Editor/Publisher Page 7 BUILD YOUR OWN BORG: SORT OF Page...

Marsbugs: The Electronic Astrobiology Newsletter Volume 11, Number 45, 6 December 2004 Editor/Publisher: David J. Thomas, Ph.D., Science Division, Lyon College, Batesville, Arkansas 72503-2317, USA. [email protected]

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 author(s) 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 Page 1 THE GULLIES OF MARS: WET OR DRY?

By Larry Klaes Page 2 MOON MARS FUNDING PASSES

Mars Society release Page 2 METHANE CONFIRMED ON MARS—IS LIFE THE

CAUSE? Mars Society release

Page 2 FUTURE ROBOTS MAY "HOP" ACROSS MARS

By Fraser Cain Page 2 MARTIAN RETROSPECTIVE

From Astrobiology Magazine Page 4 YOUNG STARS POISED FOR PRODUCTION OF ROCKY

PLANETS European Southern Observatory release

Page 5 ARTIFICIAL GRAVITY: A NEW SPIN ON AN OLD IDEA

By Leonard David Page 5 DID OUR SUN CAPTURE ALIEN WORLDS?

By Jill Johnston West Page 6 WHAT DO YOU SAY TO AN EXTRATERRESTRIAL?

By Seth Shostak Page 6 HELLO, HELLO, EARTH?

University of Michigan release Page 7 VOLCANOES SNUFFED OUT MOST LIFE 250 MILLION

YEARS AGO By Robert Roy Britt

Page 7 BUILD YOUR OWN BORG: SORT OF From Astrobiology Magazine

Page 8 THE MARTIAN METHANE SURPRISE—INTERVIEW

WITH MIKE MUMMA By Leslie Mullen

Announcements Page 10 MARS TERRAFORMING CLASSIC NOW AVAILABLE ON

INTERNET Mars Society release

Mission Reports Page 10 CASSINI-HUYGENS UPDATES

NASA/JPL releases Page 14 DEEP IMPACT DELAY

NASA/KSC release Page 14 REPORTS DETAIL ROVER DISCOVERIES OF WET

MARTIAN HISTORY NASA/JPL release 2004-280

Page 15 MARS EXPRESS: CRATER HALE IN ARGYRE BASIN

ESA release Page 16 MARS GLOBAL SURVEYOR IMAGES

NASA/JPL/MSSS release Page 16 MARS ODYSSEY THEMIS IMAGES

NASA/JPL/ASU release Page 17 ADVANCING THE WEBB

Based on Grumman report

THE GULLIES OF MARS: WET OR DRY? By Larry Klaes From The Ithaca Times 3 November 2004 Over a century ago, some astronomers thought that numerous straight lines seen all over the planet Mars were giant artificial canals, carrying water from the poles to large cities. Percival Lowell, the recognized leader of this theory, was certain that an ancient and wise civilization of Martians had built these vast waterways to hold off their eventual extinction as the planet slowly dried up. The first robot probes from Earth began arriving on Mars in the 1960s, sending back close up and detailed images of the Red Planet's surface. These early explorers proved that the "canals" seen by astronomers decades before were just optical illusions caused by viewing Mars from millions of miles away through Earth's thick and blurring atmosphere. The returned data also showed that the Red Planet could not have been home to anything much higher on the biological ladder than very hardy microbes, if at all. Mars, being half the size of Earth and twice as far as our world from the Sun, was discovered to be a very cold and very dry place, with an atmosphere no

thicker than what is found 20 miles above the surface of our planet. Other findings from those space probes left open the possibility that Mars might have been much warmer and wetter a long time ago. Huge canyons and long flowing channels covered the planet. Some areas even looked like the remnant shores of ancient seas or oceans of water. The Mars Exploration Rovers (MER), using geological technology designed by Cornell University, recently proved that, at least in the two landing areas, bodies of water existed there in the distant past. Some of the data from the three unmanned satellites currently orbiting Mars have delivered evidence that the Red Planet might not be quite as dry as originally perceived. Vast reserves of water ice may dwell not far below the planet's otherwise dusty surface in this present day. In 2000, NASA released images of Mars which showed what appeared to be gullies streaming down the sides of canyons and craters. Were these features on Earth, most geologists would automatically assume they were created by flowing water. But this is Mars, where the temperature averages 50 degrees below zero Celsius and the air pressure at the surface hovers between seven and 10 millibars (by comparison, Earth's surface air pressure averages 1,013 millibars). By all accounts, water could not last in liquid form under such conditions. So what did create these intriguing slices into the martian skin?

Marsbugs: The Electronic Astrobiology Newsletter, Volume 11, Number 45, 6 December 2004 2

The dry look This was the topic of a seminar held at Cornell's Upson Hall on October 26 titled "Are Martian Gullies Generated by Granular Flows?" by Dr. Troy Shinbrot of Rutgers University. An Associate Professor of Biomedical Engineering at the New Jersey institution, Shinbrot's regular area of study is how various pharmaceutical products flow and interact with each other. At a conference he co-organized with Cornell Professor Michel Louge in 2002, Shinbrot was discussing the "beautiful pictures" he saw of the martian gullies. To Shinbrot, these surface features looked like they were made by the sandy particles themselves moving down the sides of banks, canyons, and craters, and not by liquid water. In addition to the bitterly cold temperatures and thin atmosphere already discussed, Shinbrot also pointed out that most of the martian gullies "faced poleward," away from the feeble though not insignificant warmth of the Sun. They also seem very young in geological terms, created perhaps only 10,000 years ago or less. There are no visible craters and no detectable boulders or rocks sitting in deposits at the bottom of these gullies, the usual clues to determining advanced age on planetary surfaces. The slopes they flow from are also quite steep. From his previous granular flow research, Shinbrot knew that very light particles in a lower gravity environment act like a liquid before they eventually settle together to behave as regular solids. What this may mean The idea of the Red Planet's gullies being formed by water through various means or even other processes such as underground heat or even certain gases like carbon dioxide has certainly not been ruled out. However, Shinbrot's granular flow research has given planetary scientists something new to consider when dealing with alien worlds. Read the original article at http://www.zwire.com/site/news.cfm?newsid=13282379&BRD=1395&PAG=461&dept_id=546876&rfi=6. MOON MARS FUNDING PASSES Mars Society release 23 November 2004 Early Saturday morning, a House-Senate conference committee agreed to fully fund $16.2 billion for NASA's FY05 budget. This is the full amount that President Bush had requested to fund shuttle return to flight, ISS resupply, and seed money for the Crew Exploration Vehicle, Project Prometheus and initial spending for the Moon-Mars Space Exploration Vision! In July 2004, The Mars Society, along with members of the Space Exploration Alliance, participated in the Moon-Mars Blitz with the sole purpose of getting the initial funding for the Space Exploration Initiative. At The Mars Society 2004 Conference in Chicago, over 468 letters were sent out by members urging the President and Congress to pass the initial funding. Thank you to all who helped in this effort! The next step is to assure that the Space Exploration Vision doesn't get moon-stuck. Again, Mars Society members will be asked to visit/write Congress and the President to assure that this doesn't happen. The Political Task Force will have more information and what action is needed when Congress reconvenes in January. Until then, the PTF urges everyone to write or email their Senators and Representative a "thank you for supporting the NASA 05 budget" letter. Information on how to contact Congress is available on the PTF web site at http://home.marssociety.org/outreach/political/usa/. Click on "Making Contact with Congress and the White House". After you have written your letter, please take a minute to report it to the PTF at http://home.marssociety.org/outreach/political/usa/capitolwatch/report.html. METHANE CONFIRMED ON MARS—IS LIFE THE CAUSE? Mars Society release 23 November 2004 Evidence is pouring in confirming earlier findings of trace methane in the martian atmosphere. While geothermal formation of methane is possible, the amounts found are difficult to explain as originating from non-biologic sources. Subsurface microbes are a significant source of methane on Earth,

and liquid groundwater environments capable of supporting such microbes are believed to exist on Mars. If human explorers were to go to Mars, drilling rigs could be set up to reach and sample such groundwater. Examining it could answer the central riddles concerning life: Is life unique to the Earth? If not, is Earth life the pattern for life elsewhere, or are other biochemistries possible? The search for truth in this matter provides a compelling science-driven reason for human space exploration. The confirmation of the methane discovery received major coverage in today's (23 November) New York Times. Read the article at http://www.nytimes.com/2004/11/23/science/space/23mars.html. FUTURE ROBOTS MAY "HOP" ACROSS MARS By Fraser Cain From Universe Today 24 November 2004 Part lander, part aircraft, the gashopper (no, not grasshopper) is a unique concept being considered by NASA for future robotic exploration of Mars. Unlike landers, such as the Viking spacecraft, Beagle 2, or the upcoming Phoenix lander which can only examine a few square meters of ground, the gashopper could land, perform scientific analysis and launch itself back into the air to fly hundreds of kilometers to a new location. The gashopper would get its electricity from a large set of solar panels built on top of its wings. It would use this electricity to retrieve carbon dioxide from the martian atmosphere, and then store it as a liquid inside the aircraft. When enough gas was stored up to make a flight, it would heat up a hot bed of pellets and then pass the CO2 through it. Now hot, the gas would act as a propellant, and allow the gashopper to lift off vertically from the surface of Mars. Once airborne, it could then fire more gas out a rear thruster and begin flying as an airplane, using its large wings for lift and maneuverability. When it was ready to land, the aircraft could slow its airspeed, and then touch down gently as a vertical lander. Read the full article at http://www.universetoday.com/am/publish/mars_gashopper.html. MARTIAN RETROSPECTIVE From Astrobiology Magazine 24 November 2004 Readers of Astrobiology Magazine frequently send in questions regarding stories, but no series has attracted as many inquiries as the progress of the twin rovers, Spirit and Opportunity, on Mars. To be responsive, the questions have been assembled along with paraphrased answers culled from various mission interviews, published reports and images to illustrate the challenges and thrills of exploring our neighboring planet. As the rovers head into the dead of martian winter, activity levels are being scaled down temporarily, so this snapshot of the mission will likely prevail until cold weather breaks in late December.

Rover computer rendering on the edge of a depression, much like Opportunity's perch on the edge of Endurance Crater. Image credit: Dan Maas/NASA/JPL.


Question (Q): How long will the rovers last? Answer (A): A mechanical breakdown can be worked around, things like a stuck wheel. An electronic glitch cannot be planned for. That kind of glitch can happen anytime and also shutdown the rover's dead. There are single points of failure in the electronics. Otherwise the dust buildup on the solar panels is the remaining limit. The rovers are in the dead of winter now, particularly at Gusev from September to December this year. If the rovers survive the winter, then there are simulations that take the rovers out to 600-700 sols. Q: With three successful airbag landings, should that mode be the first choice for future missions? A: There is a mass limit to what airbags can cushion on Mars. If it is not mass-limited on the next lander, then that will likely be near the limit of what [airbags can handle]. Q: What is the chemistry of Opportunity showing? A: The Meridiani plains stood out from orbit as a region the size of Oklahoma that was iron-rich with the often water-formed mineral, hematite. Opportunity found that concentration as predicted. One chemical surprise was very high levels of magnesium sulfates (Epsom salts). At places, the Epsom salts compose 40% by weight, which makes some of the outcrops nearly all salt. That tells a story of water. Q: But how much water and in what forms? A: The particular ratios between bromine/chlorine with layered deposits supports first flowing water, and secondly evaporative pooling. What one sees with flowing water is a feature called cross-bedding in the geology, but the chemistry is mainly that chlorine will appear deeper in a layer than bromine when water evaporates. That is what happens at the Dead Sea on earth for instance.

Left: dunes at the bottom of Endurance crater, Meridiani. Middle: Bounce Rock at Meridiani. Right: First solar eclipse from another planet's surface, Phobos blocks the sun. Image credits: NASA. Q: What is the geology of Opportunity showing? A: Cross-bedding. Flowing water leads to these inclined layers, like "smiley faces" where the sand pushes forward in fits and starts, eventually cementing into layers that are not parallel to each other. Q: What are the ages or epochs when water might have flowed at Opportunity? A: One can only know relative, not absolute ages. One can say where there is intact stratigraphy that the deeper material is older than the top layers. If one knew the annual cycles, one might estimate some age like tree rings of growth or sediments in a canyon, but there is no way to calibrate that cycle on Mars. So no one really has any idea of absolute ages. To get absolute ages, a sample return is needed (probably for isotope studies on sulfur or other elements). Q: What was the uniqueness of landing in a crater (Eagle) at the Opportunity site? A: Being 20 or so feet from bedrock on the lip of the crater. Not having to drive all across the plains to find intact stratigraphy. Q: What are the blueberries? A: They are thought to be concretions, or where briny water percolates through a softer rock and buds up from a nucleus into these tiny balls. These are actually smaller than blueberries you might find in a muffin, but they

generally populate rock cracks and voids. As the soft rock weathers, the harder blueberries fall out and roll down a slope or are blown across the plains.

Left: concretions, or blueberries at Meridiani. Middle:sStriped blueberry with band aligned to rock cracks. Right: Pot of Gold under microscopic examination. Image credits: NASA/JPL. Q: Are there different shapes to the blueberries? A: There are the round ones, mainly. But there are also twins, where a budding concretion comes out of another blueberry. And then there are striped ones, marked with a division like a croquet ball. The strip always runs parallel to the lines of the underlying crack where the blueberry is budding out from. Q: What was unique about Bounce rock? A: That is the only rock of any size on the Meridiani plains, perhaps for kilometers in the otherwise flat area as far as the cameras can see. It was called Bounce rock because the rover's airbags hit it and changed direction to land in Eagle crater. The chemistry of Bounce is a near perfect overlay of the chemistry of one Mars meteorite picked up previously in Antarctica, so we went to Mars and found as expected, a Mars rock. Q: What is the chemistry of the opposite side of the planet at Gusev Crater showing? A: Basaltic lava fields ground to dust and blown by wind. Q: What is the geology of Gusev showing? A: Much smoother rocks with no layering. Blocks of basalts, high in olivine, which is easily decomposed if water were around. That is one mineralogical clue that water has not been as abundant at Gusev as Meridiani. Q: Are the plains the same as the hills? A: The hills are much older than the plains. The hills stand out as an island where the surrounding crater has eroded away from. One surprise is that the uniformly basaltic soil changes abruptly as one crosses a sharp boundary at the skirt of Columbia Hills. Maybe twenty feet can separate the lava fields from older outcrops and bedrock. Q: Has hematite been found at Gusev, like Opportunity? A: Not in the plains, which are nearly completely lava fields ground down to very fine dust. Near Columbia Hills, particularly the Pot of Gold rock at the base of the hills, those areas have hematite in the odd tendrils and spherical tops. This rock—Pot of Gold—is about the size of a potato with toothpick-like stems and jelly-bean-like protrusions at all angles. Q: Does the stuck wheel on Spirit have anything to do with the trenching procedure? Five wheels are locked and the sixth wheel digs down about half a foot into the soil. A: No. Trenching is done with the front left wheel, while the stuck wheel is the front right. Spirit is now backing up Columbia Hills to compensate for the stuck wheel that is showing higher than expected currents, and thus needs lubrication. Q: What does trenching show about Gusev? A: Nearer to Columbia Hills, one trench showed that beneath the basaltic top layer, about 5 cm, was a very rich Epsom salt layer. This is about 10-15% magnesium sulfate. Unlike Opportunity's site, where water may have flowed, this Epsom salt layer is probably percolated through soil by capillary action,


and then the water evaporates. Gusev may have been moist at one time, but not drenched like Meridiani. Q: Can the rovers look up in the sky and pick off the spectrum of methane, which seems to be observed from orbit by Mars Express and may be attributed to some decaying matter? A: No. The rovers would need about five times greater resolution to see methane in the atmospheric spectrum. Q: What non-science images have been impressive? A: The first solar eclipse seen from the surface of another planet; the first meteor seen streaking across the sky of another planet; seeing Earth from Mars as a tiny dot. Those three images come to the top of the non-science list. The non-engineering image list is probably spare parts from the rover's descent, like the backshell, parachute and heat shield. And of course the landing pod itself is interesting when viewed looking back from the mobile rover. Q: It was estimated before the mission that one day in three might be wasted logistically, and require some science re-doing. What has the actual ratio of unproductive-to-productive days on the surface? A: About ten times better than the initial estimate. Only one sol in thirty has really been unproductive or required repeating. That is outside of when the Spirit firmware problem (sol 18) arose, which took the Spirit rover down to troubleshoot for about ten days straight. Q: What lines of evidence contribute overall to the story of martian water? A: First is the chemistry: hematite, salts, particularly the evaporative deposition of chlorine in deeper layers than bromine, which matches what one sees at the Dead Sea for instance. This happens because chlorine is less soluble than bromine, and so during evaporation, the bromine will deposit last (on top). Secondly the geology and imagery shows evidence for cross-bedding, round balls or concretions, layering sedimentary rocks, and also newer evidence of polygonal cracking that may indicate freeze-thaw cycles that contract the deposits. The rovers were designed to look at the geology and chemistry together and that has delivered the story of water history on Mars. Q: How much more efficient is a trained geologist compared to a robotic one? A: The rover team did a field test on Earth with an early model called FIDO. When trained geologists walked into the terrain, they could accomplish in ten minutes what it would take a day for a rover to do. The basic tasks like finding an interesting rock, breaking it open, and examining it under a geologist's microscope. That man vs. machine comparison is excluding the specialized instruments, since a field investigator doesn't have a pocket Mossbauer spectrometer typically in the field, which these rovers do have. But the robots are much cheaper in this harsh environment. Q: What are the four items on the next rover's wish list, such as instruments or capabilities that were missing from the rover design? A: A non-solar power source, more download bandwidth, more on-board navigational autonomy, and a Raman spectrometer. That latter is to cover a spectral band in the infrared that is not covered today by the thermal imagery (mini-TES) of rock and soil temperatures from the cameras. Q: What is the bandwidth problem about? A: The pancams can pump out far more data (ten to twenty times) what can actually be downloaded to Earth. The mission planners have had to select the pictures that they think offer the most reward for the bandwidth costs. Q: Aren't there satellites overhead to store and transmit more images? A: The mission team gets 100-200 megabits from the satellite constellation (Surveyor, Odyssey and to some extent, Express). But they are fundamentally science orbiters. They fly circular orbits to map as close to the surface as possible. So from the rover viewpoint, the satellites fly over once a day for 15 minutes. What would help the download problem is a high orbit that is stationary overhead for long periods.

Q: How has it been living and working on Mars' time? A: Mars' days are 39 minutes longer than the terrestrial 24 hours. So during the first four months, everyone—both engineers and scientists—lived on a rotating day. It was tolerable for the science team which was largely away from family and normal home lives. Most of them slept with blacked out windows and did not have to go to PTA meetings or drive children to school. For the engineers, most of whom were living at home in Pasedena, those four months were difficult. That is why on September first, the mission went to distributed science. So the Cornell team will run their operations from Ithaca, NY, not Pasadena. Read the original article at http://www.astrobio.net/news/article1314.html. YOUNG STARS POISED FOR PRODUCTION OF ROCKY PLANETS European Southern Observatory [1] release 24 November 2004 The Sun was born about 4,500 million years ago from a cold and massive cloud of interstellar gas and dust that collapsed under its own gravitational pull. A dusty disc was present around the young star, in which the Earth and other planets, as well as comets and asteroids were later formed. This epoch is long gone, but we may still witness that same process by observing the infrared emission from very young stars and the dusty protoplanetary discs around them. So far, however, the available instrumentation did not allow a study of the distribution of the different components of the dust in such discs; even the closest known are too far away for the best single telescopes to resolve them. But now, as Francesco Paresce, Project Scientist for the VLT Interferometer and a member of the team from ESO explains, "With the VLTI we can combine the light from two well-separated large telescopes to obtain unprecedented angular resolution. This has allowed us, for the first time, to peer directly into the innermost region of the discs around some nearby young stars, right in the place where we expect planets like our Earth are forming or will soon form". Specifically, new interferometric observations of three young stars by an international team [2], using the combined power of two 8.2 m VLT telescopes a hundred meters apart, has achieved sufficient image sharpness (about 0.02 arcsec) to measure the infrared emission from the inner region of the discs around three stars (corresponding approximately to the size of the Earth's orbit around the Sun) and the emission from the outer part of those discs. The corresponding infrared spectra have provided crucial information about the chemical composition of the dust in the discs and also about the average grain size. These trailblazing observations show that the inner part of the discs is very rich in crystalline silicate grains ("sand") with an average diameter of about 0.001 mm. They are formed by coagulation of much smaller, amorphous dust grains that were omnipresent in the interstellar cloud that gave birth to the stars and their discs. Model calculations show that crystalline grains should be abundantly present in the inner part of the disc at the time of formation of the Earth. In fact, the meteorites in our own solar system are mainly composed of this kind of silicate. Dutch astronomer Rens Waters, a member of the team from the Astronomical Institute of University of Amsterdam, is enthusiastic: "With all the ingredients in place and the formation of larger grains from dust already started, the formation of bigger and bigger chunks of stone and, finally, Earth-like planets from these discs is almost unavoidable!" Transforming the grains It has been known for some time that most of the dust in discs around newborn stars is made up of silicates. In the natal cloud this dust is amorphous, i.e., the atoms and molecules that make up a dust grain are put together in a chaotic way, and the grains are fluffy and very small, typically about 0.0001 mm in size. However, near the young star where the temperature and density are highest, the dust particles in the circumstellar disc tend to stick together so that the grains become larger. Moreover, the dust is heated by stellar radiation and this causes the molecules in the grains to re-arrange themselves in geometric (crystalline) patterns. Accordingly, the dust in the disc regions that are closest to the star is soon transformed from "pristine" (small and amorphous) to "processed" (larger and crystalline) grains.


VLTI observations Spectral observations of silicate grains in the mid-infrared wavelength region (around 10 µm) will tell whether they are "pristine" or "processed". Earlier observations of discs around young stars have shown a mixture of pristine and processed material to be present, but it was so far impossible to tell where the different grains resided in the disc. Thanks to a hundred-fold increase in angular resolution with the VLTI and the highly sensitive MIDI instrument, detailed infrared spectra of the various regions of the protoplanetary discs around three newborn stars, only a few million years old, now show that the dust close to the star is much more processed than the dust in the outer disc regions. In two stars (HD 144432 and HD 163296) the dust in the inner disc is fairly processed whereas the dust in the outer disc is nearly pristine. In the third star (HD 142527) the dust is processed in the entire disc. In the central region of this disc, it is extremely processed, consistent with completely crystalline dust. An important conclusion from the VLTI observations is therefore that the building blocks for Earth-like planets are present in circumstellar discs from the very start. This is of great importance as it indicates that planets of the terrestrial (rocky) type like the Earth are most probably quite common in planetary systems, also outside the solar system. The pristine comets The present observations also have implications for the study of comets. Some—perhaps all—comets in the solar system do contain both pristine (amorphous) and processed (crystalline) dust. Comets were definitely formed at large distances from the Sun, in the outer regions of the solar system where it has always been very cold. It is therefore not clear how processed dust grains may end up in comets. In one theory, processed dust is transported outwards from the young Sun by turbulence in the rather dense circumsolar disc. Other theories claim that the processed dust in comets was produced locally in the cold regions over a much longer time, perhaps by shock waves or lightning bolts in the disc, or by frequent collisions between bigger fragments. The present team of astronomers now concludes that the first theory is the most likely explanation for the presence of processed dust in comets. This also implies that the long-period comets that sometimes visit us from the outer reaches of our solar system are truly pristine bodies, dating back to an era when the Earth and the other planets had not yet been formed. Studies of such comets, especially when performed in situ, will therefore provide direct access to the original material from which the solar system was formed. More information The results reported in this ESO PR are presented in more detail in a research paper "The building blocks of planets within the "terrestrial" region of protoplanetary disks", by Roy van Boekel and co-authors (Nature, November 25, 2004). The observations were made in the course of ESO's early science demonstration program. Notes [1]: This ESO press release is issued in collaboration with the Astronomical Institute of the University of Amsterdam, The Netherlands (NOVA PR) and the Max-Planck-Institut für Astronomie (Heidelberg, Germany (MPG PR). [2]: The team consists of Roy van Boekel, Michiel Min, Rens Waters, Carsten Dominik and Alex de Koter (Astronomical Institute, University of Amsterdam, The Netherlands), Christoph Leinert, Olivier Chesneau, Uwe Graser, Thomas Henning, Rainer Köhler and Frank Przygodda (Max-Planck-Institut für Astronomie, Heidelberg, Germany), Andrea Richichi, Sebastien Morel, Francesco Paresce, Markus Schöller and Markus Wittkowski (ESO), Walter Jaffe and Jeroen de Jong (Leiden Observatory, The Netherlands), Anne Dutrey and Fabien Malbet (Observatoire de Bordeaux, France), Bruno Lopez (Observatoire de la Cote d'Azur, Nice, France), Guy Perrin (LESIA, Observatoire de Paris, France) and Thomas Preibisch (Max-Planck-Institut für Radioastronomie, Bonn, Germany). [3]: The MIDI instrument is the result of collaboration between German, Dutch and French institutes.

Contacts: Michiel Min Astronomical Institute University of Amsterdam The Netherlands Phone: +31-20-525-7476 E-mail: [email protected] Francesco Paresce European Southern Observatory Garching, Germany Phone: +49-89-3200-6297 E-mail: [email protected] Christoph Leinert Max-Planck-Institut für Astronomie Heidelberg, Germany Phone: +49-6221-528264 E-mail: [email protected] Jakob Staude Max-Planck-Institut für Astronomie Heidelberg, Germany Phone: +49-6221-528229 E-mail: [email protected] Additional articles on this subject are available at: http://www.astrobio.net/news/article1320.html http://www.spacedaily.com/news/extrasolar-04zr.html http://www.universetoday.com/am/publish/right_ingredients_rocky_planets.html. ARTIFICIAL GRAVITY: A NEW SPIN ON AN OLD IDEA By Leonard David From Space.com 25 November 2004 Keeping an astronaut crew in tip-top shape during lengthy treks to and from distant Mars may demand portable gravity. There's need for long-duration space travelers to counter such debilitating effects as muscle atrophy, bone loss, cardiovascular deconditioning and balance disorders—effects seen in humans as they cope with stints in microgravity. Over the decades, artificial gravity research has been an on-again, off-again proposition. But in the last few years, and propelled by NASA's new Moon, Mars and beyond exploration mandate, artificial gravity studies are now being developed, this time with a new spin. Read the full article at http://www.space.com/businesstechnology/technology/artificial_gravity_041125.html. DID OUR SUN CAPTURE ALIEN WORLDS? By Jill Johnston West University of Utah release 1 December 2004 Computer simulations show a close encounter with a passing star about 4 billion years ago may have given our solar system its abrupt edge and put small, alien worlds into distant orbits around our sun. The study, which used a supercomputer at NASA's Jet Propulsion Laboratory in Pasadena, CA, was published in the December 2 issue of the journal, Nature, by physicist Ben Bromley of the University of Utah and astronomer Scott Kenyon of the Smithsonian Astrophysical Observatory in Cambridge, MA. Bromley and Kenyon simulated what would have happened if our sun and another star in our Milky Way galaxy had passed a relatively close 14 billion to 19 billion miles from each other a few hundred million years after our solar system formed. At that time, our solar system was a swirling "planetary disk" of gas, dust and rocks, with planets newly formed from the smaller materials. Imagine the encounter of two young solar systems by envisioning two circular saw blades brushing past each other while spinning rapidly. When they make contact, their outer edges are buzzed off by the other saw. But in the case of


planetary disks, colliding rocks at the edges of the solar systems are pulverized into pebbles, causing particles to be flung in all directions. "Any objects way out in the planetary disk would be stirred up greatly," says Bromley, an associate professor of physics at the University of Utah. Bromley and Kenyon conclude the shearing motion and dueling gravity of the passing stars could have done several things: • Taken young planets formed with circular orbits in our solar system and

catapulted them into highly elongated orbits. That may explain the existence of Sedna, a "planetoid" that orbits beyond Pluto and measures between 600 and 1,000 miles wide.

• Created a sharp edge to the solar system by shearing off the outer part of the Kuiper belt, a collection of small, rocky-and-icy objects in space starting beyond Neptune's orbit and ending abruptly about 4.7 billion miles from the sun.

• Allowed our sun and solar system to capture a planet or smaller object from the passing star's solar system. Sedna might be an example.

Houston, we have an alien... planet Astronomers have been searching for years for extrasolar planets, or planets in other solar systems. Few considered the possibility that "the nearest extrasolar planet might be right here in our solar system," says Kenyon.

Our sun and a passing star may have exchanged small planets and dust as they flew by each other. In the first stage shown in this image of a computer simulation, dust and planets orbit in circular disks in each of the two solar systems. As the sun and passing star approach each other, gravity can yank small objects from one solar system to the other, as shown in this computer image. Once the stellar encounter is complete, the disk of each solar system contains a mixture of indigenous and captured dust and planets, as shown in the final computer image. Image credits: University of Utah and Smithsonian Astrophysical Observatory. Computer simulations of a close encounter by two stars—a stellar flyby—demonstrated there is a chance a planet could be captured from another solar system. Bromley and Kenyon predicted locations in our solar system where captured objects would be, based on the angle and shape of their orbits. Finding captured objects in the predicted locations would be "proof that a flyby occurred," says Bromley. He hopes astronomers will look more closely at sections of the sky where he and Kenyon predict alien planets might be. Between 30 and 50 astronomical units from the sun—that is, 2.8 billion to 4.7 billion miles from the sun—several Kuiper belt objects larger than 600 miles in diameter are known to orbit the sun. Sedna, discovered in 2003, is similar to these cold, rock-and-ice worlds, but orbits 70 to 1,000 astronomical units from the sun. It has a high-inclination orbit, which means it does not travel around the sun in the same plane as the major planets. Sedna's orbit also is highly elliptical or elongated. Bromley says Kuiper belt objects are influenced by Neptune's gravity, but Neptune alone is too far away to have launched Sedna on its bizarre path, he says. What caused Sedna's elongated orbit? Answering this question was a key goal of Bromley and Kenyon's study. Their simulations show there is a 5 percent to 10 percent chance Sedna formed within our solar system, probably closer to Neptune or Pluto, and was later launched into its current orbit when our solar system was "buzzed" by another. "In order for a flyby [between two stars] to put Sedna on its orbit, we need to have Sedna in place at the time of the flyby," says Bromley. Bromley says it is possible Sedna is an alien planet, formed in a solar system that later flew near our own. Bromley and Kenyon's simulations suggest that there is a 1 percent chance that Sedna is a planet captured during a stellar flyby.

"There may be thousands of objects like Sedna near the edge of our solar system," Bromley says. "So there is an even greater chance that some may be alien worlds captured from another solar system." The Kuiper belt ends abruptly at 50 astronomical units from the sun and "there is no evidence that the hard edge of the Kuiper belt is in any sense natural," says Bromley. If the edge of our solar system were unperturbed, scientists would predict a gradual tapering of debris at increasing distances from the sun. The computer simulations showed that a close encounter with another solar system could explain why rocky, icy Kuiper belt objects vanish abruptly at 50 astronomical units. Does the solar system face another destructive encounter with a neighboring star? Not according to Bromley, who says the chance of that happening is "effectively nil" because the sun no longer is close to other stars in a cluster as it once was. Read the original news release at http://www.utah.edu/unews/releases/04/dec/starencounter.html. Additional articles on this subject are available at: http://www.astrobio.net/news/article1330.html http://www.space.com/scienceastronomy/sun_planets_041201.html http://www.spacedaily.com/news/extrasolar-04zs.html http://spaceflightnow.com/news/n0412/01passingstar/ WHAT DO YOU SAY TO AN EXTRATERRESTRIAL? By Seth Shostak From Space.com 2 December 2004 I once thought that worrying about what we should broadcast to extraterrestrials made as much sense as fretting over the small talk I'd venture with King Carl XVI Gustaf if I won the Nobel Prize. I reckoned there was no need to dwell on the problem, as it was both hypothetical and irrelevant. Well, I've changed my mind. Not about the chances for a Nobel Prize, but about the value in devoting some cerebral CPU cycles to the matter of interstellar messaging. Part of this shift is due to my colleague at the SETI Institute, Doug Vakoch, who has penned a number of erudite articles on the problem. A few of his insights have managed to percolate through the walls that separate our offices. In addition, new telescopes being built for SETI will soon speed up our search by factors of a hundred and more. So it's entirely possible, in my view, that we could retrieve a message from another world within just a few decades. Suddenly, the idea of "talking back" would become more than just a wry, dry academic straw man. There's also the enticement that pondering what to say and how to say it might help snag that extraterrestrial signal in the first place. It could give us a clue as to what we're looking for. Read the full article at http://www.space.com/searchforlife/seti_whattosay_041202.html. HELLO, HELLO, EARTH? University of Michigan release 2 December 2004 If ET ever phones home, chances are Earthlings wouldn't recognize the call as anything other than random noise or a star. New research shows that highly efficient electromagnetic transmissions from our neighbors in space would resemble the thermal radiation emitted by stars. University of Michigan physicist Mark Newman, along with biologist Michael Lachmann and computer scientist Cristopher Moore, have extended the pioneering 1940s research of Claude Shannon to electromagnetic transmissions in a paper published last month in the American Journal of Physics called, "The Physical Limits of Communication, or Why any sufficiently advanced technology is indistinguishable from noise." Lachmann is at the Max Planck Institute in Leipzig, Germany; Moore is at the University of New Mexico in Albuquerque.


Shannon showed that a message transmitted with optimal efficiency is indistinguishable from random noise to a receiver unfamiliar with the language in the message. For example, an e-mail message whose first few letters are AAAAA contains little information because the reader can easily guess what probably comes next—another A. The message is totally non-random. On the other hand, a message beginning with a sequence of letters like RPLUOFQX contains a lot of information because you cannot easily guess the next letter. Paradoxically, however, the same message could just be a random jumble of letters containing no information at all; if you don't know the code used for the message you can't tell the difference between an information-rich message and a random jumble of letters. Newman and his collaborators have shown that a similar result holds true for radio waves. When electromagnetic waves are used as the transmission medium, the most information efficient format for a message is indistinguishable from ordinary thermal radiation—the same kind of radio waves that are emitted by hot bodies like stars. In other words, an efficiently coded radio message coming from outer space would look no different from a normal star in the sky. So, suppose an alien in space decided to pick up signs of Earth life. It would have a pretty easy time of it, since our radio and television signals are zigzagging all over the place and are inefficiently coded and easily distinguishable from stars. But say a human tries to tune into extraterrestrial life. "People do this, and when they do, they are looking for non-random stuff," Newman said. "But what if (the aliens) have gotten it down? With a few hundred years practice at doing this, you'd have discovered the most efficient way to encode your radio messages. So to us, their communication would look just like another star, a hot object." After all, Newman said, in the universe's 12 billion-year history, it's likely that extraterrestrials—if they exist—have communicated with each other longer than our paltry 80-year history of radio broadcasting. "In which case, they've probably gotten very good at this by now." Said Newman, "Our message is that, even for the people who do believe this, they're probably wasting their time. If they did pick up a signal from little green men, it would probably look like a star to them and they would just pass over it and move on to the next thing." For information on Newman, visit: http://www-personal.umich.edu/~mejn/ For information on physics, visit: http://www.physics.lsa.umich.edu/nea/ Contact: Laura Bailey Phone: 734-647-7087 or 734-647-1848 E-mail: [email protected] Additional articles on this subject are available at: http://www.astrobio.net/news/article1331.html http://www.spacedaily.com/news/seti-04k.html http://www.universetoday.com/am/publish/mistake_et_signals.html. VOLCANOES SNUFFED OUT MOST LIFE 250 MILLION YEARS AGO By Robert Roy Britt From LiveScience.com 2 December 2004 Scientists have gone back-and-forth in recent years on what caused the various mass extinctions clearly evident in the fossil record. The worst of these, known as the Great Dying, occurred 250 million years ago. More than 90 percent of all species perished. Experts are pretty sure an asteroid was behind a more recent mass extinction, which took with it the dinosaurs, about 65 million years ago. A more controversial recent claim has been that a similar impact caused the Great Dying. But a new study finds no evidence for an impact 250 million years ago, at what is known as the end of the Permian Era. Read the full article at http://www.livescience.com/forcesofnature/041202_extinction_cause.html.

BUILD YOUR OWN BORG: SORT OF From Astrobiology Magazine 4 December 2004 Most observers of the Mars missions think the rovers are driven, like a car, but in fact they are commanded. While using a joystick or wheel to drive a rover might at first seem appealing, the 20 minute delay in transmission of each signal from Earth to Mars would make a true drive more like a very slow crawl. To counteract this delay, more autonomy has been built into loading an entire day's worth of driving in a single set of commands sequences. The core of this capability is sophisticated hazard avoidance and remote decisionmaking. While avoiding bad spots ranks highest in a decision tree, the opportunity for a rover to direct itself to interesting places becomes important, particularly for longer drives. A team of scientists has set out to combine human mobility with some of the latest off-the-shelf hardware to study what a remote geologist might do on another planet. The team calls their system, the "Cyborg Astrobiologist". The half-machine/half-human seeks out and prioritizes changes in its survey. Their recent accounts in the field are abridged as a case study of what cybernetics might deliver. Patrick McGuire is the lead author describing a mission that included robotics experts, geologists, and a wearable computer equipped with image analysis software as its pointing compass. What follows is an excerpt of his longer account of field experiences so far with the "Cyborg" project.

Left: when faced with an unknown cliff face, the image segmentation software prioritizes targets of interest using a green box to show the more interesting geology in view. Image credit: McGuire, et al., CAB. Right: Concretions, or blueberries at Meridiani. Image credit: NASA. We have developed and field-tested a "Cyborg Astrobiologist" system that now can: • Use human mobility to maneuver to and within a geological site and to

follow suggestions from the computer as to how to approach a geological outcrop;

• Use a portable robotic camera system to obtain a mosaic of color images;

• Use a "wearable" computer to search in real-time for the most uncommon regions of these mosaic images;

• Use the robotic camera system to re-point at several of the most uncommon areas of the mosaic images, in order to obtain much more detailed information about these "interesting" uncommon areas;

• Use human intelligence to choose between the wearable computer's different options for interesting areas in the panorama for closer approach; and

• Repeat the process as often as desired, sometimes retracing a step of geological approach.

The half-human/half-machine "Cyborg" approach uses human locomotion and human-geologist intuition/intelligence for taking the computer vision-algorithms to the field for teaching and testing, using a wearable computer. This is advantageous because we can therefore concentrate on developing the "scientific" aspects for autonomous discovery of features in computer imagery, as opposed to the more "engineering" aspects of using computer vision to guide the locomotion of a robot through treacherous terrain. This means the development of the scientific vision system for the robot is effectively decoupled from the development of the locomotion system for the robot. The non-human hardware of the Cyborg Astrobiologist system consists of: • a 667 MHz wearable computer (from ViA Computer Systems in

Minnesota) with a "power-saving" Transmeta "Crusoe" CPU and 112 MB of physical memory,


• an SV-6 Head Mounted Display (from Tekgear in Virginia, via the Spanish supplier Decom in Valencia) with native pixel dimensions of 640 by 480 that works well in bright sunlight,

• a Sony "Handycam" color video camera (model DCR-TRV620E-PAL), • a thumb-operated USB finger trackball from 3G Green Green Globe

Co., resupplied by ViA Computer Systems and by Decom, • a small keyboard attached to the human's arm, • a tripod for the camera, and • a Pan-Tilt Unit (model PTU-46-70W) from Directed Perception in

California with a bag of associated power and signal converters. The programming for this Cyborg Astrobiologist/Geologist project was initiated with the Sony Handycam in April 2002. The wearable computer arrived in June 2003, and the head mounted display arrived in November 2003.

NASA is developing the Wearable Augmented Reality Prototype (Warp), a personal communication device. The voice- activated wearable computer allows easy, real-time access to voice communication, pictures, video, people and technical reports. "It wasn't so much the electronics but the packaging that ended up being the big unknown..." —JPL engineer Ann Devereaux. Image Credit: JPL.

We now have a reliably functioning human and hardware and software Cyborg Geologist system, which is partly robotic with its Pan Tilt camera mount. This robotic extension allows the camera to be pointed repeatedly, precisely and automatically in different directions. Based upon the performance of the Cyborg Astrobiologist system during the first mission to Rivas in March 2004 on the outcropping cliffs near Rivas Vaciamadrid, we have decided that the system was paying too much attention to the shadows made by the 3D structure of the cliffs. We hope to improve the Cyborg Astrobiologist system in the next months in order to detect and to pay less attention to shadows. We also hope to upgrade our system to include: image-segmentation based upon micro-texture; and adaptive methods for summing the uncommon maps in order to compute the interest map. Based upon the significantly-improved performance of the Cyborg Astrobiologist system during the second mission to Rivas in June 2004, we conclude that the system now is debugged sufficiently so as to be able to produce studies of the utility of particular computer vision algorithms for geological deployment in the field. We have outlined some possibilities for improvement of the system based upon the second field trip, particularly in the improvement in the systems-level algorithms needed in order to more intelligently drive the approach of the Cyborg or robotic system towards a complex geological outcrop. These possible systems-level improvements include: a better interest-map algorithm, with adaptation and more layers; hardware and software for intelligent use of the camera's zoom lens; a memory of the image segmentation performed at greater distance or lower magnification of the zoom lens; and high-level image-interpretation capabilities.

Now that we have demonstrated that this software and hardware in the Cyborg Astrobiologist system can function for developing and testing computer-vision algorithms for robotic exploration of a geological site, we have some decisions to make as to future directions for this project, options for these future directions include: • Performing further offline analysis and algorithm-development for the

imagery obtained at Rivas Vaciamadrid: several of the parameters of the algorithms need testing for their optimality, and further enhancements of the algorithms could be made.

• Optimizing the image-processing and robotic-control code for the current Cyborg Astrobiologist system for speed and memory utilization.

• Further testing of the existing Cyborg geological exploration system at other geological sites with different types of imagery.

• Speeding up the algorithm development by changing the project from being partly a hardware project with cameras and pan-tilt units and fieldwork to being entirely a software project without robotically-obtained image mosaics and without robotic interest-map pointing; with such a change in focus, our algorithms could be significantly enhanced by studying many more types of imagery: for example, from human geologist field studies on the Earth, from robotic geologist field studies on Mars, and from orbiter or flyby studies of our solar system's moons.

What the Mars MER team has achieved is truly amazing. Firstly, the rovers can move to points 50-150 meters away in one sol with autonomous obstacle avoidance enabled for the uncertain or dangerous parts of the journey. Secondly, prior to a given sol, based upon information received after the previous sol, the MER team has the remarkable capabilities to develop a command sequence of tens or hundreds of robotic commands for the entire sol. As of July 4, 2004, this was taking 4-5 hours per sol for the mission team to complete, rather than the 17 hours per sol that it took at the beginning of the MER missions. Such capabilities for semi-autonomous teleoperated robotic "movement and discovery" are a significant leap beyond the capabilities of the previous Mars lander missions of Viking I and II and of Pathfinder and Sojourner. Nonetheless, we would like to build upon this great success of the MER rovers by developing enhancing technology that could be deployed in future robotic and/or human exploration missions to the Moon, Mars, and Europa. Read the original article at http://www.astrobio.net/news/article1326.html. THE MARTIAN METHANE SURPRISE—INTERVIEW WITH MIKE MUMMA By Leslie Mullen From Astrobiology Magazine 6 December 2004 At the recent Division of Planetary Sciences conference in Louisville, Kentucky, Michael Mumma, Director of the Center for Astrobiology at NASA's Goddard Space Flight Center, announced that relatively high levels of methane had been detected on Mars. Methane on Earth is mainly produced by life, but also can be released from volcanoes or tectonic activity. Having methane appear on Mars is something of a mystery, because the planet is not believed to have active volcanism or tectonics. Could the methane be evidence of martian life forms buried underground? In this interview with Astrobiology Magazine editor, Leslie Mullen, Mumma explains how they detected the methane, and what it could mean for the chance for life on Mars. Astrobiology Magazine (AM): I remember when a detection of methane on Mars was reported last April. Now you're saying there's a background methane level of 20 to 60 parts per billion (ppb). You've also found spikes of methane on Mars measuring 250 ppb. Mike Mumma (MM): Right. Our results were obtained in March of 2003 using the NASA Infrared Telescope Facility in Hawaii, and in May 2003 using the Gemini South telescope in Chile. But the history of the search for methane on Mars is long and storied. Most of the searches have been done at wavelengths near 3.3 or 7.7 microns, where methane has two strong vibrational bands. Comparing different results is complicated by the fact that many of the early searches were done with globally averaged fields of view, so they were less sensitive to latitudinal and


longitudinal variations. In other words, they were insensitive to local sources, because they averaged over everything.

Volcanoes are another source of methane, although the youngest active source would have to be a few million years ago, and methane without replenishment disappears in 300 years on Mars. Image credit: ESA/Mars Express.

AM: So those were studies done from telescopes on Earth, where Mars was viewed as one big pixel? MM: Exactly. Even in the case of Mariner 9's IRIS, the infrared orbiting spectrometer, Bill McGuire from our lab formed a grand average of the spectra regardless of the latitude and longitude, taken at all times of the year, and said, "Here's the spectrum." He estimated the maximum possible abundances for a dozen or so trace constituents, including methane. He found that the average mixing ratio was no more than 20 ppb. That's also what the Mars Express is now claiming to detect, but in their case one of the things that concerns me is the presence of a cloud deck. There was a major dust storm in December of 2003, and it raised the scattering level from the surface to a higher altitude—probably about 20 kilometers above the surface—and this reduced the signature of both water and methane spectral lines of reflected light. Those conditions continued until June of this year. That means that when Mars Express tried to measure methane, they were looking against that background of dust and airborne ice. That would've affected their measurements and made derived abundances appear smaller than they would otherwise be. So far, they have reported data taken in January and February and again in May, and both data sets show the effects of extinction by ice aerosols. But in March 2003, the martian atmosphere was fairly clear. We were able to measure both water vapor and methane in the same spectra at the same time. We compared the water at each position with the amount detected by the TES spectrometer on the orbiting Mars Global Surveyor.

Left: "If the methane observation is borne out, maybe there is something living there under the ice." —David Grinspoon. Right: frost dusts the red plains of southern Mars in early spring. Mars's mean annual temperature is -55°C. Image credit: MSSS/JPL/NASA. AM: To verify that what you were measuring was accurate? MM: Correct. Our water abundances were a factor of three smaller than those

of TES. We always have to add a reference level to our spectral measurements to get the true value. I didn't add those numbers in my presentation this year [at the DPS conference]. Instead, I showed the minimum amount we were seeing. AM: Why do you have to add reference values to your readings? MM: The reason we do it that way is because the telescope is looking through a column of Earth air. The photons collected from Mars traverse the same terrestrial column of air, regardless of their position along the spectrometer entrance slit. By choosing one spectrum as a reference, and subtracting it from every other measured spectrum, we can cancel these terrestrial atmospheric features perfectly. In that way, we can isolate the Mars spectrum. So we did this to find the methane abundance, and discovered that the methane shows a significant enhancement at the equatorial region. At high latitudes in the north and south, there is much less methane. It's 20 to 60 ppb in the north, and even lower in the south. But it was more than 250 ppb at the equator. AM: Does the mixture of methane in the atmosphere naturally change as you rise in altitude, or as the temperature changes? MM: No, not really. On Mars, the mixing ratio of water vapor undoubtedly changes greatly with altitude, because it condenses. But methane does not condense at martian temperatures, so it must be uniformly mixed with altitude. Now, there are caveats. There could be processes on Mars that destroy methane. If airborne dust coated with oxidants is lofted into the atmosphere, then methane could collide with that dust and be converted to other hydrocarbons, such as methanol or formaldehyde. A new study by Sushil Atreya suggests that hydrogen peroxide created by dust devils could act to scrub methane out of the atmosphere. But even if methane is being destroyed in this way, it doesn't affect our measurement. AM: Right, because there would be even more methane on Mars than the high level that you found. MM: Exactly. AM: But if methane is being actively destroyed, then doesn't that suggest that the methane you found is very current? MM: It is definitely current. AM: I heard that methane has a lifetime of about 300 years, which is very current astronomically speaking, but I meant "current" as in "being released right now." MM: We think it is being released right now. We think that's why we're seeing this intense enhancement at equatorial latitudes. Such an intense release will, over time, naturally diffuse outward in the atmosphere and be transported elsewhere, spreading around the planet and to the poles. AM: So your reading of 250 ppb in the equatorial region, that was confined to a small area? MM: Yes, it was about minus 10 degrees south to 10 degrees north. AM: And what's the topography of this region? MM: It's a transition region from the highlands to a plain—Syrtis Major Planitia. There are many scarps, or cliff faces, where the topography changes drastically. That's interesting because the other region where we showed evidence of enhanced methane was over the deep rift valley Vallis Marineris—another region with steep, high cliffs. One working model is that methane is diffusing under the permafrost and emerging at the cliff face. You wouldn't see it emerge unless there was a cliff face, or if there were fissures or ancient volcanic pipes reaching down below the permafrost. AM: On Earth, a lot of methane has an organic origin. MM: Right. Methane on Mars could be produced by non-biological methods or by biological ones. We don't yet have the evidence to support one or the other.


One possibility is drawn from Earth, where one tectonic plate is subducted under another. The subducting plate carries with it carbon dioxide, water, organic material, and so forth. When it reaches the hot magmatic region, that material reacts with olivine and converts it to a different mineral—magnetite—releasing hydrogen in the process. That hydrogen reacts with carbon to form methane, which then percolates upwards and is released. That process requires active tectonics, and we don't see any evidence for that on Mars at present. But we can test this idea by searching for other higher order hydrocarbons, and by measuring the D/H ratio—the ratio of deuterium to hydrogen—in methane. A tectonic process would most likely be consuming juvenile water stored from a time when Mars was young, and in that case it should have a lower ratio of deuterium to hydrogen than present-day water. So if methane on Mars has a low D/H ratio, that would suggest it is geothermally produced, or at least produced from the deep reservoir. Another possibility is active biology. Here you have a choice as to whether the bio-release is at the surface layer or deep below the permafrost. If it's below the permafrost, and if the permafrost is an impervious cap, then you should have sideways diffusion, with the methane later being released at the cliff faces. You could have bioforms consuming carbon dioxide and water that is relatively younger than the deep stuff, and then you'd expect to see a higher deuterium abundance. You would also expect to see depleted carbon-13, heavy carbon, in the methane released by bioforms. AM: Are these predictions based on how methanogens behave on Earth? MM: That's right. They'd have to be similar in nature, and of course we have no idea whether that would be true or not. Members of the University of Rhode Island's NASA astrobiology team have shown that methane and ethane are produced in similar abundance in cold deep-sea sediments. In that environment, the gases are probably produced by life. That's potentially important, because if life forms on Mars are similar, ethane should be released along with methane. So I'm suggesting a chemical search, using ground-based telescopes, to look for other hydrocarbons on Mars. Whether detected or not, we can fold the results into the model to constrain the possibilities. The measurement of isotopic ratios, like carbon-13 or carbon-12, probably can't be done from the ground with the accuracy required. That measurement would require an orbiter around Mars, or an airplane flying over the vents. So if the present results are upheld, they could define the course of Mars exploration for years to come. Read the original article at http://www.astrobio.net/news/article1332.html. MARS TERRAFORMING CLASSIC NOW AVAILABLE ON INTERNET Mars Society release 1 December 2004 The classic terraforming study by Averner and MacElroy "On the habitability of Mars" has now been made available on the internet as a PDF. The abstract and the link to obtain the entire document are given below. On the habitability of Mars: An approach to planetary ecosynthesis. Averner, M. M.; Macelroy, R. D. NASA Center for AeroSpace Information (CASI) NASA-SP-414, 19760101; JAN 1, 1976 The possibility of utilizing Mars as a habitat for terrestrial life, including man, is examined. Available data, assumptions, and speculations on the climate, physical state, and chemical inventory of Mars are reviewed and compared with the known requirements and environmental limits of terrestrial life. No fundamental, insuperable limitation of the ability of Mars to support a terrestrial ecology is identified. The lack of an oxygen-containing atmosphere would prevent the unaided habitation of Mars by man. The present strong ultraviolet surface irradiation is an additional major barrier. The creation of an adequate oxygen and ozone-containing atmosphere on Mars may be feasible through the use of photosynthetic organisms. The time needed to generate such an atmosphere, however, might be several millions of years. This period might be drastically reduced by the synthesis of novel, Mars-adapted, oxygen producing photosynthetic strains by techniques of genetic engineering, and modifying the present martian climate by melting of the martian polar caps and concomitant advective and greenhouse heating effects. Accession ID: 77N12718 http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19770005775_1977005775.pdf

Document ID: 19770005775 Updated/Added to NTRS: 2004-11-03 CASSINI-HUYGENS UPDATES NASA/JPL releases Cassini Shows Grandeur of Two Saturn Moons NASA/JPL image advisory 2004-278, 23 November 2004 New views of two of Saturn's moons, Titan and Tethys, represent the most detailed look at these moons to date and show a sharp contrast between them—one is foggy and one is cratered. The Cassini spacecraft captured the puzzle pieces for the full-disc view of the mysterious Titan during its first close encounter on October 26, 2004. The mosaic comprises nine images taken at distances ranging from 650,000 kilometers (400,000 miles) to 300,000 kilometers (200,000 miles). The pictures are available at http://saturn.jpl.nasa.gov, http://www.nasa.gov/cassini and http://ciclops.org.

Composite image of Tethys.

The images that make up the mosaic were processed to reduce effects of the atmosphere and to sharpen surface features. The mosaic of images has been trimmed to show only the illuminated surface and not the atmosphere around the edge of the moon. The Sun was behind Cassini, so nearly the full disc was illuminated. South polar clouds are seen at the bottom. Surface features are best seen near the center of the moon. The surface features become fuzzier toward the outside of the image, where the spacecraft is peering through more haze. The brighter region on the right side near the equator is named Xanadu Regio. Scientists are debating what processes may have created the bizarre surface brightness patterns seen there. Titan's lack of obvious craters is a hint of a young surface. However, the exact nature of that activity, whether tectonic, wind-blown, river-related, marine or volcanic, is still unknown. Two days after the close encounter with icy Titan, Cassini captured the images used in the mosaic of the battered and cratered moon Tethys. The result is the best-ever natural color view of Titan. As seen here, the surface of Tethys has a neutral hue. Three images form this natural color composite. The mosaic reveals a world nearly saturated with craters—many small craters lie on top of older, larger ones, suggesting an ancient surface. Grooves can be seen at the top and along the boundary between day and night. Tethys is known to have a density very close to that of water, indicating that it is likely composed mainly of water ice. Its frozen mysteries await Cassini's planned close flyby in September 2005. The images to create this mosaic were taken on October 28, 2004, at a distance of about 256,000 kilometers (159,000 miles) from Tethys. This view shows the trailing hemisphere of Tethys, which is the side opposite the moon's direction of motion in its orbit.


Image mosaic of Titan.

Both images were taken with the narrow angle camera onboard the Cassini spacecraft. Cassini Significant Events for 18-22 November 2004 NASA/JPL release, 24 November 2004 Due to the Thanksgiving holiday, the reporting period for this week covers three days instead of the usual five. The most recent spacecraft telemetry was acquired from the Madrid tracking station on Monday, November 22. 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://saturn.jpl.nasa.gov/operations/present-position.cfm. Apoapsis—the point in the orbit farthest from Saturn—for the current orbit occurred on November 21. At that time the Ultraviolet Imaging Spectrograph (UVIS) made a mosaic of Saturn's inner magnetosphere in neutral and ion photon emissions to derive the distribution and density of atomic and molecular species. UVIS also continued to examine the F-Ring to monitor changes in ring reflectance properties. Additional science activities included the continuation of Imaging Science Subsystem (ISS) observations of small satellites for orbit determination and to improve understanding of short and long term dynamical evolution. ISS also continued capturing of movies in search of the elusive Saturnian Ring spokes, which have not been seen by Cassini thus far. On-board activities this week included the execution of an Ion and Neutral Mass Spectrometer (INMS) operating threshold test, Orbital Trim Maneuver (OTM) #6, and the muting of the instruments in preparation for Probe Checkout #16 (PCO). PCO is a mini sequence designed to exercise the instruments on board the Probe and prepare it for the relay mission. OTM-6 was successfully completed on the spacecraft Saturday, November 20. This maneuver, performed near Rev-A apoapsis, targets Cassini to Titan for the Tb flyby. The main engine (ME) burn began at 10:10 Pacific Standard Time with a burn duration of 3 seconds—the shortest duration main engine maneuver performed to date—giving a delta-V of 0.4 m/s. As was mentioned last week, development continues for the S06 Titan-b live Inertial Vector Propagator (IVP) update. The process kicked off this week and over the weekend the science teams reviewed the materials relevant to the update. On Monday at the go/no go meeting it was determined that the update was necessary for ISS only. The result will be an update for one vector and one observation. Test files have been transferred to the Integrated Test Laboratory (ITL) and the test will begin on Tuesday, November 23.

The image shows primarily the trailing hemisphere of Dione, which is the side opposite the moon's direction of motion in its orbit. The image has been rotated so that north is up. The image was taken in visible light with the Cassini spacecraft narrow angle camera on October 27, 2004, at a distance of about 1.2 million kilometers (746,000 miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 28 degrees. The image scale is 3.5 kilometers (2.2 miles) per pixel. Sequence development is ongoing for tour sequences S06 through S12, and S37 through S41. Sequences S07 and S08 continue in the Science and Sequence Update Process (SSUP). A Science Allocation Panel meeting was held as part of the S08 process and the Preliminary Sequence Integration and Validation 1 (PSIV) products were processed and are available for review. Products were delivered for Preliminary Port 1 by all participating teams as part of the Science Operations Plan Implementation process for S39 and S40. On Friday, November 19, Deep Space Mission Systems (DSMS) held a successful Cassini-Huygens probe release, relay, and data playback Mission Event Readiness Review. The review board unanimously agreed that the DSMS is ready to support the Huygens Probe release and data playback. A program internal science talk was given this week by one of the Visual and Infrared Mapping Spectrometer (VIMS) team members on The Latest VIMS Results on Titan and the Icy Satellites. Cassini Outreach conducted a Cassini workshop for ten members of the Natural History Museum of Los Angeles education and outreach staff this week. Activities included talks by Cassini scientists, demonstration of hands-on educational activities from the Cassini education webpage, and a mission overview and science update. Cassini Captures Saturn Moon Red-Handed NASA/JPL image advisory 2004-282, 3 December 2004 Stealing is a crime on Earth, but at Saturn, apparently it is routine. The Cassini spacecraft has witnessed Saturn's moon Prometheus snatching particles from one of Saturn's rings. This potato-shaped moon is also believed to be responsible for kinks within Saturn's thin F ring, a contorted, narrow ring flanked by two small moons, Prometheus and Pandora. The thievery and the detailed behavior of kinks were observed for the first time ever in images taken by the Cassini spacecraft. In an image taken on October 29, Prometheus is seen stealing particles from the F ring while connected to the ringlets by a faint streak of material. A movie sequence of the ring, taken on October 28, captures in freeze-frame motion the zigzagging kinks and knots, some of which are almost certainly caused by Prometheus. The new still and movie are available at http://saturn.jpl.nasa.gov, http://www.nasa.gov/cassini and http://ciclops.org.


The kinks look like "hiccups" traveling around the ring. Consisting of 44 frames taken three minutes apart, the sequence represents almost two hours, or about one-eighth of the orbital period of F ring particles around the planet. Cassini was on a flight path that took the spacecraft away from the planet and farther south, so that the rings appear to tilt upward. The top portion of the F ring is closer to the spacecraft, while the bottom portion is farther away and curves around the far side of Saturn. Scientists are not sure exactly how Prometheus is interacting with the F ring here, but they have speculated that the moon might be gravitationally pulling material away from the ring. Scientists speculate that the ring particles may end up in a slightly different orbit from the one they were in prior to getting a "kick" from the moon. These kicks occur at specific locations in the rings and can actually cause large waves or knots to form. In the still image, gaps in the diffuse inner strands are seen. All these features appear to be due to the influence of Prometheus in ways that are not fully understood. Saturn's moon Prometheus is following in the footsteps of the legendary Titan for which it is named. In Greek mythology, Prometheus stole fire from the gods and gave it to the mortals. Scientists will use what they learn about Prometheus' interaction with the F ring to understand the gravitational exchanges between moons and rings, which give rise to so much of the structure that is observed in Saturn's rings. Cassini Significant Events for 23 November - 1 December 2004 NASA/JPL release, 3 December 2004 The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Monday, December 1. 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://saturn.jpl.nasa.gov/operations/present-position.cfm. The Ultraviolet Imaging Spectrograph (UVIS) continued to monitor Saturn's inner magnetosphere in neutral and ion photon emissions to derive the distribution and density of atomic and molecular species. UVIS also continued to examine the F Ring to monitor changes in ring reflectance properties. RADAR performed a Radiometric calibration of their subsystem by examining microwave sources including the Sun and Saturn among others.

In a splendid portrait created by light and gravity, Saturn's lonely moon Mimas is seen against the cool, blue-streaked backdrop of Saturn's northern hemisphere. Delicate shadows cast by the rings arc gracefully across the planet, fading into darkness on Saturn's night side. The part of the atmosphere seen here appears darker and more bluish than the warm brown and gold hues seen in Cassini images of the southern hemisphere, due to preferential scattering of blue wavelengths by the cloud-free upper atmosphere. The bright blue swath near Mimas (398 kilometers, or 247 miles across) is created by sunlight passing through the Cassini division (4,800 kilometers, or 2,980 miles wide). The rightmost part of this distinctive feature is slightly overexposed and therefore bright white in this image. Shadows of several thin ringlets within the division can be seen here as well. The dark band that stretches across the center of the image is the shadow of Saturn's B ring, the densest of the main rings. Part of the actual Cassini division appears at the bottom, along with the A ring and the narrow, outer F ring. The A ring is transparent enough that, from this viewing angle, the atmosphere and threadlike shadows cast by the inner C ring are visible through it. Images taken with red, green and blue filters were combined to create this color view. The images were obtained with the Cassini spacecraft narrow angle camera on November 7, 2004, at a distance of 3.7 million kilometers (2.3 million miles) from Saturn. The image scale is 22 kilometers (14 miles) per pixel. On-board activities this week included an Inertial Reference Unit calibration, Reaction Wheel Assembly unload, and the uplink of files for later execution for Probe Battery Depassivation #2, a Cassini to Titan vector update on 2004-346, Imaging Science Subsystem (ISS) sequence count rollover error patch, and a Magnetospheric Imaging Instrument (MIMI) STARE mode for Titan b.


The primary activity this week was the execution of the final Huygens Probe checkout (PCO). This in-flight checkout procedure was the last one planned before separation of the Huygens probe from Cassini in about three weeks. The preliminary analysis of the real-time data received showed all events in the checkout procedure occurred as, and when, expected. For more information link to http://www.esa.int/SPECIALS/Cassini-Huygens/SEM3AUWJD1E_0.html.

An intriguing knotted ringlet within the Encke Gap is the main attraction in this Cassini image. The Encke Gap is a small division near the outer edge of Saturn's rings that is about 300 kilometers (190 miles) wide. The tiny moon Pan (20 kilometers, or 12 miles across) orbits within the gap and maintains it. Many waves produced by orbiting moons are visible. The image was taken in visible light with the Cassini spacecraft narrow angle camera on October 29, 2004, at a distance of about 807,000 kilometers (501,000 miles) from Saturn. The image scale is 4.5 kilometers (2.8 miles) per pixel. Since the start of Approach Science in January of this year, 29509 ISS images and 6323 Visual and Infrared Mapping Spectrometer cubes have been acquired. The project has decided to raise the flyby altitudes of the Titan 5 and Titan 7 encounters from 950 km to 1025 km. The Titan Atmospheric Model Working Group's Ta workshop on November 15 and subsequent discussions and analyses by both scientists and engineers have produced results that render 950 km flybys questionable without at least one intermediate flyby between 1174 km and 950 km. The 1025 km altitude is low enough to provide a clear indication of spacecraft safety, or not, at 950 km, yet high enough to be certain to be safe. Preliminary indications from the Navigation team are that this action can be taken at little or no delta-V cost or impact to the occultation sequences or subsequent encounters. The altitude of Titan 4—currently at ~2500 km—lowers slightly, and timing changes to all encounters exclusively from this change are less than one minute. The navigation team will be releasing a new spacecraft ephemeris shortly. Spacecraft Operations Office (SCO) personnel reran the Probe Relay and Playback portion of the end-to-end test on Monday and Tuesday of this week. The Integrated Test Lab rerun was requested to collect additional redlines for the Probe Relay sequence and to verify the changes made to SCO procedures as a result of the earlier end-to-end simulation. Development continues for the S06 Titan-b live Inertial Vector Propagator (IVP) update. Files for the update were transferred to the Integrated Test Laboratory (ITL) and a test performed from November 24 through November 28. Initial assessments from both CDS and ACS were that the test was a success. A meeting was held on November 30 where the Titan-b flyby live IVP update files were approved and on December 1 were uplinked to the spacecraft.

As Cassini scientists work to understand the newly-exposed surface of Saturn's largest moon, Titan, they have found an interesting arrowhead-shaped feature, shown in the center of this synthetic aperture radar image. The feature is approximately 30 kilometers (19 miles) across, and it is formed from two straight lines that intersect. Looking more closely, one can distinguish other linear features that seem to follow the left side of the "arrow" and perhaps interact in some way with a dark spot. Straight lines may represent fractures or faults in the icy crust, or they may form from material that has flowed or has been shaped by wind, either recently or in the distant past. Sequence development is ongoing for tour sequences S07 through S12, and S37 through S41. A Project Briefing and Waiver Disposition meeting was held for S09. S10 Preliminary port 1 products were delivered as part of the Science Operations Plan Update process (SOPU). The products were merged and the reports published. The S11 aftermarket process concluded this week. Products will be provided from this activity to the leads for the SOPU process, which kicks off on December 9. An Assessment meeting was held for S12 to review all of the requested changes to the sequence. It looks like all of the requested changes can fit within the available resources. Unless the Target Working Teams and Orbiter Science Teams recommendations change over the next couple of weeks, it is likely that the decision meeting scheduled for December 14 will be canceled. A wrap-up meeting was held last Wednesday for tour sequences S37/S38 as part of the Science Operations Plan Implementation (SOPI) process. These sequences have now been archived and will begin the aftermarket process in August of 2007. Preliminary port #1 occurred as part of SOPI for S39/S40. The products were merged and the reports published. An ISS flight software patch to avoid warm restarts was approved last week by the Project. The uplink files were prepared and approved for uplink. The patch will be installed into the instrument on December 3. A Delivery Coordination Meeting was held for Radio Science Subsystem (RSS) software POSTLB, the final software tool in the RSS tool suite. This tool does post-processing of the Inertial Vector Definition and Doppler files generated by LMTTRK and BISTAT. It removes pointing discontinuities at ingress and egress during occultation observations. On November 20, a Bay Area Writing Project team member introduced 50 NASA education representatives to, "Reading, Writing, and Rings" at a nationwide workshop in Houston, Texas. These representatives train educators throughout the country on NASA materials. Saturn Observation Campaign members in Spain and Ireland published articles in their local magazines about the Cassini Mission to Saturn. On November 27 the Los Alamos Monitor did a follow up on Girl Scout Troup 128 who seven years ago signed on to a 3.5 billion km voyage out beyond the moon and nearby planets. Now their names are among 616,400 handwritten signatures from 81 countries on board the Cassini orbiter, as it settles in around the great ringed world of Saturn, the sixth planet from the Sun.


Check out the Cassini web site for the latest image advisory: Cassini Shows Grandeur of Two Saturn Moons. The pictures are available at http://saturn.jpl.nasa.gov. Cassini images made Astronomy Picture of the Week three times last week with images of Tethys and Dione, and a Radar Image of Titan. 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 Science Mission Directorate, Washington, DC. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, CO. Contacts: Carolina Martinez Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-9382 Heidi Finn Cassini Imaging Central Laboratory for Operations Space Science Institute, Boulder, CO Phone: 720-974-5859 Additional articles on this subject are available at: http://www.astrobio.net/news/article1321.html http://www.astrobio.net/news/article1328.html http://www.astrobio.net/news/article1329.html http://www.space.com/imageoftheday/image_of_day_041129.html http://www.spacedaily.com/news/cassini-04zzzzl.html http://www.spacedaily.com/news/cassini-04zzzzo.html http://www.spacedaily.com/news/cassini-04zzzzp.html http://www.spacedaily.com/news/cassini-04zzzzq.html http://www.spacedaily.com/news/cassini-04zzzzr.html http://www.spacedaily.com/news/cassini-04zzzzs.html http://www.spacedaily.com/news/cassini-04zzzzt.html http://www.spacedaily.com/news/cassini-04zzzzu.html http://www.spacedaily.com/news/cassini-04zzzzv.html http://www.spacedaily.com/news/cassini-04zzzzw.html http://spaceflightnow.com/cassini/041122rhea.html http://spaceflightnow.com/cassini/041123tethys.html http://spaceflightnow.com/cassini/041124titan.html http://spaceflightnow.com/cassini/041129canvas.html http://spaceflightnow.com/cassini/041201gazingdown.html http://spaceflightnow.com/cassini/041202ringgap.html http://spaceflightnow.com/cassini/041204prometheus.html http://www.universetoday.com/am/publish/best_views_titan_tethys.html http://www.universetoday.com/am/publish/detailed_view_dione.html http://www.universetoday.com/am/publish/mimas_saturn_rings.html http://www.universetoday.com/am/publish/disrupting_rings.html

DEEP IMPACT DELAY NASA/KSC release 24 November 2004 A decision has been made to reschedule the launch of the Deep Impact spacecraft to no earlier than January 8 to allow more time for evaluation of mission software. While there are no significant problems associated with the spacecraft hardware, additional time is necessary to be ready for launch. Spacecraft functional and mission readiness tests continue. The stacking of the Boeing Delta II launch vehicle on Pad 17-B began on November 22 with the hoisting of the first stage into the launcher. Hoisting of the nine strap-on solid rocket boosters, in sets of three, began on November 23 and will continue on November 29 and December 1. The second stage will be hoisted into position atop the first stage on December 3. The overall Deep Impact mission management for this Discovery class program is conducted by the University of Maryland in College Park, MD. Deep Impact project management is handled by the Jet Propulsion Laboratory in Pasadena, CA. The spacecraft was built for NASA by Ball Aerospace and Technologies Corporation. Read the original news release at http://solarsystem.jpl.nasa.gov/news/display.cfm?News_ID=10156. Additional articles on this subject are available at: http://spaceflightnow.com/delta/d311/041124delay.html REPORTS DETAIL ROVER DISCOVERIES OF WET MARTIAN HISTORY NASA/JPL release 2004-280 2 December 2004 The most dramatic findings so far from NASA's twin Mars rovers—telltale evidence for a wet and possibly habitable environment in the arid planet's past—passed rigorous scientific scrutiny for publication in a major research journal. Eleven reports by 122 authors in Friday's issue of the journal, Science, present results from Opportunity's three-month prime mission, fleshing out headline discoveries revealed earlier. Opportunity bounced to an airbag-cushioned landing on January 24. It is exploring a region called Meridiani Planum, halfway around Mars from where its twin, Spirit, landed three weeks earlier. Sedimentary rocks Opportunity examined, "clearly preserve a record of environmental conditions different from any on Mars today," report 50 rover-team scientists led by Dr. Steve Squyres of Cornell University, Ithaca, NY and Dr. Ray Arvidson of Washington University, St. Louis, MO.

High-resolution image captured by the Mars Exploration Rover Opportunity's panoramic camera.

"Liquid water was once intermittently present at the martian surface at Meridiani, and at times it saturated the subsurface. Because liquid water is a key prerequisite for life, we infer conditions at Meridiani may have been habitable for some period of time in martian history," according to Squyres, Arvidson and other co-authors. "Formal review and publication this week of these amazing discoveries further strengthens the need for continued exploration by orbiters, surface robots, sample-return missions and human explorers. There are more exciting discoveries awaiting us on the red planet," said Dr. Michael Meyer, chief scientist for Mars exploration at NASA Headquarters, Washington, DC.

Opportunity and Spirit have driven a combined 5.75 kilometers (3.57 miles), nearly five times their mission-success goal. They continue in good health after operating more than three times as long as the three-month prime missions for which they were designed. NASA's rover team makes the resulting scientific discoveries available quickly to the public and the science community. One type of evidence that Meridiani was wet is the composition of rocks there. The rocks have a high and variable ratio of bromine to chlorine; indicating "the past presence of large amounts of water," write Dr. Rudi Rieder and Dr. Ralf Gellert of Max-Planck-Institute for Chemistry, Mainz, Germany, and co-authors. Their paper and another by Dr. Phil Christensen of Arizona State University, Tempe, and


collaborators report an abundance of sulfur-rich minerals in the rocks, another clue to a watery past. Clinching the case is identification of a hydrated iron-sulfate salt called jarosite the University of Mainz, and Dr. Richard Morris of NASA's Johnson Space Center, Houston, and co-authors.

As NASA's Mars Exploration Rover Opportunity was making its way back toward its original entry path into "Endurance Crater," scientists and engineers spotted what they hoped might be a shortcut for climbing out of the crater. The possible exit path, pictured on the far right of this image where the outcrop is punctuated, was eventually deemed too hazardous for the rover to attempt. Opportunity would have had to cross terrain with a slope of 28 degrees and face a tall rock outcropping very close to the exit chute opening which, itself, is too narrow for the rover to pass. This view combines several frames taken by the rover's navigation camera during Opportunity's 297th sol on Mars (November 24, 2004). It is presented in a cylindrical projection with geometric seam correction. The location from which the image was taken has been designated as Opportunity's Site 38, Position 97. Image credit: NASA/JPL.

Soil on Mars can be a bit clumpy, as shown in this image of soil after it was compacted by one of the wheels of NASA's Mars Exploration Rover Spirit. Scientists think the light-colored material may be a global layer of airfall dust. Spirit's microscopic imager took this picture, showing an area approximately 3 centimeters (1.2 inches) square, during the rover's 314th martian day, or sol (November 19, 2004). Image credit: NASA/JPL/Cornell/USGS. Structures within the rocks add more evidence according to Dr. Ken Herkenhoff of the U.S. Geological Survey, Flagstaff, AZ, and co-authors. Plentiful cavities, about the size of shirt buttons, indicate crystals formed inside the rocks then dissolved. Minerals carried by water formed peppercorn-size gray spheres, nicknamed "blueberries," that are embedded in the rocks. Certain angled patterns of fine layers in some rocks tell experts a flowing body of surface water shaped the sediments that became the rock. Several characteristics of the rocks suggest water came and went repeatedly, as it does in some shallow lakes in desert environments on Earth. That fluctuation, plus the water's possible high acidity and saltiness, would have

posed challenges to life, but not necessarily insurmountable ones, according to researchers. If life ever did exist at Meridiani, the type of rocks found there could be good preservers of fossils, according to Squyres, Dr. John Grotzinger of the Massachusetts Institute of Technology, NASA's Jet Propulsion Laboratory, Pasadena, CA, has managed the Mars Exploration Rover project since it began in 2000. Images and additional information about the rovers and their discoveries are available on the Internet at http://www.nasa.gov/vision/universe/solarsystem/mer_main.html and at http://marsrovers.jpl.nasa.gov. Information about NASA and agency programs is available on the Web at http://www.nasa.gov. Contacts: Guy Webster Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-6278 Donald Savage NASA Headquarters, Washington, DC Phone: 202-358-1547 Additional articles on this subject are available at: http://www.astrobio.net/news/article1327.html http://www.space.com/scienceastronomy/opportunity_water_041202.html http://www.spacedaily.com/news/mars-mers-04zzzzzzzze.html http://www.spacedaily.com/news/mars-water-science-04o.html http://spaceflightnow.com/mars/mera/041202reports.html http://www.universetoday.com/am/publish/mars_once_suitable_life.html MARS EXPRESS: CRATER HALE IN ARGYRE BASIN ESA release 24 November 2004 These images, taken by the High Resolution Stereo Camera (HRSC) on board ESA's Mars Express spacecraft, show Crater Hale in the Argyre basin of the southern hemisphere of Mars. The images show an area close to the northern rim of the Argyre basin, located at latitude 36° South and longitude 324° East. The image was taken with a ground resolution of about 40 meters per pixel during Mars Express orbit 533 in June 2004. Slight periodic color and brightness variations in parts of the image indicate atmospheric waves in clouds.

Crater Hale in Argyre basin. Crater Hale, with its terraced walls, central peak and a part of the inner ring is visible in the upper (eastern) part of the image. The region has been eroded heavily by deposits caused by this impact, and subsequent processes. On the southern rim of Hale, parts of the crater wall have moved downslope towards the crater's centre (see black and white detailed image). At the bottom (western) part of the picture, as seen below in the other detailed image with high resolution, the surface shows a network of fluvial channels which may have been caused by running water.


Map showing Crater Hale in context.

Crater Hale in perspective, looking west.

Crater Hale in perspective, looking north-west.

Image resolution has been decreased for use on the internet. 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. Read the original news release at http://www.esa.int/SPECIALS/Mars_Express/SEM8AVWJD1E_0.html. An additional article on this subject is available at http://www.universetoday.com/am/publish/crater_hale.html.

MARS GLOBAL SURVEYOR IMAGES NASA/JPL/MSSS release 18 November - 1 December 2004 The following new images taken by the Mars Orbiter Camera (MOC) on the Mars Global Surveyor spacecraft are now available. Small Gullied Crater (Released 18 November 2004) http://www.msss.com/mars_images/moc/2004/11/18/ Northern Meridiani Scene (Released 19 November 2004) http://www.msss.com/mars_images/moc/2004/11/19/ North Polar Layer Exposure (Released 20 November 2004) http://www.msss.com/mars_images/moc/2004/11/20/ Hill and Depression (Released 21 November 2004) http://www.msss.com/mars_images/moc/2004/11/21/ Northern Plains of Mars (Released 22 November 2004) http://www.msss.com/mars_images/moc/2004/11/22/ A Gullied Crater Wall (Released 23 November 2004) http://www.msss.com/mars_images/moc/2004/11/23/ Inverted Valley in Arabia (Released 24 November 2004) http://www.msss.com/mars_images/moc/2004/11/24/ Sedimentary Rocks and Dunes (Released 25 November 2004) http://www.msss.com/mars_images/moc/2004/11/25/ Streamlined "Island" (Released 26 November 2004) http://www.msss.com/mars_images/moc/2004/11/26/ Meridiani's Rocks (Released 27 November 2004) http://www.msss.com/mars_images/moc/2004/11/27/ North Polar Features (Released 28 November 2004) http://www.msss.com/mars_images/moc/2004/11/28/ Bouldery Impact Ejecta (Released 29 November 2004) http://www.msss.com/mars_images/moc/2004/11/29/ East Candor cPROTO (Released 30 November 2004) http://www.msss.com/mars_images/moc/2004/11/30/ Crater Floor Yardangs (Released 01 December 2004) http://www.msss.com/mars_images/moc/2004/12/01/ All of the Mars Global Surveyor images are archived at http://www.msss.com/mars_images/moc/index.html. Mars Global Surveyor was launched in November 1996 and has been in Mars orbit since September 1997. It began its primary mapping mission on March 8, 1999. Mars Global Surveyor is the first mission in a long-term program of Mars exploration known as the Mars Surveyor Program that is managed by JPL for NASA's Office of Space Science, Washington, DC. Malin Space Science Systems (MSSS) and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 22-26 November 2004 Nighttime IR Channels (Released 22 November 2004) http://themis.la.asu.edu/zoom-20041122A.html Tinto Vallis Fluvial Channel (Released 23 November 2004) http://themis.la.asu.edu/zoom-20041123A.html


Tyrrhena Patera Nighttime IR (Released 24 November 2004) http://themis.la.asu.edu/zoom-20041124A.html Nirgal Vallis Nighttime IR (Released 25 November 2004) http://themis.la.asu.edu/zoom-20041125A.html Granicus Vallis Channels (Released 26 November 2004) http://themis.la.asu.edu/zoom-20041126A.html 29 November - 3 December 2004 Minio Vallis Channel (Released 29 November 2004) http://themis.la.asu.edu/zoom-20041129a.html Channel/Crater Interaction (Released 30 November 2004) http://themis.la.asu.edu/zoom-20041130a.html Olympica Fossae (Released 1 December 2004) http://themis.la.asu.edu/zoom-20041201a.html Olympica Fossae Redux (Released 2 December 2004) http://themis.la.asu.edu/zoom-20041202a.html Hebrus Vallis (Released 3 December 2004) http://themis.la.asu.edu/zoom-20041203a.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. ADVANCING THE WEBB Based on Grumman report From Astrobiology Magazine 28 November 2004 Balancing its position between the Sun and Earth's gravity, a next generation of Space Observatory is beginning to come off the drawing boards and onto the lathes and lens grinders of machine shops. Scheduled for launch in 2011, the Webb Space Telescope was officially named today after James E. Webb, NASA's second administrator. Particularly sensitive to the infrared range of the universe, the telescope is part of large-scale international collaborations which also may enable imaging some kinds of extrasolar planets.

NASA's James Webb Space Telescope (JWST) moved a major step forward with the opening of a state-of-the-art facility that will machine the observatory's optical components. The new facility houses advanced computer-aided manufacturing and metrology equipment that will shape JWST's optical components to a high degree of accuracy. The components consist of 18 hexagonal beryllium segments for JWST's primary mirror, measuring 1.3 meters from tip to tip, and other mirror substrates and support structures. Fabrication in the facility will begin later this month and will be completed in 2007. "Axsys Technologies' new facility is critical to providing the lightweight beryllium mirrors that enable JWST's large aperture," said Martin Mohan, JWST program manager, Northrop Grumman Space Technology. "The start of machining the beryllium blanks marks another key milestone accomplished on schedule for the JWST team." Manufacturing the observatory's mirror is a four-step process, which is being performed by a team led by Ball Aerospace. Brush Wellman compresses beryllium into large segments called "blanks"; Axsys Technologies machines the blanks; Tinsley Laboratories grinds and polishes the mirrors; and Ball incorporates the mirrors into optical assemblies and mounts them on the telescope structure. Manufacturing all 18 mirrors will take approximately four-and-a-half years. At Axsys Technologies, machining and etching of the blank's backside will reduce the mirror mass by 92 percent, from 553 pounds (250 kilograms) to 46 pounds (21 kilograms); machining of the front side prepares the optical surface for subsequent grinding and polishing. Earlier this year, Axsys Technologies started machining an engineering development unit (mirror prototype) to demonstrate its capabilities. The observatory features a 6.5-meter (20 feet) aperture primary mirror that will be the largest deployable telescope ever launched. Beryllium, one of the lightest of all metals, was selected as the mirror technology for its demonstrated track record operating at cryogenic temperatures (around -400 degrees Fahrenheit) on space-based telescopes. JWST will peer into the infrared at great distances to search for answers to astronomers' fundamental questions about the birth and evolution of galaxies, the size and shape of the universe, and the mysterious life cycle of matter. In addition to distant galaxies, the longer infrared wavelengths are sensitive to galaxies that are intrinsically red, such as elliptical galaxies and galaxies that have red colors due to a high degree of dust absorption. A component of NASA's Origins Program, JWST will reside in an orbit 940,000 miles from Earth at the L2 Lagrange point after its launch in 2011. Read the original article at http://www.astrobio.net/news/article1318.html. End Marsbugs, Volume 11, Number 45.

Date post:	31-May-2020
Category:	Documents
Upload:	others
View:	3 times
Download:	0 times

Editor/Publisher Page 7 BUILD YOUR OWN BORG: SORT OF Page...

Documents