MARSBUGS: The Electronic Astrobiology Newsletter Volume 7, Number 18, 15 May 2000. Editors: Dr. David J. Thomas, Biology and Chemistry 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://www.lyon.edu/webdata/users/dthomas/marsbugs/marsbugs.html. The purpose of this newsletter is to provide a channel of information for scientists, educators and other persons interested in exobiology and related fields. This newsletter is not intended to replace peer- reviewed journals, but to supplement them. We, the editors, envision Marsbugs as a medium in which people can informally present ideas for investigation, questions about exobiology, and announcements of upcoming events. Astrobiology is still a relatively young field, and new ideas may come 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) LIFE, TRANSPERMIA AND ALL THAT--AN NRC WORKSHOP By Oliver Morton 2) NASA IDENTIFIES TWO OPTIONS FOR 2003 MARS MISSIONS; DECISION IN JULY JPL release 3) PATHFINDER TO RETURN TO MARS? By Andrew Bridges 4) NATIVE AMERICAN STUDENTS TO USE MARS "SOIL" TO GROW SPUDS IN SPACE NASA release 00-79 5) THE OUTER SOLAR SYSTEM, EUROPA, AND THE POSSIBILITY OF LIFE British Interplanetary Society conference announcement 6) NEW ADDITIONS TO THE ASTROBIOLOGY, EXOBIOLOGY AND TERRAFORMATION INDEX By David J. Thomas 7) STARDUST STATUS REPORT JPL release ------------------------------------------------------------------------ LIFE, TRANSPERMIA AND ALL THAT--AN NRC WORKSHOP A personal perspective on the workshop by Oliver Morton 10 May 2000 I'm just back from a workshop on life detection hosted at the Carnegie Institution for the National Academies Space Studies Board and Board on Biology. If astrobiology is about anything, detecting life off the earth must be a crucial component. Unfortunately, as the meeting showed, there's not yet any real consensus on how that should be done. In fact, the discussion reflects how relatively weak our strategies are for answering the question "what is life"? A lot of this is the legacy of Viking. The life detection package on Viking was the crowning achievement of the first fifteen years of what Joshua Lederberg dubbed "exobiology". Its legacy, though, is troubling. Viking tried to find life by showing that metabolic processes were going on. But as Gerry Soffen, one of the project scientists on Viking and a participant at the NRC meeting, pointed out, the life detection results were sufficiently enigmatic for one of the scientists involved (Norm Horowitz) to say Viking "found no life and found why there was no life", while another (Gil Levin) says "the scientific process forces me to my conclusion that there is microbial life on Mars". On their own, the life detection results would have been very incoherent; only the presence of separate tests for organic molecules (not found--though in fact they may have been there, in non-volatile forms, according to Steve Benner of the University of Florida) allowed the community to side for the most part with Horowitz. One lesson from this is to shy away from trying to measure metabolisms. But if not metabolisms, what? Jim Lovelock answered that in the 1960s (an answer made before Viking, and all the more persuasive for it) when he said that far-from-equilibrium planetary atmospheres would be a telltale sign of life, basing the argument on thermodynamics. That argument is alive and well, and Jim Kasting of Penn State talked about how it would be applied to spectrographic data on extrasolar planets from the Terrestrial Planet Finder mission, currently expected some time in the mid 2010s. Though there are ways for physics to push atmospheres quite a long way from chemical equilibrium, Kasting thinks that measurements made with TPF might serve to identify telltale biogenic oxygen in atmospheres like that of the modern earth and telltale biogenic methane in atmospheres like that of the early earth. Closer to, things get harder. Lovelock's argument applies to planetary bodies where life is widespread and there's an atmosphere. But that description does not fit any of the three large-body targets in the solar system that astrobiologists are interested in--Mars, Jupiter's moon Europa, and Saturn's moon Titan. Though Lovelock thinks scarce life probably dies out, that is not an analytical truth--so it is still possible that Mars, for example, harbors scarce life, perhaps in a deep hydrosphere cut off from the surface by a global permafrost layer. Evidence of that life's ancestors might persist in detectable form on the surface, but would not necessarily be expected in the atmosphere. Life is also possible in Europa's ice-bound ocean, if it exists, and here again there is no atmosphere to give it away. No one (at least no one at the meeting) seems to believe there is life on Titan, but they think the pre-biotic chemistry there might be very revealing. Remote sensing is not going to settle any of these issues. For that we need sample return or sophisticated in situ analysis. Both approaches will be needed since proper sample return ("$ample return", on Gerry Soffen's viewgraphs) is going to be extremely costly, and in the case of Titan is not under even the most long-term discussion. (Oddly, though, a limited sample return from Europa may be quite cheap--see below). Most of the speakers in DC, sensitive to the Viking issues, avoided metabolism and went for molecular or chemical biomarkers instead (borrowing insights from, among others, thinkers on biological warfare defense and food safety). The technology discussed was truly impressive: robot PCR systems at the sub-shoebox level and a staggering range of mass spectrometers--which I always imagine being big and clunky objects the size of kennels at the least--including, in development, time of flight machines with tubes just two inches long and discrimination at one part in 300 or better (http://ww2.med.jhu.edu/mams/). The nanopore polymer detectors are very neat, too. You put a pore in a membrane (the alpha-hemolysin protein from staph seems to do nicely, but you could just machine a hole with a similar 20 angstrom bore) and monitor the current that passes through in the form of potassium ions. When a long biomolecule passes through--such as a DNA fragment--this current is interrupted. Experimental set-ups show the passage of single molecules, and there's even talk of using this technology to register the individual bases as molecules go through for ultrafast DNA sequencing (http://www.rowland.org/sequence/default.html). These may all be technologies worth flying--but none of them is a cast iron detection strategy. We have a lot of gadgets, but no real philosophy--a situation well illustrated in Wes Huntress's account of the JPL "Grand challenge" project on life detection. For detecting Earth life this lack of a definition isn't much of a problem. And detecting Earth life is part of what's needed, because you have to be able to tell if there's anything on the supposedly clean spacecraft being your sending out there, both to protect the environments of the other planets and to make sure that samples and in situ measurements are not compromised by earthly hitchhikers. If exolife is like Earth life, lacking a robust definition may still not matter that much. Norm Pace argued that, biochemically, exolife would have to be like Earth life, since it must use carbon (no other chemical can make double and triple bonds and thus be so clever in moving its electrons around) and Earth life uses the simplest suite of carbon molecules, more or less. If that's the case, just looking for a selection of earthly molecular biomarkers might be a fine strategy. Similar arguments apply if the exolife and the Earth life are actually related; that is, if Martians and Earthlings have common ancestors who went back and forth on meteorites. (I'm trying to get this process called "transpermia" to differentiate it from the more general "panspermia"; if you like the term, please use it.) A good illustration of the no-single-biomarker approach is the story of the magnetite in the martian meteorite. These little single domain crystals look just like the little magnets that some bacteria (and some other organisms) produce. Bacteria use them to give themselves a reference frame for moving up and down through sediments. Joe Kirschvink of Caltech, a devoted bio-magnetites man, lists six properties which, when found together, are diagnostic of biological magnetite. Some biological magnetite does not have all six properties; all magnetite with all six properties is biological. Quite a lot of the magnetite in ALH 84001 meets this standard. So is it biological? Kirschvink seems to suspect so, as do some of the Johnson Space Center ALH 84001 team. Others are doubtful. Now- retired UCSD meteorite man John Kerridge points out that these crystals seem in some cases to have been created within the carbonates that hold them through alteration. This seems to underline the argument that you need a constellation of biomarkers to make a hard case. Two things worth noticing about Kirschvink's case. One is that it's transpermic: the similarities between the martian magnetites and terrestrial biomagnetites would be due to the fact that they were made by the same molecular machinery, not because life as a general property needs magnets exactly like this. So Earth life and Mars life would be part of the same phylogenetic tree. The other is that it suggests that Mars developed rather differently from Earth. Evidence for magnetotactic bacteria doesn't turn up on earth until after the Archaean/Proterozoic transition, 2.4 billion years ago or so, and there's a good argument to be made that this is because they are essentially products of a world with free oxygen. All these bacteria prefer the aerobic life. What's more, the ability to store iron--storage that Kirschvink argues provided a pre-adaptation to the making of biological magnets--is not necessary when there's iron in solution all around you, as there is in the pre-oxic environment. So if there were biomagnetites on Mars at the time the ALH 84001 carbonates were laid down, 3.9 billion years ago--a time when, for those of you keeping track of such things, Mars may well still have had a magnetic field--that would seem to suggest there was oxygen, too. That would fit with a suggestion that Chris McKay and Hyman Hartman made a while back: that without plate tectonics and with relatively little volcanism, Mars might have developed a biogenic oxygen atmosphere much earlier than the earth by burying lots of reduced organic carbon. Presumably around this time some magnetobacteria would have been transferred to the more backward earth, where they would have had to eke out some sort of marginal oxygen-deprived life until the photosythesizers got the upper hand in the proterozoic, helped through a fallow 1.5 billion years by the advantage they had over the other bugs of knowing up from down. Summing up near the end, John Kerridge made two points strongly. The first is that you need multiple measurements. The second is what he calls "Knoll's rule" (for Andy Knoll of Harvard); what you detect must not just be something life produces--it must be something that non-living things don't produce. This seems obvious, but sometimes the thing in front of your nose is the hardest thing to see. Knoll's rule, for example, makes any argument to do with minerals a little suspect since so often on the earth mineralization does, in fact, depend on life. To say whether samples from a fossilized martian hot spring, for example, contained evidence of life it would be really nice to be able to point to what a sterile hot spring looks like. But on earth we have no sterile hot springs. (Joe Kirschvink's rejoinder to this argument as applied to martian magnetites is that there are strong economic incentives to come up with inorganic ways of making uniform single-domain magnetite crystals like the ones that bugs make, and no-one has done it.) This speaks to one general message of the meeting, and a clear difference between this discussion and parallel discussions in the pre-Viking era. Life is much more deeply conceived as a planetary process, one inextricably intertwined with geochemistry and geology, than it was back then. One very nice phrase acknowledging this from Bill Barker of the University of Wisconsin: "Organisms have been coexisting with minerals far longer than they have with tissues--so we should expect high specificity." Astrobiology has to learn from what Andy Knoll calls geobiology: "the study of how organisms have influenced and been influenced by Earth's environmental history" (for more, see http://www.nhm.ac.uk/hosted_sites/paleonet/paleo21/geobiology.html). When do we actually try these things out? Here things look a little sad. There are three large targets of particular note in the solar system, Mars, Europa, and Titan. Until last December, Mars sample return was due to be a multi-mission campaign starting in 2003 and climaxing with return of samples to earth in 2008. Now the chances of a start in 2003 are nil, and in 2005 more or less nil. 2007 is possible, 2009 perhaps more likely. That gives an earth sample return date of maybe 2014. Leaving aside the wishes of astrobiologists, the geochemists who have been wanting to date the rocks since Viking must be furious. Other stuff will happen before then, though. NASA is currently considering four missions to Mars for 2003, though it will certainly not fly them all. Those four missions would be: a communications orbiter, a reflight of the lost Mars Climate Orbiter, a flight of the now postponed '01 Lander, and a flight of a new, small, very rugged "scout" lander. At the same time, Mars Express, an ESA orbiter, is due there in '03, dropping off a very small British lander, Beagle 2, to look at carbon isotopes. And Japan's Nozomi turns up shortly afterwards. So late '03 is going to be a big time for the red planet. The idea behind the scout missions is that one or two will be flown at every subsequent opportunity. How this adds up to a strategy is unclear. As far as Europa is concerned, the proposed Europa Orbiter--mission: to prove there's an ocean under the ice--is clearly also being delayed. Previously planned launch in 2003 is now apparently being put back to 2005 or 2006. With a mission time of something like five years in transit (only one month on station after it gets there--the radiation environment is really nasty) that means data to earth in the early 2010s. If you wait until getting this data before designing a Europa lander--on the basis that you'll design the best craft only when you have the best knowledge--that means Europa lander launches about 2015. So surface studies of Europa may not begin until the early 2020s. Farther-out Titan, oddly, looks a little better. The ESA Huygens probe will get there with Cassini in 2004. This should be a quite exciting event, with a leisurely descent through the thick atmosphere, cloud banks, surface imaging, all sorts of good stuff. Along with Cassini stuff it should provide all the science needed to make a Titan followup feasible: a lander, a balloon, perhaps, a nuclear helicopter. That mission might conceivably fly before a Europa lander, if NASA waits for the Europa orbiter results before building one. Some people might say that it shouldn't--that a first generation Europa lander will be there to characterize the ice surface--cations and anions, salinity, pH, volatile analysis, organics--and doesn't need to choose its spot carefully on the basis of Orbiter data. Maybe, but if the orbiter finds some places of peculiar interest, shouldn't that influence mission planning and design? This will be a hard-fought argument. If TPF and Mars Sample Return are both reaching their maximum spend around 2010, there could be a crunch, since a Europa lander with any sort of serious payload is a very hard technical proposition. One should also bear in mind the possibility of another mission: the Ice Clipper, proposed as a Discovery mission a few years ago, now possibly one to think of again, both due to the delay of the orbiter and the fact that some of the Clipper's technological risk is being retired by development for the approved Discovery missions, Deep Impact and Stardust. We think of the natural progression of exploration being fly-by, orbiter, lander, (rover), sample return, but for airless bodies this is not necessarily the case--sample return can be easier than landing, or even orbiting. The clipper mission would skim by the surface of Europa; shortly before closest approach it would launch a small lump of solid copper, which would smash into the surface. The clipper would pass through the debris cloud, scooping up some of it in aerogel collector systems like those currently sampling zodiacal dust on board Stardust, and then swing round Jupiter and return to earth. If the mission were timed to coincide with the orbiter mission the engineering might be easier (as the orbiter could act as a navigation aid) and the science might be richer (extra imaging of the plume, conceivably of the impact site too). That would provide surface samples back to earth in the 2010s. (This cannonball "launch and sample" technique may be good for other missions, too. It's been proposed for sampling the moons of Mars and the polar ice at Mercury. I suppose it might conceivably be used to sample the lunar south pole soils for ice, too.) If you want a vaporized sample, then the clipper is just fine. If you want solid samples, you'll have to pay a lot more. In practice, this means better in situ instrumentation is utterly vital. Unless there's a substantial shift in resources or technology, we're more than ten years from seeing fresh Mars samples on earth and more than twenty years from Europa samples. With two out of the three main targets in the outer solar system, sample-return astrobiology using unmanned craft takes on the same sort of time scales as manned programs in the inner system. Oliver Morton is a writer who concentrates on science and technology and their impacts. He is currently working on a book about Mars and is also a contributing editor at Wired. ------------------------------------------------------------------------ NASA IDENTIFIES TWO OPTIONS FOR 2003 MARS MISSIONS; DECISION IN JULY JPL release 12 May 2000 In 2003, NASA may launch either a Mars scientific orbiter mission or a large scientific rover which will land using an airbag cocoon, like that used on the successful 1997 Mars Pathfinder mission. The two concepts were selected from dozens of options that had been under study. NASA will make a decision on the options, including whether or not to proceed to launch, in early July. Two teams, one centered at NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA, and the other at Lockheed Martin Astronautics, Denver, CO, will conduct separate, intensive two-month studies to further define the concepts. In the studies, the teams also will evaluate risk, cost, and readiness for flight, allowing 36 months of development leading to a May 2003 launch date. The reports will be submitted for review to Mars Program Director Scott Hubbard at NASA Headquarters, Washington, DC. Dr. Ed Weiler, Associate Administrator for Space Science at NASA Headquarters, will make the final decision of which mission, if any, to launch in the 2003 opportunity. If selected, the cost of the 2003 mission will be about the same as the successful 1997 Mars Pathfinder mission (adjusted for inflation). "Our budget will support only one of these two outstanding missions for the 2003 launch opportunity, and it will be a very tough decision to make," said Weiler. "Following this decision, later in the year we will have a more complete overall Mars exploration program to present to the American public which will represent the most exciting, most scientifically rich program of exploration we have ever undertaken of the planet Mars." "These two mission concepts embody the requirements we have learned through the hard lessons of two recent Mars mission failures, and either one will extend the tremendous scientific successes we have had with the Mars Global Surveyor and Mars Pathfinder," said Hubbard. The Mars Surveyor Orbiter is a multi-instrument spacecraft similar in size to the currently operating Mars Global Surveyor. It is designed to recapture all the lost science capability of the Mars Climate Orbiter mission as well as to seek new evidence of water-related materials. The orbiter's mission will be to study the martian atmosphere and trace the signs of ancient and modern water. Its instruments potentially will include a very high-resolution imaging system, a moderate-to-wide-angle multicolor camera, an atmospheric infrared sounder, a visible-to- near-infrared imaging spectrometer, an ultraviolet spectrometer, and possibly a magnetometer and laser altimeter. Telecommunications relay equipment that could be used to support Mars missions for 10 years also would be included. The rover is a based on the Athena rover design, which already has been operated in field tests and previously was considered for the canceled 2001 lander mission. The concept being proposed for the 2003 mission involves packaging the 130-kilogram (286-pound) rover in a system similar to the 1997 Mars Pathfinder structure, which would be cushioned on landing by airbags. Unlike the 1997 mission, however, the four-petal, self-righting enclosure would serve only as a means to deliver the rover to the surface and not function as a science or support station. After landing, the Mars Mobile Lander would serve as a self- contained mission, communicating directly with Earth or with an orbiting spacecraft band as the rover traverses the martian terrain. The rover would be capable of traveling up to 100 meters (100 yard) a day, providing unprecedented measurements of the mineralogy and geochemistry of the martian surface, particularly of rocks, using a newly developed suite of instruments optimized to search for clues about ancient water on Mars. The mobile surface-laboratory will be able to gain access to a broad diversity of rocks and fine-scale materials for the first time on the surface of Mars, in its search for evidence of water-related materials. The rover's mission would last for at least 30 days on the surface. "We are opening up a new frontier on the red planet, and we can't afford to overlook anything," Weiler added. "We have to make sure we plan it well, provide our people with the tools they need, and do whatever it takes to ensure the best possible chances for success." JPL is a division of the California Institute of Technology. ------------------------------------------------------------------------ PATHFINDER TO RETURN TO MARS? By Andrew Bridges 12 May 2000 NASA may send a modified version of its wildly successful Pathfinder spacecraft on a repeat journey to Mars in 2003, relying on that mission's tried-and-true method of landing to ensure the probe's survival. The proposal is just one of several options being considered for the upcoming launch opportunity, three NASA scientists told SPACE.com on Thursday, speaking on condition of anonymity. NASA had originally planned to kick off its attempt to return samples of martian rock and soil to Earth in 2003. NASA has since delayed that effort in wake of the back-to-back losses of the Mars Climate Orbiter and Polar Lander spacecraft late last year. Get the full story at http://www.space.com/missionlaunches/missions/mars2003_000512.html ------------------------------------------------------------------------ NATIVE AMERICAN STUDENTS TO USE MARS "SOIL" TO GROW SPUDS IN SPACE NASA release 00-79 12 May 2000 A 21st century, space-age simulated Mars soil and one of the world's oldest food sources--the potato--have been joined in an experiment that will fly aboard Space Shuttle Atlantis when the STS-101 mission is launched later this month. The experiment, designed by Native American science students, will test how well the soil supports plant growth. Students from Shoshone-Bannock High School on the Fort Hall Indian Reservation in southeastern Idaho will compare the plants grown in the synthetic dirt on Earth with those that fly in space. The simulated soil, known as JSC Mars-1, closely resembles the red dirt found on the surface of Mars. The coarse powder--about the color of cinnamon--is similar to what scientists know about the color, density, grain size, porosity, chemical composition, mineralogy and magnetic properties of martian soil. Known as "Spuds in Space," the experiment will be the first test of the soil simulant as a medium for growing plants in space. It also marks the second time Native American students have flown an experiment on the Shuttle. The first Native American science experiment in space--also from Shoshone-Bannock High School--flew on Discovery in 1998. "As an educator, I am always looking for ways to get students interested in science and life," said Shoshone-Bannock science teacher Ed Galindo. "This Mars soil simulant is an exciting way for students from the Fort Hall Indian Reservation to keep getting excited about space, science and growth, both plant and student." The potato experiment will be one of 10 experiments flying as part of the Space Experiment Module (SEM) program, an educational initiative to increase access to space for students from kindergarten through college. Since its first flight in 1995, SEM has allowed tens of thousands of students in the United States and other countries to fly their experiments in space. The SEM program is managed by NASA Goddard Space Flight Center's Wallops Flight Facility, Wallops Island, VA. "These simulants are natural materials that approximate, to the best of our current knowledge, the soils of the Moon and Mars," explained Dr. Carlton Allen of Lockheed Martin Space Operations, Houston, TX. He was part of the NASA Johnson Space Center, university and private industry teams that developed the simulated soils, including one (JSC-1) based on lunar samples collected by Apollo crews. "Future sample return missions will bring us actual Mars soil and rock samples, which may pave the way for eventual human missions," Allen said. In the meantime, JSC Mars-1 is supporting a wide range of research, instrument design and engineering studies. NASA encourages the use of its soil simulants in educational activities and is offering both JSC Mars-1 and JSC-1 to scientists, engineers and educators for only the cost of shipping. Those interested in obtaining samples of either simulant should send their request to the Office of the Curator, NASA Johnson Space Center, Houston, TX 77058. Additional information on the SEM program can be found at www.wff.nasa.gov/~sspp/sem/sem.html. ------------------------------------------------------------------------ THE OUTER SOLAR SYSTEM, EUROPA, AND THE POSSIBILITY OF LIFE British Interplanetary Society conference announcement 9 May 2000 Program Wednesday 24 May 2000 09:00-17:00 To be held at the Society's HQ in the UK. For details contact the BIS (bis.bis@virgin.net). Jupiter and Saturn The Jovian System from the Galileo Jupiter Orbiter, Professor Fred Taylor, University of Oxford. Comparative Aspects of the Systems of Jupiter and Saturn, Professor Carl Murray, Queen Mary and Westfield College. The Jovian System Europa and Other Icy Satellites as Possible Abodes of Life, Dr. David Rothery, Department of Earth Sciences, The Open University. "Bright Terrain" Morphology on Ganymede, Constantine Thomas, Planetary Science Research Group, Lancaster University. Titan Titan--Cassini Huygens and the Initial Exploration of Its Surface Environment, Dr. J. Zarnecki, University of Kent. The Outer Solar System and Exobiology Life Outside the Habitable Zone, Dr. Julian A. Hiscox, School of Animal and Microbial Sciences, University of Reading. Sub-Glacial Lakes of Antarctica: An Analogue for Europa, Dr. Cynan Ellis-Evans, British Antarctic Survey. Comets--Vehicles for Prebiotic Compounds? Dr. David Hughes, University of Sheffield. New Millennia Mission Concepts Are Discovery-Style Low Cost Missions to Explore Outer Solar System Bodies Feasible? Dr. David G. Fearn, DERA. Extra-Solar Planetary Systems The Current State of Play for Imaging Extra-Solar Planets, Dr. Stuart Clark, University of Hertfordshire. ------------------------------------------------------------------------ NEW ADDITIONS TO THE ASTROBIOLOGY, EXOBIOLOGY AND TERRAFORMATION INDEX By David J. Thomas 15 May 2000 Astrobiology, exobiology and terraformation articles online http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s1.html D. E. Ingber, 1998. The architecture of life. Scientific American, 280(1). T. V. Johnson, 2000. The Galileo mission to Jupiter and its moons. Scientific American, 282(2). E. L. Strickland, 1979. Soil stratigraphy and rock coatings observed in color enhanced Viking lander images. Lunar and Planetary Science, 10:1192-1194. H. Vali, S. K. Sears, N. Çiftçioglu and E. O. Kajander, 1999. Nanofossils and the size limits of life. 30th Annual Lunar and Planetary Science Conference, March 15-29, 1999, Houston, TX, abstract #1890. T. J. Wdowiak, D. G. Agresti and S. J. Clemett, 2000. MALDI for Europa planetary science and exobiology. 31st Annual Lunar and Planetary Science Conference, March 13-17, 2000, Houston, Texas, abstract #1487. Articles on human space exploration and the microgravity environment http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s3.html R. J. White, 1998. Weightlessness and the human body. Scientific American, 280(9). ------------------------------------------------------------------------ STARDUST STATUS REPORT JPL release 12 May 2000 Preparations continue for Trajectory Correction Maneuver 3 (TCM 3) to be performed on May 24. A sequence has been developed to take 29 images of the bright star Vega through various filters on the Navigation Camera, with and without the calibration lamp on. These images will be taken on May 25. The Principal Investigator, Don Brownlee, participated in a Young Astronauts Workshop in Seattle, WA. The Project Manager, Ken Atkins, and Outreach Manager, Aimee Whalen, participated in the Low Cost Mission Conference at the Applied Physics Laboratory in Laurel, MD. The Flight Director, Tom Duxbury, participated in the European Geophysical Society XXV General Assembly in Nice, France. All three activities highlighted the Stardust Project for its relevance to planetary science, low cost missions and outreach focuses. 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 7, Number 18.