcrop at Eagle Crater, but they have some differences from what we saw there." One rock called "Pyrrho" on the Endurance rim has a braided ripple pattern. Another, "Diogenes," compared with rocks seen earlier, has more of the disc-shaped cavities that scientists interpret as sites where crystals formed in the rocks, then disappeared as the chemistry of water in the rocks varied. From an overlook point on the southeastern edge of Endurance, Opportunity used its panoramic camera and miniature thermal emission spectrometer to study the inside of the crater, supplementing a similar survey made earlier from the western edge. Both instruments can be used to assess mineral composition from a distance. "We see a strong basaltic character in the sand at the bottom and in some of the rocks in the wall of the crater," Calvin said. That is a contrast to the sulfate-rich composition of the oveurlying layer, which resembles the Eagle Crater outcrop. "We expect the basaltic material to tell us about environmental conditions from an earlier time," she said. Scientists and engineers are evaluating the potential science benefits of sending Opportunity into Endurance Crater and assessing whether the rover would be able to climb back out. A decision about whether to enter the crater will be based on those factors. Mission controllers have begun frequent use of a "deep sleep" mode for Opportunity, reported JPL's Matt Wallace, mission manager. It is a more complete overnight shutdown that conserves energy but at a calculated tradeoff of risking damage to the miniature thermal emission spectrometer. The strategy has approximately tripled the amount of time the solar- powered rover can work during the day. So far, the spectrometer has survived, but as the martian winter advances, scientists expect to lose the use of that instrument. Mars Rover Opportunity Gets Green Light to Enter Crater NASA/JPL release 2004-181, 4 June 2004 NASA has decided the potential science value gained by sending Opportunity into a martian impact crater likely outweighs the risk of the intrepid explorer not being able to get back out. Opportunity has been examining the rim of stadium-sized "Endurance" crater since late May. The rover team used observations of the depression to evaluate potential science benefits of entering the crater and the traversability of its inner slopes. The soonest Opportunity could enter Endurance is early next week. It will drive to the top of a prospective entry-and-exit route on the southern edge of the crater and make a final check of the slope. If the route is no steeper than what recent testing runs at NASA's Jet Propulsion Laboratory, Pasadena, CA, suggest a rover can climb, controllers plan to radio Opportunity the command to go into the crater. "This is a crucial and careful decision for the Mars Exploration Rovers' extended mission," said Dr. Edward Weiler, NASA's Associate Administrator for Space Science. "Layered rock exposures inside Endurance Crater may add significantly to the story of a watery past environment that Opportunity has already begun telling us. The analysis just completed by the rover team shows likelihood that Opportunity will be able to drive to a diagnostic rock exposure, examine it, and then drive out of the crater. However, there's no guarantee of getting out again, so we also considered what science opportunities outside the crater would be forfeited if the rover spends its remaining operational life inside the crater." At a rock outcrop in a small impact feature nicknamed, "Eagle Crater," where Opportunity first landed, the rover found small-scale rock textures and evaporite mineral compositions testifying that a body of salty water covered the site long ago. The wet environment may have been a suitable habitat for life, if it ever existed on Mars. However, only the uppermost layer of the region's layered crust was exposed at Eagle Crater, not deeper layers that could reveal what the environment was like earlier. The rock layer seen at Eagle Crater appears at Endurance Crater, too. At Endurance, though, it lies above exposures of thicker, older layers, which are the main scientific temptation for sending Opportunity inside the crater. "Answering the question of what came before the evaporites is the most significant scientific issue we can address with Opportunity at this time," said Dr. Steve Squyres of Cornell University, Ithaca, NY, principal investigator for the science instruments on both rovers. "We've read the last chapter, the record of the final gasps of an evaporating body of water. What came before? It could have been a deep-water environment. It could have been sand dunes. It could have been a volcano. Whatever we learn about that earlier period will help us interpret the upper layer's evidence for a wet environment and understand how the environment changed." Richard Cook, project manager at JPL for the rovers, said that reaching one exposure of the older rock layers inside Endurance requires driving only about 5 to 7 meters (16 to 23 feet) into the 130-meter-diameter (140- yard-diameter) crater. The rover is on the rim at that site, which had been dubbed "Karatepe." "We'll take an incremental approach, edging our way down to the target," Cook said. The plan is to use the tools on Opportunity's robotic arm to analyze the exposed layers for several days, then drive in reverse back up the slope and exit the crater. The slope between the rim and the layered outcrop at Karatepe is about 25 degrees. "We have done testing that says we can do 25 degrees, provided the wheels are on a rock surface and not loose sand," Cook said. Engineers and scientists on the rover team built a test surface mimicking the rocks and sand seen in Opportunity's images of Endurance Crater. The surface was tilted to 25 degrees, and a test rover climbed it. If portions of the route to the outcrop turn out to be between 25 and 30 degrees, the team plans to proceed slowly and use Opportunity to assess the amount of traction the rover is getting. NASA Rovers Continue Unique Exploration of Mars NASA/JPL release 2004-144, 8 June 2004 NASA's Mars Opportunity rover began its latest adventure today inside the martian crater informally called Endurance. Opportunity will roll in with all six wheels, then back out to the rim to check traction by looking at its own track marks. "We're going in, but we're doing it cautiously," said Jim Erickson, deputy project manager for the Mars Exploration Rovers at NASA's Jet Propulsion Laboratory, Pasadena, CA. Barring any surprises, Opportunity will enter the stadium-sized crater Wednesday for two to three weeks of scientific studies. "NASA has made a careful decision. The potential science benefits of sending Opportunity into the crater are well worth the calculated risk the rover might not be able to climb back out," said JPL's Dr. Firouz Naderi, manager of NASA's Mars Exploration Program. "Inside the Endurance crater waits the possibility for the most compelling science investigations Opportunity could add to what it has already accomplished. We have done the ground testing necessary to evaluate the likelihood of exiting the crater afterwards." "Spirit and Opportunity are well into their bonus periods after successfully completing their three-month primary missions in April," Naderi said. "Both rovers are starting new chapters. Spirit is within a stone's throw of Columbia Hills, and Opportunity is entering the crater." Dr. Steve Squyres of Cornell University, Ithaca, NY, the rovers' principal investigator, said, "We expect the science return of going a short way into Endurance to be very high." The target for inspection within the crater is an exposure of rock layers beneath a layer that corresponds to rocks Opportunity previously examined in the shallower Eagle crater, where the rover landed in January. The sulfur-rich layer seen in Eagle yielded evidence that a body of gently flowing water once covered the area. The underlying rock layers come from an earlier period. Opportunity's observations from the rim of Endurance already have shown their composition differs from the Eagle crater's layers. "If there was a change in rock type, there was a change in environment," Squyres said. "This unit will tell us what came before the salty water environment the Eagle crater unit told us about. We want to get to the contact between the two units to see how the environment changed. Is it gradual? Is it abrupt?" Even if the lower layers formed under dry conditions, they may have been exposed to water later. The water's effect on them could have left telltale evidence of that interaction." One section of the target outcrop is only five to seven meters (16 to 23 feet) from the crater rim in an area dubbed Karatepe. The rover team's plan is to get there, examine the rocks for several days, and then exit the crater. Reaching lower-priority targets, like at the bottom of the crater, would entail driving on sand, with a higher risk of not getting out again. The strategy for driving on the crater's inner slope is to keep wheels on rock surfaces instead of sand, said JPL rover- mobility engineer Randy Lindemann. The team ran trials with a test rover on a surface specifically built to simulate Karatepe's surface conditions. "The tests indicate we have a substantial margin of safety for going up a rocky slope of 25 degrees," Lindemann said. Opportunity's observations from the rim at the top of the planned entry route show a slope of less than 20 degrees. Spirit, launched one year ago Thursday, has driven more than 3.2 kilometers (2 miles) inside the Gusev Crater. A trench it dug in May exposed soil with relatively high levels of sulfur and magnesium, reported Dr. Johannes Brueckner, of Max-Planck-Institut fuer Chemie, Mainz, Germany. Spirit's alpha particle X-ray spectrometer showed concentrations of these two elements varied in parallel at different locations in the trench, suggesting they may be paired as a magnesium sulfate salt. Squyres said, "The most likely explanation is water percolated through the subsurface and dissolved out minerals. As the water evaporated near the surface, it left concentrated salts behind. I'm not talking about a standing body of water like we saw signs of at Eagle crater, but we also have an emerging story of subsurface water at Gusev," he said. JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover project for NASA's Office of Space Science, Washington, DC. Images and additional information about the project are available from JPL at http://marsrovers.jpl.nasa.gov and from Cornell University, Ithaca, NY, at http://athena.cornell.edu. Daily MER updates are available at: http://marsrovers.jpl.nasa.gov/mission/status_spirit.html http://marsrovers.jpl.nasa.gov/mission/status_opportunity.html Contacts: Guy Webster Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-6278 Donald Savage NASA Headquarters, Washington, DC Phone: 202-358-1547 Additional articles on this subject are available at: http://www.astrobio.net/news/article1003.html http://www.cnn.com/2004/TECH/space/06/03/mars.rover.trucking/index.html http://www.space.com/missionlaunches/rovers_update_050602.html http://www.space.com/missionlaunches/rover_crater_040605.html http://www.space.com/missionlaunches/rovers_winter_040608.html http://www.spacedaily.com/news/mars-mers-04zzzzr.html http://www.spacedaily.com/news/mars-mers-04zzzzs.html http://www.spacedaily.com/news/mars-mers-04zzzzt.html http://www.spacedaily.com/news/mars-mers-04zzzzu.html http://www.spacedaily.com/news/mars-mers-04zzzzv.html http://www.spacedaily.com/news/mars-mers-04zzzzw.html http://www.spacedaily.com/news/mars-mers-04zzzzx.html http://spaceflightnow.com/mars/mera/040602status.html http://spaceflightnow.com/mars/mera/040604crater.html http://www.universetoday.com/am/publish/spirit_sees_layered_rock.html http://www.universetoday.com/am/publish/opportunity_will_enter_crater.html http://www.universetoday.com/am/publish/opportunity_exit_strategy.html __________________________________________________________________________ MARS GLOBAL SURVEYOR IMAGES NASA/JPL/MSSS release 27 May - 2 June 2004 The following new images taken by the Mars Orbiter Camera (MOC) on the Mars Global Surveyor spacecraft are now available. Arabia Crater Cluster (Released 27 May 2004) http://www.msss.com/mars_images/moc/2004/05/27/index.html Sand Dunes in Noachis (Released 28 May 2004) http://www.msss.com/mars_images/moc/2004/05/28/index.html Ascraeus Lava Flows (Released 29 May 2004) http://www.msss.com/mars_images/moc/2004/05/29/index.html Martian City Map (Released 30 May 2004) http://www.msss.com/mars_images/moc/2004/05/30/index.html Dunes with Frost (Released 31 May 2004) http://www.msss.com/mars_images/moc/2004/05/31/index.html Global With OSM-7 (Released 01 June 2004) http://www.msss.com/mars_images/moc/2004/06/01/index.html Gullies and Dunes (Released 02 June 2004) http://www.msss.com/mars_images/moc/2004/06/02/index.html All of the Mars Global Surveyor images are archived at http://www.msss.com/mars_images/moc/index.html. 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. An additional article on this subject is available at http://www.spacedaily.com/news/mars-surveyor-04a.html. __________________________________________________________________________ MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 31 May - 4 June 2004 Cliff Face (Released 31 May 2004) http://themis.la.asu.edu/zoom-20040531a.html Ceti Mensa (Released 1 June 2004) http://themis.la.asu.edu/zoom-20040601a.html Kasei Valles (Released 2 June 2004) http://themis.la.asu.edu/zoom-20040602a.html Ganges Chasma (Released 3 June 2004) http://themis.la.asu.edu/zoom-20040603a.html Outcrops in Coprates Chasma (Released 4 June 2004) http://themis.la.asu.edu/zoom-20040604a.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. __________________________________________________________________________ ROSETTA: MOVING TOWARDS CRUISE PHASE ESA release 7 June 2004 The reporting period (28 May - 4 June) covered part of the transition from the payload commissioning activities to the start of the Cruise 1 phase, which will take place next week. The ALICE PAT test was finally and, after two cancellations due to different reasons in the past weeks, successfully carried out. The first pass of the extra slot requested by OSIRIS to repeat some of the measurements taken in slot 2 was also successfully carried out. On the subsystems side two passes were dedicated to TTC commissioning. The LGA TC threshold test could not be completed due to a problem in the New Norcia station, which prevented the use of the Low Power Amplifier. Due to the relatively short distance to the Earth, the low threshold for LGA commanding could not be reached with the High Power Amplifier and the test will have to be re-scheduled to a later stage in the Cruise. On a second New Norcia pass the S-band ranging test with both transponders was successfully completed. An important mission milestone this week was the fact that for the first time one of the daily New Norcia passes was skipped on 30 May. This means that Rosetta was left without ground contact for 42 hours. The spacecraft was prepared on the day before (reduce TM generation rate, increase TC link timeout) and was found in a perfect state when contact was re- acquired on the evening of 31 May. It is planned to gradually increase the period of non-contact during the first month of Cruise 1, to arrive at weekly passes by mid July. At the end of the last New Norcia pass in the reporting period (DOY 156, 02:00) Rosetta was at 44.7 million km from the Earth. The one-way signal travel time was 2 minutes 29 seconds. Science results On 30 April Rosetta targeted the comet C/2002 T7 (LINEAR) for its first scientific observations. Data was successfully acquired by the four instruments ALICE, MIRO, VIRTIS and OSIRIS and will be fully analyzed after the calibration of the instruments is completed. OSIRIS acquired this image of the comet at a distance of about 95 million kilometers through a blue filter, showing the comet's nucleus and tenuous tail extending for over 2 million km. Read the original news release at http://sci.esa.int/science- e/www/object/index.cfm?fobjectid=35203. __________________________________________________________________________ End Marsbugs, Volume 11, Number 24