MARSBUGS: The Electronic Astrobiology Newsletter Volume 8, Number 8, 27 February 2001. Editors: Dr. David J. Thomas, Math and 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 quarterly basis as warranted by the number of articles and announcements. Copyright of this compilation exists with the editors, except for specific articles, in which instance copyright exists with the author/authors. While we cannot copyright our mailing list, our readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing list. The editors do not condone “spamming” of our subscribers. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editors. E-mail subscriptions are free, and may be obtained by contacting either of the editors. Article contributions are welcome, and should be submitted to either of the two editors. Contributions should include a short biographical statement about the author(s) along with the author(s)’ correspondence address. Subscribers are advised to make appropriate inquiries before joining societies, ordering goods etc. Back issues and Adobe Acrobat PDF files suitable for printing may be obtained from the official Marsbugs web page at http://welcome.to/marsbugs. The purpose of this newsletter is to provide a channel of information for scientists, educators and other persons interested in exobiology and related fields. This newsletter is not intended to replace peer- reviewed journals, but to supplement them. We, the editors, envision Marsbugs as a medium in which people can informally present ideas for investigation, questions about exobiology, and announcements of upcoming events. Astrobiology is still a relatively young field, and new ideas may come from the most unexpected places. Subjects may include, but are not limited to: exobiology and astrobiology (life on other planets), the search for extraterrestrial intelligence (SETI), ecopoeisis and terraformation, Earth from space, planetary biology, primordial evolution, space physiology, biological life support systems, and human habitation of space and other planets. --------------------------------------------------------------------- CONTENTS 1) NEW GROUP OF MICROORGANISMS DISCOVERED IN THE OPEN SEA National Science Foundation release 01-05 2) HOW PLANTS TELL WHICH WAY IS UP From SpaceDaily 3) ASTRONOMERS DESCRIBE SEARCH FOR HABITABLE PLANETS BEYOND SOLAR SYSTEM AS NEW OBSERVATORIES DETECT MOLECULES OF LIFE Cornell University release 4) ASTEROID OR COMET TRIGGERED LARGEST MASS EXTINCTION IN EARTH’S HISTORY, FORESHADOWING FATE OF DINOSAURS NASA release 01-23 5) ASTROBIOLOGY SPECIAL REPORT: LOOKING FOR LIFE BEYOND EARTH By David Pacchioli 6) SPACE ART CONTEST—YOU CAN PARTICIPATE IN A REAL MARS MISSION! Planetary Society release 7) NEW EVIDENCE STRENGTHENS CLAIMS OF ANCIENT LIFE ON MARS STUDY OF MARTIAN METEORITE REVEALS MAGNETIC FOSSILS NASA/JSC release J01-17 8) CASE FOR LIFE ON MARS WITHSTANDS CRITICISM, GAINS SCIENTIFIC SUPPORT NASA/JSC release J01-20 9) METEORITES POINT TO ABUNDANT WATER ON MARS LONG AGO From SpaceDaily 10) EXPLORING A DISTANT WORLD OF ICE AND HYDROCARBONS By Bruce Moomaw 11) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 12) CASSINI WEEKLY SIGNIFICANT EVENTS JPL release 13) THIS WEEK ON GALILEO JPL releases 14) GALILEO MILLENNIUM MISSION STATUS JPL release 15) MARS GLOBAL SURVEYOR STATUS REPORT JPL release 16) STARDUST STATUS REPORT JPL release --------------------------------------------------------------------- NEW GROUP OF MICROORGANISMS DISCOVERED IN THE OPEN SEA National Science Foundation release 01-05 http://www.nsf.gov/cgi-bin/getpub?pr0105 24 January 2001 Archaea, one of three separate domains of life on our planet, were undiscovered until 1970. Since then, they had been found mostly in extreme environments such as high-temperature volcanic vents on the ocean floor, continental hot springs and fumeroles, and highly salty or acidic waters. Now, scientists funded by the National Science Foundation (NSF) have found unexpected, astounding numbers of archaea living in Earth’s largest biome, the open sea. The researchers—David Karl and Markus Karner of the University of Hawaii, and Edward DeLong of the Monterey Bay Aquarium Research Institute—have published a paper in this week’s issue of the journal Nature on their discovery, “Archaeal dominance in the mesopelagic zone of the Pacific Ocean.” The concentration of archaea in their study leads the scientists to conclude that archaea are “a large percentage of the biomass of the open ocean,” says Karl. “These organisms could make up 50 percent of life in the open sea.” The research is the first to note their numerical abundance. “This remarkable new insight will have a major impact on our view of how the oceans function ecologically, “says Phil Taylor, director of NSF’s biological oceanography program, which, along with NSF’s chemical oceanography program, funded the research. “We are compelled by this discovery to increase our efforts to understand the diversity of life in the oceans, and the specific roles that important species and groups play in the sea.” The research is part of the Hawaii Ocean Time-series (HOT) project, an NSF-sponsored study of the north Pacific Ocean. Monthly sampling was conducted throughout the water column, from the surface to 4,750 meters deep. Two specific archaeal groups—pelagic euryarchaeota and pelagic crenarchaeota—were found in high numbers in the samples. In the past, archaea were known as archaebacteria, but it has since been found that they are fundamentally distinct from true bacteria. Very little is known about these life forms. According to Karl, they were only discovered because of “their unusual genetic and molecular structures.” Marine scientists have yet to understand how archaea take in nutrients, multiply, or what ecological role they play. The habitat range for these archaea, the Nature paper authors note, is unusually broad. “As a dominant component of the ocean, archaea are thus far from confined to extreme niche habitats,” they write. “Rather, the distribution of these archaea suggests that a common adaptive strategy has allowed them to radiate throughout nearly the entire water column.” The discovery of these numbers of a group of microorganisms living in a previously unsampled area “points out the basic ignorance we have of the planet we live on,” maintains Karl. This research, he says, further reveals the need for a reclassification of the characteristics of the archaea kingdom. Media contact: Cheryl Dybas Phone: 703-292-8070 cdybas@nsf.gov Program contacts: Phil Taylor Phone: 703-292-8580 prtaylor@nsf.gov Don Rice Phone: 703-292-8580 drice@nsf.gov --------------------------------------------------------------------- HOW PLANTS TELL WHICH WAY IS UP From SpaceDaily 18 February 2001 After being knocked over by wind or hail, many plants quickly grow upward again. Scientists at North Carolina State University and the University of Michigan have discovered that oats and maize use a chemical, also present in the human brain, to “perceive” almost instantly that something is amiss—and then bend in the proper direction within minutes or hours. Those findings, which expand our understanding of how gravity affects plant growth, have implications for agriculture and space travel, the researchers explain. “If humans are going to go on sustained space missions, we’ll need to use plants to turn carbon dioxide into oxygen, to cleanse water and to provide food,” said Dr. Wendy Boss, an NC State professor of botany who is one of 10 principal investigators on the project. “Before we create such long-term life-support systems, we need to know how gravity affects the growth of plants.” Boss will present the group’s findings at 9:00 AM Sunday, February 18, at the American Association for the Advancement of Science (AAAS) annual meeting in San Francisco. The AAAS meeting is the year’s largest and most important science conference. Get the full story at http://www.spacedaily.com/news/food-01a.html. --------------------------------------------------------------------- ASTRONOMERS DESCRIBE SEARCH FOR HABITABLE PLANETS BEYOND SOLAR SYSTEM AS NEW OBSERVATORIES DETECT MOLECULES OF LIFE Cornell University release 19 February 2001 Using spectral tools for infrared and submillimeter wave observations, astronomers are looking for the building blocks of life in all the right places: where there might be oxygen and where it is wet. “We may now have the tools to find those elements that are the preconditions for life,” says Martin Harwit, professor emeritus of astronomy at Cornell University in Ithaca, NY. He will host a symposium, “Infrared Astronomy: In Search of the Molecules of Life,” at the annual meeting of American Association for the Advancement of Science at the Hilton San Francisco today (February 19, 9:00 AM to noon). “In the past we were not able to see water vapor or molecular oxygen in the distant universe through our own atmosphere, because Earth’s atmosphere blocks out those spectral features,” says Harwit. Now with space-borne tools such as the Submillimeter Wave Astronomy Satellite (SWAS) and the Infrared Space Observatory (ISO), observations are being undertaken for the conditions from which life might evolve. Harwit is a member of a team of astronomers planning the design of a space observatory that could search the heavens for habitable planets. That means examining regions of the cosmos where there is a very faint object that could be a planet near a very bright star. “We will need a widely spaced array of small telescopes operating in unison to separate out the planet’s faint image,” says Harwit. “Coupled to this will have to be a spectrometer to search the planet’s atmosphere for molecules that could act as tracers for life.” At the symposium, Gary Melnick, of the Harvard-Smithsonian Center for Astrophysics, will explain key SWAS findings, such as how interstellar space is substantially more parched than previously believed. Recently, Melnick and colleagues from Cornell reported they had found that water is 10,000 times less abundant in interstellar, molecular clouds. So scarce, in fact, that it is found in the ratio of only one part in a hundred million compared with hydrogen molecules, which are the most common component. Molecular oxygen is at least 100 times less abundant than had been predicted. This paucity of molecular oxygen and water makes finding life- sustaining planets much more difficult, since both elements are considered essential constituents of the molecular clouds from which stars form. Astronomers think these elements might be locked in a primordial deep freeze. The molecular clouds are as cold as only 30 degrees above absolute zero—or a frigid minus 240 degrees Celsius. Thus water might be frozen on the dust grains in the clouds, making detection hard for radio telescopes. But with an array of spectral tools, astronomers can still be hot on this frosty trail. Martin Kessler, of the European Space Agency, Madrid, will discuss the key findings of ISO, which operated with near-perfection from 1995 to 1998. The astronomer will present the first clear evidence of interstellar water vapor, obtained by the far-infrared spectrometer aboard the observatory. ISO also has detected frozen carbon dioxide, carbon monoxide and methane dust in interstellar clouds. Edwin A. Bergin, of the Harvard-Smithsonian Center for Astrophysics, will re-evaluate the chemical composition of interstellar matter, in light of the new spectral findings. He will show how cosmic water vapor freezes on the surface of dust grains in the cold, dark expanse of molecular clouds. In this planetary nursery, water-ice-coated grains eventually coagulate to form pre-planetary rocks and comets, which ultimately could form the interiors and atmospheres of planets. Thijs de Graauw, of the SRON Laboratory/Kapteyn Institute, The Netherlands, will report on the detection, by the short wavelength spectrometer aboard ISO, of water molecules in some unexpected places, such as Jupiter and Saturn. De Graauw also will explain how the mineral forsterite—found in dust clouds around young stars and in comet Hale-Bopp in our own solar system—could lead to understanding how elemental molecules and minerals form together in interstellar space and eventually appear here on Earth. Contacts: David Brand deb27@cornell.edu Blaine P. Friedlander, Jr. Phone: 607-255-3290 bpf2@cornell.edu Additional articles on this subject are available at: http://www.cnn.com/2001/TECH/space/02/20/chemistry.of.life.ap/index.h tml http://www.space.com/scienceastronomy/astronomy/water_space_010220.ht ml http://www.spacedaily.com/news/life-01f.html --------------------------------------------------------------------- ASTEROID OR COMET TRIGGERED LARGEST MASS EXTINCTION IN EARTH’S HISTORY, FORESHADOWING FATE OF DINOSAURS NASA release 01-23 22 February 2001 New findings provide evidence that Earth’s most severe mass extinction—an event 250 million years ago that wiped out 90 percent of the life on Earth—was triggered by a collision with a comet or asteroid. Over 90 percent of all marine species and 70 percent of land vertebrates perished as a result, according to the NASA-funded research team, led by Dr. Luann Becker of the University of Washington (UW), Seattle. The team’s findings will be published tomorrow in the journal Science. The collision wasn’t directly responsible for the extinction but rather triggered a series of events, such as massive volcanism, and changes in ocean oxygen, sea level and climate. That in turn led to species extinction on a wholesale level, according to the team. “If the species cannot adjust, they perish. It’s a survival-of-the- fittest sort of thing,” said Becker, UW acting assistant professor of Earth and Space Sciences. “To knock out 90 percent of organisms, you’ve got to attack them on more than one front.” The scientists do not know the site of the impact 250 million years ago, when all Earth’s land formed a supercontinent called Pangea. However, the space body left a calling card—complex carbon molecules called buckminsterfullerenes, or Buckyballs, with the noble gases helium and argon trapped inside the caged structure. Fullerenes, which contain at least 60 carbon atoms and have a structure resembling a soccer ball or a geodesic dome, are named for Buckminster Fuller, inventor of the geodesic dome. The researchers know [that] these particular Buckyballs are extraterrestrial because the noble gases trapped inside have an unusual ratio of isotopes, atoms whose nuclei have the same number of protons but different numbers of neutrons. Terrestrial helium is mostly helium-4, while extraterrestrial helium is mostly helium-3. “These things form in carbon stars. That’s what’s exciting about finding fullerenes as a tracer,” Becker said. The extreme temperatures and gas pressures in carbon stars are perhaps the only way extraterrestrial noble gases could be forced inside a fullerene, she said. These gas-laden fullerenes were formed outside the Solar System, and their concentration in the sedimentary layer at the boundary of the Permian and Triassic periods means they were delivered by comets or asteroids. The researchers estimate the comet or asteroid was roughly 3 3/4 to 7 1/2 miles (6 to 12 kilometers) across, or about the same size as the asteroid believed responsible for the extinction of the dinosaurs 65 million years ago. The telltale fullerenes containing helium and argon were extracted from sites where the Permian-Triassic boundary layer had been exposed in Japan, China and Hungary. The evidence was not as strong from the Hungary site, but the China and Japan samples bear strong evidence, Becker said. The team’s work was made more difficult because there are few 250 million-year-old rocks left on Earth since most rocks of that age have been recycled through the planet’s tectonic processes. “It took us two years to do this research, to try to narrow it down enough so that we could see this fullerene signature,” Becker said. Scientists have long known of the mass extinction 250 million years ago, since many fossils below the boundary—such as trilobites, which once numbered more than 15,000 species—diminish sharply close to the boundary and are not found above it. There also is strong evidence suggesting the extinction happened very rapidly, on the order of 8,000 to 100,000 years, which the latest research supports. Previously, it was thought that any asteroid or comet collision would leave strong evidence of the element iridium, the signal found in the sedimentary layer from the time of the dinosaur extinction. Iridium was found at the Permian-Triassic boundary, but not nearly in the concentration as from the dinosaur extinction. Becker believes that difference is because the two space bodies that slammed into Earth had different compositions. Members of the research team are Becker; Robert Poreda and Andrew Hunt from the University of Rochester, NY; Ted Bunch of the NASA’s Ames Research Center, Moffett Field, CA; and Michael Rampino of New York University and NASA’s Goddard Institute of Space Sciences, New York. Funding for the research was provided by NASA’s Astrobiology and Cosmochemistry programs and the National Science Foundation. Images are available at http://www.washington.edu/newsroom/news/images/extinct Contacts: Donald Savage Headquarters, Washington, DC Phone: 202-358-1547 Vince Stricherz University of Washington, Seattle Phone: 206-543-2580 Additional articles on this subject are available at: http://www.astronomy.com/Content/Dynamic/Articles/000/000/000/324uqml f.asp http://news.bbc.co.uk/hi/english/sci/tech/newsid_1184000/1184556.stm http://www.cnn.com/2001/TECH/science/02/22/big.extinction.02/index.ht ml http://www.msnbc.com/news/533468.asp http://science.nasa.gov/headlines/y2001/ast23feb_1.htm http://www.sciencemag.org/cgi/content/abstract/291/5508/1530 http://www.universetoday.com/html/topics/asteroids.html --------------------------------------------------------------------- ASTROBIOLOGY SPECIAL REPORT: LOOKING FOR LIFE BEYOND EARTH By David Pacchioli From Space.com and Pennsylvania State University 22 February 2001 It isn’t a new field: Carl Sagan was arguing for the plausibility of other worlds—and other life—way back in 1966. But astrobiology, in recent years, has seen a rebirth. The rapid-fire discovery of a few dozen extrasolar planets will do that. Ditto the finding of what could be fossil bacteria in a hunk of Martian meteorite. Then there are the fresh insights about life here at home. Who knew, 15 years ago, that there was more of it embedded in rocks beneath Earth’s surface than there is above ground? Or that living things thrive in boiling hotsprings and Antarctic wastes? On the lookout for life of the extraterrestrial kind, today’s astrobiologists—trained in chemistry, geology, and molecular biology, as well as astronomy—have refined their ideas about where, and whether, they’re likely to find it. Get the full story at http://www.space.com/searchforlife/astrobiology_special_010215.html. --------------------------------------------------------------------- SPACE ART CONTEST—YOU CAN PARTICIPATE IN A REAL MARS MISSION! Planetary Society release http://planetary.org/rrgtm/Training_Mission/art_competition/artcontes t.htm 22 February 2001 Attention artists: space isn’t just for rocket scientists! The Planetary Society invites you to participate in an international space art contest. The Planetary Society needs your artistic talents and imagination! The Student Scientists chosen for The Planetary Society’s Red Rover Goes to Mars Training Mission have been studying the Martian surface in detail. Their goal was to choose a place on Mars suitable for selecting rock and soil samples to bring back to Earth. Now that they have narrowed the potential landing sites down to just a few, here’s where you come in. We would like you to draw what you think an interesting Mars landing site might look like from the ground—both now and in 100 years. Contest instructions and entry rules Draw, paint, or otherwise artistically depict by hand what you think the surface of Mars will look like near the site of an upcoming robotic exploration mission and what that same site might look like one hundred years from now. (Computer-generated art will not be accepted.) Be creative, and use your imagination! You can include a spacecraft in the picture, but it is not required. An entry consists of one “Mars landing site terrain now” picture, one “Mars landing site terrain 100 years from now” picture of the same region, and a brief written description of your drawings. These two drawings may be judged separately or as a pair, at the judges’ discretion. Type or print your full name, age, mailing address (including country), telephone number, e-mail address, language preference, and other contact information on a piece of paper. Include one paragraph describing your two drawings, the spacecraft (if any), why your Martian terrain looks different in 100 years, and what may have caused those changes. These descriptions may accompany the winning entries in any exhibition or public display of the artwork. Print your contact information on the back of both pictures as well, in case they become separated. Entries must be 2-dimensional images (not sculptures), with maximum dimensions of 11” x 17” (28 cm by 43 cm) per picture, in any non- electronic artistic medium. Computer-generated artwork is prohibited from entry. Only one entry (the two drawings and descriptive paragraph outlined above) per person is permitted. The Planetary Society and members of the International Association of Astronomical Artists (IAAA) will judge the art. Winning entries will be acknowledged in The Planetary Report and on The Planetary Society’s web site. The Planetary Society reserves the right to reproduce the winning entries. The individual artist will retain the copyright. All entries become the property of The Planetary Society and cannot be returned. Entry requirements People of all ages may enter. Winners will be selected in three age categories: 10 and under, 11 to 18, and over 18 years of age. Artwork will be judged on creativity, knowledge of Mars, and artistic merit. Submissions will be judged at the regional and national level for countries that have Planetary Society Red Rover Goes to Mars Regional and National Centers. The number of national finalists and special merit honorable mention winners will depend on the number and quality of the entries received. National Centers will send their finalists’ art to The Planetary Society in Pasadena, California for international judging. The decision of the judges is final. International 1st, 2nd, and 3rd place winners will be selected in each age category. The best art from each nation will also receive recognition. Contest dates Entries will be accepted starting on January 2, 2001. The deadline for submissions to Regional Centers (or National Centers in nations that have National Centers but no Regional Centers) is April 2, 2001, and international winners will be announced in August 2001. Prizes All winners and national finalists will receive a year of free membership in The Planetary Society. 1st, 2nd, and 3rd place winners and “best of nation” winners in each age category, as well as special merit honorable mention winners, will have their artwork included on a CD-ROM and displayed at prominent space science institutions around the world. International 1st prize winners will be acknowledged on The Planetary Society’s web site, and will receive a $100 gift certificate for merchandise from The Planetary Store. International 2nd prize winners will receive a $50 gift certificate for merchandise from The Planetary Store. International 3rd prize winners will receive a $25 gift certificate for merchandise from The Planetary Store. Special merit honorable mention winners and “best of nation” winners will receive a Planetary Society lapel pin and a Mars panoramic poster. The artwork by the three 1st prize winners (one from each age category) will be posted on The Planetary Society’s web site in August 2001 and the public will have the opportunity to vote via the Internet for their favorite Mars terrain picture. One Grand Prize winner will be selected from among these three pictures, based on “viewer’s choice.” Be sure to visit http://planetary.org to vote in August 2001! The Grand Prize winner’s art will be displayed prominently on the cover of the finalists’ CD-ROM. The Grand Prize winner will also receive an autographed print by a professional space artist. We hope you will join us in this opportunity to explore your imagination and to expand your knowledge of Mars. For more information, please contact: Rachel Zimmerman Space Art Contest The Planetary Society 65 North Catalina Avenue Pasadena, California 91106 USA Phone: 626-793-5100 Fax: 626-793-5528 e-mail: rachel.zimmerman@planetary.org web site: http://www.planetary.org --------------------------------------------------------------------- NEW EVIDENCE STRENGTHENS CLAIMS OF ANCIENT LIFE ON MARS STUDY OF MARTIAN METEORITE REVEALS MAGNETIC FOSSILS NASA/JSC release J01-17 Researchers have found magnetic material in a 4.5-billion-year-old Martian meteorite that could only have been produced by bacteria. This new data strongly supports the primitive life on Mars hypothesis of David McKay and co-authors in 1996. “There are no known reports of any organic process that could produce such magnetites,” said Kathie Thomas-Keprta, an astrobiologist at NASA’s Johnson Space Center and the lead researcher on the study. The Martian magnetites are identical to those found in a bacteria strain on Earth called MV-1. “This group of magnetite deeply embedded in the Mars meteorite is so similar to the ones produced by the Earth bacteria that they cannot be told apart by any known measurement,” said David McKay, a geologist at JSC and a co-author on the paper. “We considered that perhaps earth bacteria or earth magnetite had gotten into the Mars meteorite,” McKay continued, “but extensive examination and testing by both our team and many other investigators eliminated that possibility.” Scientists generally agree that ALH84001 is a member of the group of 16 meteorites found on Earth that originated on Mars. The potato- sized igneous rock is the oldest of them—about 4.5 billion years. It lay in Antarctic ice for more than 13,000 years. But the biogenic- type magnetite crystals are embedded in 3.9-billion-year-old carbonates within ALH84001. Previous work by co-author Chris Romanek, of the Savannah River Ecology Laboratory has shown that these carbonates formed on Mars; thus the magnetite crystals must also have formed on Mars. Using electron microscopy, team members examined the Martian magnetites still embedded in the carbonate and also removed about 600 crystals and examined the individual particles to determine their chemical composition and crystal geometry. “These crystals are so tiny, ranging from 10 to 200 nanometers, that nearly a billion of them would fit on the head of a pin,” said Thomas-Keprta. The authors found that about a quarter of the Martian magnetites from ALH84001 are identical to magnetites produced on Earth by the magnetotactic bacteria strain MV-1, which has been extensively studied by co-author Dennis Bazylinski, a geobiologist and microbiologist at Iowa State University who has developed many ways of culturing these difficult to grow microorganisms. No one has found terrestrial inorganic magnetites, produced either naturally or in the laboratory, that mimic all the properties displayed by biogenic magnetites. “There is currently no known inorganic chemical means of producing these magnetite crystals with their unique morphologies,” he said. Magnetite (Fe3O4) is produced inorganically on Earth. But the magnetite crystals produced by magnetotactic bacteria are different— they are chemically pure and defect-free. Their size and shape is distinct. Magnetotactic bacteria arrange these magnetite crystals in chains within their cells. These characteristics make the magnetite crystals very efficient compasses, which are essential to the survival behavior of the bacteria by helping them locate sources of food and energy. “Mars is smaller than Earth and it developed faster,” co-author Simon Clemett of Lockheed-Martin at JSC noted. “Consequently, bacteria able to produce tiny magnets could have evolved much earlier on Mars.” “The process of evolution has driven these bacteria to make perfect little bar magnets, which differ strikingly from anything found outside of biology,” added, Joe Kirschvink, a geobiologist at Caltech and a co-author of the paper. “In fact, an entire industry devoted to making small magnetic particles for magnetic tapes and computer disk drives has tried and failed for the past 50 years to find a way to make similar particles. A good fossil is something that is difficult to make inorganically, and these magnetosomes are very good fossils.” Mars has long been understood to provide sources of light energy and chemical energy sufficient to support life. Early Mars, the authors note, may have had even more chemical energy produced by active volcanism and hydrothermal activity. Also, when the team asserted in 1996 that Martian meteorite ALH84001 showed signs of life existing on Mars, that planet was not known to have ever had a strong magnetic field. But since then, the Mars Global Surveyor has observed magnetized stripes in the crust of Mars that show a strong magnetic field existed early in the planet’s history, about the same time as the carbonate containing the unique magnetites was formed. Surface features also suggest that early Mars had large oceans and lakes. These attributes, coupled with a CO2-rich atmosphere, provided the necessary environment for the evolution of microbes similar to the fossils found in ALH84001. A team of 10 researchers collaborated on the four-year study, which was published February 27 in a special Astrobiology issue of the Proceedings of the National Academy of Science. The team, led by Thomas-Keprta of Lockheed Martin at Johnson Space Center, was funded by the NASA Astrobiology Institute. Co-authors of the study are Simon Clemett and Susan Wentworth of Lockheed Martin at the JSC; Dennis Bazylinski of Iowa State University (funded by the National Science Foundation); Joseph Kirschvink of the California Institute of Technology; David McKay, Everett Gibson and Mary Fae McKay of JSC; and Christopher Romanek of the Savannah River Ecology Laboratory. For a more technical discussion of this paper please see http://ares.jsc.nasa.gov/astrobiology/biomarkers/recentnews.html. Contact: Catherine E. Watson Johnson Space Center, Houston, TX (Phone: 281/483-5111) info@jsc.nasa.gov Additional articles on this subject are available at: http://spaceflightnow.com/news/n0102/27marslife/ http://www.spacedaily.com/news/mars-life-01b.html --------------------------------------------------------------------- CASE FOR LIFE ON MARS WITHSTANDS CRITICISM, GAINS SCIENTIFIC SUPPORT NASA/JSC release J01-20 26 February 2001 Researchers who stunned the world in 1996 with the announcement that a Martian meteorite contained evidence of ancient life on the red planet have released new evidence that strengthens their original hypothesis and allays many of the criticisms leveled at the first paper. In this latest paper, published in the scientific journal, Precambrian Research, February 17, two additional Martian meteorites were examined—Nakhla and Shergotty, 1.3 billion and 165 to 175 million years old, respectively. Both younger meteorites showed the same evidence of microfossils and other remnants of early life as the original meteorite, the 4.5-billion-year-old ALH84001. “If the features observed in the two younger Martian meteorites are confirmed to have a biogenic origin, life may have existed on Mars from 3.9 billion years ago to as recently as 165 to 175 million years ago,” said Everett K. Gibson, a geochemist at the NASA Johnson Space Center in Houston and the senior author on the paper. Clusters of very small spheres found in the two younger meteorites are very similar to those seen in bacteria-containing samples from deep beneath the Earth’s surface in the Columbia River Basalts in eastern Washington. Whether or not these sphere-like structures are true biomarkers has yet to be determined, but the fact that they are embedded in or coated by clays that are clearly of Martian origin suggests that they too were formed on Mars. Studies using a transmission electron microscope have provided further evidence of fossils in the original Martian meteorite, ALH84001. This evidence is in the form of tiny magnetite crystals, identical to those used by aqueous bacteria on Earth as compasses to find food and energy. Magnetite (Fe3O4) is produced inorganically on Earth, but the magnetite crystals produced by magnetotactic bacteria are different—they are chemically pure and defect-free, with a distinct size and shape. Magnetotactic bacteria arrange these magnetite crystals in chains within their cells. Additional studies showed that a substantial portion of the hydrocarbons found in the meteorites were in them when they left Mars and are not the result of terrestrial contamination. There is also strong evidence that most of the carbonates in all three meteorites was formed at a time when Mars was warmer and wetter—an environment much more conducive to life than the current surface of Mars. Terrestrial contamination of extraterrestrial samples is an issue not only with these meteorites, according to the authors, but one that is being studied in relation to the future return of Martian samples to Earth. “It’s clear that we need to better understand the biosignatures of terrestrial and extraterrestrial samples so that when Martian samples are eventually brought back to Earth, we can determine the presences or absence of life with certainty,” Gibson said. “However, if water exists beneath the Martian surface, why shouldn’t life be present today on Mars?” The other authors of this work, which was funded by NASA’s Exobiology Program and NASA’s Astrobiology Institute, are David S. McKay of JSC; Kathie L. Thomas-Keprta, Susan J. Wentworth, and Mary Sue Bell of Lockheed Martin at JSC; Frances Westall, a National Research Council Fellow at the Lunar & Planetary Institute in Houston; Andrew Steele and Jan Toporski of the University of Portsmouth, England; and Christopher S. Romanek of the Savannah River Ecology Laboratory. Of these, Gibson, McKay, Thomas-Keprta and Romanek were authors of the original paper on the subject. For a more technical discussion of this paper please see http://ares.jsc.nasa.gov/astrobiology/biomarkers/recentnews.html. Contact: Catherine E. Watson Johnson Space Center, Houston, TX Phone: 281-483-5111 info@jsc.nasa.gov An additional article on this subject is available at http://www.spacedaily.com/news/mars-life-01c.html. --------------------------------------------------------------------- METEORITES POINT TO ABUNDANT WATER ON MARS LONG AGO From SpaceDaily 26 February 2001 Chemical analysis of Martian meteorites supports the controversial theory of water on Mars, according to Meenakshi Wadhwa, Ph.D., associate curator of meteoritics at The Field Museum in Chicago. Her research was published in the February 23rd issue of Science. Last year, an analysis of images of Mars taken by NASA’s Mars Global Surveyor spacecraft revealed surprising evidence that the planet was once a watery place. On Earth, sedimentary rock is formed by deposition from water, and the photographs of Mars show hundreds of layers of sedimentation. It has generally been assumed that Mars is more oxidized than Earth, partly because of its red surface, which is caused by the presence of iron oxides. But the new evidence indicates that only the outermost rind (i.e., crust) of Mars is moderately to heavily oxidized. This leads to the question of just how did the crust of Mars become oxidized? “On Earth, the most common oxidizing agent is water, so my research supports the idea that abundant water was present in the crust of Mars at one time,” Dr. Wadhwa says. Whether water was ever present on Mars is especially intriguing because water is thought to be a necessary ingredient of life. Get the full story at http://www.spacedaily.com/news/mars-meteorite- 01a.html. --------------------------------------------------------------------- EXPLORING A DISTANT WORLD OF ICE AND HYDROCARBONS By Bruce Moomaw 27 February 2001 Titan is an utterly unique member of the Solar System: an icy moon only slightly bigger than the planet Mercury, but possessing an atmosphere fully four times denser than Earth’s at its surface. Because of the orange organic smog that fills its atmosphere and shields its surface from visible-light viewing, it’s probably the most mysterious world left to explore in our the Solar System—even more so than Pluto, be it a planet or not... ...it’s extremely important scientifically, because it’s a rich natural laboratory for the synthesis of complex organic molecules of the sort that must have served for the beginning of life’s evolution on ancient Earth. Get the full story at http://www.spacedaily.com/news/cassini- 01c.html. --------------------------------------------------------------------- NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.h tml 27 February 2001 Articles about astrobiology, exobiology and terraformation http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s1.html J. Foust, 2001. New evidence found to suggest ancient Mars life. SpaceFlight Now. D. Pacchioli, 2001. Astrobiology special report: looking for life beyond Earth. Space.com. Scientific American, 2001. 100 years ago: canals on Mars. Scientific American, 284(3):14. SpaceDaily, 2001. Case for life on Mars withstands criticisms as support grows. SpaceDaily. SpaceDaily, 2001. Meteorites point to abundant water on Mars long ago. SpaceDaily. SpaceDaily, 2001. Scientists find evidence of ancient microbial life on Mars. SpaceDaily. Articles about human space exploration and the microgravity environment http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s3.html S. Carlson, 2001. Microgravity: geotropism, one last time. Scientific American, 284(3):78-79. SpaceDaily, 2001. How plants tell which way is up. SpaceDaily. Articles about primordial evolution and prebiotic chemistry http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s5.html B. Moomaw, 2001. Exploring a distant world of ice and hydrocarbons [Titan]. SpaceDaily. Associated Press, 2001. Astronomers find key ingredients for formation of life. CNN. L. Becker, R. J. Poreda, A. G. Hunt, T. E. Bunch and M. Rampino, 2001. Impact event at the Permian-Triassic boundary: evidence from extraterrestrial noble gases in fullerenes. Science, 291(5508):1530- 1533. NASA Science News, 2001. Apocalypse then. NASA Science News. P. Recer, 2001. Water found in deep space. Space.com. SpaceDaily, 2001. Search for distant biospheres sniffs first molecules of life. SpaceDaily. --------------------------------------------------------------------- CASSINI WEEKLY SIGNIFICANT EVENTS JPL release 15-21 February 2001 The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Wednesday, February 21. The Cassini spacecraft is in an excellent state of health and is operating normally. Cassini is currently traveling at 46,799 kph relative to the sun, and is 51.2 million kilometers away from Jupiter. The speed of the spacecraft can be viewed on the “Present Position” web page at http://www.jpl.nasa.gov/cassini/english/where/. Post Jupiter science operations continued this week with the spacecraft alternating between Optical Remote Sensing (ORS) movies / atmosphere and torus observations, and Magnetospheric Imaging Instrument (MIMI) magnetospheric data collection. Activities included uplinks of a mini-sequence to modify the Composite Infrared Spectrometer (CIRS) Instrument Expanded Block (IEB), Radio and Plasma Wave Science (RPWS) commands to change to the EZ sensor for dust impact detection, a patch to the MIMI Low Energy Magnetospheric Measurement Subsystem (LEMMS) motor flight software, and activation of the MIMI Ion and Neutral Camera (INCA) sensor. Additional activities included a CDS-B automatic SSR repair, a Reaction Wheel Assembly (RWA) momentum unload, RWA Slow Time Memory Read-out, and a Radio Science Subsystem (RSS) Test. The RSS Team conducted a test this week to help characterize a discrepancy observed in one-way data by Cassini’s Navigation Team. The open-loop receiver (the DSP) was used to record one-way data. This was repeated on three occasions. During the test the one-way signal appeared in the RF spectrum where it was predicted to be. Since no error was detected in the one-way data using the open-loop receiver, it is presumed that the cause of the problem is in the closed-loop receiver system on the ground. Investigation is continuing. The Cassini Instrument Operations (IO) Team and the Multi Mission Image Processing Laboratory have produced and delivered 23,864 ISS images—16,699 from the NAC and 7,165 from the WAC—and 4,963 Visual and Infrared Mapping Spectrometer (VIMS) cubes since Jupiter encounter began. The Spacecraft Office developed and tested Trajectory Correction Maneuver (TCM)-17 products this past week. The TCM will be used to meet the flushing requirement for the bi-propellant propulsion system. The requirement specifies a main engine burn of 5 seconds or greater to be performed every 400 days and ensures that oxidation buildup from the oxidizer is “flushed” through the propulsion system. This course correction, originally placed as a Jupiter fly-by cleanup maneuver, is a main engine burn of 5.4 seconds duration and will be performed next week on Wednesday, February 28, 2001. The second and final C26 Science Planning Virtual Team (SPVT) product delivery port closed this week. Science Planning is now in the process of merging the files and will deliver them to AACS for the final end-to-end pointing check. The Atmospheres Working Group (AWG) held a telecon to work on science and orbit priorities for Tour. The group made assignments to its members asking them to examine in more detail the periods of interest to the AWG. A Titan Orbiter Science Team (TOST) meeting was also held this week. Members examined the integration of observations associated with the first ten Titan flybys for the period around +/- 1 day from Titan closest approach. Mission Support & Services Office (MSSO) staff has begun preparation of a “Jupiter Fly-by” network analysis report. This report will be used by Cassini’s hardware infrastructure group to determine what type of problems and network usage may be expected during tour. Mission Sequence Subsystem (MSS) D7.4.1 Patch Delivery for the Sequence of Events Generator (SEG) was held this week. The new version is able to read the configuration code for the new Radio Science equipment at DSS-25 and issues keywords based on that code to the DSN to configure the equipment. A Delivery Coordination Meeting for Cosmic Dust Analyzer FSW was also held this week. The delivered version 8.4.0 will correct an error in version 8.0.0 that caused the instrument to default to a previous FSW load. 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. Visit the JPL Cassini home page at http://www.jpl.nasa.gov/cassini/ for more information about the Cassini Project. --------------------------------------------------------------------- THIS WEEK ON GALILEO JPL releases 19-25 February 2001 It is going to be yet another quiet week for the Galileo spacecraft. Long cruise periods between encounters can be that way! On Tuesday, the spacecraft performs standard maintenance on its tape recorder system. Playback of the data stored on the tape from the December 27 flyby of Ganymede continues. At the time of this writing, we are running about a day ahead of schedule on our playback plan. This can happen when the data compress more efficiently on the spacecraft than we had planned for, and therefore take less time to transmit to the ground. If the trend continues, we will be able to take advantage of the time gained and retrieve more data, either by specifying additional time periods or more wavelengths to play back, choosing larger fractions of images (we don’t always play back the whole frame), or asking the spacecraft to compress the data less. Since our image compression technique is similar to the popular JPEG image format used throughout the World Wide Web, when we specify a high level of compression, the image will look much blockier, but will take fewer bits and less time to transmit. If we have more bits available, we can specify a lower level of compression, and the image will provide much more detail to the scientists. This week we will continue to receive pictures of the Ganymede aurora taken by the camera while the satellite was in shadow. Additional Photopolarimeter Radiometer data taken during the artificial night of the Ganymede eclipse, and data taken when the satellite returned to the daylight, will show how various surface areas warm up, and will complement the data taken earlier, which showed how those areas cooled down when entering the shadow. Most of the week, however, will be taken up with a set of color pictures of the boundary area of Ganymede’s North Polar Cap. Since this flyby of Ganymede occurred near 60 degrees North latitude, this will provide us with a view of the North Polar Cap which we haven’t seen since our seventh orbit in April of 1997, during the Prime Mission. It is equivalent to flying by the Earth just south of Anchorage, Alaska. Only our second flyby of Ganymede in September of 1996 was at a higher latitude (80 degrees). Near the end of the week, we should begin to see additional images taken of an equatorial region of Ganymede named Dardanus Sulcus. Also expected are infrared data taken at moderate spatial resolution of Ganymede. This is the final such data from Ganymede planned to be taken by the Near Infrared Mapping Spectrometer instrument for the remainder of Galileo’s mission at Jupiter. 26 February - 4 March 2001 Playback of the data stored on the tape from the December 28 flyby of Ganymede continues. This week, quite a variety of observations are planned to be returned, including several taken at or near the same times as observations acquired by the Cassini spacecraft, which also passed by Jupiter on its way out to Saturn. The Photopolarimeter Radiometer instrument (PPR) returns data from some of its observations of Ganymede, Io, Europa, and the atmosphere of Jupiter. First, we expect to see a full temperature map of the day side of Ganymede, taken one to two hours after the satellite left the shadow of Jupiter. This continues an investigation of the composition and structure of surface materials and how they heat up in sunlight. Playback of PPR data continues with multiple observations of both Io and Europa. By viewing these satellites as the angles between the Sun, their surfaces, and Galileo change, scientists gain insight into the structure and composition of those surfaces. In cooperation with the Cassini Composite Infrared Spectrometer instrument, PPR also looked at Jupiter’s North Equatorial Belt, between 3 and 20 degrees north latitude, and at the northwest region of the Great Red Spot, a giant storm in Jupiter’s atmosphere which is about three times the size of Earth, and has persisted for at least 330 years! The Galileo instrument can observe at longer wavelengths of light than the Cassini counterpart, and because of the relative distances of the spacecraft from Jupiter at the times of the flybys, can provide higher spatial resolution. The Galileo Near Infrared Mapping Spectrometer (NIMS) will return a global image of Ganymede obtained with the current full complement of NIMS wavelengths. This will give information about the composition of different areas of the satellite surface. Observations of Io help to monitor that satellite’s volcanic activity. In cooperation with the Cassini Visible and Infrared Mapping Spectrometer instrument, NIMS observations were also made of Callisto and Europa, though both at considerably greater distances than the Ganymede observations. During this pass through the Jupiter system, the closest Galileo came to Europa was nearly 800,000 kilometers (500,000 miles), and to Callisto 2,339,000 kilometers (1,450,000 miles). NIMS also viewed the turbulent region of the atmosphere of Jupiter trailing the Great Red Spot, investigated hot spots in the clouds, and looked for aurorae in the south polar region of the giant planet. The Galileo Solid State Imaging camera will return some global color images of Io, in cooperation with the Cassini imaging experiment, helping to maintain an inventory of the volcanic plumes of that active satellite, and look for changes from previous orbits in the plumes and surface markings due to ongoing volcanic activity. For more information on the Galileo spacecraft and its mission to Jupiter, please visit the Galileo home page at one of the following URL’s: http://galileo.jpl.nasa.gov http://www.jpl.nasa.gov/galileo --------------------------------------------------------------------- GALILEO MILLENNIUM MISSION STATUS JPL release 21 February 2001 Engineers are narrowing down possible causes for an intermittent problem with the camera on NASA’s Galileo spacecraft that may be related to effects of Jupiter’s radiation belts. The spacecraft signaled an alarm from the camera system three times while Galileo passed close to Jupiter from December 28, 2000, to January 1, 2001. Each time, the camera either restored itself to normal functioning or was restored by commands from the ground. The incidents appear to be related to a single similar event five months earlier, and the underlying cause may be cumulative exposure of electronic components to the intensely radioactive environment near Jupiter, said Dr. Eilene Theilig, Galileo project manager at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. Galileo, now in its sixth year of what was originally planned as a two-year mission orbiting Jupiter, has weathered more than three times the radiation dose it was designed to withstand. “We are able to clear the fault by power-cycling the instrument—turning the power off and on—and reloading its memory. The fact that the camera can fix itself without our intervention is puzzling but provides valuable information to analyze what is happening,” Theilig said. Engineers have examined a small sampling of the camera data recorded while Galileo passed through the inner portion of the Jupiter system in late December. The sampling indicates that more than half of the 120 pictures taken during that encounter period were captured properly, including all the ones taken December 28 as the spacecraft flew by the moon Ganymede during an eclipse. In pictures taken while the camera fault was present, however, images are blank, as if entirely saturated with light. The first transmissions of complete images from the encounter will come later this month. Experiments at JPL with an engineering model of the camera system are aiding analysis of events on the spacecraft. The main suspect is an amplifier in the circuitry that processes signals from the camera’s CCD (charge-coupled device), a light-sensor grid akin to the ones in video cameras. “The investigation is continuing,” Theilig said. “When we get a better understanding of the fault and what triggers it, we should be able to identify some workarounds, such as planning ahead to power-cycle the camera at appropriate times, so we can minimize the impact to our imaging objectives.” Galileo’s next encounter will be a flyby of Jupiter’s moon Callisto on May 25. Additional information about the mission is available at http://galileo.jpl.nasa.gov. Galileo was launched in 1989 and began orbiting Jupiter in 1995. JPL, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA’s Office of Space Science, Washington, DC. --------------------------------------------------------------------- MARS GLOBAL SURVEYOR STATUS REPORT JPL release 21 February 2001 Launch / Days since Launch = November 7, 1996 / 1568 days Start of Mapping / Days since Start of Mapping = April 1, 1999 / 692 days Total Mapping Orbits = 8,759 Total Orbits = 10,442 Recent events The spacecraft continues to operate nominally in performing the beta- supplement daily recording and transmission of sciencedata. The mm114 sequence executed successfully from 01-046 (2/15/00) through01- 048 (2/17/01). The mm115 sequence has performed well since it started on 01-049 (2/18/01). It terminates on 01-052 (2/21/01). The mm116 sequence, successfully uplinked on 01-051 (2/20/01), begins executing on 01-053 (2/22/01). MGS performed flawlessly during the Roll Only Targeted Observation demonstration executed on orbit #8690 of 01-047 (2/16/00). Post-test analyses of the engineering data verified nominal performance by all subsystems. Spacecraft health All subsystems report nominal health. Uplinks There have been 6 uplinks to the spacecraft during the past week, including instrument command loads and the background sequences cited above. There have been 5,135 command files radiated to the spacecraft since launch. Upcoming events The mm117 background sequence will be uplinked on 01-054 (2/23/01). Because the ROTO demonstration was successful, standard procedure will be to uplink two ROTO mini-sequences each week. The ROTO mini- sequences for this next week are mz073 and mz074. --------------------------------------------------------------------- STARDUST STATUS REPORT JPL release 23 February 2001 There were fifteen Deep Space Network (DSN) tracking passes in the past week and all subsystems are performing normally. A test to determine the capacity of the battery was successfully performed. Power will be limited at the next aphelion in April 2002, when Stardust will be 2.72 AU, about 408 million kilometers, from the Sun. Therefore knowledge about the battery’s performance is needed now to plan operations around aphelion. The test commanded a low charge rate for approximately twenty-four hours to determine what pressure the battery reached at its maximum charge capacity. Data from this test will be used to establish new operating parameters starting when the spacecraft reaches approximately 2.4 AU from the Sun, in October 2001. 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 8, Number 8.