Marsbugs: The Electronic Astrobiology Newsletter Volume 11, Number 16, 13 April 2004 Editor/Publisher: David J. Thomas, Ph.D., Science Division, Lyon College, Batesville, Arkansas 72503-2317, USA. dthomas@lyon.edu Marsbugs is published on a weekly to monthly basis as warranted by the number of articles and announcements. Copyright of this compilation exists with the editor, except for specific articles, in which instance copyright exists with the author/authors. Opinions expressed in this newsletter are those of the authors, and are not necessarily endorsed by the editor or by Lyon College. E-mail subscriptions are free, and may be obtained by contacting the editor. Information concerning the scope of this newsletter, subscription formats and availability of back-issues is available at http://www.lyon.edu/projects/marsbugs. The editor does not condone "spamming" of subscribers. Readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing lists. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editor. __________________________________________________________________________ Articles and News 1) FOR THE SAKE OF LAND AND CLIMATE, COAXING SOIL TO SOAK UP CARBON Pacific Northwest National Laboratory release 2) ASTRONOMERS TAKE SEARCH FOR EARTH-THREATENING SPACE ROCKS TO SOUTHERN SKIES By Lori Stiles 3) STARFIELD OF DREAMS: THE ASTROBIOLOGY SCIENCE CONFERENCE, 2004 By Leslie Mullen 4) WEB-BASED PROGRAM CALCULATES EFFECTS OF AN EARTH IMPACT By Lori Stiles 5) DELAYED GRATIFICATION ZONES By Leslie Mullen 6) MODERN MARS: LATEST SPACECRAFT FINDINGS REDEFINE FUTURE MISSIONS By Leonard David 7) NASA RADAR AIDS HIGH-TECH DIGS By Rosemary Sullivant 8) A BLACK BOX FOR PEOPLE By Karen Miller 9) HOW LONG DOES IT TAKE FOR EARTH'S MAGNETIC FIELD TO REVERSE? LONG- DEBATED, A FIRM ANSWER IS NOW ON THE HORIZON National Science Foundation release 10) ASTROBIOLOGY: ASKING BIG QUESTIONS TO LEARN SCIENCE By Edna DeVore 11) DANGEROUS SPACE ROCKS UNDER WATCH From Reuters and CNN 12) EXPERIMENT HARNESSES STATE-OF-THE-ART SEQUENCING TECHNOLOGY TO DETECT LIFE ON MARS By Robert Sanders 13) CAN SETI PROBE FOR PROBES? INTERVIEW WITH SCOT STRIDE From Astrobiology Magazine Announcements 14) ERRATUM: DOWN THAT LONG DUSTY TRAIL Corrections by Corien Bakermans 15) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas Mission Reports 16) CASSINI SIGNIFICANT EVENTS NASA/JPL release 17) CASSINI: TWO STORMS CAUGHT IN THE ACT ON SATURN NASA/JPL release 2004-098 18) NASA EXTENDS MARS ROVERS' MISSION NASA/JPL release 2004-097 19) MARS GLOBAL SURVEYOR IMAGES NASA/JPL/MSSS release 20) MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 21) ROSETTA STATUS REPORT: ONGOING COMMISSIONING ACTIVITIES ESA release __________________________________________________________________________ FOR THE SAKE OF LAND AND CLIMATE, COAXING SOIL TO SOAK UP CARBON Pacific Northwest National Laboratory release 1 April 2004 In a novel approach to stalling global warming while reinvigorating nutrient-depleted farmland, chemists have found they can promote soil's natural ability to soak up greenhouse-gas carbon dioxide from the surrounding air. Experiments led by Jim Amonette at the Department of Energy's Pacific Northwest National Laboratory in Richland, WA, and reported today at the American Chemical Society national meeting, show that maintaining a proper alkalinity plus frequent wetting and drying cycles can coax soil to retain more carbon. "Globally, soils contain four times as much carbon as the atmosphere, and half of the soil carbon is in the form of organic matter," said Amonette, a PNNL senior research scientist. Until about 30 years ago, soil tillage released more carbon dioxide to the atmosphere than burning of fossil fuels. Some agricultural soils have lost a third of their carbon from tillage. "These carbon-depleted soils are a tremendous potential reservoir for carbon that can help slow the increase in atmospheric carbon dioxide," Amonette said. "The amount of carbon added to soil in a year is incredible. Today, 99 percent of it comes out the top as carbon dioxide. If we can increase the fraction that is retained in soil by even a small amount, it will make a huge difference." Amonette's experiments promoted the activity of tyrosinase, a common enzyme that catalyzes soil's natural "humification" process. This process involves the gradual incorporation of carbon from dead plants and microbes into stable organic matter called humus, which is responsible for the dark color in many soils. Tyrosinase increases the reaction rate between oxygen and humus precursors, such as phenols and hydroxybenzoic acids, to form quinones. The quinones react with amino acids released by soil microbes to form complex, durable molecules called humic polymers. "Because humic polymers are less easily degraded by microbes than the precursor molecules, they survive to diffuse into small pores in soil aggregates where they are stabilized for decades, if not centuries," Amonette said. The humification rate depends on many factors: enzyme stability, moisture, alkalinity, oxygen availability, microbial population and the physical properties of different soils. Amonette's experiments were designed to weigh the importance of these many factors and to learn ways they might be manipulated to increase humification. In the lab, Amonette assembled 72 elaborate plastic-tube configurations he likens to "those Russian nesting dolls," matrioshkas. The tubes allowed Amonette to control individual moisture levels and oxygen availability. Each soil sample was placed between the inner and outer walls of water- tight but gas-porous concentric cylinders. These were placed inside yet a larger "chimney" tube to control the humidity as well as the type of gas and its flow rate. Amonette was particularly interested in identifying soil components and soil additives that might improve tyrosinase's natural ability to promote humification. He found that an alkaline, porous material called "fly ash," a byproduct of coal combustion, "speeds up the normal humification process by promoting the reaction of the quinones with the amino acids and providing small pores to protect humic polymers," he said. "Frequent cycles of wetting and drying appear to be important, too, for fostering a rich microbial community that supplies many of the humic precursors and for aiding the formation of soil aggregates." Amonette is eager to put his results to the test where it matters most-in the field. He will get his wish in May, when he travels to a field outside of Charleston, SC. There, he and collaborators from the U.S. Forest Service and Oak Ridge National Laboratory will plant 72 pots containing various controlled mixtures of soil and catalysts. PNNL is a DOE Office of Science laboratory that solves complex problems in energy, national security, the environment and life sciences by advancing the understanding of physics, chemistry, biology and computation. Read the original news release at http://www.pnl.gov/news/2004/04-25.htm. __________________________________________________________________________ ASTRONOMERS TAKE SEARCH FOR EARTH-THREATENING SPACE ROCKS TO SOUTHERN SKIES By Lori Stiles University of Arizona release 6 April 2004 The hunt for space rocks on a collision course with Earth has so far been pretty much limited to the Northern Hemisphere. But last week astronomers took the search for Earth-threatening asteroids to southern skies. Astronomers using a refurbished telescope at the Australian National University's Siding Spring Observatory discovered their first two near- Earth asteroids (NEAs) on March 29. NEAs are asteroids that pass near the Earth and may pose a threat of collision. Siding Spring Survey (SSS) astronomer Gordon Garradd detected a roughly 100-meter (about 300-foot) diameter asteroid and 300-meter (about 1,000- foot) diameter asteroid in images he obtained with the 0.5-meter (20-inch) Uppsala Schmidt telescope. SSS partner Robert H. McNaught confirmed both discoveries in images he took with the Siding Spring 1-meter (40-inch) that same night. The 100-meter asteroid, designated 2004 FH29, makes a complete orbit around the sun every 2.13 years. It missed Earth by 3 million kilometers (1.9 million miles), or 8 times the Earth-to-moon distance, yesterday, traveling at 10 km per second (22,000 mph) relative to Earth. The 300- meter asteroid, designated 2004 FJ29, orbits the sun about every 46 weeks. It came within 20 million kilometers (12 million miles), or within 52 lunar distances of Earth, last Tuesday, March 30, traveling at 18 km per second (40,000 mph) relative to Earth. Neither object poses a direct threat of colliding with Earth. Had the asteroids not missed, damage from their impacts would have depended on what kind of rock they're made of. The 100-meter object likely would mostly burn up in Earth's atmosphere in an airblast equivalent to 10 megatons of TNT, comparable to the 1908 explosion above the Tunguska River valley in Siberia, McNaught said. The 300-meter rocky asteroid likely would reach Earth's surface, dumping the equivalent of 1,400 megatons of TNT energy into Earth's atmosphere, he added. That's comparable to 200 Tunguskas, or 24 times the largest thermonuclear bomb explosion, a 58 megaton Soviet bomb exploded in 1961. The new survey is a joint collaboration between the University of Arizona Lunar and Planetary Laboratory and ANU's Research School of Astronomy and Astrophysics. It is funded by NASA's Near-Earth Object Observation Program, a 10-year effort to discover and track at least 90 percent of the one kilometer (six-tenths of a mile) or larger NEOs with the potential to become impact hazards. When astronomers detect what they suspect is an NEA, they immediately must take additional images to confirm their discovery, McNaught said. Surveys often have to suspend their NEA searches and spend observing time confirming NEAs, or they risk losing them altogether because follow-up observations were made too late, he added. The SSS plan is to use the 1-meter (40-inch) telescope for part of the month to quickly confirm suspect asteroids detected with the Uppsala, freeing the smaller telescope to continue it searches. "Our confirmation strategy worked beautifully on our first try," McNaught said. The Uppsala Schmidt telescope was built in the 1950s for Uppsala Observatory in Sweden. It was sited at Stromlo as the Uppsala Southern Station to make wide field photographs of the southern sky. Increasing light pollution from Canberra led to its relocation to Siding Spring, near Coonabarabran in New South Wales, in 1982. Despite its high quality optics, the telescope drifted into disuse because it used photographic film rather than modern electronic detectors and had to be operated manually. In 1999, McNaught and Stephen M. Larson of UA's Lunar and Planetary Laboratory joined in an effort to refurbish and upgrade the Uppsala telescope. Larson had similarly just overhauled a manually operated, photographic wide-field Schmidt telescope in the Santa Catalina Mountains north of Tucson for his Catalina Sky Survey (CSS), part of the NASA-funded program to spot and track asteroids headed toward Earth. The SSS builds on telescope control, detector technology and software developed for the CSS in Tucson. During the upgrade, the Uppsala was completely reconditioned, and fitted with computer control, a large format (16 megapixel) solid state detector array, and extensive support computers and software that detects objects moving against background stars. Larson said his reaction to the SSS milestone was "one of relief, since it took several years to make the telescope and facility modifications. Now the real work begins." Larson and Catalina Sky Survey team member Ed Beshore worked on commissioning the Uppsala telescope during the past few months. Commissioning a telescope is like commissioning a ship: you have to get all the parts working and working together, and adjust things so they perform as expected. "We actually achieved 'first light' last summer, with good images from the start," Larson said. McNaught and Garradd will operate SSS about 20 nights each month. They suspend operations when the week around full moon brightens the sky, making faint object detection difficult. The Catalina telescope, which Larson and his team upgraded again in May 2000, features new optics that give it a 69 centimeter (27-inch) aperture and a new, more sensitive camera. In addition to Larson and Beshore, Eric Christensen, Rik Hill, David McLean, and Serena Howard operate CSS. Both CSS and SSS telescopes can detect objects as faint as 20th magnitude, close to sky background level generated by scattered city light and auroral glow that brightens Earth's upper atmosphere. Read the original news release at http://uanews.org/cgi- bin/WebObjects/UANews.woa/4/wa/SRStoryDetails?ArticleID=8916. Additional articles on this subject are available at: http://www.spacedaily.com/news/deepimpact-04d.html http://spaceflightnow.com/news/n0404/09asteroid/ http://www.universetoday.com/am/publish/asteroid_search_looks_south.html. __________________________________________________________________________ STARFIELD OF DREAMS: THE ASTROBIOLOGY SCIENCE CONFERENCE, 2004 By Leslie Mullen From Astrobiology Magazine 7 April 2004 The possibility of finding alien life is tantalizingly close. The recent discovery of ancient water features on the surface of Mars suggests life could have once existed right next door. Discoveries of planets in other solar systems hint at the potential for life in the far reaches of our galaxy, and scientists predict that within a decade we will discover Earth-like worlds orbiting distant stars. Over 700 scientists and engineers from around the world pondered these and other topics last week at the 2004 Astrobiology Science Conference at NASA's Ames Research Center in Mountain View, California. Discussions ranged from the smallest forms of life, including viruses, to the evolution of the most intelligent life we know of so far--human beings--to the possibility of contacting advanced aliens in other solar systems. Many scientists said if we do find alien life, it will be a microbe. Earth is a microbial world, and nearly every biosphere on the planet teems with life in this miniscule form. Microbial life on Earth has evolved to live comfortably in extreme environments such as scalding heat, frigid cold, and acid solutions. Microbes even can survive the radiation and vacuum of space. Although microbes have not yet been discovered beyond Earth, the universe is infused with the organic building blocks of life. While astrobiologists try to figure out where life could thrive beyond Earth, the origin of life on our own planet remains a mystery. Scientists discussed drilling projects that aim to reach subsurface life. These projects may not only help shed light on the origins of life here on Earth, but could indicate places where life may exist on Mars. Cornell University's Steve Squyres, lead scientist for the Mars rovers team, gave an overview of the progress made by the Spirit and Oppportunity rovers. Squyres seemed confident that the chemical signatures and features discovered by the rover Opportunity were indicative of a flow of salty water that once existed on the martian surface, and he hinted at new evidence to come that could confirm that theory. While the past remains a hot topic, the future also seems to be heating up. Much of the conference was devoted to the question, "Where are we going?" Scientists examined the impact of humans on Earth's environment, and wondered at the fate of our world. The discovery of over 100 extrasolar planets so far are helping tailor the search for life elsewhere, and future missions like Kepler and the Terrestrial Planet Finder will further refine this search. The future of Mars was the centerpiece of a debate on terraforming sponsored by Astrobiology Magazine and The Science Fiction Museum and Hall of Fame. Moderated by Donna Shirley, the original leader of the team that built the Mars Pathfinder rover, the panelists debated the scientific and ethical implications of turning Mars into a world made habitable for humans. Science fiction authors Greg Bear and Kim Stanley Robinson joined in the discussion with astrobiologists Chris McKay, James Kasting, Lisa Pratt, and David Grinspoon, as well as NASA's Planetary Protection officer John Rummel. Renowned science fiction author Arthur C. Clarke was linked to the debate by telephone from Sri Lanka. Many of the debaters agreed that our first priority should be to search for life on Mars. If life is there, terraforming would have to wait until we could study that life and determine if it is related to life on Earth, or an entirely unique genesis. Because life can live deep underground, it could be several decades before we can say for sure if Mars is alive or dead. If we do decide to terraform Mars, it will be a long, difficult and costly task. The panelists seemed divided on whether terraforming would be worthwhile. Chris McKay, for instance, advocated bringing life to the Red Planet, "to give Mars back its heartbeat." But others were more hesitant, wondering if we should alter an alien world when we have so many problems maintaining a healthy environment on our own planet. Anyone still wrestling with their conscience could attend a session on ethics, where panelists discussed the many historical, religious, sociological and philosophical implications of human exploration. In the end, one's position could be determined by a simple question. When you see photos of rover tracks made in the red soil of Mars, how does it make you feel? Do you see it as the defacement of a pristine planet? Or do you see it as the exciting fingerprint of man? When asked if we should terraform Mars, Arthur C. Clarke responded, "Perhaps we should ask the Martians first." Read the original article at http://www.astrobio.net/news/article913.html. __________________________________________________________________________ WEB-BASED PROGRAM CALCULATES EFFECTS OF AN EARTH IMPACT By Lori Stiles University of Arizona release 7 April 2004 Next time an asteroid or comet is on a collision course with Earth you can go to a web site to find out if you have time to finish lunch or need to jump in the car and drive. University of Arizona scientists are launching an easy-to-use, web-based program that tells you how the collision will affect your spot on the globe by calculating several environmental consequences of its impact. Starting today, the program is online at http://www.lpl.arizona.edu/impacteffects. You type in your distance from the predicted impact site, the size and type of projectile (e.g., ice, rock, or iron) and other information. Then the Earth Impact Effects Program calculates impact energies and crater size. It next summarizes thermal radiation, seismic shaking, ejecta deposition (where all that flying stuff will land), and air-blast effects in language that non-scientists understand. For those who want to know how all these calculations are made, the web page will include "a description of our algorithm, with citations to the scientific sources used," said Robert Marcus, a UA undergraduate in the UA/NASA Space Grant Program. He discussed the project recently at the 35th Lunar and Planetary Science Conference meeting in Houston, Texas. Marcus developed the web site in collaboration with planetary sciences Regents' Professor H. Jay Melosh and research associate Gareth Collins of UA's Lunar and Planetary Laboratory. Melosh is a leading expert on impact cratering and one of the first scientists reporters call when rumors of big, Earth-smashing objects begin to circulate. Reporters and scientists both want to know the same thing: how much damage a particular collision would wrack on communities near the impact site. The web site is valuable for scientists because they don't have to spend time digging up the equations and data needed to calculate the effects, Melosh said. Similarly, it makes the information available to reporters and other non-scientists who don't know how to make the calculations. "It seemed to us that this is something we could automate, if we could find some very capable person to help us construct the web site," Melosh said. That person turned out to be Marcus, who is majoring in computer engineering and physics. He applied to work on the project as a paid intern through the UA/NASA Space Grant Program. Marcus built the web- based program around four environmental effects. In order of their occurrence, they are: 1) Thermal radiation. An expanding fireball of searing vapor occurs at impact. The program calculates how this fireball will expand, when maximum radiation will occur, and how much of the fireball will be seen above the horizon. The researchers based their radiation calculations on information found in "The Effect of Nuclear Weapons." This 1977 book, by the U.S. Defense Department and U.S. Department of Energy, details "considerable research into what different degrees of thermal radiation from blasts will do," Melosh noted. "We determine at a given distance what type of damage the radiation causes," Marcus said. "We have descriptions like when grass will ignite, when plywood or newspaper will ignite, when humans will suffer 2nd or 3rd degree burns." 2) Seismic shaking. The impact generates seismic waves that travel far from the impact site. The program uses California earthquake data and computes a Richter scale magnitude for the impact. Accompanying text describes shaking intensity at the specified distance from the impact site using a modified Mercalli scale. This is a set of 12 descriptions ranging from "general destruction" to "only mildly felt." Now suppose the dinosaurs had this program 65 million years ago. They could have used it to determine the environmental consequences of the 15- kilometer-diameter asteroid that smashed into Earth, forming the Chicxulub Crater. The program would have told them to expect seismic shaking of magnitude 10.2 on the Richter scale. They also would have found (supposing that the continents were lined up as they are now) that the ground would be shaking so violently 1,000 kilometers (600 miles) away in Houston that dinosaurs living there would have trouble walking, or even standing up. If the Chicxulub Crater-impact occurred today, glass in Houston would break. Masonry and plaster would crack. Trees and bushes would shake, ponds would form waves and become turbid with mud, sand and gravel banks would cave in, and bells in Houston schools and churches would ring from ground shaking. 3) Ejecta deposition. The team used a complicated ballistics travel-time equation to calculate when and where debris blown out of the impact crater would rain back down on Earth. Then they used data gathered from experimental explosions and measurements of craters on the moon to calculate how deep the ejecta blanket would be at and beyond the impact- crater rim. They also determined how big the ejecta particles would be at different distances from impact, based on observations that Melosh and UA's Christian J. Schaller published earlier when they analyzed ejecta on Venus. OK, back to the dinosaurs. Houston would have been covered by an 80.8- centimeter- (32-inch-) thick blanket of debris, with particles averaging 2.8 mm (about 1/8th inch) in size. They would have arrived 8 minutes and 15 seconds after impact (meaning they got there at more than 4,000 mph). 4) Air blast. Impacts also produce a shock wave in the atmosphere that, by definition, moves faster than the speed of sound. The shock wave creates intense air pressure and severe winds, but decays to the speed of sound while it's still close to the fireball, Melosh noted. "We translate that decreasing pressure in terms of decibels--from ear-and-lung-rupturing sound, to being as loud as heavy traffic, to being only as loud as a whisper." The program calculates maximum pressures and wind velocities based on test results from pre-1960s nuclear blasts. Researchers at those blasts erected brick structures at the Nevada Test Site to study blast wave effects on buildings. The UA team used that information to describe damage in terms of buildings and bridges collapsing, cars bowled over by wind, or forests being blown down. Dinosaurs living in Houston would have heard the Chicxulub impact as loud as heavy traffic and basked in 30 mph winds. Read the original news release at http://uanews.org/cgi- bin/WebObjects/UANews.woa/1/wa/SRStoryDetails?ArticleID=8820. Additional articles on this subject are available at: http://www.space.com/scienceastronomy/mystery_monday_040412.html http://www.spacedaily.com/news/deepimpact-04e.html http://www.universetoday.com/am/publish/asteroid_impact_simulator.html __________________________________________________________________________ DELAYED GRATIFICATION ZONES By Leslie Mullen From Astrobiology Magazine 7 April 2004 We are doomed. One day the Earth will be a burnt cinder orbiting a swollen red star. This is the ultimate fate of any planet living close to a main sequence star like our sun. Main sequence stars run on hydrogen, and when this fuel runs out, they switch over to helium and become a red giant. While the sun's transition into a red giant is sad news for Earth, the icy planets in the most distant regions of our solar system will bask in the sun's warmth for the first time. The sun has been slowly but steadily growing brighter and hotter over the course of its lifetime. When the sun becomes a red giant in about 4 billion years, our familiar yellow sun will turn a vivid red, as it mainly emits the lower frequency energy of infrared and visible red light. It will grow thousands of times brighter and yet have a cooler surface temperature, and its atmosphere will expand, slowly engulfing Mercury, Venus and possibly even the Earth. While the sun's atmosphere is predicted to reach Earth's orbit of 1 AU, red giants tend to lose a lot of mass, and this wave of expelled gases could push Earth just out of range. But whether the Earth is consumed or merely singed, all life on Earth will have passed into oblivion. Yet the conditions that make life possible could appear elsewhere in the solar system, according to a paper published in the journal Astrobiology by S. Alan Stern, Director of the Southwest Research Institute's Department of Space Studies in Boulder, Colorado. He says that planets located 10 to 50 AU will be in the red giant sun's habitable zone. The habitable zone of a solar system is the region where water can remain in a liquid state. The habitable zone will shift gradually through the 10 to 50 AU region as the sun grows brighter and brighter, evolving through its red giant phase. Saturn, Uranus, Neptune and Pluto all lie within 10 to 50 AU, as do their icy moons and the Kuiper Belt Objects. But not all these worlds will have an equal chance at life. The prospects for habitability on the gaseous planets Saturn, Neptune and Uranus may not be affected all that much by the red giant transition. Astronomers have discovered gaseous planets orbiting very close to their parent star in other solar systems, and these "hot Jupiters" seem to hold onto their gaseous atmospheres despite their proximity to the intense radiation. Life as we know it is not likely to appear on gaseous planets. Stern thinks Neptune's moon Triton, Pluto and its moon Charon, and the Kuiper Belt Objects will have the best chances for life. These bodies are rich in organic chemicals, and the heat of the red giant sun will melt their icy surfaces into oceans. "When the sun is a red giant, the ice worlds of our solar system will melt and become ocean oases for tens to several hundreds of millions of years," says Stern. "Our solar system will then harbor not one world with surface oceans, as it does now, but hundreds, for all of the icy moons of the giant planets, and the icy dwarf planets of the Kuiper Belt will also bear oceans then. Because Pluto's temperature will not be very different then, than Miami Beach's temperature now, I like to call these worlds 'warm Plutos,' in analogy to the plethora of hot Jupiters found orbiting sun- like stars in recent years." The influence of the sun is not the whole story, however--the characteristics of a planetary body go a long way toward determining habitability. Such characteristics include a planet's internal activity, the reflectivity, or "albedo" of a planet, and the thickness and composition of the atmosphere. Even if a planet has all the elements that favor habitability, life will not necessarily appear. "We don't know what is needed to start life," says Don Brownlee, an astronomer with the University of Washington in Seattle and co-author of the book, The Life and Death of Planet Earth. Brownlee says that if warm wet interiors and organic materials are all that's needed, then Pluto, Triton, and the Kuiper Belt Objects could harbor life. "As a word of caution, however, the interiors of asteroids that produced the carbonaceous chondrite meteorites were warm and wet for perhaps millions of years in the early history of the solar system," says Brownlee. "These bodies are extremely rich in both water and organic materials, and yet there is no compelling evidence that any asteroidal meteorite ever had living things in it." A planetary body's orbit also will affect its chances for life. Pluto, for instance, doesn't have a nice, regular orbit like the Earth. The orbit of Pluto is comparatively eccentric, varying in distance from the sun. From January 1979 through February 1999, Pluto was closer to the sun than Neptune, and in a hundred years, it'll be almost twice as far out as Neptune. This type of orbit will cause Pluto to undergo extreme heating alternating with extreme cooling. Triton's orbit, too, is peculiar. Triton is the only large moon to orbit backwards, or "retrograde." Triton may have this unusual orbit because it formed as a Kuiper Belt Object and then was captured by Neptune's gravity. It's an unstable alliance, since the retrograde orbit creates tidal interactions with Neptune. Scientists predict that someday Triton will either crash into Neptune, or break up into tiny pieces and form a ring around the planet. "The timescale for the tidal decay of Triton's orbit is uncertain, so it could be around, or it might have already crashed by the time the sun goes red giant," says Stern. "If Triton is around, it'll probably end up looking like the same kind of organic-rich ocean world as Pluto." The sun will burn as a red giant for about 250 million years, but is that enough time for life to get a foothold? During most of the red giant lifetime, the sun will be only 30 times brighter than its current state. Toward the end of the red giant phase the sun will grow more than 1,000 times brighter, and occasionally release pulses of energy reaching 6,000 times current brightness. But this period of intense brightness will last for a few million years, or tens of millions of years at most. The brevity of the red giant's brightest phases suggests to Brownlee that Pluto doesn't hold much promise for life. Because of Pluto's average orbit of 40 AU, the sun would have to be 1,600 times brighter for Pluto to get the same solar radiation we currently get on Earth. "The sun will reach this brightness, but only for a very brief period of time--only a million years or so," says Brownlee. "The surface and atmosphere of Pluto will be 'improved' from our point of view, but it won't be a nice place for any significant period of time". After the red giant phase, the sun will become fainter, and will shrink to the size of the Earth, becoming a white dwarf. The distant planets that basked in the light of the red giant will become frozen ice worlds once again. So if life is to appear in a red giant system, it will need a quick start. Life on Earth is thought to have originated 3.8 billion years ago, some 800 million years after our planet was born. But that is probably because the planets in the inner solar system experienced 800 million years of heavy asteroid bombardment. Even if life had gotten started immediately, the early rain of asteroids would've wiped the Earth clean of that life. Brownlee says a new era of bombardment could begin for the outer planets, because the red giant sun could disturb the vast number of comets in the Kuiper Belt. "When the red giant sun is 1,000 times brighter, it loses almost half of its mass to space," says Brownlee. "This causes orbiting bodies to move outward. Gas loss and other effects might destabilize the Kuiper Belt and create another period of interesting bombardment." But Stern says that planets made habitable by a red giant sun won't be bombarded as often as the early Earth was, because the ancient asteroid belt had much more material than the Kuiper Belt has today. In addition, the outer planets won't experience the same ultraviolet (UV) levels that Earth has had to endure, since red giants have very low UV radiation. The higher intensity UV of a main sequence star can be damaging to the delicate proteins and RNA strands needed for life's origin. Life on Earth could only originate underwater, in depths protected from this light intensity. Life on Earth is therefore inextricably linked to liquid water. But who knows what sort of life might originate on planets that have no need for UV shielding? Stern thinks we should look for evidence of life on Pluto-like worlds orbiting around red giants today. We currently know of 100 million solar- type stars in the Milky Way galaxy that burn as red giants, and Stern says that all of these systems could have habitable planets within 10 to 50 AU. "It would be a good test of the time required to create life on warm, water-rich worlds," he says. "The idea of organic-rich distant bodies getting baked by a red giant star is an intriguing one, and could provide very interesting if short-lived habitats for life," adds Brownlee. "But I am glad that our sun has a good margin of time left." What's next? While much of what we know about the outer solar system is based on distant measurements made from Earth-based telescopes, on January 2, 2004, scientists caught a close-up glimpse of a Kuiper Belt Object. The Stardust spacecraft passed within 136 kilometers of comet Wild2, an enormous snowball that spent most of its 4.6 billion-year lifetime orbiting in the Kuiper Belt. Wild2 now orbits mostly inside the orbit of Jupiter. Brownlee, who is the Principle Investigator for the Stardust mission, says that the Stardust images show fantastic surface details of a body shaped both by its ancient and recent history. Stardust images show gas and dust jets shooting off the comet, as Wild2 rapidly disintegrates in the strong solar heat of the inner solar system. To learn more about the outer solar system, we'll need to send a spacecraft out there to investigate. In 2001, NASA selected the New Horizons mission for just such a purpose. Stern, who is the Principal Investigator for the New Horizons mission, reports that the spacecraft assembly is scheduled to begin this summer. The spacecraft is due to launch in January 2006, and arrive at Pluto the summer of 2015. The New Horizons mission will allow scientists to study the geology of Pluto and Charon, map their surfaces, and take their temperatures. Pluto's atmosphere also will be studied in detail. In addition, the spacecraft will visit the icy bodies in the Kuiper Belt in order to make similar measurements. Read the original article at http://www.astrobio.net/news/article912.html. An additional article on this subject is available at http://www.universetoday.com/am/publish/outer_planets_warm_up_sun_dies.htm l. __________________________________________________________________________ MODERN MARS: LATEST SPACECRAFT FINDINGS REDEFINE FUTURE MISSIONS By Leonard David From Space.com 7 April 2004 Mars is a wanted world--dead or alive. Scientists find themselves awash in a range of intriguing findings regarding the distinctive landscapes of the red planet. The onslaught of sensor data from trailblazing Mars orbiters--along with the ongoing Spirit and Opportunity rover missions -- are setting the stage for more refined inquiries into the planet's past and its present status. Still open for debate is whether that far-away globe is a "has been" planet for life, or may still act as home base for biology. The observation by Europe's Mars Express orbiter that methane (CH4) has been found on Mars is new data in the form of old news. However, this information could well put scientists on the pathway for seeing a different Mars. Read the full article at http://www.space.com/scienceastronomy/modern_mars_040407.html. __________________________________________________________________________ NASA RADAR AIDS HIGH-TECH DIGS By Rosemary Sullivant NASA/JPL release 7 April 2004 History can be hard to find. A forgotten letter molders in an attic. An ancient temple hides beneath jungle greenery. Even knowing that something is there doesn't necessarily make it easier to find--the classic needle in the haystack. But locating many archaeological sites isn't just difficult; it is required by law. Federal legislation mandates that all archaeological sites on federal lands be located and evaluated by federal managers, particularly if the sites could be damaged by construction or military maneuvers. Legislation also specifically protects Native American burial sites on federal lands. However, less than 10 percent of the more than 700-million acres under federal control have been surveyed, according to a recent National Park Service report. In a conventional survey, archaeologists usually cover an area on foot. Sometimes they have to dig holes to see beneath the surface. It's a slow and expensive procedure. Last year, the defense department's Strategic Environmental Research and Development Program turned to researchers Dr. Ronald Blom, a JPL geologist, and Dr. Douglas Comer, an archaeologist, to see if a JPL instrument with an advanced type of radar could help speed up the process and make it more economical. To test the idea, Blom, Comer and their colleagues set out for San Clemente Island. Controlled by the Navy, the narrow, 16-kilometer-long (25-mile-long) island is about 50 kilometers (31 miles) offshore northwest of San Diego. There are no ancient cities, temples or monuments. However, evidence remains of the Native Americans who camped and fished there for hundreds and thousands of years before the Spanish arrived in the 18th century. "The archaeological sites on San Clemente are usually 10 to 20 meters (33 to 66 feet) wide and marked by rich, organic soil produced by campfires and food remains, scatterings of rock brought there to be used as tools or in windbreaks, and concentrations of shell discarded after shellfish were eaten," says Comer. "In size and character, they are similar to the great majority of archaeological sites in North America." Often the most visible sign of an archaeological site is a change in vegetation, caused by the rich soils. For example, a group of prickly pear cactus in a field of grass may signal that humans changed the environment in that particular location. Small mounds and depressions also show where people lived and worked. Researchers began the old-fashioned way--by closely analyzing some of these known sites on foot. Then they collected radar data over the island with a unique instrument called Airsar, short for airborne synthetic aperture radar. Airsar isn't new to archaeology. In the 1990s, it revealed a previously unknown section of the ancient city of Angkor in Cambodia. Last month it was used to survey selected archaeological sites in Central America. "Radar is particularly good at describing the physical environment and sensing changes, especially man-made changes," says Blom. The idea in the San Clemente project was to collect Airsar data over a large area, process the data to bring out indications of past human presence, and then combine the results with other information, such as detailed topographical measurements, to target the most likely spots to search for archaeological sites. Radar works by sending out pulses of radio waves and collecting the waves that are reflected back. Airsar is unique because it can send out radio waves of three different lengths and can polarize them both vertically and horizontally. This flexibility allows researchers to modify the radar signals to pick out certain features that signal past human presence. "On San Clemente shorter radar wavelengths seem to be most useful," Blom explains. "There are no big things there, and the short waves work better for small features. Different polarizations help us characterize the shape of objects and tell the difference between vegetation types, for example." The next step was to process the data to reveal a signature of past human activity. They used their knowledge of the sites they had surveyed in person to help. So far, the results are promising. "Yes, we can find archaeological sites," says Blom. "They show up as bright radar spots. Now we need to refine the system and find ways to screen out false positives." The researchers are incorporating the radar results into a geographic information system, where they can be combined with detailed topographical measurements and information on soils, proximity of fresh water, drainage and vegetation. "We're looking for patterns that link the archaeological sites with the island's geography," says Blom. "We know, for example, that most sites will be within 200 meters (about 220 yards) or so of a source of fresh water. So far, radar has not only shown us where many sites arue, it has also told us so much about the environment that we know where the sites should be." The final result, they hope, will be a model that can predict which bright spot on the radar image will indeed be a potential archaeological site -- in other words, using radar to look at the haystack and predict where the needle will be. "Of course, our ultimate goal," says Blom, "is to identify and protect our cultural heritage so that we can both learn from those who came before and honor them." Contact: Alan Buis Phone: 818-354-0474 __________________________________________________________________________ A BLACK BOX FOR PEOPLE By Karen Miller From NASA Science News 7 April 2004 When planes have a problem, analysts can usually figure out what went wrong. They simply check the plane's "black box," which records exactly what was happening to the plane at the time. Now, there's something similar for people. Under the leadership of Stanford University professor Greg Kovacs and engineers Carsten Mundt (NASA/Ames) and Kevin Montgomery (Stanford), researchers have developed a device that is like a black box or flight recorder for human beings. Just as a plane's black box records crucial mechanical data, NASA's device, the CPOD (pronounced "see-pod"), keeps track of biological data, like changes in heart rate, the amount of oxygen in the blood stream, how the wearer is moving... and much more. The CPOD, first envisioned by John Hines of NASA's Astrobionics Technology Program, was intended to make it easier to monitor the vital signs of astronauts in space. Right now, such a process involves hooking the astronauts up "with a whole bunch of wires to a huge rack of equipment." In some cases, says Mundt, the data are recorded on paper and entered into a laptop by hand. The CPOD changes all that. It's a compact, portable, wearable device--a single piece of equipment that gathers a wide variety of vital signs. About the size of a computer mouse, a CPOD is worn around the waist. It's comfortable enough to be worn while sleeping. It's non-invasive. It takes only minutes to don. Importantly, it can track a person's physiologic functioning as they go about their normal routine--they don't have to be tethered to some stationary device. It can store data for eight-hour periods for later downloading; alternatively, it can send it wirelessly, in real time, to some other device. "This is a new tool," says Kovacs. "It allows monitoring of the body without invasion of the body--without tethering the person down, letting them go about their normal business." Such data would, of course, be invaluable to researchers trying to understand how the human body adapts to extreme conditions--like space, the moon, or Mars. The ability to monitor astronauts so closely, as they work, and in real time, would also make the astronauts much safer. For one thing, the CPOD could notice problems before the astronauts even became aware of them. "We have alarms set in our device," says Mundt. "If the heart rate goes, let's say, above 170, the CPOD would beep, and then the astronaut would know it's time to take it easy." And, in the case of an emergency, the CPOD could provide vital signs within seconds--and it could quickly stream that information back to doctors on Earth. The CPOD typically tracks heart performance, blood pressure, respiration, temperature, and blood oxygen levels. Using three tiny accelerometers, it also tracks a person's movements--it can tell whether they're running, for example, or spinning or tumbling. And it can be reconfigured. If researchers choose, almost any kind of sensor could be plugged into the device. The CPOD could, for example, keep track of ambient air pressure, or monitor the concentrations of atmospheric gases. With such capabilities, the CPOD is likely to prove as important on Earth as it could be to conquering space. Using the CPOD, EMT's at an accident scene could quickly gain information about a victim's condition. CPODs could monitor the blood oxygen levels of firefighters inside burning buildings. Physicians could use CPODs for "outcome monitoring," using them to track a patient's reactions to a particular procedure or drug. Athletes, like divers and mountain climbers, could use them to keep track of their exertion levels. The CPODs could help monitor pollution, and even treat soldiers on a battlefield. "There's just tremendous opportunity for a box like this," says Kovacs. Mundt believes that CPODs will be helping out in space in a matter of years. Right now, though, the researchers are still testing its performance in a variety of space-analog conditions. Astronauts, for example, have worked with the CPOD on a NASA mission aboard the Aquarius, an underwater habitat located off the coast of Key Largo. The Aquarius is similar to the space station's living quarters, the Zvezda Service Module, and Mundt and his team wanted to test wireless streaming in that kind of "metal can" environment. "It's very similar to the space shuttle," said Mundt. "There's a lot of reflection of wireless signals, and lots of interference." The CPOD has also been tested onboard the KC-135--NASA's "vomit comet" aircraft that achieves almost 30 seconds of weightlessness for passengers by flying high parabolic arcs. "The flights went really well!" says Kovacs. Next, Kovacs and colleagues plan to make the device smarter. They're in the process of adding software that can help diagnose problems by analyzing the massive amounts of data that the CPOD collects. Such software could hunt out correlations that might explain an anomaly. For example, if a person's heart rate suddenly spiked, such software could connect that to what was happening at the time: whether the person was exercising, or being still, for example. The CPOD, says Kovacs, is an elegant job of putting the current state of the art in sensors in a compact, integrated package. "It's an incredibly versatile tool," he says. "It's a medical monitor that just about any doctor can use." And it can be used just about anywhere. Despite a CPOD's small size, he says, "it's a huge thing--a really huge thing." Read the original article at http://science.nasa.gov/headlines/y2004/07apr_blackbox.htm. __________________________________________________________________________ HOW LONG DOES IT TAKE FOR EARTH'S MAGNETIC FIELD TO REVERSE? LONG- DEBATED, A FIRM ANSWER IS NOW ON THE HORIZON National Science Foundation release 7 April 2004 The time it takes for Earth's magnetic field to reverse polarity is approximately 7000 years, but the time it takes for the reversal to occur is shorter at low latitudes than at high latitudes, a geologist funded by the National Science Foundation (NSF) has concluded. Brad Clement of Florida International University published his findings in this week's issue of the journal Nature. The results are a major step forward in scientists' understanding of how Earth's magnetic field works. The magnetic field has exhibited a frequent but dramatic variation at irregular times in the geologic past: it has completely changed direction. A compass needle, if one existed then, would have pointed not to the north geographic pole, but instead to the opposite direction. Such polarity reversals provide important clues to the nature of the processes that generate the magnetic field, said Clement. Since the time of Albert Einstein, researchers have tried to nail down a firm time-frame during which reversals of Earth's magnetic field occur. Indeed, Einstein once wrote that one of the most important unsolved problems in physics centered around Earth's magnetic field. Our planet's magnetic field varies with time, indicating it is not a static or fixed feature. Instead, some active process works to maintain the field. That process is most likely a kind of dynamic action in which the flowing and convecting liquid iron in Earth's outer core generates the magnetic field, geologists believe. Figuring out what happens as the field reverses polarity is difficult because reversals are rapid events, at least on geologic time scales. Finding sediments or lavas that record the field in the act of reversing is a challenge. In the past several years, however, new polarity transition records have been acquired in sediment cores obtained through the international Ocean Drilling Program, funded by NSF. These records make it possible to determine the major features of reversals, Clement said. "It is generally accepted that during a reversal, the geomagnetic field decreases to about 10 percent of its full polarity value," said Clement. "After the field has weakened, the directions undergo a nearly 180 degree change, and then the field strengthens in the opposite polarity direction. A major uncertainty, however, has remained regarding how long this process takes. Although this is usually the first question people ask about reversals, scientists have been forced to answer with only a vague 'a few thousand years.'" The reason for this uncertainty? Each published polarity transition reported a slightly different duration, from just under 1,000 years to 28,000 years. "Now, through the innovative use of deep-ocean sediment cores, Clement has demonstrated that magnetic field reversal events occur within certain time-frames, regardless of the polarity of the reversal," said Carolyn Ruppel, program director in NSF's division of ocean sciences. "Sediment cores originally drilled to meet disparate scientific objectives have led to a result of global significance, which underscores the value of collecting and maintaining cores and associated data." Clement examined the database of existing polarity transition records of the past four reversals. The overall average duration, he found, is 7,000 years. But the variation is not random, he said. Instead it alters with latitude. The directional change takes half as long at low-latitude sites as it does at mid- to high-latitude sites. "This dependence of duration on site latitude was surprising at first, but it's exactly as would be predicted in geometric models of reversing fields," Clement said. Read the original news release at http://www.nsf.gov/od/lpa/newsroom/pr.cfm?ni=71. Additional articles on this subject are available at: http://www.space.com/scienceastronomy/earth_poles_040407.html http://www.spacedaily.com/news/earth-magnetic-04a.html http://www.universetoday.com/am/publish/field_reversal_takes_7000_years.ht ml __________________________________________________________________________ ASTROBIOLOGY: ASKING BIG QUESTIONS TO LEARN SCIENCE By Edna DeVore From Space.com 8 April 2004 "Teacher, why do I need to learn this?" "What's it good for?" Students ask these questions when faced with content that seems unrelated to their lives. Motivating students is fundamental to promoting achievement in any classroom, even in science, which encompasses the entire natural world, the whole universe. Good questions and quality experiences support science learning for all students, not just those who are already science- friendly. The relatively new discipline of astrobiology asks great questions. How does life begin and evolve? Is there life elsewhere in the Universe? What is the future of life on Earth and beyond? Compare these with a commonly asked classroom science question. Does the length of the string change the performance of a pendulum? Do objects fall at different speeds according to their weights? And so forth. No, I'm not picking on physics here, but these sorts of investigations--which can be fun--need to be in a larger context to motivate many students. Read the full article at http://www.space.com/searchforlife/seti_devore_why_040408.html. __________________________________________________________________________ DANGEROUS SPACE ROCKS UNDER WATCH From Reuters and CNN 8 April 2004 They are out there, ready to smack into the Earth and wipe out human civilization, but astronomers said on Wednesday they are well on their way to finding every asteroid that poses a threat. The next task will be to look for smaller objects that might just destroy, say, a city, the experts told the U.S. Senate's Subcommittee on Science, Technology and Space. In an update on the Near Earth Object Observation Program, experts told the Senate subcommittee that they are on schedule to finding everything bigger than 1 kilometer in diameter that might approach the planet. "The survey officially started in 1998 and to date more than 700 objects of an estimated population of about 1,100 have been discovered, so the effort is now believed to be over 70 percent complete and well on the way to meeting its objective by 2008," NASA's Lindley Johnson told the hearing. Read the full article at http://www.cnn.com/2004/TECH/space/04/08/space.collision.reut/index.html. __________________________________________________________________________ EXPERIMENT HARNESSES STATE-OF-THE-ART SEQUENCING TECHNOLOGY TO DETECT LIFE ON MARS By Robert Sanders University of California, Berkeley release 12 April 2004 The same cutting-edge technology that speeded sequencing of the human genome could, by the end of the decade, tell us once and for all whether life ever existed on Mars, according to a University of California, Berkeley, chemist. Richard Mathies, UC Berkeley professor of chemistry and developer of the first capillary electrophoresis arrays and new energy transfer fluorescent dye labels--both used in today's DNA sequencers--is at work on an instrument that would use these technologies to probe Mars dust for evidence of life-based amino acids, the building blocks of proteins. With two development grants from NASA totaling nearly $2.4 million, he and team members from the Jet Propulsion Laboratory (JPL) at the California Institute of Technology and UC San Diego's Scripps Institution of Oceanography hope to build a Mars Organic Analyzer to fly aboard NASA's roving, robotic Mars Science Laboratory mission and/or the European Space Agency's ExoMars mission, both scheduled for launch in 2009. The ExoMars proposal is in collaboration with Pascale Ehrenfreund, associate professor of astrochemistry at the University of Leiden in The Netherlands. The Mars Organic Analyzer, dubbed MOA, looks not only for the chemical signature of amino acids, but tests for a critical characteristic of life- based amino acids: They're all left handed. Amino acids can be made by physical processes in space--they're often found in meteorites--but they're about equally left- and right-handed. If amino acids on Mars have a preference for left-handed over right-handed amino acids, or vice versa, they could only have come from some life form on the planet, Mathies said. "We feel that measuring homochirality--a prevalence of one type of handedness over another--would be absolute proof of life," said Mathies, a UC Berkeley member of the California Institute for Quantitative Biomedical Research (QBR). "That's why we focused on this type of experiment. If we go to Mars and find amino acids but don't measure their chirality, we're going to feel very foolish. Our instrument can do it." The MOA is one of a variety of instruments under development with NASA funding to look for the presence of organic molecules on Mars, with final proposals for the 2009 mission due in mid-July. Mathies and colleagues Jeffrey Bada of Scripps and Frank Grunthaner of JPL, who plan to submit the only proposal that tests for amino acid handedness, have put the analyzer to the test and shown that it works. The details of their proposal are now on the Web at http://astrobiology.berkeley.edu. In February, Grunthaner and UC Berkeley graduate student Alison Skelley traveled to the Atacama desert of Chile to see if the amino acid detector- -called the Mars Organic Detector, or MOD--could find amino acids in the driest region of the planet. The MOD easily succeeded. However, because the second half of the experiment--the "lab-on-a-chip" that tests for amino acid handedness--had not yet been married to the MOD, the researchers brought the samples back to UC Berkeley for that part of the test. Skelley has now successfully finished these experiments demonstrating the compatibility of the lab-on-a-chip system with the MOD. "If you can't detect life in the Yungay region of the Atacama Desert, you have no business going to Mars," Mathies said, referring to the desert region in Chile where the crew stayed and conducted some of their tests. Mathies, who 12 years ago developed the first capillary array electrophoresis separators marketed by Amersham Biosciences in their fast DNA sequencers, is confident that his group's improvements to the technology utilized in the genome project will feed perfectly into the Mars exploration projects. "With the kind of microfluidic technology we've developed and our capability to make arrays of in situ analyzers that conduct very simple experiments relatively inexpensively, we don't need to have people on Mars to perform valuable analyses," he said. "So far, we've shown this system can detect life in a fingerprint, and that we can do a complete analysis in the field. We're really excited about the future possibilities." Bada, a marine chemist, is the exobiologist on the team, having developed nearly a dozen years ago a novel way to test for amino acids, amines (the degradation products of amino acids) and polycyclic aromatic hydrocarbons, organic compounds common in the universe. That experiment, MOD, was selected for a 2003 mission to Mars that was scrapped when the Mars Polar Lander crashed in 1999. Since then, Bada has teamed with Mathies to develop a more ambitious instrument that combines an improved MOD with the new technology for identifying and testing the chirality of the amino acids detected. The ultimate goal is to find proof of life on Mars. The Viking landers in the 1970s unsuccessfully tested for organic molecules on Mars, but their sensitivity was so low that they would have failed to detect life even if there were a million bacteria per gram of soil, Bada said. Now that the NASA rovers Spirit and Opportunity have almost certainly shown that standing water once existed on the surface, the aim is to find organic molecules. Bada's MOD is designed to heat martian soil samples and, in the low pressures at the surface, vaporize any organic molecules that may be present. The vapor then condenses onto a cold finger, a trap cooled to Mars' ambient nighttime temperature, approximately 100 degrees below zero Fahrenheit. The cold finger is coated with fluorescamine dye tracers that bind only to amino acids, so that any fluorescent signal indicates that amino acids or amines are present. "Right now, we are able to detect one trillionth of a gram of amino acids in a gram of soil, which is a million times better than Viking," Bada said. The added capillary electrophoresis system sips the condensed fluid off the cold finger and siphons it to a lab-on-a-chip with built-in pumps and valves that route the fluid past chemicals that help identify the amino acids and check for handedness or chirality. "MOD is a first stage interrogation where the sample is examined for the presence of any fluorescent species including amino acids," Skelley said. "Then, the capillary electrophoresis instrument does the second stage analysis, where we actually resolve those different species and can tell what they are. The two instruments are designed to complement and build on one another." "Rich has taken this experiment into the next dimension. We really have a system that works," Bada said. "When I started thinking about tests for chirality and first talked to Rich, we had conceptual ideas, but nothing that was actually functioning. He has taken it to the point where we have an honest-to-God portable instrument." Amino acids, the building blocks of proteins, can exist in two mirror- image forms, designated L (levo) for left-handed and D (dextro) for right- handed. All proteins on Earth are composed of amino acids of the L type, allowing a chain of them to fold up nicely into a compact protein. As Mathies describes it, the test for chirality takes advantage of the fact that left-handed amino acids fit more snugly into a left-handed chemical "mitt" and right-handed amino acids into a right-handed mitt. If both left- and right-handed amino acids travel down a thin capillary tube lined with left-handed mitts, the left-handed ones will travel more slowly because they slip into the mitts along the way. It's like a left-handed politician working a crowd, he said. She'll move more slowly the more left-handed people in the crowd, because those are the only people she will shake hands with. In this case, the left-handed mitt is a chemical called cyclodextrin. Different amino acids--there are 20 different kinds used by humans--also travel down the tube at different rates, which allows partial identification of those present. "After amino acids are detected by MOD, the labeled amino acid solution is pumped down into microfluidics and crudely separated by charge," Mathies said. "The mobility of the amino acids tells us something about charge and size and, when cyclodextrins are present, whether we have a racemic mixture, that is, an equal amount of left- and right-handed amino acids. If we do, the amino acids could be non-biological. But if we see a chiral excess, we know the amino acids have to be biological in origin." The state-of-the-art chip designed and built by Skelley consists of channels etched by photolithographic techniques and a microfluidic pumping system sandwiched into a four-layer disk four inches in diameter, with the layers connected by drilled channels. The tiny microfabricated valves and pumps are created from two glass layers with a flexible polymer (PDMS or polydimethylsiloxane) membrane in between, moved up and down using a pressure or vacuum source. UC Berkeley physical chemist James Scherer, who designed the capillary electrophoresis instrument, also developed a sensitive fluorescence detector that quickly reads the pattern on the chip. One of the team's current NASA grants is for development of a next- generation Microfabricated Organic Laboratory, or MOL, to fly to Mars, Jupiter's moon Europa or perhaps a comet and conduct even more elaborate chemical tests in search of a more complete set of organic molecules, including nucleic acids, the structural units of DNA. For now, however, the goal is an instrument ready by 2009 to go beyond the current experiments aboard the Mars 2003 rovers and look for amino acids. "You have to remember, so far we have not detected any organic material on Mars, so that would be a tremendous step forward," Bada said. "In the hunt for life, there are two requirements: water and organic compounds. With the recent findings of the Mars rovers that suggests that water is present, the remaining unknown is organic compounds. That's why we are focusing on this. The Mars Organic Analyzer is a very powerful experiment, and our great hope is to find not only amino acids, but amino acids that look like they could come from some sort of living entity." Read the original news release at http://www.berkeley.edu/news/media/releases/2004/04/12_mars.shtml. Additional articles on this subject are available at: http://www.spacedaily.com/news/mars-life-04c.html http://spaceflightnow.com/news/n0404/12marslife/ __________________________________________________________________________ CAN SETI PROBE FOR PROBES? INTERVIEW WITH SCOT STRIDE From Astrobiology Magazine 12 April 2004 When NASA's Voyager spacecraft left the boundaries our solar system last year, it carried a golden record with greetings from our civilization for posterity--or for eventual discovery by space archaeologists from another civilization. The golden record was a beacon to the future. The idea of our own civilization using its probes as surrogate representatives prompts the question: Can we probe for such beacons in our own solar system? Esteemed physicist, Freeman Dyson of Princeton's Advanced Institute, has gone so far as to wager a bet that any contact is most likely to arise from some object other than a planet or moon. For Scot Stride of NASA's Jet Propulsion Laboratory, one possibility is detecting evidence of a probe. His fascination with robotic exploration is partly based on first-hand experience, he wrote, since "many of the scientists and engineers at this NASA center don't see our robotic probes as just machines, but as extensions of our senses, intellect and being. Indeed, Matt Golombeck used to humorously call the Mars Pathfinder Sojourner rover a "mini-geologist" version of himself. My views are similar. This has indirectly resulted in a personal interest in how advanced extraterrestrial intelligence (ETI) might carry out galactic exploration and the construction of interstellar robotic probes." Indeed, the search for life is often summarized more as a search for evidence of the technology produced by life. To underscore the differences, Director of SETI Research, Jill Tarter at the SETI Institute's wrote, "The question of where to seek life is another domain in which astrobiology and SETI are inextricable. Today's SETI is working to expand its target list of stars each time a new planet is found, a happy reality that was virtually unthinkable a scant decade ago. Our improved knowledge of the extreme conditions in which life can thrive has forced us to reexamine our conception of habitable zones around stars, again enlarging the scope of today's SETI search." Tarter was the inspiration for the main character of Carl Sagan's novel, Contact. Stride also has taken up the question of where to seek technological evidence for life. Whether space probes might be available from other civilizations--and whether we are even technically capable of investigating this possibility--was the topic of a recent paper co- authored by Stride and Bruce Cornet in the "Contact in Context" series, entitled "Solar System SETI Using Radio Telescope Arrays". Astrobiology Magazine had the opportunity to talk with Scot Stride of NASA's Jet Propulsion Laboratory about the survey opportunities within our solar system. Astrobiology Magazine (AM): Could you give some background on the history of looking for signals in our neighborhood, or Solar System SETI? Scot Stride (SS): Solar System SETI (S3ETI) is a strategy that hypothesizes ETI, in some material or physical form, may be present in our solar system. The idea that an ET civilization could be close enough to physically journey to Earth has its roots in ancient history with the Babylonian and Sumerian writings. Since then science has surpassed myth and superstition, and our knowledge of the universe, space travel and the prospects of discovering extraterrestrial civilizations has vastly improved. In more recent times the search for other intelligences in the solar system can be traced to Lowell and his belief that canals on Mars were built by its industrious inhabitants. Other people of that era considered signaling to possible ET in the solar system. In these cases it was believed the ET were native to our solar system and living on some planet like Mars or Venus. Given our present knowledge of solar system habitats, we are quite certain there are no intelligent ET now living on any of the non-terrestrial planets or moons in our solar system. The environments are extreme in one respect or another which limits the complexity of life as we know it. Simple microbial life may exist in some remote crevice of the solar system but that is for the astrobiologists to discover. Any ET intelligence that may be present in the solar system is expected to have originated from somewhere out in deep interstellar space. We have enjoyed remarkable success exploring interplanetary space and planetary environments with robotic spacecraft and rovers. Likewise, a highly advanced ET civilization, if one exists, may be exploring the nearby cosmos with artificially intelligent robotic probes--a gradual program of exploration covering long timescales and interstellar distances. Just such a highly advanced robotic probe may now, by chance, be exploring our solar system. It was hypothesized in the early 1960's that objects could be parked, suspended or trapped in either the L4 or L5 Earth-Sun Lagrange points [locations in space where gravitational forces and the orbital motion of a body balance each other]. Between 1961 and 1982 at least eight groups of researchers made observations of these regions using optical telescopes and low frequency pulsed radar. Two of these groups attempted to search specifically for robotic probe artifacts, functioning or not, in these regions. Nothing was found, but those efforts were a defining moment in the scientific search for ETI in the solar system. Other targets in the solar system, like the moon and Mars, are also considered candidates to search for ET artifacts. So far government-funded investigations of the planets have not included a search for signatures of ETI. However, there are ways to search indirectly for ET technology in the solar system using radio telescopes, like the Allen Telescope Array now being constructed at Hat Creek, California. Using radio telescope arrays to find evidence ETI in the solar system is the thrust of contemporary Solar System SETI efforts. AM: You propose to use the Allen Telescope Array as one method to search for microwave frequencies. The Allen Telescope Array will consist of 350 individual 20-foot antennas linked to form the equivalent of a single large antenna. When fully operational in 2005, the Allen Telescope Array will have more collecting area than the newly completed Green Bank Telescope in West Virginia, and better resolution than the venerable Arecibo dish in Puerto Rico. Based on your research, can you describe what a top priority might be when that work is begun around 2005? SS: A search for Anomalous Microwave Phenomena (AMP) or Unidentified Radio Signals (URS) within the solar system can be modeled after traditional SETI searches, that is, "All-Sky" surveys or "Targeted" examinations. AMP or URS can radiate the Earth from practically any direction, but the probability is higher for regions within the plane of the solar system. In that respect there is a preference to search within ±17 degrees of the ecliptic plane, which encompasses all the planet-moon systems in the solar system. AMP or URS could be caused by a naturally occurring event, like the noise bursts observed on Jupiter when the Shoemaker-Levy comet impacted its atmosphere, or it could be artificial in origin. There is no top priority list per se, because any planet can potentially produce AMP or have an ET robotic probe orbiting it. In 2005 each planet can be observed for several hours each day. In terms of the diversity of the targets, Saturn is a good candidate because it has several moons which vary in size and possess a range of features. In 2005 there are three major planetary conjunction alignments, with < 2.5 degrees of angular separation, that can be observed. The conjunctions of Jupiter+Uranus, Jupiter+Neptune and Saturn+Neptune offer an opportunity to carry out between 104 and 133 days of targeted observations to search for AMP or URS. Conjunction events are rich with targets because there are numerous bodies (i.e., moons) within the target area. In the case of conjunctions, the observation needs to include some kind of direction-finding capability. Configuring the radiotelescope array to function as a phase-comparison monopulse antenna will allow the determination of the angle-of-arrival of the signal. In that way, some information about the origin of the AMP can be learned, possibly revealing if it was near a specific moon, a planet, or in motion. AM: You have noted elsewhere that "It might be argued that if an ETI probe were within our solar system and transmitting a signal toward Earth, intended for us or not, that we would detect it with the current SETI effort. No one with a working knowledge of the current SETI effort would accept this allegation for any frequencies other than the 1 to 3 GHz band (particularly the 18 and 21 cm lines)". This raises the question of how to hail a probe. Are there considerations in selecting a frequency (such as the water-stretch band) that might differ between what would be a planetary transmission vs. a parked spaceprobe as you describe the classical listening channels, or frequency selections by Morrison, et al.? SS: The hydroxyl (OH) and neutral hydrogen emission lines identified by Cocconi and Morrison were good first choices for an artificial ET hailing frequency. However, after 44 years of searching around those frequencies no confirmed signals have been found, and there is some doubt whether any frequency is "magic." It's interesting to note that in 1974 the Arecibo message was transmitted at 2380 MHz, a frequency well above the "water hole" band. In Earth's first "Active SETI" attempt we didn't transmit at a well known and preferred frequency of either 1420 or 1665 MHz. Furthermore, 2380 MHz is the second harmonic of no particularly special frequency. The Arecibo transmitter was designed for S-band planetary radar experiments and SETI used it because it was available. ET may make a similar decision for transmitting a beacon frequency--a decision based solely upon the economy or convenience of operating their transmitter at some given wavelength. Hence, searching much wider frequency swaths, and higher bands like 12 to 60 GHz, is a worthy decision. The Allen Telescope Array will be optimized to search between 1 and 11 GHz, which covers a significantly wider band of electromagnetic spectra than has been previously searched. Selecting a preferred search frequency for robotic probe emissions within the solar system is difficult because the motives and electromagnetic emissions of a probe are unknown. If a probe becomes aware of our civilization and desires to engage us in communication, it can scan our planetary emissions and choose a quiet frequency or spectral band to get our attention. There are several protected frequencies used for radioastronomy (e.g., Carbon Sulphide at 97.981 GHz) that a probe might try hailing us on with a low power beacon. Hypothetically, if the probe were small and could only accommodate a small, say 0.1 m aperture directional antenna, then we might expect its beacon frequencies to be high in the mm-wave region. Using a system limited to detecting energy between 1 and 11 GHz could overlook higher frequency artificial emissions if they occurred. On the other hand, if the probe were larger and emitted gamma bursts from its propulsion system, we might want to concentrate on electromagnetic byproducts of such events which may be very broadband. AM: The Arecibo telescope's beam, as used for Project Phoenix, covers all of a 100 light-year-distant solar system out to two thousand times the Earth-Sun distance. One targeting priority for SETI using the Allen Array will be based on similar suns to our own within 90 light years. Can you expand on why current SETI strategies usually treat nearby beacons as part of the extended solar system exploration program, rather than a target that is actively sought in its own right? SS: In the microwave SETI hypothesis the targets and search space lie outside the solar system--among the stars. Within the confines of the traditional microwave search strategy, energy-based arguments assume that ET can't get here because it's too expensive. Another reason assumes they don't know we are here because our radio leakage has only reached about 70 light years (~4,500 star systems), and the nearest civilization is expected to be farther away. Conservatism and self-imposed constraints have kept traditional SETI from searching within the solar system. Sometimes during SETI surveys solar system targets have been within the antenna's main beam or a sidelobe of the beam. With a single radiotelescope having limited direction-finding capability, it's difficult to know from just the Doppler drift, or Gaussian shape of the energy detected, whether the detected signal originated inside or outside the solar system. An example of a case where a planet-moon system transited a SETI antenna beam has been found. During the five year Megachannel Extraterrestrial Assay, or META-I, search, 37 candidates were identified that exceeded the average 1.7x10-23 W/m2 sensitivity of the receiver (see Horowitz and Sagan, "Five years of Project META - An all-sky narrow-band radio search for extraterrestrial signals", Astrophysical Journal, Part 1, vol. 415, no. 1, pp. 218-235, 1993). None of the signals were detected upon re- observation. Two of these candidates were detected when the antenna was pointed conspicuously close to Saturn and its moons. During the re- observation of these two signals Saturn and its moons had shifted in right ascension and declination and were not in the antenna beam when the coordinates were checked. It is unclear whether the researchers even realized that a planet-moon system had been in the antenna beam during 2 of the 37 candidate events. In hindsight they should have done an immediate follow-up examination of Saturn using a drift-scan mode, and looked for fast-moving emissions or signals with unusual Doppler drifts. Analysis of the Doppler drift of a signal is primarily used to determine its relative motion (linear or rotational). Traditional SETI searches compensate the detected signals for the CMB, GBC and LSR inertial frames which don't apply to solar system targets. These compensations if added to signals originating from solar system targets may cause them to be rejected if the Doppler drift doesn't fit the expected sidereal rate. Solar system targets can be included in microwave SETI observations, but while they're within the antenna beam the detected signals must be processed differently to try to determine if the signal was close or far away. AM: Are there any constraints in a solar system search based on the location of the array itself? For instance, what is visible in the Northern Hemisphere is a current constraint on sky searches from Arecibo, and the question is, are there any nearby objects that are not accessible from the orbital mechanics, such as the far-side of the moon as a trivial example? SS: All the solar system bodies, with the exception of Pluto, lie very close to the ecliptic plane. They are all visible during certain times of the year from the Hat Creek (i.e., ATA) latitude. One parameter that does affect the search is the amount of time a body is observable during the year. The observing time for a planet also depends on where it is in relation to the sun. Mercury has the fewest number of observable days during a given year because it has a higher frequency of a small angular separation from the sun, or transits the sun more than the other planets. Planets that come within a separation angle of less than 3 degrees from the sun are not deemed observable because thermal noise from the disk of the sun would dominate any weak emission that might emanate near the body under observation--the SNR would be unacceptable. The Sun-Earth-Planet separation angle is an observational constraint. Another constraint is the time period a body is visible to two antennas. Independent verification of a signal requires two or more antennas detect the same signal from the same astronomical coordinates. Arecibo is a great resource for verifying signals that are detected by the ATA. However, the Arecibo antenna can't observe certain bodies when the ATA can and vice-versa. If a signal happens to be detected when the Arecibo can't observe the coordinates where the ATA is pointed then real- time verification will be a problem. In that case, other antennas will need to be sequestered to assist in verifying the signal. AM: Proponents of this style of search target list are looking for technical markers of probes, proxies, machines, craft and phenomenon of suspected extraterrestrial origin which are inside heliocentric radius of the Earth's Solar System, or near the Earth. In such a nearby or solar system search, does a parked probe need a definitive purpose that may not involve such passive or unintentional announcements? In other words, does it have to be an active beacon? SS: No, the Solar System SETI strategy attempts to detect any signals from an ET probe artifact whether they are leakage or intentional. Note that "intentional" and "beacon" usually mean a signal that's designed to be detected by us or some other civilization. There is no reason to assume that a robotic probe would come to our solar system strictly to communicate with Earth. SETI authorities point out that contact via microwaves or optical can occur over interstellar distances and does not necessitate launching space probes. If that's true, then intentional signals are less likely than leakage. If intentional signals are emitted they may not be for our consumption, but rather meant to signal someone or something outside the solar system. If advanced robotic probes transmit their signals in the infrared-visible-ultraviolet [IR-VIS-UV] wavelengths using a pulsed laser then leakage from microwave pump amplifiers used to drive the laser may be detectable. An active beacon would be a great find, but leakage is more likely. AM: How does one include an error analysis to exclude what would be terrestrial "leakage" of radiation in a nearby search? You include for instance the emissions from comets and meteors which presumably would be too weak when pointing to a distant object. Does this differ from traditional far-away search problems in any fundamental ways? SS: Terrestrial noise and interference affect all microwave SETI efforts. Solar System SETI efforts must leverage off the same interference analysis and filtering techniques of modern SETI efforts and those proposed for the ATA. Interfering signals in the vicinity of solar system targets could be our own interplanetary probes, like Cassini, or probes orbiting asteroids or comets. These signals have well known carrier frequencies and sidebands so they can be eliminated when detected. Noise bursts detected while targeting the gas giants could be caused by natural impact events, like small comets or asteroids. These are notable because we need to discriminate between them and something possibly artificial. Looking for periodicity in spurious noise bursts is one way to determine artificiality which must be followed immediately by testing for manmade interference. We must also not forget pulsars which are both periodic and energetic in the microwave region. If periodic pulses are detected while observing a solar system target, these can be checked against the periods of known pulsars. It should be fairly straightforward to determine if the object is a newly discovered pulsar because its motion would be sidereal relative to an orbiting planet. Another analysis involves examining the polarization of the signal. Naturally occurring emissions should have random polarizations and not be coherent. Detecting a statistical weighting of more energy in one polarization (e.g., right-hand) implies a non-natural source. Another concern is the constellation of spacecraft orbiting Earth. Some satellites will undoubtedly transit the SETI antenna beam, but these kinds of interferers affect near and far searches alike and are treated the same and rejected. AM: One of the most interesting examples from our own solar system exploration was the Galileo flyby of Earth. The spacecraft initially could not verify that the earth itself was hospitable from a chemical spectrum, because the closeness of the Earth saturated its detection and it was calibrated for the more intense Jupiter flyby yet to come. Is this example illustrative of differences in a nearby vs. faraway search strategy? SS: The Galileo flyby example highlights concerns about using an instrument to observe a certain target it was not calibrated for nor intended to observe. Using the ATA to observe solar system targets when it was designed for far away searches is not an obstacle for Solar System SETI. Indeed, some of the targets in the solar system should be avoided during SETI searches while using highly sensitive phased arrays. The most obvious target is the sun. Other than using the sun as a known "hot body" noise source for determining system noise calibrations, it serves to lessen the sensitivity of the receiving system and should be avoided. The moon and Jupiter are also sources of hot body noise. While observing these targets some amount of degradation of the system noise temperature is expected, but it is not enough to saturate the detection system with noise. Furthermore, using a configurable phased array allows nulls to be placed on noise sources. Non-thermal radio sources like Cassiopeia A, the Crab Nebula, M87 and Cygnus A can be nulled out, if necessary, during observations where they could transit the antenna beam during a targeted search of some region in the solar system. Radio telescopes like the ATA are wonderful because they can be configured so that during solar system searches noise sources can be rejected. Following the construction of the ATA is the Square Kilometer Array (SKA) which could also serve the needs of traditional SETI and Solar System SETI. AM: Are there future plans for expanding your research? SS: Beyond that of a published paper on the strategy ["Solar System SETI Using Radio Telescope Arrays"], it's too early to predict whether Solar System SETI can expand or not. Carrying out solar system observations with the ATA or SKA for fundamental radioastronomy research should be acceptable to everyone in the scientific community since the intent is not to search for ETI. Radioastronomy proposals in this area will no doubt be submitted and some should be accepted. Some of the success of Solar System SETI depends on the willingness of the ATA and SKA managers to accept Solar System SETI proposals. The first hurdle is to submit technical proposals to the ATA; get them accepted and actually secure some observing time, either prime or piggyback, to search for anomalous microwave signals. Winning observing time on the ATA opens the doors of opportunity to alternate search strategies which SETI definitely needs. There will be a lot to learn about the operation of the ATA and the implementation of Solar System SETI observational experiments. Solar System SETI research can only expand and grow if we gain practical experience in carrying out the search. If SETI doesn't carry out alternatives due to conservatism surrounding what's out there, we'll never know if ETI has discovered our solar system or not. What's next? Projected to come online in 2005, the development of the Allen Telescope Array is marked by many innovations crafted with the express purpose of building a world-class state-of-the-art astronomical facility at a fraction of the price of existing radio telescopes. Although the physical structure of the Allen Telescope Array is dominated by the network of many small dishes--or "metal in the meadow"-- what truly makes it distinctive is that it will be one of the first digital radio telescopes to allow astronomers to look at completely different frequencies at the same time, and to observe completely different parts of the sky concurrently. This means that the Allen Telescope Array is not just one instrument, but in effect, many. There are no currently planned searches for solar system SETI. When the Allen Telescope Array turns on sometime next year, it will be capable of searching to the farthest of 17,000 nearby habitable stars, just beyond 300 parsecs (a distance of 978 light-years from Earth). For those search distances, an electromagnetic communication, if detected, would have begun broadcasting around a millennium ago, just about 1000 AD on a terrestrial calendar. Read the original article at http://www.astrobio.net/news/article919.html. __________________________________________________________________________ ERRATUM: DOWN THAT LONG DUSTY TRAIL Corrections by Corien Bakermans Original article by Usha Sutliff (Volume 10, Number 49, 15 December 2003) 13 April 2004 Two errors in this article have been discovered. 1) Corien Bakermans' name was misspelled as "Bakersman". 2) The statement that "it [Psychrobacter cyropegella] isn't able to replicate at that extreme temperature (-20°C)" is incorrect. The researchers don't know whether or not it can replicate at -20°C. Read the original article as it originally appeared in Marsbugs at: http://www.lyon.edu/projects/marsbugs/2003/20031215.txt http://www.lyon.edu/projects/marsbugs/2003/20031215.pdf __________________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/projects/marsbugs/astrobiology/ 13 April 2004 Astrobiology and planetary engineering articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles1.html L. David, 2004. Modern Mars: latest spacecraft findings redefine future missions. Space.com. E. DeVore, 2004. Astrobiology: asking big questions to learn science. Space.com. L. Mullen, 2004. Starfield of dreams: the astrobiology science conference, 2004. Astrobiology Magazine. R. Sanders, 2004. Chemists teaming to develop Mars-life finder. Spaceflight Now. R. Sanders, 2004. Scientists to develop organic analyzer to find life on Mars. SpaceDaily. Human space exploration articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles3.html K. Miller, 2004. A black box for people. NASA Science News. SETI articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles4.html Astrobiology Magazine, 2004. Can SETI probe for probes? Interview with Scot Stride. Astrobiology Magazine. Evolution (biological, chemical and cosmological) articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles5.html G. L. Arnold, A. D. Anbar, J. Barling and T. W. Lyons, 2004. Molybdenum isotope evidence for widespread anoxia in mid-Proterozoic oceans. Science, 304(5667):87-90. S. D. Dyall, M. T. Brown and P. J. Johnson, 2004. Ancient invasions: from endosymbionts to organelles. Science, 304(5668):253-257. L. Mullen, 2004. Delayed gratification zones. Astrobiology Magazine. University of Florida, 2004. Siberia, the big bang of life? Astrobiology Magazine. Planetary protection articles http://www.lyon.edu/projects/marsbugs/astrobiology/online_articles6.html R. R. Britt, 2004. When north becomes south: new clues to Earth's magnetic flip-flops. Space.com. Reuters, 2004. Dangerous space rocks under watch. CNN. L. Stiles, 2004. Asteroid search looks south. Universe Today. L. Stiles, 2004. Astronomers take search for Earth-threatening space rocks to southern skies. SpaceDaily. L. Stiles, 2004. Earth impact effects program. SpaceDaily. L. Stiles, 2004. New asteroid impact simulator available. Universe Today. __________________________________________________________________________ CASSINI SIGNIFICANT EVENTS NASA/JPL release 1-7 April 2004 The most recent spacecraft telemetry was acquired from the Madrid tracking station on Wednesday, April 7. The Cassini spacecraft is in an excellent state of health and is operating normally. Information on the present position and speed of the Cassini spacecraft may be found on the "Present Position" web page located at http://jpl.convio.net/site/R?i=lK51CrKmPu1O- 3BCLCXxIg. C44, the final Approach Science sequence before the start of the tour sequences, began execution this week. At the start of the sequence, instruments performed set-up activities and loaded instrument expanded block files (IEB). Science data collection continued where it left off in C43. Additional activities included execution of an ACS Reaction Wheel Assembly bias and an Imaging Science Subsystem (ISS) photometric calibration. Planning has begun for a Saturn Orbit Insertion (SOI) Data Evaluation and Ground System test to be performed during C44 in early May. As part of the test all teams will be expected to query the ground system as though it were SOI data being returned. In addition, all teams will be expected to perform any analysis necessary to determine whether or not they received sufficient data. Preliminary and official port 1 deliveries were made this week as part of Science Operations Plan implementation of the S25/S26 tour sequences. In addition, a preliminary port 1 delivery was made for sequences S27/S28. Requested discretionary changes were due this week from the instrument teams and Spacecraft Operations office in preparation for the start of the S04 Aftermarket process. In the last week, 556 ISS images and 11 Visual and Infrared Mapping Spectrometer (VIMS) cubes were returned and distributed, bringing the total of images acquired since the start of Approach Science up to 2561, and the number of cubes up to 674. The Cassini Program completed the Saturn Orbit Insertion (SOI) Critical Event Readiness Review on April 1. The one day review had board members from within JPL, from other NASA centers, from private industry, and two reviewers from the newly established NASA Engineering and Safety Center. In general, the board agreed that Cassini was well prepared for SOI activities with very positive remarks on the technical preparations. The board identified some areas in contingency preparedness and operational readiness testing where additional work would benefit the project. The SOI team is evaluating these recommendations and will incorporate them into the current work plan. A Planetary Data System (PDS) peer review was held for Magnetometer Subsystem data at the end of March. The Integrated Test Laboratory (ITL) was extremely busy this week, running tests for both the ACS A8.6.7 flight software (FSW) uplink and the Phoebe closest approach baseline sequence. The FSW test ran successfully and will execute on board the spacecraft at the end of April. The Phoebe test also executed successfully. However, some instrument testbeds did not receive the expected data. ITL is currently troubleshooting the problem. The Automated Sequence Processor (ASP) has been released for operational use. ASP allows science team members to send instrument internal real time commands directly to their instrument without the involvement of sequence team personnel. ASP will provide a considerable savings in effort and time required to generate and execute real time commands as the number of such commands increases throughout the Saturn tour. Delivery coordination meetings were held this week for Mission Sequence Subsystem D10.3 and for Version 1 of the Cassini Archive Tracking Tool. The Cassini Archive Tracking System is a web application tool that tracks required archive submissions into PDS. It allows the project and PDS to accurately and efficiently report on archive submission status. It facilitates communication between teams, the project, and PDS. The Cassini Outreach Literacy Team presented a series of workshops and talked with teachers at the National Science Teachers' Association (NSTA) annual convention in Atlanta, Georgia. Workshops by the team were attended by roughly 300 teachers from across the nation. Response to "Reading, Writing, and Rings" was excellent. The Cassini Literacy Team is a partnership with the Cassini Mission, the Bay Area Writing Project, Project FIRST (Foundations In Reading Through Science and Technology), and the Caltech Pre-College Science Initiative (CAPSI). The European Southern Observatory has released an article and new detailed images from the Very Large Telescope from the Paranal Observatory in Chile relating to weather forecasting on Titan. For more information link to: http://jpl.convio.net/site/R?i=uRpHjjC2b4ZO-3BCLCXxIg.. This week's Cassini image of the week is another beautiful, natural color image of Saturn, sporting atmospheric features in the southern hemisphere not seen until now. The image may be found at http://saturn.jpl.nasa.gov/cgibin/gs2.cgi?path=../multimedia/images/saturn /images/PIA05385.jpg&type=image. 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. __________________________________________________________________________ CASSINI: TWO STORMS CAUGHT IN THE ACT ON SATURN NASA/JPL release 2004-098 8 April 2004 Three months before Saturn arrival, the Cassini spacecraft has observed two storms in the act of merging into one larger storm. This is only the second time this phenomenon has been observed on the ringed planet. "Merging is one of the distinct features of storms in the giant planet atmospheres," said Dr. Andrew Ingersoll, member of the Cassini imaging team and professor of planetary science at the California Institute of Technology in Pasadena, CA. "On Earth, storms last for a week or so and usually fade away when they enter the mature phase and can no longer extract energy from their surroundings. On Saturn and the other giant planets, storms last for months, years, or even centuries, and instead of simply fading away, many storms on the giant planets end their lives by merging. How they form, however, is still uncertain," said Ingersoll. With diameters close to 1,000 kilometers (621 miles), both storms were seen moving west, relative to the rotation of Saturn's interior, for about a month before they merged on March 19 through 20, 2004. The northern storm moved about twice as fast as the southern storm, 11 meters per second versus 6 meters per second (25 miles per hour versus 13 miles per hour) respectively. They approached each other like two cars on a highway and spun around each other in a counterclockwise direction as they merged. This is the opposite of how hurricanes spin in the southern hemisphere on Earth. Just after the merger, on March 20, the new storm was elongated in the north-south direction, with bright clouds on either end. Two days later the storm settled into a more circular shape and the bright clouds were spread around the circumference to form a halo. Whether the bright clouds are particles of a different composition or simply at a different altitude is uncertain. Although these storms move slowly west, storms at Saturn's equator move east at speeds up to 450 meters per second (1,000 miles per hour), which is 10 times the speed of Earth's jet streams and three times greater than the equatorial winds on Jupiter. "Saturn is the windiest planet in the solar system," said Ingersoll, "and that's a huge mystery. We'll be getting closer to the planet all the way through June, so maybe we'll find out." Images from the Voyager spacecraft flybys of Saturn in August 1981 show storms partially merging, but to see them with Cassini this far out from Saturn is a mouthwatering surprise to scientists because they will get even closer during Cassini's four-year Saturn tour. "I'm optimistic because these images are already so good. The best is yet to come," said Ingersoll. The Cassini-Huygens mission 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, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, DC. The Cassini orbiter and the two cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, CO. A series of Cassini images documenting this event can be found at the Cassini-Huygens mission home pages, http://saturn.jpl.nasa.gov and http://ciclops.org. Contacts: Carolina Martinez Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-9382 Donald Savage NASA Headquarters, Washington, DC Phone: 202-358-1727 Heidi Finn Space Science Institute, Boulder, CO Phone: 720-974-5859 Additional articles on this subject are available at: http://www.astrobio.net/news/article914.html http://www.spacedaily.com/news/cassini-04d.html http://www.universetoday.com/am/publish/cassini_sees_merging_storms.html. __________________________________________________________________________ NASA EXTENDS MARS ROVERS' MISSION NASA/JPL release 2004-097 8 April 2004 NASA has approved an extended mission for the Mars Exploration Rovers, handing them up to five months of overtime assignments as they finish their three-month prime mission. The first of the two rovers, Spirit, met the success criteria set for its prime mission. Spirit gained check marks in the final two boxes on April 3 and 5, when it exceeded 600 meters (1,969 feet) of total drive distance and completed 90 martian operational days after landing. Opportunity landed three weeks after Spirit. It will complete the two-rover checklist of required feats when it finishes a 90th martian day of operations April 26. Each martian day, or "sol," lasts about 40 minutes longer than an Earth day. "Given the rovers' tremendous success, the project submitted a proposal for extending the mission, and we have approved it," said Orlando Figueroa, Mars Exploration Program director at NASA Headquarters, Washington, DC. The mission extension provides $15 million for operating the rovers through September. The extension more than doubles exploration for less than a two percent additional investment, if the rovers remain in working condition. The extended mission has seven new goals for extending the science and engineering accomplishments of the prime mission. "Once Opportunity finishes its 91st sol, everything we get from the rovers after that is a bonus," said Dr. Firouz Naderi, manager of Mars exploration at NASA's Jet Propulsion Laboratory, Pasadena, Calif., where the rovers were built and are controlled. "Even though the extended mission is approved to September, and the rovers could last even longer, they also might stop in their tracks next week or next month. They are operating under extremely harsh conditions. However, while Spirit is past its 'warrantyL,' we look forward to continued discoveries by both rovers in the months ahead." JPL's Jennifer Trosper, Spirit mission manager, said even when a memory- management problem on the rover caused trouble for two weeks, she had confidence the rover and the operations team could get through the crisis and reach the 90-sol benchmark. "We never felt it was over, but certainly when we were getting absolutely no data from the spacecraft and were trying to figure out what happened, we were worried," she said. Trosper was less confident about Spirit's prospects for reaching the criterion of 600 meters by sol 91, given the challenging terrain of the landing area within Gusev Crater. On sol 89 Spirit accomplished that goal and set a short-lived record for martian driving, with a single-sol distance of 50.2 meters (165 feet) that pushed the odometer total to 617 meters (2,024 feet). Two days later, Opportunity shattered that mark with a 100-meter (328-foot) drive. Beyond the quantifiable criteria, such as using all research tools at both landing sites and investigating at least eight locations, the rovers have returned remarkable science results. The most dramatic have been Opportunity's findings of evidence of a shallow body of salty water in the past in the Mars Meridiani Planum region. "We're going to continue exploring and try to understand the water story at Gusev," said JPL's Dr. Mark Adler, deputy mission manager for Spirit. Spirit is in pursuit of geological evidence for an ancient lake thought to have once filled Gusev Crater. Reaching "Columbia Hills," which could hold geological clues to that water story, is one of seven objectives for Spirit's extended mission. Opportunity has a parallel one, to seek geologic context for the outcrop in the "Eagle" crater by reaching other outcrops in the "Endurance" crater and perhaps elsewhere. Other science objectives are to continue atmospheric studies at both sites to encompass more of Mars' seasonal cycle, and to calibrate and validate data from Mars orbiters for additional types of rocks and soils examined on the ground. Three new engineering objectives are to traverse more than a kilometer (0.62 mile) to demonstrate mobility technologies; to characterize solar- array performance over long durations of dust deposition at both landing sites; and to demonstrate long-term operation of two mobile science robots on a distant planet. During the past two weeks, rover teams at JPL have switched from Mars-clock schedules to Earth-clock schedules designed to be less stressful and more sustainable over a longer period. JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover project for NASA's Office of Space Science, Washington, DC. Images and additional information about the project are available from JPL at http://marsrovers.jpl.nasa.gov and from Cornell University, Ithaca, NY, at http://athena.cornell.edu. Daily MER updates are available at: http://marsrovers.jpl.nasa.gov/mission/status_opportunity.html http://marsrovers.jpl.nasa.gov/mission/status_spirit.html Contacts: Guy Webster Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-5011 Donald Savage NASA Headquarters, Washington, DC Phone: 202-358-1547 Additional articles on this subject are available at: http://www.astrobio.net/news/article915.html http://www.cnn.com/2004/TECH/space/04/05/mars.rovers.ap/index.html http://www.space.com/missionlaunches/spirit_update_040406.html http://www.spacedaily.com/news/mars-mers-04zzzp.html http://www.spacedaily.com/news/mars-mers-04zzzr.html http://www.spacedaily.com/news/mars-mers-04zzzs.html http://spaceflightnow.com/mars/mera/status.html http://spaceflightnow.com/mars/mera/040408extension.html http://www.universetoday.com/am/publish/rover_mission_extended.html http://www.universetoday.com/am/publish/whats_next_mars_rovers.html __________________________________________________________________________ MARS GLOBAL SURVEYOR IMAGES NASA/JPL/MSSS release 1-7 April 2004 The following new images taken by the Mars Orbiter Camera (MOC) on the Mars Global Surveyor spacecraft are now available. South Polar Dunes (Released 01 April 2004) http://jpl.convio.net/site/R?i=_2XdZm3Ci4FO-3BCLCXxIg Gullies in Crater (Released 02 April 2004) http://jpl.convio.net/site/R?i=WdD3dkDtLd5O-3BCLCXxIg East Candor Layers (Released 03 April 2004) http://jpl.convio.net/site/R?i=9b6e_Qfx8R1O-3BCLCXxIg South Polar Mesas and Hills (Released 04 April 2004) http://jpl.convio.net/site/R?i=YRIRgEhyiJtO-3BCLCXxIg Lava Tubes of Olympus (Released 05 April 2004) http://jpl.convio.net/site/R?i=oeBOTh16TglO-3BCLCXxIg Gullies in Crater Wall (Released 06 April 2004) http://jpl.convio.net/site/R?i=TnVAugX3WT5O-3BCLCXxIg Oblique Impact (Released 07 April 2004) http://jpl.convio.net/site/R?i=ePL9Nh2qeQhO-3BCLCXxIg All of the Mars Global Surveyor images are archived at http://jpl.convio.net/site/R?i=Fm04CapP5AFO-3BCLCXxIg. 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. __________________________________________________________________________ MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 5-9 April 2004 Flows from Olympus Mons (Released 5 April 2004) http://jpl.convio.net/site/R?i=Pu4ktwZ6lYBO-3BCLCXxIg Olympus Mons Lava Flows (Released 6 April 2004 http://jpl.convio.net/site/R?i=-nunOYXkXStO-3BCLCXxIg Arsia Mons Flows in Infrared (Released 7 April 2004) http://jpl.convio.net/site/R?i=aqJXTK93DI9O-3BCLCXxIg Infrared of Meroe Patera Flows (Released 8 April 2004) http://jpl.convio.net/site/R?i=LBu3WK3u6PpO-3BCLCXxIg Young and Old Flows (Released 9 April 2004) http://jpl.convio.net/site/R?i=xz4VNLJHjI1O-3BCLCXxIg All of the THEMIS images are archived at http://jpl.convio.net/site/R?i=Q1FZKawLVe1O-3BCLCXxIg. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, DC. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. __________________________________________________________________________ ROSETTA STATUS REPORT: ONGOING COMMISSIONING ACTIVITIES ESA release 5 April 2004 Payload commissioning activities continued in the reporting period. The Radio Science Instrument (RSI) commissioning covered the first four passes, followed by the initial activation and commissioning of the MIRO instrument. The latter included a very complex pointing profile resulting in a triple-spiral scanning of the planet Venus with the +Z axis of the spacecraft, which is also the pointing direction of MIRO. This activity was repeated twice in the reporting period. On the spacecraft subsystems side several software maintenance activities were carried out, including: * Update of the Star Trackers' software to allow data multiplexing over the link with the AOCS; * Update of the pointing bias values for the high gain antenna, resulting from the calibration carried out in the previous reporting period; * Uplink of a patch to the AOCS software to avoid autonomous activation of substitution heaters for the high gain antenna motor. All activities were executed according to plan and in some cases the operations planned for a full night pass could be finished well ahead of time. At the end of the last New Norcia pass in the reporting period (DOY 093, 08:00) Rosetta was at 10.6 million km from the Earth. The one-way signal travel time was 35.3 seconds. Read the original news release at http://sci.esa.int/science- e/www/object/index.cfm?fobjectid=34921. __________________________________________________________________________ End Marsbugs, Volume 11, Number 16. 43 Marsbugs: The Electronic Astrobiology Newsletter, Volume 11, Number 15, 6 April 2004