Marsbugs: The Electronic Astrobiology Newsletter Volume 10, Number 29, 18 July 2003. 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. 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. 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 from the Marsbugs web page at http://www.lyon.edu/projects/marsbugs/. ________________________________________________________________________ CONTENTS 1) READERS DOUBT CLAIM OF OLDEST PLANET By Robert Roy Britt 2) DON'T PANIC--MORE SUPERNOVAE ON THE WAY! Carnegie Institution of Washington release 3) GOALS FOR THE NEXT CENTURY: TO THE MOON, MARS AND BEYOND By Brian Berger 4) ASTEROID HUNTERS DISCOVER NEAR-EARTH OBJECT WITH NEW CAMERA NASA release 2003-099 5) FEWER EARTHBOUND ASTEROIDS WILL HIT HOME Imperial College London release 6) IS THE LIZARD HIDING ANOTHER EARTH? ESA release 7) MARS SOCIETY ANNOUNCES THE CREATION OF AN ON-LINE LIBRARY Mars Society release 8) THE COGS OF PRECOGNITION From Astrobiology Magazine 9) NASA HUMAN RATING REQUIREMENTS AVAILABLE ON WEB SITE NASA note N03-069 10) SMOKING SUPERNOVAE SOLVE A TEN BILLION YEAR-OLD MYSTERY Joint Astronomy Centre release 11) EARTH'S BIRTH DATE TURNED BACK: FORMED EARLIER THAN BELIEVED By William J. Cromie 12) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 13) CONTINUING COVERAGE OF THE COLUMBIA DISASTER By David J. Thomas 14) FAREWELL TO THE EARTH AND THE MOON--ESA'S MARS EXPRESS SUCCESSFULLY TESTS ITS INSTRUMENTS ESA release 44-2003 15) MARS GLOBAL SURVEYOR IMAGES NASA/JPL/MSSS release ________________________________________________________________________ READERS DOUBT CLAIM OF OLDEST PLANET By Robert Roy Britt From Space.com 11 July 2003 Regarding the discovery of the oldest known planet, announced Thursday, a few readers took SPACE.com and the scientists to task. They wonder how astronomers could find a point of light in the sky--a white dwarf star--and conclude the age and wild travels of an unseen planet around it. Some readers were also dubious of speculation that this presumed planet might have harbored life shortly after the universe began and well before most scientists had ever considered it possible. Read the full article at http://www.space.com/scienceastronomy/oldest_planet_030711.html. ________________________________________________________________________ DON'T PANIC--MORE SUPERNOVAE ON THE WAY! Carnegie Institution of Washington release 14 July 2003 Recent near-infrared images from a new camera called PANIC (Persson's Auxiliary Nasmyth Infrared Camera) on the 6.5-meter Clay telescope at Las Campanas Observatory, Chile, confirm that the camera and telescope hold a promising future for understanding the nature of dark energy, exploring the formation and evolution of distant galaxies, and identifying protoplanetary material around young stars. Installed on the Clay telescope of the Magellan Project, PANIC can image some of the faintest targets ever observed. Under the best conditions, the immense light-gathering power and superb image quality of the Clay telescope will be used to observe supernovae in extremely distant galaxies, observations that will help to reveal the nature of the mysterious dark energy that comprises the majority of the energy in the universe. The nature of this dark energy is one of the outstanding questions in modern astrophysics. "PANIC's superb image quality can measure distant supernovae extremely precisely, measurements that are crucial for understanding the nature of the dark energy," states Dr. Eric Persson, Carnegie Observatories astronomer and principal designer of the instrument. Among the first objects PANIC has imaged is the Antennae--the famous pair of interacting galaxies laced with many young, massive star clusters and dust. Using observations from the Hubble Space Telescope and PANIC, the PANIC team made a composite image that demonstrates the excellent image quality of the camera and reveals red star clusters barely visible in the HST data. "Near-infrared observations with PANIC can see through clouds of gas and dust that obscure our normal vision. They open up a whole new window to study star formation, distant galaxies, and supernovae," noted Dr. Wendy Freedman, director of the Carnegie Observatories. In the second image, using a filter that isolates light from molecular hydrogen, the team viewed the planetary nebula NGC 3132--a remnant gas shell from an old red star. PANIC is the first near-infrared camera built for the Magellan Project, a consortium with over 300 astronomers from five institutions: the Carnegie Observatories, Harvard University, the University of Arizona, the Massachusetts Institute of Technology, and the University of Michigan. It was built at Carnegie over the last two years and began operations in Chile in April. High Resolution PANIC images are available at http://www.ociw.edu/instrumentation/panic/commissioning.html. The Magellan Project is a collaboration of the Magellan Consortium, which designed, built, and uses the twin 6.5-meter Baade and Clay Telescopes at Carnegie's Las Campanas Observatory in Chile. The Carnegie Institution of Washington (www.CarnegieInstitution.org), a pioneering force in basic scientific research since 1902, is a private, nonprofit organization with six research departments in the U.S.: Plant Biology, Global Ecology, Embryology, the Geophysical Laboratory, the Department of Terrestrial Magnetism, and the Carnegie Observatories. Contacts: Tina McDowell Carnegie Institution 1530 P. Street NW Washington, DC 20005 Phone: 202-939-1120 E-mail: tmcdowell@pst.ciw.edu Paul Martini at the Observatories 813 Santa Barbara Street Pasadena, CA 91101 Phone: 626-577-1122 E-mail: martini@ociw.edu ________________________________________________________________________ GOALS FOR THE NEXT CENTURY: TO THE MOON, MARS AND BEYOND By Brian Berger From Space News 14 July 2003 Setting foot on Mars, returning humans to the moon to stay, sending robotic scouts beyond the solar system, harnessing the sun's energy and harvesting the mineral abundance of asteroids are all space missions that should be within humanity's reach over the next century. While fascination with space is as old as the first starry night, humanity's first half-steps into outer space occurred only 46 years ago this October when a Soviet rocket punched through the clouds and put the first artificial satellite in orbit. Many thousands of satellites have since followed Sputnik into orbit, the vast majority of them used for communications and keeping tabs on what's happening down below. A smaller number have broken free of Earth's orbit and sent back often stunning picture postcards of some of the other inhabitants in this corner of the galaxy. Read the full story at http://www.space.com/spacenews/spacenews_businessmonday_030714b.html. ________________________________________________________________________ ASTEROID HUNTERS DISCOVER NEAR-EARTH OBJECT WITH NEW CAMERA NASA release 2003-099 15 July 2003 NASA astronomers in pursuit of near-Earth asteroids have already made a discovery with the newly installed Quasar Equatorial Survey, or "Quest," camera mounted in mid-April on Palomar Mountain's 1.2-meter (48-inch) Oschin telescope. "The Quest camera is still undergoing commissioning trials," said Dr. Steven Pravdo, project manager for the Near-Earth Asteroid Tracking Project at NASA's Jet Propulsion Laboratory in Pasadena, CA. "But that doesn't mean we can't do some real science in the meantime. What we found was a near-Earth asteroid, estimated to be about 250 meters (820 feet) in size." The detection of the near-Earth object, 2003 NL7, occurred on the evening of July 8. It has been confirmed by follow-up measurements from three other observatories and subsequently certified by the official clearinghouse of the solar system's smaller inhabitants, the Minor Planet Center. While 2003 NL7 has been labeled a near-Earth asteroid, it is considered non-hazardous, with a 2.97-year orbit of the Sun in which its closest approach to Earth's orbit is about 25.1 million kilometers (15.6 million miles). The Quest camera is being developed as a multi-purpose instrument by Yale and Indiana universities with Dr. Charles Baltay, chairman of Yale's physics department, as the principal investigator. It is designed for use in detecting and characterizing quasars, near-Earth asteroids, trans-Neptunian objects, supernovas, and a large variety of other astrophysical phenomena, by scientists from Yale, JPL and the California Institute of Technology in Pasadena. The complex camera consists of 112 electronic chips known as charged coupled devices (CCDs) arranged over the Oschin telescope's focal plane. This gives the Quest camera 161-megapixel capability. By comparison, a good store-bought digital camera would probably be in the four-megapixel range. "When Quest becomes operational, it will be a significant advancement for the Near-Earth Asteroid Tracking team," said Dr. Raymond Bambery, the Near-Earth Asteroid Tracking Project's principal investigator. "We expect the new camera to increase the efficiency of detection of near- Earth asteroids by some 3 to 4 times that of the camera it replaced. This will make a major contribution to NASA's goal of discovering more than 90 percent of near-Earth objects that are greater that 1 kilometer (0.62 mile) in diameter. The Near-Earth Asteroid Tracking System is managed by JPL for NASA's Office of Space Science, Washington, DC. JPL is a division of Caltech. More information on the Near-Earth Asteroid Tracking Program is available at http://neat.jpl.nasa.gov/. Contact: D. C. Agle Phone: 818-393-9011 ________________________________________________________________________ FEWER EARTHBOUND ASTEROIDS WILL HIT HOME Imperial College London release 16 July 2003 Scientists report in Nature today that significantly fewer asteroids could hit the Earth's surface than previously reckoned. Researchers from Imperial College London and the Russian Academy of Sciences have built a computer simulation that predicts whether asteroids with a diameter up to one kilometer will explode in the atmosphere or hit the surface. The results indicate that asteroids with a diameter greater than 200 meters (the length of two football pitches) will hit the surface approximately once every 160,000 years--way down on previous estimates of impacts every 2,500 years. The findings also predict that many more asteroids blow up in the atmosphere than previous estimates, which means the hazard posed by impact-generated tidal waves or tsunamis is lower than previous predictions. The researchers suggest that proposals to extend monitoring of Near Earth Objects (NEO) to include much smaller objects should be reviewed. Dr. Phil Bland of Imperial's Department of Earth Science and Engineering and a Royal Society University Research Fellow, said: "There is overwhelming evidence that impacts from space have caused catastrophes for life on Earth in the past, and will do so again. "On the Moon it's easier to track the number, frequency and size of collisions because there is no atmosphere, so everything hits the surface. On Earth the atmosphere acts like a screen and geological activity erodes many craters too. "Massive impacts of the type thought to have wiped out the dinosaurs leave an indelible print on the Earth but we have not been able to accurately document the effect of smaller impacts. Now, we have a handle on the size of 'rock' we really need to worry about and how well the Earth's atmosphere protects us." When small asteroids hit the atmosphere the two forces collide like two objects smashing together, which often breaks the asteroid into fragments. Until now, scientists have relied on the "pancake" model of asteroid impact to calculate whether the asteroid will explode in the atmosphere. This treats the cascade of fragments as a single continuous liquid that spreads out over a larger area to form a "pancake". But a new model known as the "separate fragment" (SF) model, which was developed by co-author of the study, Dr. Natalya Artemieva of the Russian Academy of Science, has challenged this approach. "While the pancake model can accurately predict the height from the Earth's surface at which the asteroid will break up, it doesn't give an accurate picture of how the asteroid will impact," explains Dr. Bland. "The SF model tracks the individual forces acting on each fragment as it descends through the atmosphere." To create a more accurate model of how asteroids interact with the atmosphere the researchers ran more than 1,000 simulations using both models. Objects made of either iron or stone, known as "impactors", were used to reflect the composition of asteroids and experiments were run with varying diameters up to 1 km. The researchers found the number of impacts for iron impactors were comparable using both models. For stone the pancake model significantly overestimated the survivability rate across the range used. The SF simulations also allowed the researchers to define the different styles of fragmentation and impact rates for iron and stone, which correspond closely with crater records and meteorite data. "Our data show that over most of the size range we investigated stony asteroids need to be 1,000 times bigger than the iron ones to make a similar sized crater. Much larger objects are disrupted in the atmosphere than previously thought. But we are not out of the woods yet," added Dr. Bland. "Asteroids that fragment in the atmosphere still pose a significant threat to human life." Dr. Phil Bland is a member of the Meteorite and Impact Group that includes scientists from Imperial College London and the Natural History Museum. Contact: Judith H. Moore Imperial College of Science, Technology and Medicine Phone: 44-0-20-7594 6702 E-mail: j.h.moore@imperial.ac.uk http://www.imperial.ac.uk An additional article on this subject is available at http://www.space.com/scienceastronomy/asteroid_breakup_030716.html. ________________________________________________________________________ IS THE LIZARD HIDING ANOTHER EARTH? ESA release 16 July 2003 If the sky is clear tonight, look up high and try to find Lacerta (the constellation of the Lizard), between Cygnus and Cassiopeia. How many stars can we see, and could any of them be hiding habitable planets? Astronomers working on ESA's planet-finder mission, Eddington, aim to find out and have chosen to search this area of the sky for rocky planets of similar size to our own. So far, over a hundred planets are now known to orbit other stars. However, they are all giant planets, like Jupiter in our Solar System. To find the smaller, rocky planets like Earth, we need specially-designed tools. ESA's Eddington mission is this kind of tool. Eddington will search for these planets in a tiny region of Lacerta. This constellation in the northern sky contains no bright stars and has no claim to fame. Although picking it out with the naked eye is tricky for us, it is just visible to amateur sky watchers, but it is perfect for Eddington because bright stars would "blind" its sensitive telescopes. Visible to the naked eye Luckily for sky watchers, Lacerta sits between two prominent constellations: Cygnus (The Swan) and Cassiopeia. Cygnus is high overhead and dominates the summer sky with its "cross" shape, representing the swan's outstretched wings, tail and long neck. Cassiopeia is easy to spot because its brightest stars trace out a "W" across the sky. To find the location that Eddington will search for its crop of planets, imagine a line joining the brightest star of Cygnus to that of Cassiopeia. Lacerta is about halfway along that line. The Eddington search field covers an area of the sky ten times wider than the full Moon. Looking at 20,000 stars Eddington will find rocky planets by looking for the drop in light caused every time a planet crosses in front of its parent star. Astronomers call such a celestial alignment a "transit". They anticipate that not all stars will have Earth-sized planets and, of those that do, not all will be oriented in space to produce transits. Eddington must therefore view a huge quantity of stars to increase its chances of finding large numbers of planets. In Lacerta, Eddington will be able to see 20,000 Sun-like stars. Very few other regions in the sky present so many stars for study, another reason for the choice of this field of view. No one knows which stars have rocky planets, so no one knows when a planet may pass in front of its central star. For a planet in an Earth-sized orbit, it will only be in front of its star for a few hours, once every year. Blink and you miss it. Eddington will therefore stare at this region of space constantly for three years, to make sure it catches every transit as it happens. Astronomers have identified a few back-up regions of the sky, such as one in the Southern Cross. ESA will study these in detail in the future, as alternative targets. What will happen after Eddington's expected harvest of the first Earth- like planets around other stars? In the period 2010-2012, ESA will launch its star-mapper mission, Gaia, to provide the most accurate distances to these stars ever obtained, allowing astronomers to analyze their nature even more fully. Read the original release at http://www.esa.int/export/esaSC/SEMVQJXO4HD_exploring_0.html. ________________________________________________________________________ MARS SOCIETY ANNOUNCES THE CREATION OF AN ON-LINE LIBRARY Mars Society release 16 July 2003 The Mars Society announces the creation of an on-line library of papers dealing with Mars and available to Mars Society members. Categories of Mars papers have been established ranging from analog research stations, technologies for robotic and human Mars exploration, utilization of Mars resources, the search for life, settlement, to related societal and philosophical implications that may be expressed in fiction or non- fiction. The current Marspapers Library contains the text of all papers from the 1998 Founding Convention and the complete text and graphics of 57 previously unpublished Mars Society papers including 38 papers from the 2002 Mars Society Convention. While the public can view the abstracts of all papers, only Mars Society members can download the complete papers by logging into the members-only portion of the Mars Society web site. The Marspapers Library was created for the Mars Society by Frank Crossman, a volunteer with the Northern California chapter, with help from our able webmaster, Harold Miller. Our intent is to expand the library well beyond the papers presented at Mars Society Conventions to include all other relevant papers of dealing with Mars exploration and settlement and related space technology and societal issues. We are doing this to provide a service to the community and provide a strong incentive for people to join and annually renew their membership in the Mars Society. We encourage all Mars Society members and others involved in space exploration to contribute their works to this library. Good thinking is too important to present once at a conference and then be forgotten. Make sure your papers are available to the space community forever. Submit your paper to the Marspapers Library today. Details can be found by clicking on the Marspapers link in the left hand column of the Mars Society main web page at www.marssociety.org. ________________________________________________________________________ THE COGS OF PRECOGNITION From Astrobiology Magazine 16 July 2003 Which gadgets can unlock the next technological revolutions? What is the next big thing? To propose answers to this question, the sixteen nations of the European Space Agency commissioned a project called "Innovative Technologies from Science Fiction for Space Applications" (ITSF). Their results were co-published with two supervisory foundations, the Swiss museum Maison d'Ailleurs and the astronautical society, or OURS Foundation. One aim was to discover what their study called the facts of "hard science-fiction": literature that uses either established or carefully extrapolated science as its backbone. As Caltech physicist, author and visiting scholar for NASA's Exobiology Center, David Brin, described in his PBS interview for the special, Closer to Truth: "perhaps an alternative name could have been 'speculative history' because [hard science-fiction authors] deal in different pasts, alternate presents, extension of the human drama into the future... Einstein used the word gedanken experiment and he coined it, he said that just sitting on a streetcar in Bern, leaving the clock tower and imagining he was riding on a beam of light, was 50% of the work [of relativity]." Augmented science: Galileo's ship The history of drawing inspiration from speculative literature is deep with success stories. As early as 1632, to advocate for his classical principle of relativity, Galileo used a fictional character called Salviati who while locked in a closed room below a ship deck, observes a small fish tank which remains quiescent and undisturbed unless the ship accelerates. In dialogue format, he answers all the common scientific arguments against the idea that the earth moves. Predating lunar travel classics by H. G. Wells and Jules Verne were Cyrano de Bergerac's Comical History of the States and Empires of the Moon (1656), space travel in Voltaire's Micromégas (1752), and alien cultures in Jonathan Swift's Gulliver's Travels (1726). Even as the liquid-propelled rockets were first being tested by Robert Goddard in the 1920's, technical proposals had already appeared for planetary landers (1928) and aerodynamically-stabilized rocket fins (1929). Perhaps the most detailed and famous publication was Sir Arthur C. Clarke's 1945 paper, "Can Rocket Stations Give World-wide Radio Coverage?" that laid down the principles of modern satellite communications and geostationary orbits [Wireless World, October 1945]. A half-century later, even a few hours of interruption in this global network today would seem catastrophic: crippled health care delivery, financial disruption including failed automated teller machines and credit card validations, grounded travelers for lack of airline weather tracking, and global TV blackouts. But in 1945, the idea of geostationary satellites had a different kind of reception, as Clarke wrote: "Many may consider the solution proposed [for extra-terrestrial relay services] too far-fetched to be taken seriously. Such an attitude is unreasonable, as everything envisaged here is a logical extension of developments in the last ten years..." The European space study, appropriately timed for Clarke's "Space Odyssey" series, completed its first project phase in 2001. Altogether fifty fact sheets and technical dossiers were published to catalog the inventions that should be made real. In addition, more than two hundred technologies were outlined and graded for future feasibility studies. Ranging from astrobiology to propulsion, their complete "what-if" list is available in broad categories online [at http://www.itsf.org/resources/categories.php]. Examples pushing the envelope One mission that has been described in the ESA study is soon to become closer to fact: a fantastic mission to a comet. Seventeen years ago, astrobiologist David Brin's "Heart of the Comet" [1986], extended Jules Vernes' mythical tour of the solar system on a comet. Verne got many of his science guesses right. For instance, although not well-understood at the time, he correctly attributed that--given the distance of his travelers from the Sun--then a comet would resemble something more like an ice-ball, and not a fiery-hot world. He wrote, "The solidity of the ice was perfect; the utter stillness of the air at the time when the final congelation of the waters had taken place had resulted in the formation of a surface that for smoothness would rival a skating-rink; without a crack or flaw it extended far beyond the range of vision." But the asteroid and cometary science planned for international missions is approaching the realm of fantastic. On Valentine's Day, 2001, the Near-Shoemaker spacecraft successfully landed on the asteroid, Eros. Its remarkable journey--to soft-land on a peanut shaped asteroid--about 176 million kilometers (109 million miles) from Earth, prompted Andrew Cheng, NEAR Project Scientist, to note, "On Monday, 12 February 2001, the NEAR spacecraft touched down on asteroid Eros, after transmitting 69 close-up images of the surface during its final descent. Watching that event was the most exciting experience of my life." In May 2003, a Japanese probe [called Muses-C] lifted off on the world's first mission to collect samples from the surface of an asteroid, part of a four-year journey covering nearly 400 million miles. On January 2, 2004, the spacecraft called Stardust will fly within 75 miles of a cometary main body (called Wild-2), close enough to trap small particles from the coma, the gas-and-dust envelope surrounding the comet's nucleus. Stardust will be traveling at about 13,400 miles per hour and will capture comet particles traveling at the speed of a bullet fired from a rifle. Launched in February 1999, Stardust was designed to capture particles from Wild 2 and return them to Earth for analysis. The spacecraft already has collected grains of interstellar dust. It is the first U.S. sample-return mission since the last moon landing in 1972. In the next 5 or so years, there will be multiple encounters of spacecraft with comets and asteroids. All the following missions are fully funded, though only not all have already been launched. 2001 September 22 Comet Borrelly Deep Space One (simple flyby) 2004 January 1 Comet Wild 2 Stardust (coma sample return) 2005 July 3 Comet Tempel 1 Deep Impact (big mass impact) 2005 September Asteroid 1998 SF36 Muses-C (sample return) Pre-emptive fiction But according to David Brin, the most intriguing categories of his speculative histories are the ones that are either interrupted or pre- empted. Brin explained, "I think the most powerful science fiction stories are not those that accurately predict the future, but, rather, those that have prevented futures, the self-preventing prophecy that came across so chilling, and so many people read it and were so moved, that the very scenario that might have plausibly happened didn't happen, the two that really prevented the futures they described, 1984, by George Orwell, and probably the greatest science fiction author who ever lived, Karl Marx's Das Kapital, which utterly prevented the scenario that it described". What's next? This year offers a case of what seems to be science fiction as astronomical fact: the closest approach between Mars and the Earth in 73,000 years. Four current Mars missions hope to take advantage of the confluence, as this summer the Red Planet will appear brighter than Jupiter as the brightest object in the night sky. As a timely prelude of things to come, the moon will eclipse Mars tonight in North America for up to 90 minutes. But more than a hundred years ago, in 1894--one of the last times such dramatic astronomical events gripped the visual imagination of authors--many of the modern concepts about intelligent life elsewhere first took shape. The celestial mechanics of the night sky translated to a cultural picture of what life elsewhere might resemble. For instance, the idea that Mars might have a humanoid civilization is relatively modern, but needed both an event and a real-world, technological boost from telescope builders. Mars as a home needed first for astronomers to describe what appeared to them as an elaborate martian canal system. This lineage continued from when astronomer Percival Lowell began advocating for the canals on Mars, until H. G. Wells further propagated those civilizations in his classic, War of the Worlds. In an interview on the ESA project for Radio Netherlands, NASA astrobiologist Chris McKay pointed out this lineage--and that science and our cultural ideas about astrobiology are intertwined with these events. "When people first started pointing telescopes at Mars," McKay explained, "they noticed seasonal changes very much like on Earth. Then Percival Lowell reported seeing 'canals' on Mars and created an elaborate story that they had been made by a dying martian civilization." From Galileo's ship to Einstein's thought experiments about traveling on a light beam, the technical dossier of "what will be the next big thing?" continues to be a relevant question for both speculative historians and science planners alike. Read the original article at http://www.astrobio.net/news/article526.html. ________________________________________________________________________ NASA HUMAN RATING REQUIREMENTS AVAILABLE ON WEB SITE NASA note N03-069 16 July 2003 NASA has posted the "Human Rating Requirement and Guidelines for Space Flight Systems," on the agency's Web site. The document contains requirements and guidelines for certifying the design of future agency space vehicles carrying humans. An interdisciplinary team of agency experts and engineers produced this NASA Procedures and Guidelines document. It will serve as a "blueprint" for providing the maximum reasonable assurance the design and operations of future human space flight systems present minimum risk to the flight crew and occupants, as well as those involved in and exposed to space flight activities. The "Human Rating Requirements" document can be accessed at http://nodis3.gsfc.nasa.gov/library/displayDir.cfm?Internal_ ID=N_PG_8705_0002_&page_name=main. For more information about NASA and human space flight on the Internet, visit http://www.nasa.gov. Contact: Al Feinberg NASA Headquarters, Washington, DC Phone: 202-358-4504 ________________________________________________________________________ SMOKING SUPERNOVAE SOLVE A TEN BILLION YEAR-OLD MYSTERY Joint Astronomy Centre release 16 July 2003 A team of UK astronomers have announced the discovery that some supernovae have bad habits--they belch out huge quantities of "smoke" known as cosmic dust. This solves a mystery more than 10 billion years in the making. The new observations, published on 17th July in the journal, Nature, answer long-standing questions about the origin of the first solid particles ever to form in the Universe. The team measured the cold cosmic dust in Cassiopeia A, the remnant of a supernova explosion in our own Galaxy, about 11,000 light years from Earth. The amount of dust was a thousand times what had been previously detected, suggesting that these powerful explosions are one of the most efficient ways to create cosmic dust. This also answers the riddle of how large quantities of dust recently discovered in the early universe were formed. Unlike household dust, cosmic dust actually consists of tiny solid grains (mostly carbon and silicates) floating around in interstellar space, with similar sizes to the particles in cigarette smoke. The presence of dust grains around young stars helps them to form and they are also the building blocks of planets. Dr. Loretta Dunne from Cardiff University, who led the research says, "Effectively, we live on a very large collection of cosmic dust grains! The question of the origin of cosmic dust is in fact that of the origin of our planet and others." The smoking gun Supernovae are the violent explosions of stars at the ends of their lives. In a single instant, a supernova can release more energy than our Sun will produce in its entire nine billion year lifetime. They also make large amounts of heavy elements like carbon and oxygen and throw them out into interstellar space. Since these are the ingredients of cosmic dust grains, it was suspected that supernovae might be important in explaining the origin of dust. However, until now, only tiny amounts of dust had ever been found in supernovae--leaving astronomers with a smoking gun, but not enough smoke. Haley Morgan, a Ph.D. student at Cardiff University, explains, "Some supernovae are the violent ends of stars that live fast and die young. These stars are many times the mass of our own Sun, and they burn their fuel thousands of times faster, in only a few million years. If supernovae were efficient dust 'factories' they would each be producing more than the mass of the Sun in dust." The team looked at Cassiopeia A, the 300 year-old supernova remnant created when a star about 30 times more massive than the Sun exploded. The material from the explosion is still traveling outwards at speeds of 10,000 km per second, sweeping up the surrounding gas and dust into a blast wave shell. Dust grains block half of all the visible light from stars and galaxies, but this dusty cloud has a silver lining as they also shine this stolen starlight back out as far-infrared and submillimeter waves (at wavelengths between 0.1 and 1 millimeter). To detect these wavelengths, the team used "SCUBA", the world's most powerful submillimetre-wave camera, attached to the James Clerk Maxwell Telescope in Hawaii. Cold hard evidence SCUBA detected a dust shell in Cassiopeia A with a total mass around 1-4 times that of the Sun. Dr. Steve Eales, also of Cardiff University, says, "This is over a thousand times what's been seen before! Cassiopeia A must have been extremely efficient at creating dust from the elements available." Professor Mike Edmunds, head of the School of Astronomy at Cardiff adds, "Astronomers have been searching for dust in supernova remnants for decades, but they could only detect the tiny fraction of dust which was relatively warm. With SCUBA we can at last see the dust which is very cold, at a temperature of -257 degrees Celsius." In recent years, SCUBA has also found distant galaxies full of dust, more than ten billion light years from Earth. The light from them has taken so long to reach us that we are seeing them as they were when the universe was only about one billion years old--less than one tenth of its current age. Supernova sleuths The origin of this ancient dust was a mystery. Astronomers had thought that dust was mostly made in the winds from cool, giant stars in the late stages of their lives. But stars such as our Sun take about nine billion years to reach this stage, so it was impossible for the dust to be created by stellar winds within the first billion years of the universe. With dust created quickly in supernovae, the mystery has been solved. Dunne says, "Dust has been swept under the cosmic carpet--for years astronomers have treated it as a nuisance because of the way it hides the light from the stars. But then we found that there is dust right at the edge of the universe in the earliest stars and galaxies, and we realized that we were ignorant of even its basic origin. Now, with these supernova dust factories, we can explain how that dust was made." Dr. Rob Ivison of the UK Astronomy Technology Centre in Edinburgh says, "Massive stars become supernovae in the blink of an eye by astronomical standards, so we can now explain why the early universe is so dusty." "These observations give us a tantalising glimpse of how the first solid particles in the universe were created," adds Haley Morgan. This work will be published in Nature, 17th July 2003, Volume 474, page 285. Background information SCUBA (the Submillimeter Common-User Bolometer Array) is the world's most powerful submillimeter-wave camera. It is attached to the James Clerk Maxwell Telescope, and contains sensitive detectors called bolometers, which are cooled to 60 milliKelvin, 0.06 degrees above absolute zero (60 milliKelvin is about -273.1 Celsius, -459.6 Fahrenheit). The James Clerk Maxwell Telescope (JCMT) is the world's largest single- dish submillimeter-wave telescope. It collects faint submillimeter- wavelength signals with its 15 meter diameter dish. It is situated near the summit of Mauna Kea on the Big Island of Hawaii, at an altitude of approximately 4000 meters (14,000 feet) above sea level. It is operated by the Joint Astronomy Centre, on behalf of the UK Particle Physics and Astronomy Research Council, the Canadian National Research Council, and the Netherlands Organization for Scientific Research. Supernovae happen about once every 50 years in our Galaxy, and there are two main types--1a and II. Cassiopeia A is an example of a type II. Type II supernovae are the explosions of very massive stars, more than 8 times larger than the Sun. These stars "live fast and die young" using up their hydrogen and helium fuel in only a few million years (thousands of times faster than the Sun burns it's fuel). When the fuel supply is exhausted the star must make heavier and heavier elements until, finally, when it can do no more to keep itself alive the central part of the star collapses to become a neutron star or black hole, and the outer parts are flung off in the cataclysm we call a supernova. The explosion of a supernova acts like the explosion of a nuclear bomb, driving a blast-wave into the surrounding material. The gas is heated to very high temperatures (over a million degrees) so that it produces X-rays, and it also generates powerful radio emission as electron spiral in strong magnetic fields. If the nearest massive star, Betelgeuse, were to go supernova it would (for a short time) be brighter than the full moon. Elements such as silicate and carbon are formed in stars and can condense out of the gas to make solid dust grains. This happens when certain conditions of temperature and pressure are met; the process is similar to how snowflakes form but happens at much higher temperatures. Web links * Joint Astronomy Centre public outreach site http://outreach.jach.hawaii.edu/ * Further details and pictures http://www.astro.cf.ac.uk/news/research/smokeysne.html Images [Image 1] The "Cassiopeia A" supernova remnant as seen by SCUBA, revealing a shell of cosmic dust about 12 light years across. This is an image taken with submillimeter wavelengths of light. The black and dark blue colors represent fainter emission, whilst the light blue and white areas shine the brightest. Image credit: Loretta Dunne (Cardiff University) et al. http://outreach.jach.hawaii.edu/pressroom/2003_casa/scubacasa.png (full size PNG 737kB) http://outreach.jach.hawaii.edu/pressroom/2003_casa/scubacasa_small.png (smaller size PNG 232kB) [Image 2] Photograph of the James Clerk Maxwell Telescope, atop Mauna Kea on the Big Island of Hawaii. Image credit: Nik Szymanek. http://outreach.jach.hawaii.edu/pressroom/2003_casa/jcmt.jpg (full size JPEG 240kB) http://outreach.jach.hawaii.edu/pressroom/2003_casa/jcmt_small.jpg (smaller size JPEG 24kB) Contacts: Dr. Douglas Pierce-Price Science Outreach Specialist Joint Astronomy Centre E-mail: outreach@jach.hawaii.edu Phone: +1 808 969 6524 Fax: +1 808 961 6516 Dr. Loretta Dunne Department of Physics and Astronomy, Cardiff University E-mail: loretta.dunne@astro.cf.ac.uk Phone: +44 (0)29 20876782 Fax: +44 (0)29 20874056 Dr. Steve Eales Department of Physics and Astronomy, Cardiff University E-mail: steve.eales@astro.cf.ac.uk Phone: +44 (0)29 20876168 Fax: +44 (0)29 20874056 Dr. Rob Ivison UK Astronomy Technology Centre, Royal Observatory Edinburgh E-mail: rji@roe.ac.uk Phone: +44 (0)131 668 8361 Fax: +44 (0)131 668 8407 Miss Haley Morgan Department of Physics and Astronomy, Cardiff University E-mail: haley.morgan@astro.cf.ac.uk Phone: +44 (0)29 20876782 Fax: +44 (0)29 20874056 ________________________________________________________________________ EARTH'S BIRTH DATE TURNED BACK: FORMED EARLIER THAN BELIEVED By William J. Cromie Harvard University release 17 July 2003 Our planet is 50 to 90 million years older than previously thought, according to new evidence found in meteorites. Mixtures of radioactive elements, which tick away like clocks, show that most of Earth had formed only 10 million years after the sun was born as a star, which took place about 4,567 million years ago. Previous measurements indicated an Earth birth of 60 million to 100 million years after the sun's nuclear fires began to burn. Mars, about half the size of Earth, may have formed 5 million years or less after our star's birth, or, like Earth, much faster than anyone believed. While Earth was still young, a stray boulder the size of Mars, or about 4,000 miles across, struck it and knocked off enough pieces to form the moon. "That occurred 30 million years after the sun formed, and it completed the building of Earth from gas and dust particles left over from the formation of the sun," says Stein Jacobsen, professor of geochemistry at Harvard University, who made the measurements. But Earth still was not covered by a hard crust. Jacobsen and Charles Harper, a former research associate in his laboratory, previously determined that this was not completed until 100 million years after the sun began to shine. The oldest rocks found on our planet date back to about 4,000 million (4 billion) years ago. Therefore, some 600 million years of history were lost in the melting and reworking of rocks as the young planet cooled down. There would be no way to make up for that loss without the radioactive clocks in meteorites that geologists are sure formed at the same times as Earth and the other planets. "One class of meteorites, known as chondrites, are the most primitive material in the solar system," Jacobsen points out. "They have never been melted like the rocks of the planets, so retain the earliest record of our solar system." Rock clock ticks Radioactive elements in rocks decay in a predictable way, like the ticking of a well-made clock that can run for millions of years. The decay marks a change in character of the elements; one type of uranium, for example, decays into lead. Jacobsen and his colleagues used a radioactive type of hafnium, a rare heavy metal, which decays into tungsten, a more familiar gray-white metal. The ratio of this type of tungsten to a stable variety of the same metal reveals how much hafnium decayed away, or how long the clock has ticked. "After 50 million years, the hafnium-tungsten timepiece is a dead clock because all the radioactive hafnium has decayed away," Jacobsen explains. "But for the first 50 million years of solar system history, it is ideal for tracking a planet's growth." Hafnium was not even known until the early 1920s. It was named after the Latin word for Copenhagen (Hafniae), where it was discovered. Measuring the ratio of hafnium-derived tungsten to stable tungsten requires special instruments, and is so difficult that no one succeeded until Jacobsen and Harper did it in an iron meteorite in the mid-1990s. Making the same measurement on chondrite meteorites, however, involves a higher level of difficulty. Scientists at the University of Michigan tried but did not find any differences in tungsten ratios between chondrites and the Earth, so they concluded that our planet must have formed 60 to 100 million years after the sun's formation. Jacobsen worked on improving the technique, and, with the help of research associate Qingzhu Yin, found that the amount of tungsten produced by radioactive hafnium in Earth's rocks is higher than that in the chondrites. These more accurate measurements showed that Earth built itself up from solar leftovers in only 10 million years, or quicker than anyone believed before. "Within 100,000 years of the formation of the sun, the first embryos of the planets Mercury, Venus, Earth, and Mars had formed," Jacobsen reported in the June 6 issue of Science. "Some grew more rapidly than others, and within 10 million years, about 65 percent of Earth had formed." The "Big Whack" No meteorites have been found from furnace-hot Mercury, the closet planet to the sun, or from cloud-shrouded Venus, the next one out. Then comes Earth, some 93 million miles from the sun, then Mars, another 50 million to 248 million miles away. (The distance varies with the orbits of the red planet and Earth.) Pieces of Mars have been knocked off the martian surface by meteorites from farther away, and were found in earthly places like Antarctica. From measurements made of these rocks and geological data sent back by unmanned spacecraft that landed on Mars, Jacobsen estimates that our neighbor could have been built in 5 million years or less. The hafnium clock was still ticking when a huge rock orbiting near Earth, perhaps a sister planet, took a gravitational turn for the worse. It slammed into Earth, scattering rocks beyond the pull of our gravity to attract them back. Their own gravities, however, pulled them together into a satellite 2,160 miles wide, circling 240,000 miles from us. Astronauts brought back hundreds of pounds of these rocks picked up during six moon landings. Examinations of the samples fit well with the so-called Big Whack theory of the moon's origin, and Jacobsen's work provides a lunar birth date of 4,537 million years. What on Earth happened after the hafnium clock stopped 4,517 million years ago? Before Jacobsen learned to read the clock so precisely, he and Harper used other kinds of radioactive rock clocks to determine when Earth became solid enough to stand on. They came up with a date of 4,467 years, or 100 million years after the interstellar gas and dust accreted into a fiery sun. Where did this gas and dust come from? Most astronomers believe it was debris from more primitive stars that blew up when they ran out of nuclear fuel. Such supernovas, as they are called, have been lighting up the universe for 10-12 billion years. Gravity gathers these construction materials into massive black clouds. Spectacular images of the insides of such clouds, taken by the Hubble Space Telescope, show young stars being born inside them. Billions of years from now the sun will finish burning its gas, and implode to pieces. The leftovers will join those from shorter-lived stars and solar systems. There will be radioactive hafnium in the mix and the clocks will start over again, timing the formation of new planets and moons, some of which may develop life intelligent enough to tell time by these exotic means. Images supporting this article are available at http://www.news.harvard.edu/gazette/2003/07.17/01-earthbirth.html. ________________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/projects/marsbugs/astrobiology/astrobiology.html 18 July 2003 Astrobiology and planetary engineering articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles1.html Astrobiology Magazine, 2003. The cogs of precognition. Astrobiology Magazine. Human space exploration articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles3.html B. Berger, 2003. Goals for the next century: to the Moon, Mars and beyond. Space News. Evolution (biological, chemical and cosmological) articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles5.html NASA Goddard Space Flight Center, 2003. NASA research seeks to discover if comets seeded life. Spaceflight Now. Planetary protection articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles6.html R. R. Britt, 2003. Small stony asteroids will explode and not hit Earth, study shows. Space.com. Extrasolar planets articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles7.html R. R. Britt, 2003. SPACE.com mailbag: readers doubt claim of oldest planet. Space.com. ________________________________________________________________________ CONTINUING COVERAGE OF THE COLUMBIA DISASTER By David J. Thomas 18 July 2003 The investigation of the Columbia tragedy continues. I have included (below) a non-exhaustive list of links to recent articles on the subject. http://www.space.com/news/walker_future_030715.html http://www.space.com/businesstechnology/technology/osp_okeefe_030715.htm l http://www.space.com/missionlaunches/return_flight_030716.html http://www.space.com/missionlaunches/safety_panel_030716.html http://www.space.com/missionlaunches/sts107_dean_030716.html http://www.spacedaily.com/news/shuttle-03za.html http://www.spacedaily.com/2003/030711175931.6h06hphp.html http://spaceflightnow.com/shuttle/sts107/030715crewmodule/ ________________________________________________________________________ FAREWELL TO THE EARTH AND THE MOON--ESA'S MARS EXPRESS SUCCESSFULLY TESTS ITS INSTRUMENTS ESA release 44-2003 17 July 2003 A unique view of our home planet and its natural satellite--the Moon--is one of the first data sets coming from ESA's Mars Express. "It is very good news for the mission," says ESA's Mars Express Project Scientist, Agustin Chicarro. These and other data, such as those recording the major constituents of Earth as seen from space, are the actual proof that the instruments on board Mars Express, launched 2 June 2003, are working perfectly. The routine check-outs of Mars Express's instruments and of the Beagle-2 lander, performed during the last weeks, have been very successful. "As in all space missions little problems have arisen, but they have been carefully evaluated and solved. Mars Express continues on its way to Mars performing beautifully", comments Chicarro. The views of the Earth/Moon system were taken on 3 July 2003 by Mars Express's High Resolution Stereo Camera (HRSC), when the spacecraft was 8 million kilometers from Earth. The image taken shows true colors; the Pacific Ocean appears in blue, and the clouds near the Equator and in mid to northern latitudes in white to light grey. The image was processed by the Instrument Team at the Institute of Planetary Research of DLR, Berlin (Germany). It was built by combining a super resolution black and white HRSC snap-shot image of the Earth and the Moon with color information obtained by the blue, green, and red sensors of the instrument. "The pictures and the information provided by the data prove the camera is working very well. They provide a good indication of what to expect once the spacecraft is in its orbit around Mars, at altitudes of only 250-300 kilometers: very high resolution images with brilliant true color and in 3D," says the Principal Investigator of the HRSC, Gerhard Neukum, of the Freie Universität of Berlin (Germany). This camera will be able to distinguish details of up to 2 meters on the martian surface. Another striking demonstration of Mars Express' instruments high performance is the data collection by the OMEGA spectrometer. Once at Mars, this instrument will provide the best map of the molecular and mineralogical composition of the whole planet, with 5% of the planetary surface in high resolution. Minerals and other compounds such as water will be charted as never before. As the Red Planet is still too far away, the OMEGA team devised an ingenious test for their instrument--to detect the Earth's surface components. As expected, OMEGA made a direct and unambiguous detection of major and minor constituents of the Earth's atmosphere, such as molecular oxygen, water and carbon dioxide, ozone and methane, among other molecules. "The sensitivity demonstrated by OMEGA on these Earth spectra should reveal really minute amounts of water in both martian surface materials and atmosphere," says the Principal Investigator of OMEGA, Jean Pierre Bibring , from the Institut d'Astrophysique Spatiale, Orsay, France. The experts will carry on testing Mars Express's instruments up till the arrival to the Red Planet, next December. The scientists agree on the fact that these instruments will enormously increase our understanding of the morphology and topography of the martian surface, of the geological structures and processes--active now and in the past, and eventually of Mars's geological evolution. With such tools, Mars Express is also able to address the important "water" question, namely how much water there is today and how much there was in the past. Ultimately, this will also tell us whether Mars had environmental conditions that could favor the evolution of life. The Mars Express High Resolution Stereo Camera (HRSC) was developed by the German Aerospace Centre (DLR) and built by EADS-Astrium GmbH in Friedrichshafen, Germany. The Mars Express OMEGA spectrometer was developed and built by the Institut d'Astrophysique Spatiale, Orsay, France, in cooperation with LESIA at Meudon/Paris Observatory, France, IFSI in Frascati, Italy, and IKI in Moscow, Russia. For more information about Mars Express visit: http://www.esa.int/science/marsexpress http://www.esa.int/EuropetoMars For more information about the ESA Science Programme visit: http://www.esa.int/science Contacts: ESA Communication Department Media Relations Office Phone: +33(0)1 5369 7155 Fax: +33(0)1 5369 7690 Agustin Chicarro, ESA Mars Express Project Scientist Estec - Noordwijk, The Netherlands Phone: +31 71 565 3613 E-mail: Agustin.Chicarro@esa.int Professor Dr. Gerhard Neukum, Mars Express HRSC Principal Investigator Freie Universität Berlin, Earth Sciences Dept., Germany Phone: +49 30 8387 0579 (secretary: -575) E-mail: gneukum@zedat.fu-berlin.de Dr. Jean-Pierre Bibring, Mars Express OMEGA Principal Investigator Institut d'Astrophysique Spatiale, Orsay, France Phone: +33 1 6985 8686 E-mail: bibring@ias.u-psud.fr ________________________________________________________________________ MARS GLOBAL SURVEYOR IMAGES NASA/JPL/MSSS release 10-16 July 2003 The following new images taken by the Mars Orbiter Camera (MOC) on the Mars Global Surveyor spacecraft are now available. North Polar Sand Dunes (Released 10 July 2003) http://www.msss.com/mars_images/moc/2003/07/10/index.html Dark Valley in Newton Crater (Released 11 July 2003) http://www.msss.com/mars_images/moc/2003/07/11/index.html Tractus Fossae Collapse Pit (Released 12 July 2003) http://www.msss.com/mars_images/moc/2003/07/12/index.html Sedimentary Rock Near Coprates (Released 13 July 2003) http://www.msss.com/mars_images/moc/2003/07/13/index.html Southern Auqakuh Vallis (Released 14 July 2003) http://www.msss.com/mars_images/moc/2003/07/14/index.html South Polar "Poodle" (Released 15 July 2003) http://www.msss.com/mars_images/moc/2003/07/15/index.html Eastern Cerberus (Released 16 July 2003) http://www.msss.com/mars_images/moc/2003/07/16/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. ________________________________________________________________________ End Marsbugs, Volume 10, Number 29.