Marsbugs: The Electronic Astrobiology Newsletter Volume 12, Number 15, 27 April 2005 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, but individual authors retain the copyright of specific articles. 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) CARBON DIOXIDE ROLE IN PAST CLIMATE REVEALED British Antarctic Survey release 2) MARS, KNOCKED OFF ITS AXIS? From Astrobiology Magazine 3) THE FAINT AND THE BRIGHT By Maggie Turnbull 4) THE MISERY OF READING PAGE ONE By Greg Little 5) NASA'S SPITZER TELESCOPE SEES SIGNS OF ALIEN ASTEROID BELT NASA release 05-101 6) EXECUTIONER'S SONG: DECIDING WHICH SPACE MISSIONS LIVE OR DIE By Leonard David 7) LIVERMORE LAB PHYSICIST DATES LIFETIME OF SOLAR NEBULA AT TWO MILLION YEARS Lawrence Livermore National Laboratory release 8) YELLOWSTONE DISCOVERY BODES WELL FOR DETECTING EVIDENCE OF LIFE ON MARS, SAYS CU-BOULDER STUDY University of Colorado at Boulder release 9) WHAT IF EVERYBODY IS LISTENING AND NOBODY IS TRANSMITTING? By Jill Tartar 10) NEW HIBERNATION TECHNIQUE MIGHT WORK ON HUMANS By Robert Roy Britt 11) DON'T BREATHE THE MOONDUST By Trudy E. Bell and Tony Phillips 12) STATE-OF-THE-ART MINERALOGY FOR MARS By Stephen Hart 13) LOW LEVEL OF EXTINCTION DURING ICE AGE LINKED TO ADAPTABILITY Johns Hopkins University release 14) JOLTED BACTERIA MAKE HYDROGEN FROM HUMAN WASTE From LiveScience.com 15) QUESTIONING TERRESTRIAL PLANETS By Maggie Turnbull Announcements 16) SETI INSTITUTE SCIENCE DAY SETI Institute release Mission Reports 17) CASSINI UPDATES NASA/JPL releases 18) NASA ANNOUNCES KEY GENESIS SCIENCE COLLECTORS IN EXCELLENT SHAPE NASA release 05-102 19) MER MOVIE CLIP SHOWS WHIRLWINDS CARRYING DUST ON MARS NASA/JPL image advisory 2005-061 20) MARS EXPRESS: THE MESAS OF AUREUM CHAOS ESA release 21) MARS GLOBAL SURVEYOR IMAGES NASA/JPL/MSSS release 22) MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 23) ROSETTA: FIRST IN-FLIGHT TEST OF NEAR SUN HIBERNATION MODE (REPORT FOR PERIOD 8-22 APRIL 2005) ESA release __________________________________________________________________________ CARBON DIOXIDE ROLE IN PAST CLIMATE REVEALED British Antarctic Survey release 11 April 2005 Researchers at the British Antarctic Survey (BAS) and the University of California, Santa Cruz have discovered that Earth's last great global warming period, 3 million years ago, may have been caused by levels of CO2 in the atmosphere similar to today's. Reporting this week in a leading earth science journal, Geochemistry Geophysics Geosystems, the scientists describe how they tested two widely held ideas that attempted to explain the balmy conditions on Earth at that time. Their findings clearly demonstrate that studying past climates can help us to understand the likely impact of greenhouse gas emissions and global warming. BAS Principal Investigator Dr Alan Haywood said, "There are two schools of thought about past warm intervals. Many scientists suggest that they were caused by ocean currents (like the Gulf Stream) moving greater amounts of warm water from the tropics to the polar regions. Others speculate that increased levels of CO2 in the atmosphere initiated warming all over the planet. We used the latest supercomputing technology combined with chemical analysis of seabed sediments to make a sophisticated reconstruction of past sea temperatures. If the warming was caused by ocean currents, we would expect to see cooling at the tropics and warming at the poles. Conversely, if CO2 was the cause then we would expect both the tropics and the poles to warm. The sea temperature pattern we found points the finger squarely at CO2 rather than the ocean currents. This is a real breakthrough for those of us investigating past climate--we've made a major contribution to a long standing argument and our findings are critical to understanding how climate may respond to emissions of greenhouse gases in the future." Clues to past sea-surface temperature come from tiny marine algae that live near the surface. They produce chemicals called alkenones that record the sea temperature. When the algae die they sink and become part of the seabed. Therefore, a record of past sea temperatures is stored within the sediments. Sea-surface temperatures were also predicted using a climate model running on a sophisticated supercomputer based at Manchester. This is capable of billions of calculations per second. Journal reference: Alan M. Haywood, Petra Dekens, Ana Christina Ravelo and Mark Williams, 2005. Warmer tropics during the mid-Pliocene? Evidence from alkenone paleothermometry and a fully coupled ocean-atmosphere GCM. Geochemistry Geophysics Geosystems, Volume 6, Number 3, doi:10.1029/2004GC000799. Contacts: Linda Capper British Antarctic Survey Press Office Phone: +44 1223 221448 Mobile: 07714 233744 E-mail: l.capper@bas.ac.uk Athena Dinar British Antarctic Survey Press Office Phone: ++44 1223 221414 Mobile: 07740 822229 E-mail: a.dinar@bas.ac.uk Alan M Haywood British Antarctic Survey, High Cross Phone: + 44 (0)1223 221420 Mark Williams British Antarctic Survey, High Cross Phone: + 44 (0)1223 221427 Petra Dekens and Ana Christina Ravelo Ocean Sciences Department, University of California Santa Cruz, California, USA Phone: 00 1 831-459-3722 Read the original news release at http://www.antarctica.ac.uk/News_and_Information/Press_Releases/story.php? id=161. __________________________________________________________________________ MARS, KNOCKED OFF ITS AXIS? From Astrobiology Magazine Based on an American Geophysical Union report 19 April 2005 Since the time billions of years ago when Mars was formed, it has never been a spherically symmetric planet, nor is it composed of similar materials throughout, say scientists who have studied the planet. Since its formation, it has changed its shape, for example, through the development of the Tharsis bulge, an eight kilometer [five mile] high feature that covers one-sixth of the martian surface, and through volcanic activity. As a result of these and other factors, its polar axis has not been stable relative to surface features and is known to have wandered through the eons as Mars rotated around it and revolved around the Sun. Now, a Canadian researcher has calculated the location of Mars' ancient poles, based upon the location of five giant impact basins on the planet's surface. Jafar Arkani-Hamed of McGill University in Montreal, Quebec, has determined that these five basins, named Argyre, Hellas, Isidis, Thaumasia, and Utopia, all lie along the arc of a great circle. This suggests that the projectiles that caused the basins originated with a single source and that the impacts trace the martian equator at the time of impact, which was prior to the development of the Tharsis bulge, he says. Writing in the Journal of Geophysical Research (Planets), Arkani-Hamed calculates that the source of the five projectiles was an asteroid that had been circling the Sun in the same plane as Mars and most of the other planets. At one point, it passed close to the planet, until the force of martian gravity surpassed the tensile strength of the asteroid, at which point it fragmented. The five large fragments would have remained in the same plane, that of Mars' then-equator. They hit in different spots around the martian globe, due to Mars' rotation on its then-axis and the differing lengths of time the fragments took before impacting on Mars. Arkani-Hamed describes the locations of the resulting basins, only three of which are well preserved. The two others have been detected by analysis of martian gravitational anomalies. The great circle they describe on the martian surface has its center at latitude -30 and longitude 175. By realigning the map of Mars with that spot as the south pole, the great circle marks the ancient equator. Arkani-Hamed estimates that the mass of the asteroid captured by Mars was about one percent of that of Earth's Moon. Its diameter was in the range of 800 to 1,000 kilometers [500 to 600 miles], depending upon its density, which cannot be determined. The significance of Arkani-Hamed's findings, if borne out by further research, is that the extent of presumed underground water on Mars would have to be reassessed. "The region near the present equator was at the pole when running water most likely existed," he said in a statement. "As surface water diminished, the polar caps remained the main source of water that most likely penetrated to deeper strata and has remained as permafrost, underlain by a thick groundwater reservoir. This is important for future manned missions to Mars." Journal reference: Jafar Arkani-Hamed, 2005. Giant impact basins trace the ancient equator of Mars. Journal of Geophysical Research (Planets), 110(E4):E04012, http://www.agu.org/pubs/crossref/2005/2004JE002343.shtml. Read the original article at http://www.astrobio.net/news/article1528.html. __________________________________________________________________________ THE FAINT AND THE BRIGHT By Maggie Turnbull From Astrobiology Magazine 20 April 2005 Maggie Turnbull, an astronomer with the Carnegie Institution, has spent many years thinking about what kind of stars could harbor Earth-like planets. Her database of potentially habitable star systems could be used as a target list for NASA's upcoming Terrestrial Planet Finder (TPF) mission. Turnbull presented a talk, "Remote Sensing of Life and Habitable Worlds: Habstars, Earthshine and TPF," at a NASA Forum for Astrobiology Research on March 14, 2005. This edited transcript of the lecture is part three of a four-part series. From the TPF engineer's perspective, we scientists are asking for some very challenging technology, and ultimately we may just have to settle for what the engineers can reasonably build. So the questions are: Of the 500 scientifically interesting stars within 30 parsecs, how many habitable zones will we be able to image? If there's a planet in those habitable zones, how detectable will that planet be? To answer those questions, we first have to think about two different kinds of star brightness: intrinsic versus apparent. Some stars look brighter because they are hotter and more massive than other stars. The big blue O and B-class stars, for instance, are intrinsically brighter, or more luminous, then a G star like our sun. The more intrinsically luminous a star is, the more it will swamp the light from a planet in the habitable zone. On the other hand, faint, cool stars can still appear bright in the sky because they are nearer to us, being more common in the galaxy than intrinsically bright stars. These nearby stars are apparently bright (in the sky) but intrinsically faint (in reality). Planets orbiting intrinsically faint stars can be easier to image because the reflected light from the planet is not overwhelmed by the star's light. Within about 10 years, engineers expect they will be able to design a coronagraph that can see a planet that is one-ten-billionth as bright as the star it orbits. With that limit, to image a planet at the inner edge of the habitable zone, we will have to look at stars that are intrinsically less luminous than two-and-a-half times the luminosity of the sun. For the outer habitable zone, where any planets will be reflecting even less starlight, the stars have to be fainter than about half the luminosity of the sun. Lucky for us, these intrinsically fainter stars happen to be the most common stars in the universe. The other factor is that we want our intrinsically faint stars to also be apparently bright. The greater the apparent brightness of a star, the greater the angle will appear to be between the star and its habitable zone, and the better we can resolve the star's habitable zone. The engineers tell us that we will be able to observe habitable zones that, looking from Earth, have an angular size of 40 milliarcseconds or larger. Forty milliarcseconds is about the size of a dime seen from 16 miles away, so the engineers are doing pretty well here--this is the cutting edge of astronomical imaging technology. In terms of apparent brightness, that 40 milliarcsecond habitable zone translates into a six- and-a-half magnitude star or brighter to resolve the whole habitable zone, or a seven-and-a-half or eighth magnitude star to observe at least the outer part of a habitable zone. So out of all the stars within 30 parsecs--about 2400 stars in the Hipparcos Catalogue--that leaves us with 105 stars where an Earth-like planet in the inner habitable zone will be detectable. Those stars are G stars, late K stars, and some late F stars: stars that are similar to the sun. For the outer habitable zone, we're going to be looking at slightly fainter stars: late G stars and early K type stars. If I cross reference those stars with the list of the 500 habitable star systems that I would like to observe as a scientist, I come up with 56 Habstars that are at least partially observable with TPF. However, only 10 of those are fully observable, meaning we can image the full habitable zone with TPF and discover a planet. I think those 10 stars are definitely our most interesting targets, and should be in the core TPF target list. We're building a stellar database now so that astronomers can go online and play around with making their own target lists for TPF, using the information on the locations of habitable zones, variability, companions, metallicity, and so on. But we still have many unanswered questions, such as, "How much do the spectral signatures of a planet vary over time?" Also, "How would they vary if you take Earth and put it around a star of a different spectral type?" There's a lot of basic data that just doesn't exist in the literature right now, so there's more that we need to do. Read the original article at http://www.astrobio.net/news/article1529.html. __________________________________________________________________________ THE MISERY OF READING PAGE ONE By Greg Little From Ad Astra and Space.com 20 April 2005 Just a couple weeks ago, I was sitting in a hotel room in Nashville reading the local daily. On the front page appeared a story about how Kid Rock had been arrested for getting into a bar brawl. Inside that same paper, I think on about page A9, was a story about how it has all but been confirmed that life did exist on Mars and maybe still does today. The article explained how the oceans of Mars likely went underground and still exist, producing methane gas, one of the by products of life. As a newspaper editor, it galls me no end how some in my profession treat certain stories. Sure, the fact mega-nerd Kid Rock was arrested is probably a big deal in Nashville, Music City, USA. But almost certain proof of life beyond our planet? I often wonder where the priorities of editors and the public lie. I'm sure the rationale of the editor was determining what would sell the newspaper. I do it every day. Read the full article at http://www.space.com/adastra/adastra_mars_misery_050420.html. __________________________________________________________________________ NASA'S SPITZER TELESCOPE SEES SIGNS OF ALIEN ASTEROID BELT NASA release 05-101 20 April 2005 NASA's Spitzer Space Telescope has spotted what may be the dusty spray of asteroids banging together in a belt that orbits a star like our sun. The discovery offers astronomers a rare glimpse at a distant star system that resembles our home, and may represent a significant step toward learning if and where other Earths form. "Asteroids are the leftover building blocks of rocky planets like Earth," said Dr. Charles Beichman, California Institute of Technology (Caltech), Pasadena, CA. Beichman is lead author of a paper that will appear in the Astrophysical Journal. "We can't directly see other terrestrial planets, but now we can study their dusty fossils," he added. Asteroid belts are the junkyards of planetary systems. They are littered with the rocky scraps of failed planets, which occasionally crash into each other, kicking up plumes of dust. In our own solar system, asteroids have collided with Earth, the moon and other planets. If confirmed, the new asteroid belt would be the first detected around a star about the same age and size as our sun. The star, called HD69830, is located 41 light-years away from Earth. There are two other known distant asteroid belts, but they circle younger, more massive stars. While this new belt is the closest known match to our own, it is not a perfect twin. It is thicker than our asteroid belt, with 25 times as much material. If our solar system had a belt this dense, its dust would light up the night skies as a brilliant band. The alien belt is also much closer to its star. Our asteroid belt lies between the orbits of Mars and Jupiter, whereas this one is located inside an orbit equivalent to that of Venus. Yet, the two belts may have one important trait in common. In our solar system, Jupiter acts as an outer wall to the asteroid belt, shepherding its debris into a series of bands. Similarly, an unseen planet the size of Saturn or smaller may be marshalling the star's rubble. One of NASA's future planet-hunting missions, SIM PlanetQuest, may ultimately identify such a planet orbiting this star. The mission, which will detect planets as small as a few Earth masses, is scheduled to launch in 2011. Beichman and colleagues used Spitzer's infrared spectrograph to observe 85 sun-like stars. Only HD 69830 was found to possibly host an asteroid belt. They did not see the asteroids themselves, but detected a thick disk of warm dust confined to the inner portion of the star system. The dust most likely came from an asteroid belt in which dusty smash-ups occur relatively frequently, about every 1,000 years. "Because this belt has more asteroids than ours, collisions are larger and more frequent, which is why Spitzer could detect the belt," said Dr. George Rieke, University of Arizona, Tucson, co-author of the paper. "Our present-day solar system is a quieter place, with impacts of the scale that killed the dinosaurs occurring only every 100 million years or so." To confirm the dust detected by Spitzer is indeed ground-up asteroids, a second less-likely theory will have to be ruled out. According to the astronomers, it is possible a giant comet, almost as big as Pluto, got knocked into the inner solar system and is slowly boiling away, leaving a trail of dust. This hypothesis came about when the astronomers discovered the dust around the star consists of small silicate crystals like those found in comet Hale-Bopp. One of these crystals is the bright green- colored gem called forsterite. "The 'super comet' theory is more of a long shot," Beichman said, "but we'll know soon enough." Future observations of the star using Spitzer and ground-based telescopes are expected to conclude whether asteroids or comets are the source of the dust. The Jet Propulsion Laboratory manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center, at Caltech. For artist's concepts and more information related to this release on the Internet, visit www.spitzer.caltech.edu/spitzer. For information about NASA and agency programs on the Internet, visit http://www.nasa.gov. Journal reference: http://www.journals.uchicago.edu/ApJ/ (At the publication time of this issue of Marsbugs, the journal article has not been published.) Contacts: Dolores Beasley NASA Headquarters, Washington, DC Phone: 202-358-1753 Whitney Clavin Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-4673 Additional articles on this subject are available at: http://www.astrobio.net/news/article1530.html http://www.space.com/scienceastronomy/050420_alien_asteroid.html http://www.universetoday.com/am/publish/alien_asteroid_belt.html __________________________________________________________________________ EXECUTIONER'S SONG: DECIDING WHICH SPACE MISSIONS LIVE OR DIE By Leonard David From Space.com 20 April 2005 There has been a scientific and public backlash at the thought of shutting down spacecraft, like the vintage Voyager missions, all for the want of a few millions dollars. But Voyager is likely to be an early signal from a growing dilemma of finding cash to keep NASA spacecraft functioning beyond their initial work period. There are plenty of examples, like the still-going strong Mars Exploration Rovers. Also count on keeping the Hubble Space Telescope alive. Toss in an extended Cassini mission at Saturn too. Also, there's early talk about the Deep Impact flyby spacecraft possibly using its telescopic gear to scout about after it completes its main choir of hurling an impactor at comet Tempel 1 and monitoring the upshot this coming July. But now there is growing talk of setting up something analogous to a "hit squad" at NASA that impartially agrees what projects should be ended, when, and under what rules. Read the full article at http://www.space.com/businesstechnology/technology/050420_last_missions.ht ml. __________________________________________________________________________ LIVERMORE LAB PHYSICIST DATES LIFETIME OF SOLAR NEBULA AT TWO MILLION YEARS Lawrence Livermore National Laboratory release 20 April 2005 The oxygen and magnesium content of some of the oldest objects in the universe are giving clues to the lifetime of the solar nebula, the mass of dust and gas that eventually led to the formation of our solar system. By looking at the content of chondrules and calcium aluminum-rich inclusions (CAIs), both components of the primitive meteorite Allende, Lab physicist Ian Hutcheon, with colleagues from the University of Hawaii at Manoa, the Tokyo Institute of Technology and the Smithsonian Institution, found that the age difference between the two fragments points directly to the lifetime of the solar nebula. CAIs were formed in an oxygen-rich environment and date to 4.567 billion years old, while chondrules were formed in an oxygen setting much like that on Earth and date to 4.565 billion, or less, years old. "Over this span of about two million years, the oxygen in the solar nebula changed substantially in its isotopic makeup," Hutcheon said. "This is telling us that oxygen was evolving fairly rapidly." The research appears in the April 21 edition of the journal, Nature. One of the signatures of CAIs is an enrichment of the isotope Oxygen 16 (O- 16). An isotope is a variation of an element that is heavier or lighter than the standard form of the element because each atom has more or fewer neutrons in its nucleus. The CAIs in this study are enriched with an amount of O-16 4 percent more than that found on Earth. And, while 4 percent may not sound like much, this O-16 enrichment is an indelible signature of the oldest solar system objects, like CAIs. CAIs and chondrules are tens of millions of years older than more modern objects in the solar system, such as planets, which formed about 4.5 billion years ago. "By the time chondrules formed, the O-16 content changed to resemble what we have on Earth today," Hutcheon said. In the past, the estimated lifetime of the solar nebula ranged from less than a million years to ten million years. However, through analysis of the mineral composition and oxygen and magnesium isotope content of CAIs and chondrules, the team was able to refine that lifespan to roughly two million years. "In the past the age difference between CAIs and chondrules was not well- defined," Hutcheon said. "Refining the lifetime of the solar nebula is quite significant in terms of understanding how our solar system formed." Journal reference: Alexander N. Krot, Hisayoshi Yurimoto, Ian D. Hutcheon and Glenn J. MacPherson, 2005. Chronology of the early Solar System from chondrule- bearing calcium-aluminium-rich inclusions. Nature, 434:998-1001, http://www.nature.com/nature/journal/v434/n7036/abs/nature03470.html. Read the original news release at http://www.llnl.gov/pao/news/news_releases/2005/NR-05-04-02.html. Additional articles on this subject are available at: http://www.astrobio.net/news/article1532.html http://www.spacedaily.com/news/stellar-chemistry-05r.html http://www.universetoday.com/am/publish/solar_nebula_2_million.html __________________________________________________________________________ YELLOWSTONE DISCOVERY BODES WELL FOR DETECTING EVIDENCE OF LIFE ON MARS, SAYS CU-BOULDER STUDY University of Colorado at Boulder release 20 April 2005 University of Colorado at Boulder researchers say a bizarre group of microbes found living inside rocks in an inhospitable geothermal environment at Wyoming's Yellowstone National Park could provide tantalizing clues about ancient life on Earth and help steer the hunt for evidence of life on Mars. The CU-Boulder research team reported the microbes were discovered in the pores of rocks in a highly acidic environment with high concentrations of metals and silicates at roughly 95 degrees F in Yellowstone's Norris Geyser Basin. The new study shows the microbe communities are subject to fossilization and have the potential to become preserved in the geologic record. Scientists believe similar kinds of geothermal environments may once have existed on Mars, where astrobiologists have intensified the search for past and present life forms in recent years. A paper by CU-Boulder doctoral student Jeffrey Walker, postdoctoral fellow John Spear and Professor Norman Pace of CU-Boulder's molecular, cellular and developmental biology department and the Center for Astrobiology appears in the April 21 issue of Nature. The research was funded by the National Science Foundation and NASA. "This is the first description of these microbial communities, which may be a good diagnostic indicator of past life on Mars because of their potential for fossil preservation," said Walker. "The prevalence of this type of microbial life in Yellowstone means that martian rocks associated with former hydrothermal systems may be the best hope for finding evidence of past life there." Located about 20 miles northwest of Yellowstone Lake, Norris Geyser Basin is considered to be the hottest and most active geyser basin in Yellowstone and perhaps the world. It also is extremely acidic, according to the researchers. "The pores in the rocks where these creatures live has a pH value of one, which dissolves nails," said Pace. "This is another example that life can be robust in an environment most humans view as inhospitable." The process used to identify the organisms developed by Pace is much more sensitive than standard lab-culturing techniques that typically yield a small, biased fraction of organisms from any environment, said Walker. In this method, the researchers detected and identified organisms by reading gene sequences. "Each kind of organism has a unique sequence, which is used to map its position in the tree of life," said Walker. "It's a family tree of sorts that describes the genetic relationship between all known organisms." Walker discovered the new microbe community in 2003 after breaking apart a chunk of sandstone-like rock in the Norris Geyser Basin. "I immediately noticed a distinctive green band just beneath the surface," he said. "It was one of those 'eureka' moments." An analysis determined the green band was caused by a new species of photosynthetic microbes in the Cyanidium group, a kind of alga that is among the most acid-tolerant photosynthetic organisms known, said Walker. Cyanidium organisms made up about 26 percent of the microbes identified in the Norris Geyser Basin study by the CU-Boulder team, Walker said. Surprisingly, the most abundant microbes identified by the team were a new species of Mycobacterium, a group of microbes best known for causing human illnesses like tuberculosis and leprosy, Walker said. Extremely rare and never before identified in such extreme hydrothermal environments, Mycobacterium made up 37 percent of the total number of microbes identified by the CU-Boulder team. Pace described the new life form in the Norris Geyser Basin as "pretty weird." "It may well be a new type of lichen-like symbiosis," said Pace, who won a MacArthur Fellowship, or "genius grant," in 2001. "It resembles a lichen, but instead of being comprised of a symbiosis between a fungus and an alga, it seems to be an association of the Mycobacterium with an alga." While photosynthesis appears to be a key energy source for most of the creatures, at least some Yellowstone microbes are believed to get energy from the dissolved metals and hydrogen found in the pore water of the rock, Walker said. A study by the CU-Boulder team published by the National Academy of Sciences in January 2005 indicated Yellowstone microbe populations living in hot springs at temperatures more than 158 degrees F use hydrogen as their primary fuel source. The research effort in the Norris Geyser Basin shows that rock formation processes occurring in the hydrothermal environment under study make very real fossil imprints of the organisms embedded in the rock at various stages, showing how the distinctive fossils develop over time, according to the research team. "Remnants of these communities could serve as 'biosignatures' and provide important clues about ancient life associated with geothermal environments on Earth or elsewhere in the Solar System," the authors wrote in Nature. Journal reference: Jeffrey J. Walker, John R. Spear and Norman R. Pace, 2005. Geobiology of a microbial endolithic community in the Yellowstone geothermal environment. Nature, 434:1011-1014, http://www.nature.com/nature/journal/v434/n7036/abs/nature03447.html. Contacts: Norman Pace Phone: 303-735-1864 E-mail: nrpace@colorado.edu Jeffrey Walker Phone: 303-735-1808 E-mail: jeffrey.walker@colorado.edu Jim Scott Phone: 303-492-3114 Read the original news release at http://www.colorado.edu/news/releases/2005/183.html. Additional articles on this subject are available at: http://www.astrobio.net/news/article1531.html http://www.terradaily.com/news/life-05za.html http://www.universetoday.com/am/publish/extreme_life_yellowstone.html __________________________________________________________________________ WHAT IF EVERYBODY IS LISTENING AND NOBODY IS TRANSMITTING? By Jill Tartar 21 April 2005 Whenever I present a public lecture on SETI, I can almost guarantee that the title of this article will be one of the questions I get from the audience. During our 1997-99 workshops on the next two decades of SETI research here at the SETI Institute, the workshop participants took the question of an active transmission strategy very seriously. The results of their deliberations have been published as SETI 2020: A Roadmap for the Search for Extraterrestrial Intelligence. They concluded that transmission is not an appropriate strategy, at least for the next two decades. Humans need to grow up first. Read the full article at http://www.space.com/searchforlife/seti_tarter_transmit_050421.html. __________________________________________________________________________ NEW HIBERNATION TECHNIQUE MIGHT WORK ON HUMANS By Robert Roy Britt From Space.com 21 April 2005 A new trick could one day put humans into a hibernation-like state without all the frigid antics of an Austin Powers movie or an Arthur C. Clarke story. Using a natural chemical humans and other animals produce in their bodies, scientists have for the first time induced hibernation in mammals, putting mice into a state similar to suspended animation for up to six hours and then bringing them back to normal life. The breakthrough suggests humans along with other mammals might harbor a mostly unused ability to hibernate on demand. Further research into the phenomenon could lead to medical advances, such as buying time for humans awaiting an organ transplant, scientists said. "We are, in essence, temporarily converting mice from warm-blooded to cold-blooded creatures, which is exactly the same thing that happens naturally when mammals hibernate," said lead researcher Mark Roth of the Fred Hutchinson Cancer Research Center in Seattle. Journal reference: Eric Blackstone, Mike Morrison and Mark B. Roth, 2005. H2S induces a suspended animation-like state in mice. Science, 308(5721):518. Read the full article at http://www.livescience.com/humanbiology/050421_hibernation.html. __________________________________________________________________________ DON'T BREATHE THE MOONDUST By Trudy E. Bell and Tony Phillips From NASA Science News 22 April 2005 This is a true story. In 1972, Apollo astronaut Harrison Schmitt sniffed the air in his Lunar Module, the Challenger. "[It] smells like gunpowder in here," he said. His commander Gene Cernan agreed. "Oh, it does, doesn't it?" The two astronauts had just returned from a long moonwalk around the Taurus-Littrow valley, near the Sea of Serenity. Dusty footprints marked their entry into the spaceship. That dust became airborne--and smelly. Later, Schmitt felt congested and complained of "lunar dust hay fever." His symptoms went away the next day; no harm done. He soon returned to Earth and the anecdote faded into history. But Russell Kerschmann never forgot. He's a pathologist at the NASA Ames Research Center studying the effects of mineral dust on human health. NASA is now planning to send people back to the Moon and on to Mars. Both are dusty worlds, extremely dusty. Inhaling that dust, says Kerschmann, could be bad for astronauts. "The real problem is the lungs," he explains. "In some ways, lunar dust resembles the silica dust on Earth that causes silicosis, a serious disease." Silicosis, which used to be called "stone-grinder's disease," first came to widespread public attention during the Great Depression when hundreds of miners drilling the Hawk's Nest Tunnel through Gauley Mountain in West Virginia died within half a decade of breathing fine quartz dust kicked into the air by dry drilling--even though they had been exposed for only a few months. "It was one of the biggest occupational-health disasters in U.S. history," Kerschmann says. This won't necessarily happen to astronauts, he assures, but it's a problem we need to be aware of--and to guard against. Quartz, the main cause of silicosis, is not chemically poisonous: "You could eat it and not get sick," he continues. "But when quartz is freshly ground into dust particles smaller than 10 microns (for comparison, a human hair is 50+ microns wide) and breathed into the lungs, they can embed themselves deeply into the tiny alveolar sacs and ducts where oxygen and carbon dioxide gases are exchanged." There, the lungs cannot clear out the dust by mucous or coughing. Moreover, the immune system's white blood cells commit suicide when they try to engulf the sharp-edged particles to carry them away in the bloodstream. In the acute form of silicosis, the lungs can fill with proteins from the blood, "and it's as if the victim slowly suffocates" from a pneumonia-like condition. Lunar dust, being a compound of silicon as is quartz, is (to our current knowledge) also not poisonous. But like the quartz dust in the Hawk's Nest Tunnel, it is extremely fine and abrasive, almost like powdered glass. Astronauts on several Apollo missions found that it clung to everything and was almost impossible to remove; once tracked inside the Lunar Module, some of it easily became airborne, irritating lungs and eyes. Martian dust could be even worse. It's not only a mechanical irritant but also perhaps a chemical poison. Mars is red because its surface is largely composed of iron oxide (rust) and oxides of other minerals. Some scientists suspect that the dusty soil on Mars may be such a strong oxidizer that it burns any organic compound such as plastics, rubber or human skin as viciously as undiluted lye or laundry bleach. "If you get martian soil on your skin, it will leave burn marks," believes University of Colorado engineering professor Stein Sture, who studies granular materials like Moon- and Mars-dirt for NASA. Because no soil samples have ever been returned from Mars, "we don't know for sure how strong it is, but it could be pretty vicious." Moreover, according to data from the Pathfinder mission, martian dust may also contain trace amounts of toxic metals, including arsenic and hexavalent chromium--a carcinogenic toxic waste featured in the docudrama movie Erin Brockovich (Universal Studios, 2000). That was a surprising finding of a 2002 National Research Council report called Safe on Mars: Precursor Measurements Necessary to Support Human Operations on the Martian Surface. The dust challenge would be especially acute during windstorms that occasionally envelop Mars from poles to equator. Dust whips through the air, scouring every exposed surface and sifting into every crevice. There's no place to hide. To find ways of mitigating these hazards, NASA is soon to begin funding Project Dust, a four-year study headed by Masami Nakagawa, associate professor in the mining engineering department of the Colorado School of Mines. Project Dust will study such technologies as thin-film coatings that repel dust from tools and other surfaces, and electrostatic techniques for shaking or otherwise removing dust from spacesuits. These technologies, so crucial on the Moon and Mars, might help on Earth, too, by protecting people from sharp-edged or toxic dust on our own planet. Examples include alkaline dust blown from dry lakes in North American deserts, wood dust from sawmills and logging operations, and, of course, abrasive quartz dust in mines. The road to the stars is surprisingly dusty. But, says Kerschmann, "I strongly believe it's a problem that can be controlled." Read the original article at http://science.nasa.gov/headlines/y2005/22apr_dontinhale.htm. __________________________________________________________________________ STATE-OF-THE-ART MINERALOGY FOR MARS By Stephen Hart From Astrobiology Magazine 25 April 2005 Planetary exploration proceeds by steps. Because life on Earth requires liquid water, the MER mission aimed to search for signs that liquid water existed on Mars in the past. MER has found such signs. The aptly named Mars Science Laboratory scheduled for launch in 2009 will take a step further. It will search for detailed evidence that the area where it lands could have supported life in the past. That seemingly small step requires more precise characterization of the minerals in the MSL rover's surroundings. On Earth, scientists use three general methods to identify minerals. In the field, they first use their eyes (with and without magnification). On MSL, this job goes to the MastCam, the imaging part of the ChemCam, and the Mars Hand Lens Imager. These three packages are mounted on the mast or the robotic arm of the rover. In the laboratory, earthbound scientists try to analyze the chemical composition of a mineral sample. They can grind a sample and heat it, breaking down the mineral into gasses such as carbon dioxide or sulfur dioxide. Each mineral yields its gasses in a characteristic pattern as the temperature rises. To achieve the most precise mineral identification, though, mineralogists beam x-rays at the sample, measuring the radiation that returns to a detector. The internal chemical and mineralogical laboratory on the MSL rover will contain two instruments that for the first time on Mars will be capable of performing the all of these laboratory tests. "We are trying to really bring sophisticated laboratory capabilities to Mars to some extent. With this mission, we have the resources to be able to push in that direction," says planetary scientist Paul Mahaffy, of the Goddard Space Flight Center. Sniffing martian air Mahaffy is the principal investigator for the instrument package called Sample Analysis at Mars, or SAM. SAM's two main instruments deal with gasses, both organic molecules and inorganic molecules important to biological activities. SAM analyzes gasses in the atmosphere and those produced by heating dust, sand or crushed rock. The goal, Mahaffy says, is "to do a general survey for the range of organic compounds that might be there, and then really to focus in on molecules that we know are relevant to terrestrial life, such as amino acids, nucleobases, the types of things that proteins and DNA and life on Earth are made of." SAM can analyze atmospheric gasses directly, first passing them through an instrument called a gas chromatograph-mass spectrometer (GCMS). Because such GCMS systems are widely used in laboratories on Earth separating out molecules based on their masses results obtained on Mars can be compared easily with earthly libraries to identify specific molecules. "The gas chromatograph system basically serves to separate out the organics into individual components that can be individually detected and uniquely identified by comparing the mass spectrometer fragmentation pattern with libraries," Mahaffy says. A second SAM instrument, called a tunable laser spectrometer, specializes in detecting particular isotopes, Mahaffy says. It "measures the isotope ratios in carbon, hydrogen and oxygen and sulfur" in gas molecules such as water, methane, carbon monoxide, carbon dioxide and hydrogen peroxide. For example, the instrument could separate carbon 12, the usual form of the element, from carbon 13, a rarer form. An elevated ratio of carbon 13 to carbon 12 could indicate that life was once present. Sniffing martian rocks Using the same gas-analysis system to analyze rocks requires some preparatory steps. The sample must be picked up and ground to a fine sand before being presented to the instruments. The rover will contain a complete subsystem for this step. "SAM will basically accept samples delivered by the MSL sample processing system into little cups--we have 84 cups planned--and move one cup at a time into an oven, basically, where the sample is heated to about 1,100 degrees" Celsius (about 2000 degrees Fahrenheit), Mahaffy explains. As the temperature rises, molecules escape from the sample as gas. Both the mass spectrometer and the tunable laser spectrometer analyze these gasses. In a second step, the gasses are passed to the gas chromatograph. For both instruments, the scientists link the data with the slowly increasing temperature. "We do our heating of the samples in a very controlled manner--instead of the rapid heating to a final temperature that Viking used," Mahaffy says. Among other advances on Viking's instruments are SAM's high-capacity, high-throughput gas pumps. "At the very lowest temperatures, where we'll start our thermal processing, we will be driving off gasses that are just on the surface of porous materials. And then, as we go up in temperature, we will start driving off the water that is chemically bonded, and then when we get up to very high temperatures in the 500- to 800-degree [Celsius, or 900- to 1500-degree Fahrenheit] range, we really start breaking minerals apart." Minerals release specific molecules at characteristic temperatures, so the pattern of gasses released over time as the oven heats up will tell scientists what minerals are present in a sample. "We know at what temperatures we expect various minerals to break up and release simple gasses like carbon dioxide, sulfur dioxide, nitrogen compounds and so on," Mahaffy says. Computer analysis of the raw data can tease apart the characteristic signatures even from mixtures of minerals." The gold standard for minerals Analyzing gasses produced by heating minerals provides important evidence. But on Earth, the mineralogical gold standard is x-ray diffraction, says astrobiologist David F. Blake, of NASA Ames Research Center. Blake is the principal investigator for the second half of the MSL rover's chemical and mineralogical laboratory, called CheMin. "X-ray diffraction is the only definitive way to characterize minerals absolutely," Blake says. "This is really the first fully definitive measurement of mineralogy that will be done on the Mars surface." CheMin also includes an x-ray fluorescence detector, functionally similar to instruments on MER and Viking. "There's an x-ray tube that produces a small pencil-like beam of x-rays that goes through a sample of material, crushed rock, or dust, and there's a CCD detector that receives all of the x-rays that come from the sample." Beaming x-rays on a sample can cause two different results. The radiation can be diffracted and it can be absorbed and re-emitted as fluorescence. Diffraction occurs when radiation, such as visible light or x-rays, changes direction as it passes an opaque edge. X-ray diffraction uniquely identifies a mineral. But diffraction is a rare event, Blake says. "If you have a single crystal and you shine a beam of x-rays through it, it's actually unlikely that you'll get any diffracted beam." Diffraction requires that the x-ray fall on the crystal at a particular angle. To deal with this problem, Blake says, earthbound mineralogists grind minerals to a fine powder, creating, "essentially an infinite number of little, tiny, tiny crystals in the beam, so that there's all possible orientations of those crystals to produce all possible diffraction." CheMin will use a few mechanical tricks to come close to duplicating this effect. "The imperfect powder that's produced by the MSL's rock crusher can be made to look like a very nice, fine grained powder." Fluorescence occurs when an atom absorbs electromagnetic radiation and then emits radiation at a different frequency. Where x-ray diffraction identifies a mineral, x-ray fluorescence identifies particular atoms within that mineral. Another pair of twins? Because the double-rover strategy NASA used for the MER mission was so successful, the agency is considering "the possibility of doing two rovers in 2011 instead of just one rover in 2009," Mahaffy says. "You kind of double the places that you are able to access and you give the entire mission a degree of scientific robustness. Of course then you wait two years longer to get your data, so that's the downside." Mahaffy has proposed some liquid chemistry experiments for SAM, but NASA has not yet decided if the rover can accommodate those. Liquid chemistry would give SAM the ability to preprocess certain chemical compounds that are too fragile to survive a gas chromatograph. The less sophisticated GCMS on Viking might have missed such compounds. But however advanced MSL's scientific suite, Blake sees some limits to what MSL will be able to do. "It would be wonderful to be able to age- date samples," he says. "That's just not possible right now in a spacecraft instrument. It's actually a difficult thing to do on the Earth. Presently, that's something that you only could do with a sample return." Read the original article at http://www.astrobio.net/news/article1534.html. __________________________________________________________________________ LOW LEVEL OF EXTINCTION DURING ICE AGE LINKED TO ADAPTABILITY Johns Hopkins University release 25 April 2005 A Johns Hopkins University graduate student may have figured out why rates of extinction were so low for many of the major groups of marine life during one of the greatest ice ages of them all, which occurred from about 330 million to 290 million years ago, late in the Paleozoic Era. The likely answer: because those aquatic life forms that did survive during this era were singularly equipped to endure severe fluctuations in temperature and sea levels. Those that were not so equipped died in a mass extinction that heralded the ice age's onset. "These results not only clue us in to what happened many millions of years ago, but they also have implications for understanding the modern marine ecosystem," said Matthew Powell, a doctoral candidate in the Morton K. Blaustein Department of Earth and Planetary Sciences at The Johns Hopkins University's Zanvyl Krieger School of Arts and Sciences. His paper on the topic appears in the May issue of Geology, published by the Geological Society of America. "If the patterns I detected also are true for the modern ice age--and other researchers' results suggest that they may be--then modern marine life ought to be relatively resistant to extinction," he said. "Yet species are dying off at an alarming rate. It may be that humans have altered the environment so much that we are now causing the extinction of species that should be relatively immune. Though it's difficult to say exactly what the implications are for the world we live in, what I can say is that it is worrisome." Powell looked at extinctions during an age when glaciers reached to within 35 degrees of the equator, roughly as far south as a line between present- day Raleigh, Memphis and Albuquerque or nearly as far north as Buenos Aires. Powell tackled the question of why extinction rates were so low during that great ice age by closely examining geographic patterns of evolution and extinction in brachiopods, simple shelled sea creatures that were abundant and well-fossilized during the Paleozoic. He constructed a database that charted latitudinal patterns of evolution and extinction through the late Paleozoic. "This database is the first ever; no other database of this kind exists for any interval of geologic time, from which to study geographic patterns of macroevolution," Powell said. According to Powell's analysis, brachiopods that lived primarily near the equator suffered the highest extinction rates and did not re-appear in great numbers until the ice age ended. "The absence of these particular brachiopods during the ice age left the oceans populated almost entirely with those who lived over a wider geographic area," Powell said. "What I found is that the uniquely low global rates of evolution and extinction for brachiopods during the late Paleozoic ice age were caused by the loss and lack of recovery of those that had existed in narrow latitudinal ranges." Powell believes that those brachiopods that existed within narrow latitudinal ranges became victims of the extremes in the annual minimum and maximum temperatures that were typical of the late Paleozoic. During that era, "seasonality"--the difference between annual temperatures' highs and lows--was amplified by the presences of glaciers. "I've suggested that those brachiopods which eventually became extinct had adapted only to small temperature changes, and thus did not survive," he said. "The other competing hypothesis is that large fluctuations of sea level, driven by the melting and reforming of glaciers, disrupted marine communities, and the ones which survived were those able to adjust." Powell's research was funded by the Morton K. Blaustein Department of Earth and Planetary Sciences. Journal reference: Matthew G. Powell, 2005. Climatic basis for sluggish macroevolution during the late Paleozoic ice age. Geology, 33(5):381-384, http://www.gsajournals.org/gsaonline/?request=get- abstract&doi=10.1130%2FG21155.1. Contact: Lisa De Nike Phone: 443-287-9960 E-mail: lde@jhu.edu Read the original news release at http://www.jhu.edu/news_info/news/home05/apr05/iceage.html. An additional article on this subject is available at http://www.astrobio.net/news/article1535.html. __________________________________________________________________________ JOLTED BACTERIA MAKE HYDROGEN FROM HUMAN WASTE From LiveScience.com 26 April 2005 A newly developed process that uses bacteria to consume human waste and other biomass produces four times more hydrogen than previous efforts. Some scientists and politicians envision an economy of the future fueled by hydrogen rather than fossil fuels. Others say that idea is rubbish. The new technique won't by itself create a hydrogen economy, but it could help make wastewater treatment less costly. "While there is likely insufficient waste biomass to sustain a global hydrogen economy, this form of renewable energy production may help offset the substantial costs of wastewater treatment as well as provide a contribution to nations able to harness hydrogen as an energy source," said Penn State Professor Bruce Logan. Journal reference: http://pubs.acs.org/journals/esthag/ (At the publication time of this issue of Marsbugs, the journal article has not been published.) Read the full article at http://www.livescience.com/technology/050426_hydrogen_waste.html. __________________________________________________________________________ QUESTIONING TERRESTRIAL PLANETS By Maggie Turnbull From Astrobiology Magazine 27 April 2005 Maggie Turnbull, an astronomer with the Carnegie Institution, has spent many years thinking about what kind of stars could harbor Earth-like planets. Her database of potentially habitable star systems could be used as a target list for NASA's upcoming Terrestrial Planet Finder (TPF) mission. Turnbull presented a talk, "Remote Sensing of Life and Habitable Worlds: Habstars, Earthshine and TPF," at a NASA Forum for Astrobiology Research on March 14, 2005. In this fourth and final part of the edited transcript, Turnbull answers questions from an audience of fellow scientists. Question (Q): The Galileo spacecraft's main camera saw Earth as only a few pixels and tried to do spectroscopy on that. Will any such observations be done by the Cassini spacecraft? Answer (A): I haven't heard anything about Cassini doing this, and now it is too late because, from Cassini's current point of view, the Earth is very close to the sun. We are looking into getting spectra of the Earth with the Messenger mission, which is en route to Mercury but will be making an Earth flyby later in the year. There are some issues with the position of the sunshade, but that satellite has a low resolution spectrograph in the optical and the near infrared. That would be perfect if they could point it at the Earth, and, I think, the next logical step in preparation for TPF. Q: Have you considered looking for biosignatures that would be characteristic of intelligent life, for instance, pollutants like CFCs that have a spectral signature in the infrared? A: I've heard it mentioned in passing, but as far as I know that idea hasn't been pursued. I think it might be a problem of detectability. I don't know the wavelengths of all the stuff that we're spewing into the atmosphere. If they're dust particles or large molecules, they may be too far to the infrared for TPF to detect. But methane is another biosignature that would be of interest, especially for younger planets. Methane on our planet today does to some extent reflect the presence of humans. But methane is hard to disentangle from geological activity, as we're now finding out with the detection of methane on Mars. Q: Is there a maximum size for a terrestrial planet? How much does that detection envelope expand as you consider larger rocky planets? A: No one really knows if you can make a rocky giant planet--we have no analogue for this in our solar system. As far as we know, the maximum size of a terrestrial planet is somewhere between one and ten Earth masses, or between the mass of the Earth and the mass of Neptune. As a planet gets larger, the fractional planet brightness goes up. So TPF will have a much easier time detecting larger terrestrial or giant gaseous planets, but we still want to mostly try to detect planets that are Earth- sized. Q: How narrowly do we define something as being Earth-like? For large fractions of the Earth's history, the planet has been glaciated. The optical absorption in a forest is much greater than for the Earth as a whole, since oceans and glaciers have a different signature. So if you had a glaciated Earth or a heavily watered Earth, TPF could miss it completely. You could still see the oxygen signature, but that brings up another issue: on Earth there are something like 20 different bacterial metabolic pathways. One happened to win the fight. Other photosynthetic pathways include rhodopsin, a purple [bacterial pigment] that has a different optical spectrum than chlorophyll. So what would a "rhodopsin world" look like? That world would still be Earth-like, except for the fact that we couldn't live there. A: Right. We should look into those different possibilities, and try to model what, spectrally speaking, an Earth would look like with those different and easily conceivable life forms dominating. But as far as biosignatures are concerned, unless you've got some sort of spectrally distinct organism covering the surface, I don't see how you can hope to detect it. Glacier and water worlds would have very different spectra than the Earth, and they might still be perfectly habitable. Maybe looking for atmospheric signatures that are in strong disequilibrium with each other is one way to approach that problem. Q: In your talk you said Mars would come into the habitable zone in about 2 billion years, but it looks like Mars was habitable maybe 3-and-a-half or 4 billion years ago. That suggests that the habitable zone could go out beyond 1.5 AU--the sun was about 25 percent less bright 4 billion years ago, so Mars then would've been at the equivalent distance of about 1.8 AU. Maybe TPF should be looking for wider habitable zones. Planets further out are also easier to see from an angular separation standpoint. A: Although, as far as detectability is concerned, at the outer edge of the habitable zone, the planets are getting fainter as you move them away from the star. So angularly the planets will be easy to see, but as far as fractional brightness goes, they will quickly become invisible. Q: For binary stars, has anyone looked at the effects on the habitable zone of the luminosity of the more distant star? A: You not only worry about that, but the radiation field is varying chaotically, because you've got the planet going around its main star and the second star also going around that main star. So the radiation field is constantly changing in a way that is not regular. When I was choosing my Habstars, I threw out those that experienced a radiation field change of more than 3 percent. But that's pretty conservative--I think 3 percent is not going to destroy all detectable life on a planet. I'm not quite sure where to draw that line, but I think we can draw it more generously than where I've drawn it, in which case it's the dynamical stability that's the big concern. Q: Have you looked at going to shorter wavelengths to resolve planets closer to their host stars? A: The big problem at shorter wavelengths is the Earth becomes pitch black, because the ozone layer absorbs everything. So the planet becomes invisible. Also, at shorter wavelengths you have fewer photons to work with, since sun-like stars emit less shorter wavelength light, and the planet itself is only reflecting that light. Q: Will SIM and Kepler influence the selection of targets for TPF? A: Kepler will give us some idea of how many stars we have to look at in order to have some hope of finding a terrestrial planet. If, in observing thousands of stars, Kepler finds that only one out of a hundred stars has a terrestrial planet, then we're going to be in trouble with a TPF core target list of only 35 stars, and we will have to rethink the mission. The final target list for TPF will probably depend on what SIM finds as well. If SIM is not downscaled, and retains the full capability that is currently envisioned, then that mission will be able to put limits on the presence of planets more than a few Earth-masses located 1 or 2 AU from the star. This will be extremely helpful for choosing TPF targets. Read the original article at http://www.astrobio.net/news/article1538.html. __________________________________________________________________________ SETI INSTITUTE SCIENCE DAY SETI Institute release 26 April 2005 The SETI Institute invites you to our 2nd Annual Science Day! A day of lectures featuring scientists and educators from: The Center for the Study of Life in the Universe, The Center for SETI Research, and Education and Public Outreach. Date: Saturday 14 May 2005 Time: 11:00 AM - 3:00 PM Place: NASA Ames Research Center, Public Affairs Building (building 943), Eagle Room Moffett Field, Mountain View, CA 94043 (No badging is necessary as this building is outside the main gate). Refreshments will be served. Admission is free and open to the public. Space is limited. To reserve your seat, please RSVP at http://www.seti.org/scienceday2.htm. __________________________________________________________________________ CASSINI UPDATES NASA/JPL releases Organic Materials Spotted High Above Titan's Surface NASA/JPL release 2005-062, 25 April 2005 During its closest flyby of Saturn's moon Titan on April 16, the Cassini spacecraft came within 1,027 kilometers (638 miles) of the moon's surface and found that the outer layer of the thick, hazy atmosphere is brimming with complex hydrocarbons. Scientists believe that Titan's atmosphere may be a laboratory for studying the organic chemistry that preceded life and provided the building blocks for life on Earth. The role of the upper atmosphere in this organic "factory" of hydrocarbons is very intriguing to scientists, especially given the large number of different hydrocarbons detected by Cassini during the flyby. Cassini's ion and neutral mass spectrometer detects charged and neutral particles in the atmosphere. It provides scientists with valuable information from which to infer the structure, dynamics and history of Titan's atmosphere. Complex mixtures of hydrocarbons and carbon-nitrogen compounds were seen throughout the range of masses measured by the Cassini ion and neutral mass spectrometer instrument. "We are beginning to appreciate the role of the upper atmosphere in the complex carbon cycle that occurs on Titan," said Dr. Hunter Waite, principal investigator of the Cassini ion and neutral mass spectrometer and professor at the University of Michigan, Ann Arbor. "Ultimately, this information from the Saturn system will help us determine the origins of organic matter within the entire solar system." Hydrocarbons containing as many as seven carbon atoms were observed, as well as nitrogen-containing hydrocarbons (nitriles). Titan's atmosphere is composed primarily of nitrogen, followed by methane, the simplest hydrocarbon. The nitrogen and methane are expected to form complex hydrocarbons in a process induced by sunlight or energetic particles from Saturn's magnetosphere. However, it is surprising to find the plethora of complex hydrocarbon molecules in the upper reaches of the atmosphere. Titan is very cold, and complex hydrocarbons would be expected to condense and rain down to the surface. "Biology on Earth is the primary source of organic production we are familiar with, but the key question is: what is the ultimate source of the organics in the solar system?" added Waite. Interstellar clouds produce abundant quantities of organics, which are best viewed as the dust and grains incorporated in comets. This material may have been the source of early organic compounds on Earth from which life formed. Atmospheres of planets and their satellites in the outer solar system, while containing methane and molecular nitrogen, are largely devoid of oxygen. In this non-oxidizing environment under the action of ultraviolet light from the Sun or energetic particle radiation (from Saturn's magnetosphere in this case), these atmospheres can also produce large quantities of organics, and Titan is the prime example in our solar system. This same process is a possible pathway for formation of complex hydrocarbons on early Earth. This was Cassini's sixth flyby of Titan, but its exploration has just begun. Thirty-nine more flybys of this strange, remote world are planned during Cassini's nominal mission. The next Titan flyby is August 22. The latest images from the Titan flyby are available at http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini. Cassini Finds Particles near Saturn's Moon Enceladus NASA/JPL release 2005-063, 26 April 2005 The Cassini spacecraft has discovered intriguing dust particles around Saturn's moon Enceladus. The particles might indicate the existence of a dust cloud around Enceladus, or they may have originated from Saturn's outermost ring, the E-ring. "We are making measurements in the plane of the E-ring," said Dr. Thanasis Economou, a senior scientist at the University of Chicago's Enrico Fermi Institute. Economou is the lead researcher on the high rate detector, part of a larger instrument on Cassini called the cosmic dust analyzer. "It will take a few more flybys to distinguish if the dust flux is originating from the E-ring as opposed to a source at Enceladus." Enceladus is rapidly becoming a very interesting target for Cassini. So much so that scientists and engineers are planning to revise the altitude of the next flyby to get a closer look. Additional Cassini encounters with Enceladus are scheduled for July 14, 2005, and March 12, 2008. The July 14 flyby was to be at an altitude of 1,000 kilometers (620 miles), but the mission team now plans to lower that altitude to about 175 kilometers (109 miles). This will be Cassini's lowest-altitude flyby of any object during its nominal four-year tour. Earlier this year Cassini completed two flybys of Enceladus. On February 17, Cassini encountered Enceladus at an altitude of 1,167 kilometers (725 miles). On that date, the cosmic dust analyzer with its high rate detector recorded thousands of particle hits during a period of 38 minutes. Cassini executed another flyby of Enceladus on March 9 at an altitude of 500 kilometers (310 miles). "Again we observed a stream of dust particles," said Economou. The largest particles detected measure no more than the diameter of a human hair--too small to pose any danger to Cassini. Scientists have speculated that Enceladus is the source of Saturn's E ring, the planet's widest, stretching 302,557 kilometers (188,000 miles). It's possible, the scientists say, that tidal interactions between Enceladus and Mimas, two other moons of Saturn, have heated Enceladus' interior causing water volcanism. "These measurements are extremely important in order to understand the role of Enceladus as the source of the water ice particles in the E ring," said Dr. Ralf Srama, of the Max Planck Institute for Nuclear Physics, Heidelberg, Germany. Srama is principal investigator of the cosmic dust analyzer science team. This study requires precise measurements of dust densities near the Enceladus region, "but without the high rate detector this would not be possible," said Srama. Another of Cassini's instruments, the magnetometer, recently discovered water ions which could be part of a very thin atmosphere around Enceladus. Enceladus is a relatively small moon. The amount of gravity it exerts is not enough to hold an atmosphere very long. Therefore a strong, continuous source is required to maintain the atmosphere. Enceladus measures 500 kilometers (310 miles) in diameter and reflects nearly 100 percent of the light that hits its ice-covered surface. It orbits Saturn at a distance of approximately 237,378 kilometers (147,500 miles), about two-thirds the distance from Earth to the moon. The cosmic dust analyzer provides direct observations of small ice or dust particles in the Saturn system in order to investigate their physical, chemical and dynamical properties. It is made up of two detectors. The University of Chicago built the high rate detector, which made these observations. With further analysis, the cosmic dust analyzer might be able to determine whether the particles are made of ice or dust. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Science Mission Directorate, Washington, DC. Contacts: Carolina Martinez Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-9382 Steve Koppes University of Chicago News Office Phone: 773-702-8366 http://www.astrobio.net/news/article1524.html http://www.astrobio.net/news/article1537.html http://www.spacedaily.com/news/cassini-05zn.html http://www.spacedaily.com/news/cassini-05zo.html http://www.spacedaily.com/news/cassini-05zp.html http://spaceflightnow.com/cassini/050422titan.html http://www.universetoday.com/am/publish/false_colour_titan_april16.html http://www.universetoday.com/am/publish/hydrocarbons_titan_atmosphere.html __________________________________________________________________________ NASA ANNOUNCES KEY GENESIS SCIENCE COLLECTORS IN EXCELLENT SHAPE NASA release 05-102 20 April 2005 Scientists have closely examined four Genesis spacecraft collectors, vital to the mission's top science objective, and found them in excellent shape, despite the spacecraft's hard landing last year. Scientists at NASA's Johnson Space Center (JSC) in Houston removed the four solar-wind collectors from an instrument called the concentrator. The concentrator targets collected solar-oxygen ions during the Genesis mission. Scientists will analyze them to measure solar-oxygen isotopic composition, the highest-priority measurement objective for Genesis. The data may hold clues to increase understanding about how the solar system formed. "Taking these concentrator targets out of their flight holders and getting our first visual inspection of them is very important," said Karen McNamara, Genesis curation recovery lead. "This step is critical to moving forward with the primary science Genesis was intended to achieve. All indications are the targets are in excellent condition. Now we will have the opportunity to show that quantitatively. The preliminary assessment of these materials is the first step to their allocation and measurement of the composition of the solar wind," she said. The targets were removed at JSC by a team from Los Alamos National Laboratory, Los Alamos, NM, where the concentrator was designed and built. "Finding these concentrator targets in excellent condition after the Genesis crash was a real miracle," said Roger Wiens, principal investigator for the Los Alamos instruments. "It raised our spirits a huge amount the day after the impact. With the removal of the concentrator targets this week, we are getting closer to learning what these targets will tell us about the sun and our solar system," he added. The Los Alamos team was assisted by JSC curators and Quality Assurance personnel from NASA's Jet Propulsion Laboratory in Pasadena, CA. Curators at JSC will examine the targets and prepare a detailed report about their condition, so scientists can properly analyze the collectors. The targets will be imaged in detail and then stored under nitrogen in the Genesis clean room. Genesis was launched August 8, 2001, from Cape Canaveral Air Force Station, FL, on a mission to collect solar wind particles. Sample collection began December 5, 2001, and was completed April 1, 2004. After an extensive recovery effort, following its September 8, 2004, impact at a Utah landing site, the first scientific samples from Genesis arrived at JSC October 4, 2004. Still imagery of scientists removing the concentrator targets is available at http://www.nasa.gov/mission_pages/genesis/multimedia/gen_team_images.html. For more information about the Genesis mission on the Web, visit http://www.nasa.gov/genesis. Contacts: Dolores Beasley NASA Headquarters, Washington, DC Phone: 202-358-1753 William Jeffs NASA Johnson Space Center, Houston, TX Phone: 281-483-5111 Nancy Ambrosiano Los Alamos National Laboratory, NM Phone: 505-667-0471 Additional articles on this subject are available at: http://www.spacedaily.com/news/genesis-05b.html http://www.spacedaily.com/news/genesis-05c.html http://www.universetoday.com/am/publish/genesis_recovery_well.html __________________________________________________________________________ MER MOVIE CLIP SHOWS WHIRLWINDS CARRYING DUST ON MARS NASA/JPL image advisory 2005-061 21 April 2005 NASA's Mars Exploration Rover Spirit is taking movies of dust devils-- whirlwinds carrying dust--scooting across a plain on Mars. Clips consisting of a few frames of two different dust devils are available online at http://www.nasa.gov/vision/universe/solarsystem/mer_main.html and http://marsrovers.jpl.nasa.gov. These were taken on April 15 and April 18, and capture more movement as seen from the surface than any previous imaging of martian dust devils. "This is the best look we've ever gotten of the wind effects on the martian surface as they are happening," said Dr. Mark Lemmon, a rover team member and atmospheric scientist at Texas A&M University, College Station. Spirit, operated from NASA's Jet Propulsion Laboratory in Pasadena, CA, has been using its navigation camera to routinely check for dust devils. It began seeing dust devils last month in individual frames from the camera. Lemmon said, "We're hoping to learn about how dust is kicked up into the atmosphere and how the wind is interacting with the surface. It's exciting that we now have a systematic way of capturing dust devils in movies rather than isolated still images." Spirit and its twin, Opportunity, successfully completed three-month primary missions in April, 2004, and have been exploring at increasing distances from their landing sites since then. JPL, a division of the California Institute of Technology in Pasadena, manages NASA's Mars Exploration Rover project for NASA's Science Mission Directorate, Washington, DC. Contacts: Guy Webster Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-6278 Dolores Beasley NASA Headquarters, Washington, DC Phone: 202-358-1753 Additional articles on this subject are available at: http://www.astrobio.net/news/article1533.html http://www.marsdaily.com/news/mars-mers-05zm.html http://www.marsdaily.com/news/mars-mers-05zo.html http://www.spacedaily.com/news/mars-mers-05zn.html http://www.universetoday.com/am/publish/spirit_bedrock_columbia.html __________________________________________________________________________ MARS EXPRESS: THE MESAS OF AUREUM CHAOS ESA release 22 April 2005 These images, taken by the High Resolution Stereo Camera (HRSC) on board ESA's Mars Express spacecraft, show the "chaotic" terrain of the Aureum Chaos region on Mars. The HRSC obtained these images during orbit 456 with a resolution of approximately 25 meters per pixel. The scenes show an area located at about 3º South and 335º East. Aureum Chaos is located in the eastern part of Valles Marineris, south- west of the 280 kilometer-wide impact crater Aram Chaos. Like this impact basin, both regions are two examples of the chaotic terrain contained in this part of the Valles Marineris. As the name "chaos" suggests, this terrain is characterized by randomly oriented, large-scale mesas and knobs that are heavily eroded and dominate the area. As seen in the main color image, these mesas range from a few kilometers to tens of kilometers wide. In the north (right-hand side) of this image, a well-defined scarp extends in an east-west direction. "Slump and collapse" blocks can be distinguished at the base of this scarp, as highlighted in this close-up perspective view. Near the southern border (middle left-hand side) of the color image, a roughly five kilometer-wide region of bright material is observed. This material appears to form distinct layers that may have been created by the evaporation of fluids or by hydrothermal activity (see lower right-hand corner of the perspective view below). Another interesting region of bright material also extends north to south in the centre of the color image and is also visible along the left side of this perspective view. The history of Aureum Chaos is complex. It appears that this basin was filled with sediment and then experienced the formation of chaotic terrain. It is thought that this extremely rough terrain is caused by collapse of the surface due to the removal of subsurface ice, magma or water. By supplying new image data for Aureum Chaos, the HRSC allows scientists to improve their understanding of Mars. In particular, the color and stereo capability of the HRSC allows improved studies of the planet's morphology (the evolution of rocks and landforms). By analyzing reflected light at different wavelengths, we can determine minerals that make up the various geological features within the scene. Data from the HRSC, coupled with information from the other instruments on ESA's Mars Express and other missions, will provide new insights into the geological evolution of the Red Planet and also pave the way for future missions. The color images were processed using the HRSC nadir (vertical view) and three color channels. The perspective views were calculated from the digital terrain model derived from the stereo channels. The 3D anaglyph image was created from the nadir channel and one of the stereo channels. Stereoscopic glasses are needed to view the 3D image. Image resolution has been decreased for use on the internet. Read the original news release at http://www.esa.int/SPECIALS/Mars_Express/SEMF19NQS7E_0.html. Additional articles on this subject are available at: http://www.marsdaily.com/news/marsexpress-05k.html http://www.space.com/scienceastronomy/050425_mars_chaos.html http://www.universetoday.com/am/publish/aureum_chaos_mars.html __________________________________________________________________________ MARS GLOBAL SURVEYOR IMAGES NASA/JPL/MSSS release 14-20 April 2005 The following new images taken by the Mars Orbiter Camera (MOC) on the Mars Global Surveyor spacecraft are now available. Polygons in Utopia (Released 14 April 2005) http://www.msss.com/mars_images/moc/2005/04/14/ Gale Sedimentary Rocks (Released 15 April 2005) http://www.msss.com/mars_images/moc/2005/04/15/ East Tharsis Flows (Released 16 April 2005) http://www.msss.com/mars_images/moc/2005/04/16/ Valley Near Moreux (Released 17 April 2005) http://www.msss.com/mars_images/moc/2005/04/17/ Fretted Terrain Mass Movement (Released 18 April 2005) http://www.msss.com/mars_images/moc/2005/04/18/ Mars at Ls 193 Degrees (Released 19 April 2005) http://www.msss.com/mars_images/moc/2005/04/19/ Fractured Ground (Released 20 April 2005) http://www.msss.com/mars_images/moc/2005/04/20/ All of the Mars Global Surveyor images are archived here at http://www.msss.com/mars_images/moc/index.html. Mars Global Surveyor was launched in November 1996 and has been in Mars orbit since September 1997. It began its primary mapping mission on March 8, 1999. Mars Global Surveyor is the first mission in a long-term program of Mars exploration known as the Mars Surveyor Program that is managed by JPL for NASA's Office of Space Science, Washington, DC. Malin Space Science Systems (MSSS) and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. __________________________________________________________________________ MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 18-22 April 2005 Kasei Vallis Topography (Released 18 April 2005) http://themis.la.asu.edu/zoom-20050418a.html Kasei Vallis Erosion (Released 19 April 2005) http://themis.la.asu.edu/zoom-20050419a.html Kasei Vallis Channel Splitting (Released 20 April 2005) http://themis.la.asu.edu/zoom-20050420a.html Multidepth Channels (Released 21 April 2005) http://themis.la.asu.edu/zoom-20050421a.html Kasei Vallis Mosaic (Released 22 April 2005) http://themis.la.asu.edu/zoom-20050422A.html All of the THEMIS images are archived at http://themis.la.asu.edu/latest.html. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, DC. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. __________________________________________________________________________ ROSETTA: FIRST IN-FLIGHT TEST OF NEAR SUN HIBERNATION MODE (REPORT FOR PERIOD 8-22 APRIL 2005) ESA release 25 April 2005 The main activity in the reporting period was the successful first in- flight test of the Near Sun Hibernation Mode (NSHM), during which the spacecraft spent five days in this special low activity mode, with attitude controlled via Star Tracker and thrusters only (gyroscopes and reaction wheels are inactive). The NSHM test started on 11 April and ended on 15 April, with a transition back into the normal GSEP attitude control mode. During the five days of test daily monitoring of the spacecraft performance confirmed the attitude control worked as expected. This test validated the NSHM approach that will be applied in the next few weeks for a full scale commissioning of the mode. On 19 April a pass was dedicated to a MIDAS health check, following the commanding problems that occurred during the Passive Checkout (see report #39). The result of the activity was the confirmation that MIDAS is fully functional. Taking advantage of this activity, new versions of the MIDAS switch ON and OFF OBCPs (On-Board Control Procedures), modified according to a request by the PI Team, were uploaded and verified. No other payload operations were carried out, with the exception of SREM, which is active continuously for radiation monitoring. A total of 10 New Norcia passes of a fixed duration of 7 hours commanding were taken at three passes per week. In one case, on 21 April, the pass duration was reduced to less than 3 hours to cover an unplanned support request by SMART-1. At the end of the last New Norcia pass in the reporting period (DOY 112) Rosetta was at 16.02 million km from the Earth. The one-way signal travel time was 53.4 seconds. Read the original news release at http://sci.esa.int/science- e/www/object/index.cfm?fobjectid=37015. __________________________________________________________________________ End Marsbugs, Volume 12, Number 15.