Marsbugs: The Electronic Astrobiology NewsletterVolume 12, Number 7, 22 February 2005

Editor/Publisher: David J. Thomas, Ph.D., Science Division, Lyon College, Batesville, Arkansas 72503-2317, USA. dthomas@lyon.edu

Marsbugs is published on a weekly to monthly basis as warranted by the number of articles and announcements. Copyright of this compilation exists with the editor, but individual authors retain the copyright of specific articles. Opinions expressed in this newsletter are those of the authors, and are not necessarily endorsed by the editor or by Lyon College. E-mail subscriptions are free, and may be obtained by contacting the editor. Information concerning the scope of this newsletter, subscription formats and availability of back-issues is available at http://www.lyon.edu/projects/marsbugs. The editor does not condone "spamming" of subscribers. Readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing lists. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editor.

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the remains of two impact craters that were filled, buried, and then exhumed from within layered sedimentary rock in the martian crater, Gale. Wind erosion has sculpted tapered yardang ridges in the uppermost rock layers exposed at this location. This is the 1000 th captioned image release from the MGS MOC team. The first release occurred in July 1997, when the spacecraft was still speeding toward the red planet. Many people have asked, "Why are the releases numbered starting with 'MOC2'?" The MGS MOC is the second MOC, so it is designated "MOC2". The first MOC was flown on the Mars Observer spacecraft, which was lost just before arrival at Mars in August 1993. The MOC science investigation was originally selected by NASA in 1986. The MGS MOC effort is currently in its third extended mission, and is funded through at least October 2006. [http://www.msss.com/mars_images/moc/2005/02/12/]

Articles and News

Page 1 PLANETS GALORE: 12 NEW DISCOVERIES ANNOUNCEDBy Randall Jackson

Page 2 ULTRASOUND FOR ASTRONAUTSBy Karen Miller

Page 3 SOMETHING BIGGER THAN LIFE (INTERVIEW WITH AL DIAZ)By Michael Benson

Page 4 SCRIPPS RESEARCHERS FIND CLEAR EVIDENCE OF HUMAN-PRODUCED WARMING IN WORLD'S OCEANSScripps Institute release

Page 5 WATER SPREAD ACROSS MUCH OF ANCIENT MARS, CREATING CONDITIONS FOR LIFE By Robert Roy Britt

Page 5 NASA OBSERVES ONE OF BRIGHTEST COSMIC EXPLOSIONSNASA release 05-051

Page 6 TITAN'S ATMOSPHERE MAY HAVE COME FROM AMMONIA, HUYGENS DATA SAYBy Lori Stiles

Page 7 NASA STATEMENT ON FALSE CLAIM OF EVIDENCE OF LIFE ON MARSNASA release 05-052

Page 7 EVIDENCE FOR LARGE WATER RESOURCES FOUND NEAR MARS EQUATOR Mars Society release

Page 7 OPEN UNIVERSITY SCIENTIST HELPS DISCOVER FROZEN SEA OF WATER ON MARSOpen University release

Announcements

Page 8 LIFE AT THE LIMITS: EARTH, MARS, AND BEYONDLunar and Planetary Institute release

Mission Reports

Page 8 CASSINI UPDATESNASA/JPL releases

Page 12 MARS EXPLORATION ROVERS UPDATESAdapted from NASA/JPL releases

Page 12 SCIENCE FROM MARS EXPRESS AFTER ONE YEAR IN ORBITESA release 10-2005

Page 13 MARS GLOBAL SURVEYOR IMAGESNASA/JPL/MSSS release

Page 13 MARS ODYSSEY THEMIS IMAGESNASA/JPL/ASU release

PLANETS GALORE: 12 NEW DISCOVERIES ANNOUNCEDBy Randall JacksonNASA/JPL/PlanetQuest release15 February 2005

The past four weeks have been heady ones in the planet-finding world. Three teams of astronomers announced the discovery of 12 previously unknown worlds, bringing the total count of planets outside our solar system to 145.

Just a decade ago, scientists knew of only the nine planets—those in our local solar system. In 1995, improved detection techniques produced the first solid evidence of a planet circling another star. A proliferation of discoveries followed, and now dozens of ongoing search efforts around the globe add steadily to the roster of worlds. Most of these planets differ markedly from the planets in our own solar system. They are more similar to Jupiter or Saturn than to Earth, and are considered unlikely to support life as we know it.

The news of the past four weeks has included: The discovery of six new gas-giant planets by two teams of European

planet-hunters was announced this week. Two of these planets are similar in mass to Saturn; three belong to a class known as "hot jupiters" because of their close proximity to the host stars. The sixth is a gas giant at least four-and-a-half times the mass of Jupiter. All were discovered as part of the High Accuracy Radial velocity Planet Search (HARPS), an ongoing search program based at La Silla Observatory in Chile.

On January 20, a paper posted in the online edition of the Astrophysical Journal described five new gas-giant type planets detected by a team of U.S. astronomers. These planets provide further statistical information about the distribution and properties of planetary systems, according to the paper. The U.S. team based its finding on observations obtained at the W. M. Keck Observatory in Hawaii, which is jointly operated by the

Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 7, 22 February 2005

University of California and Caltech. Observation time was granted by both NASA and the University of California.

Last week, Penn State's Alex Wolszczan and Caltech's Maciej Konacki announced the discovery of the smallest planet-like body detected beyond our solar system. The object belongs to a strange class known as "pulsar planets." It is about one-fifth the size of Pluto and orbits a rapidly spinning neutron star, called a pulsar.

New discoveries were announced based on observations made with the W. M. Keck Observatory (left) and the La Silla Observatory (right).

A pulsar is a dense and compact star that forms from the collapsing core left over from the death of a massive star. The new pulsar planet is the fourth to be discovered; all orbit the same pulsar, named PSR B1257+12. Because the planets around the pulsar are continually strafed by high-energy radiation, they are considered extremely inhospitable to life. (The current planet count posted on the PlanetQuest web site includes only planets around normal stars—http://planetquest.jpl.nasa.gov/.)

Two methods of detection

The pulsar planet was discovered by observing the neutron star's pulse arrival times, called pulsar timing. Variations in these pulses give astronomers an extremely precise method for detecting the phenomena that occur within a pulsar's environment.

The gas-giant planets were detected using the radial velocity method, which infers the presence of an unseen companion because of the back-and-forth movement induced in the host star. This movement is detectable as a periodic red shift and blue shift in the star's spectral lines. (For more about this method, see the article, "Finding Planets," at http://planetquest.jpl.nasa.gov/science/finding_planets.html.)

The names of the new planets around main sequence stars are: HD 2638 bHD 27894 bHD 63454 bHD 102117 bHD 93083 bHD 142022A bHD 45350 bHD 99492 bHD 117207 bHD 183263 bHD 188015 b

Additional articles on this subject are available at:http://www.astrobio.net/news/article1447.htmlhttp://www.spacedaily.com/news/extrasolar-05i.htmlhttp://www.universetoday.com/am/publish/12_new_planets.html

ULTRASOUND FOR ASTRONAUTSBy Karen MillerFrom NASA Science News16 February 2005

When you hear the word "ultrasound" you probably think of pregnant moms and their babies. Add one more to that list: astronauts. Nobody's pregnant in space, but astronauts onboard the International Space Station (ISS) are using ultrasound, looking inside themselves as part of a NASA project called ADUM, short for "ADvanced Ultrasound in Microgravity." Dr. Scott Dulchavsky, a surgeon at the Henry Ford Hospital in Detroit, heads the project. His team, which includes co-investigators Doug Hamilton, Shannon Melton and Ashot Sargsyan, of Wyle Laboratories, in Houston, is studying how ultrasound can be used to diagnose medical problems onboard spaceships.

Onboard the International Space Station, Gennady Palalka performs an ultrasound exam on Mike Fincke.

Here on Earth, doctors can look at broken bones with an x-ray machine, they can look for tumors with a CAT scanner, and they can examine your brain with an MRI. None of those bulky instruments is available on any NASA spacecraft. There is, however, an ultrasound machine onboard the ISS.

Ultrasound offers several advantages: Compared to other diagnostic imaging tools, ultrasound machines are compact and lightweight. This is important on cramped spaceships where every ounce of payload costs money to launch. Furthermore, ultrasound images appear instantly. You don't have to wait for, say, x-ray films to be developed. Got a problem? Ultrasound can find it quickly.

An ultrasound probe works somewhat like radar. It sends high-frequency sound waves into the body. When those waves encounter an organ—say, the liver—some bounce back immediately, and some continue, bouncing back when they reach the next organ—say, the kidney. Because sound waves travel through each organ, or tissue, at a different speed, the probe is able to "see" what the reflected sound waves have found.Typically, ultrasound has been used to look at internal organs. It's often used to examine fetuses. But Dulchavsky and his team have been expanding its repertoire. They're working out ways to look at eyes, teeth, lungs, bones and muscles. They believe that ultrasound can be used for about two-thirds of a list of approximately 500 medical conditions that might hypothetically occur on a spacecraft.

An ultrasound view of ISS astronaut Mike Fincke's biceps tendon. "D" denotes the deltoid muscle. "T" is the proximal intracapsular end of the long biceps tendon.

And, in some cases, ultrasound works even better in space than it does on Earth. That's because in low gravity, internal organs move around. "The

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heart shifts up... The liver moves about three inches north." The result is that organs often end up closer to each other. That's good. Sound waves move from one to the other with less distortion, providing a clearer ultrasound picture.

Traditionally, ultrasound probes are operated by technicians with several hundred hours of training. Astronauts only get about four hours training. How do they manage? "We're helping them," says Dulchavsky. As the astronauts work the probe, they're in constant contact with experts on the ground.

Recently, the procedure was tested with ISS astronauts Mike Fincke and Gennady Padalka. The ground crew and the astronauts relied on a satellite downlink to share information. "[Mike] puts the probe to the skin, and then, two seconds later we in the Johnson Space Center get to see the same image he sees," says Dulchavsky.

It's an interactive process: "We go, 'Mike, that's not quite right. Can you move the probe an inch closer to the elbow?' So, Mike slides it down an inch closer. 'Ah, that's really good, you need to push harder.' Mike pushes harder. 'Almost perfect, move it half-an-inch to the back. Ahh, you've got it. Perfect!'"

Dr. Scott Dulchavsky (far right) shows Detroit Red Wings trainer Piet Van Zant (far left) how to use an ultrasound machine.

This technique, non-doctors using ultrasound to obtain diagnostic quality pictures under the guidance of remote experts, turns out to have important applications on Earth—on battlefields, for instance, or in rural areas where doctors are far away.

"We're looking at modifying how we transmit the information, so we could do it through a cell phone," says Dulchavsky. Picture this: "we could put ultrasound probes on ambulances." Emergency room doctors could set up a treatment before the patient even arrives at the hospital.

The process has already been used successfully on the ground—in the locker room of the Red Wings, Detroit's hockey team. "Players get hurt a lot in NHL games," says Dulchavsky, a fan. "Last season, we trained one of their trainers to use the probe. It worked famously."

It works well in space, too. In the ISS experiment, Fincke and Padalka examined each others' shoulders. That joint was picked, says Dulchavsky, because it's so complicated. And, even though the shoulder is one of the most challenging ultrasound examinations to do, the astronauts were able to obtain clear, diagnostic-quality views. A paper describing the procedure was published in the February issue of the journal, Radiology; it's the first article ever submitted from orbit.

Right now, Dulchavsky and his colleagues are analyzing their data. The next step, he says, is to put together a program that will teach the astronauts to do more and more on their own. This would enable ultrasound to be used even on long-range exploration missions, like trips to Mars, where guidance from the ground is less practical. The ADUM project is significant, says Dulchavsky, because it has pushed the limits of what ultrasound technology can do. He and his colleagues plan to push those boundaries even more.

Read the original article at http://science.nasa.gov/headlines/y2005/16feb_ultrasound.htm.

SOMETHING BIGGER THAN LIFE (INTERVIEW WITH AL DIAZ)By Michael BensonFrom Astrobiology Magazine16 February 2005

The successful arrival of the European Space Agency's Huygens atmospheric probe on the distant Saturnian moon of Titan in mid-January was a moving event. Many in the multinational contingent of scientists, engineers and administrators that had gathered at ESA's control facility in Darmstadt, Germany had worked on the mission for a decade or more. Once it was clear that the probe was working as planned, a palpable euphoria—a compound of relief and pride—pervaded the proceedings. One of ESA's high-ranking NASA visitors was Al Diaz, director of the agency's new science organization, the Science Mission Directorate. Although the Huygens part of Cassini-Huygens was designed and built in Europe and led by ESA, the mission was conducted in close collaboration with NASA. Huygens itself had been brought to Saturn by Cassini. The interview took place at ESA Headquarters in Darmstadt on January 15th, the day after Huygens's pictures of smoggy Titan revealed an icy orange-tinged topography sculpted by liquid ethane rivers and lakes—a place of shorelines, creeks and fog that's utterly alien, and yet also fascinatingly Earth-like in many respects.

Texture of landing sites. Upper left, the moon; upper right, Venus; middle left, Pathfinder 1997 Mars; middle right, Viking 1977 Mars; lower left, airbag imprint in Eagle Crater, Meridiani Planum 2004; lower right, airbag drag mark, Meridiani Planum, 2004 Opportunity site. Image credit: NASA/ JPL.

Michael Benson (MB): You were head of NASA's Goddard Space Flight Center.

Al Diaz (AD): I was.

MB: So you know about earth science.

AD: I do.

MB: To what extent is the exploration of the solar system about discovering processes on Earth? For instance, taking information about the atmospheres of Titan, Mars, or Venus, and then using this larger context of the solar system to learn about atmospheric processes here on Earth.

AD: That's an excellent question, because what we're learning about earth science can be informed by our exploration of the solar system, as well as benefit our exploration of the solar system, in a far more substantial way than

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we've taken advantage of. When you think about the kinds of issues that we're going to be dealing with if humans are going to go to Mars, many of them are the same kinds of issues that we've tried to deal with on the Earth. So we think that there's a lot of competency, capability, and a lot of tools that have been developed for earth science that we can apply to missions to Mars. We've already seen evidence of that.

In the case of the Spirit and Opportunity Mars landings, earth science-developed models were used to better design the second landing, based on the uncertainty in the density of the atmosphere. I don't believe that would have happened 10 years ago, because the modeling hadn't reached that level, and people weren't as aware of the kinds of capabilities that the models could introduce. So we think there's a tremendous opportunity to integrate earth science and space science for the benefit of both. And that's what we're trying to do.

MB: What about vice versa. I mean, Venus has a runaway greenhouse. Mars has lost most of its atmosphere and is exposed to merciless ultraviolet radiation. We are in the middle...

AD: This is Goldilocks and the three bears.

MB: You mean, which bowl of porridge is just right...

AD: And Earth is just right. But why is it just right? Why is the water cycle on Mars apparently inactive? Why do we have a runaway greenhouse on Venus? And to what extent does that inform our understanding of what is happening on Earth, and where we might end up? So, yeah, there's a lot of comparative planetology that we think will benefit both earth science and solar system exploration.

MB: Recently there was a call for papers from the scientific community, connected to this Moon, Mars and Beyond vision. It seems like all the examples given had to do with finding water.

AD: We've had some discussions about that recently in developing our Mars strategy. The whole Mars strategy has been following water. The whole search for life strategy has been following water. That's really because of this habitability issue. Astrobiologists tell us that, without water, there isn't any evidence that life as we know it can be supported.

MB: The Galileo probe was ordered to dive into Jupiter at the end of its mission for planetary protection reasons. There may have been Earth microbes that had survived on Galileo, so they wanted to make sure that there was no chance the probe would impact on Europa. We don't know if there's any life on Mars, but we have landed a number of missions on the surface that were sterilized as much as possible. Now we're planning on landing astronauts, eventually. How are we going to protect the potential biosphere there from our own microbes, our own life?

AD: That's a good question, and it's the focus of a whole discipline called interplanetary protection. For every mission that we send, we have to do a consequence analysis that looks at what the impact is to the planet in terms of introducing any overburden of biology. For Mars, every analysis that we've done has indicated that the introduction is so small as to be considered innocuous in terms of any consequence.

Now, you're right, at some point in time, we are going to have to do something more substantial. I think, between now and the human landings on Mars, we want to do analyses that would indicate whether or not there is life extant there. We need to determine that before the human landings. We also don't want to disturb the pristine environment for future attempts to search for life. That discussion is taking place right now, in our strategic road mapping about the Mars Sample Return mission. So that debate is ongoing.

MB: What's your sense of what really motivates people when it comes to their interest in space exploration?

AD: People are interested in space exploration for the same reason that I got emotional about the Huygens probe landing on Titan. This is something that's bigger than life! And it's an opportunity for people to participate in something that has historic proportions. I believe that it is not motivated by economic returns, although there are people that have that vision. It is not motivated by national defense, although it has that benefit as well. I really believe that the public's interest in it is that it's an activity of historic proportions that they have an opportunity to be involved in. And I think in the future, they won't

be satisfied with being able to visit web sites to see what we are doing. I think in the future, they are going to demand that they be involved, and that they have the opportunity to participate in some significant way.

Read the original article at http://www.astrobio.net/news/article1444.html.

SCRIPPS RESEARCHERS FIND CLEAR EVIDENCE OF HUMAN-PRODUCED WARMING IN WORLD'S OCEANSScripps Institute release17 February 2005

Scientists at Scripps Institution of Oceanography at the University of California, San Diego, and their colleagues have produced the first clear evidence of human-produced warming in the world's oceans, a finding they say removes much of the uncertainty associated with debates about global warming. In a new study conducted with colleagues at Lawrence Livermore National Laboratory's Program for Climate Model Diagnosis and Intercomparison (PCMDI), Tim Barnett and David Pierce of Scripps Institution used a combination of computer models and real-world "observed" data to capture signals of the penetration of greenhouse gas-influenced warming in the oceans. The authors make the case that their results clearly indicate that the warming is produced anthropogenically, or by human activities.

"This is perhaps the most compelling evidence yet that global warming is happening right now and it shows that we can successfully simulate its past and likely future evolution," said Tim Barnett, a research marine physicist in the Climate Research Division at Scripps. Barnett says he was "stunned" by the results because the computer models reproduced the penetration of the warming signal in all the oceans. "The statistical significance of these results is far too strong to be merely dismissed and should wipe out much of the uncertainty about the reality of global warming."

At a news briefing (February 17 at 2:00 PM EST) and symposium presentation (February 18 at 1:45-4:45 PM EST) during the 2005 American Association for the Advancement of Science annual meeting in Washington, DC, Barnett will discuss the details of the study and explain why the results hold implications for millions of people in the near future.

According to Barnett, the climate mechanisms behind the ocean study will produce broad-scale changes across the atmosphere and land. In the decades immediately ahead, the changes will be felt in regional water supplies, including areas impacted by accelerated glacier melting in the South American Andes and in western China, putting millions of people at risk without adequate summertime water. Similarly, recent research by Barnett and his colleagues with the Accelerated Climate Prediction Initiative analyzed climate warming impacts on the western United States using one of the models involved in the new study. The earlier study concluded that climate warming will likely alter western snow pack resources and the region's hydrological cycle, posing a water crisis in the western U.S. within 20 years.

"The new ocean study, taken together with the numerous validations of the same models in the atmosphere, portends far broader changes," said Barnett. "Other parts of the world will face similar problems to those expected—and being observed now—in the western U.S. The skill demonstrated by the climate models in handling the changing planetary heat budget suggests that these scenarios have a high enough probability of actually happening that they need to be taken seriously by decision makers."

In the new study, Barnett and his colleagues used computer models of climate to calculate human-produced warming over the last 40 years in the world's oceans. In all of the ocean basins, the warming signal found in the upper 700 meters predicted by the models corresponded to the measurements obtained at sea with confidence exceeding 95 percent. The correspondence was especially strong in the upper 500 meters of the water column. It is this high degree of visual agreement and statistical significance that leads Barnett to conclude that the warming is the product of human influence. Efforts to explain the ocean changes through naturally occurring variations in the climate or external forces- such as solar or volcanic factors—did not come close to reproducing the observed warming.

In addition to Barnett and Pierce, coauthors of the study include Krishna Achutarao, Peter Gleckler and Benjamin Santer of Lawrence Livermore National Laboratory. The global climate models used in the study included the Parallel Climate Model from the National Center for Atmospheric Research and Department of Energy (DOE) and the HadCM3 from the Hadley

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Centre (United Kingdom). The sharing of these model results made this study possible, says Barnett. The work was a contribution on behalf of the International Detection and Attribution Group (IDAG), which is sponsored by the National Oceanic and Atmospheric Administration's (NOAA) Climate Change Data Detection Program, a jointly funded NOAA and DOE program. Additional support was provided by DOE through support of PCMDI and Scripps.

Scripps Institution of Oceanography: http://scripps.ucsd.eduScripps News: http://scrippsnews.ucsd.edu

Contacts: Mario AguileraMobile: 858-245-3175

Scripps CommunicationsPhone: 858-534-3624E-mail: scrippsnews@ucsd.edu

WATER SPREAD ACROSS MUCH OF ANCIENT MARS, CREATING CONDITIONS FOR LIFE By Robert Roy BrittFrom Space.com17 February 2005

Water was common across a vast region of ancient Mars, creating habitable conditions for long stretches of time billions of years ago, scientists said Thursday. New data reveal water in the Meridiani Planum region of Mars extended across hundreds of thousands of square miles, at least as groundwater and possibly as shallow lakes or seas. The work significantly expands the amount of surface area on Mars known to have once been water-laden, and it extends the period of time that the water was present.

Rocks that clearly formed in water extend throughout 980 feet (300 meters) of layered material in several locations across the plains, said Ray Arvidson, an Earth and planetary sciences expert at Washington University in St. Louis, Missouri. The layers were built up over time, which means water was present, at least off and on, for extended periods of the early martian history. The findings mean that the conditions for life were present.

Read the full article at http://www.space.com/scienceastronomy/mars_water_050217.html.

NASA OBSERVES ONE OF BRIGHTEST COSMIC EXPLOSIONSNASA release 05-05118 February 2005

Scientists detected a flash of light from across the Galaxy so powerful; it bounced off the moon and lit up the Earth's upper atmosphere.The flash was brighter than anything ever detected from beyond our Solar System, and it lasted over a tenth of a second. NASA and European satellites and many radio telescopes detected the flash and its aftermath on December 27, 2004. Two science teams are reporting about this event at a special press conference today at 2:00 PM EST at NASA Headquarters, Washington.

Artist conception of the December 27, 2004 gamma ray flare expanding from SGR 1806-20 and impacting Earth’s atmosphere. Image credit: NASA.

NASA's Swift satellite and the National Science Foundation-funded Very Large Array (VLA) were two of many observatories that observed the event arising from neutron star SGR 1806-20. It is a unique neutron star called a magnetar, about 50,000 light years from Earth in the constellation Sagittarius. The apparent magnitude was brighter than a full moon and all historical star explosions. The light was brightest in the gamma-ray energy range, far more energetic than visible light or X-rays and invisible to our eyes.

"This might be an once-in-a-lifetime event for astronomers, as well as for the neutron star," said Dr. David Palmer of Los Alamos National Laboratory, NM. He is lead author on a paper describing the Swift observation. "We know of only two other giant flares in the past 35 years, and the December event was 100 times more powerful," he added.

An artist conception of the SGR 1806-20 magnetar including magnetic field lines. After the initial flash, smaller pulsations in the data suggest hot spots on the rotating magnetar’s surface. The data also show no change in the magentar’s rotation after the initial flash. Image credit: NASA.

Dr. Bryan Gaensler of the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA, is lead author on a report describing the VLA observation, which tracked the ejected material as it flew out into interstellar space. Other key scientific teams are associated with radio telescopes in Australia, The Netherlands, United Kingdom, India and the United States, as well as with NASA's High Energy Solar Spectroscopic Imager (RHESSI).

Neutron stars form from collapsed stars. They are dense, fast-spinning, highly magnetic, and only about 15 miles in diameter. Only about 12 magnetars are known among the millions of regular neutron stars in our Galaxy and neighboring galaxies. SGR 1806-20 is also a soft gamma repeater (SGR) because it randomly flares and releases gamma rays. Only four SGRs are known. The giant flare on SGR 1806-20 was millions to billions of times more powerful than typical SGR flares. For a tenth of a second, the giant flare unleashed more energy than the sun emits in 150,000 years. Magnetic fields around magnetars are responsible for SGR outbursts, but the details remain unclear.

SGR-1806 is an ultra-magnetic neutron star, called a magnetar, located about 50,000 light years away from Earth in the constellation Sagittarius. Image credit: NASA.

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"The next biggest flare ever seen from any soft gamma repeater was peanuts compared to this incredible December 27 event," Gaensler said. "Had this happened within 10 light years of us, it would have severely damaged our atmosphere. Fortunately, all the magnetars we know of are much farther away than this," he added.

During the 1980s scientists wondered whether gamma-ray bursts were star explosions from beyond our Galaxy or eruptions on nearby neutron stars. By the late 1990s it became clear gamma-ray bursts did indeed originate far away. But the extraordinary giant flare on SGR 1806-20 reopens the debate, according to Dr. Chryssa Kouveliotou of NASA's Marshall Space Flight Center, Huntsville, AL, who coordinated multiwavelength follow-up observations. A small percentage of short gamma-ray bursts, less than two seconds, could be from SGR flares.

"An answer to the short gamma-ray burst mystery could come any day now that Swift is in orbit", said Swift lead scientist Neil Gehrels.

Scientists around the world have been following the December 27 event. RHESSI detected gamma rays and X-rays from the flare. Drs. Kevin Hurley and Steven Boggs of the University of California, Berkeley, are leading the effort to analyze these data. For more information about the event on the Internet, visit http://www.nasa.gov/vision/universe/watchtheskies/swift_nsu_0205.html.

Swift is a first-of-its-kind multi-wavelength observatory dedicated to the study of gamma ray burst (GRB) science. Its three instruments will work together to observe GRBs and afterglows in the gamma ray, X-ray, ultraviolet, and optical wavebands. Swift is designed to solve the 35-year-old mystery of the origin of gamma-ray bursts. Scientists believe GRB are the birth cries of black holes. Image credit: NASA.

Contacts:Dolores BeasleyNASA Headquarters, Washington, DCPhone: 202-358-1753

Nancy Neal JonesNASA Goddard Space Flight Center, Greenbelt, MDPhone: 301-286-0039

Additional articles on this subject are available at:http://www.space.com/scienceastronomy/bright_flash_050218.htmlhttp://www.spacedaily.com/news/stellar-05g.htmlhttp://www.spacedaily.com/news/gamma-05b.htmlhttp://spaceflightnow.com/news/n0502/19grb/http://story.news.yahoo.com/news?tmpl=story&u=/afp/20050218/sc_afp/astronomyspaceflare_050218192323http://www.universetoday.com/am/publish/gamma_ray_flare.html

TITAN'S ATMOSPHERE MAY HAVE COME FROM AMMONIA, HUYGENS DATA SAYBy Lori StilesUniversity of Arizona release18 February 2005

Cassini-Huygens supplied new evidence about why Titan has an atmosphere, making it unique among all solar system moons, a University of Arizona planetary scientist says. Scientists can infer from Cassini-Huygens results that Titan has ammonia, said Jonathan I. Lunine, an interdisciplinary scientist for the European Space Agency's Huygens probe that landed on Titan last month.

"I think what's clear from the data is that Titan has accreted or acquired significant amounts of ammonia, as well as water," Lunine said. "If ammonia is present, it may be responsible for resurfacing significant parts of Titan."

He predicts that Cassini instruments will find that Titan has a liquid ammonia-and-water layer beneath its hard, water-ice surface. Cassini will see—Cassini radar has likely already seen—places where liquid ammonia-and-water slurry erupted from extremely cold volcanoes and flowed across Titan's landscape. Ammonia in the thick mixture released in this way, called "cryovolcanism," could be the source of molecular nitrogen, the major gas in Titan's atmosphere.

Lunine and five other Cassini scientists will discuss the latest results from the Cassini-Huygens mission at the American Association for the Advancement of Science meeting in Washington, DC, tomorrow (February 19).Cassini scientists are also presenting some of these results at a 1:00 PM EST news briefing at AAAS today.

Cassini radar imaged a feature that resembles a basaltic flow on Earth when it made its first close pass by Titan in October 2004. Scientists believe that Titan has a rock core, surrounded by an overlying layer of rock-hard water ice. Ammonia in Titan's volcanic fluid would lower the freezing point of water, lower the fluid's density so it would be about as buoyant as water ice, and increase viscosity to about that of basalt, Lunine said. "The feature seen in the radar data suggests ammonia is at work on Titan in cryovolcanism."

Both Cassini's Ion Neutral Mass Spectrometer and Huygen's Gas Chromatograph Mass Spectrometer (GCMS) sampled Titan's atmosphere, covering the uppermost atmosphere down to the surface. But neither detected the non-radiogenic form of argon, said Tobias Owen of the University of Hawaii, a Cassini interdisciplinary scientist and member of the GCMS science team. That suggests that the building blocks, or "planetesimals," that formed Titan contained nitrogen mostly in the form of ammonia.

Titan's eccentric, rather than circular, orbit can be explained by the moon's subsurface liquid layer, Lunine said. Gabriel Tobie of the University of Nantes (France), Lunine and others will publish an article about it in a forthcoming issue of Icarus.

"One thing that Titan could not have done during its history is to have a liquid layer that then froze over, because during the freezing process, Titan's rotation rate would have gone way, way up," Lunine said. "So either Titan has never had a liquid layer in its interior—which is very hard to countenance, even for a pure water-ice object, because the energy of accretion would have melted water—or that liquid layer has been maintained up until today. And the only way you maintain that liquid layer to the present is have ammonia in the mixture."

Cassini radar spotted a crater the size of Iowa when it flew within 1,577 kilometers (980 miles) of Titan on Tuesday, February 15. "It's exciting to see a remnant of an impact basin," said Lunine, who discussed more new radar results that NASA released today. "Big impact craters on Earth are nice places for getting hydrothermal systems. Maybe Titan has a kind of analogous 'methanothermal' system," he said.

Radar results that show few impact craters are consistent with very young surfaces. "That means Titan's craters are either being obliterated by resurfacing, or they are being buried by organics," Lunine said. "We don't know which case it is." Researchers believe that hydrocarbon particles that fill Titan's hazy atmosphere fall from the sky and blanket the ground below. If this has occurred throughout Titan's history, Titan would have "the biggest hydrocarbon reservoir of any of the solid bodies in the solar system," Lunine noted.

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In addition to the question about why Titan has an atmosphere, there are two other great questions about Saturn's giant moon, Lunine added. A second question is how much methane has been destroyed throughout Titan's history, and where all that methane comes from. Earth-based and space-based observers have long known that Titan's atmosphere contains methane, ethane, acetylene and many other hydrocarbon compounds. Sunlight irreversibly destroys methane in Titan's upper atmosphere because the released hydrogen escapes Titan's weak gravity, leaving ethane and other hydrocarbons behind.

When the Huygens probe warmed Titan's damp surface where it landed, its instruments inhaled whiffs of methane. That is solid evidence that methane rain forms the complex network of narrow drainage channels running from brighter highlands to lower, flatter dark areas. Pictures from the UA-led Descent Imager-Spectral Radiometer experiment document Titan's fluvial features.

The third question—one that Cassini was not really instrumented to answer—Lunine calls the "astrobiological" question. It is, given that liquid methane and its organic products rain down from Titan's stratosphere, how far has organic chemistry progressed on Titan's surface? The question is, Lunine said, "To what extent is any possible advanced chemistry at Titan's surface at all relevant to prebiotic chemistry that presumably occurred on Earth prior to the time life began?"

The Cassini-Huygens mission is a collaboration between NASA, ESA and ASI, the Italian Space Agency. The Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology in Pasadena, is managing the mission for NASA's Science Mission Directorate, Washington, DC. JPL designed, developed and assembled the Cassini oribter while ESA operated the Huygens probe.

Contacts:Lori StilesUA News ServicesPhone: 520-621-1877

Jonathan I. LunineUniversity of ArizonaPhone: 520-621-2789Mobile: 520-241-4739E-mail: jlunine@lpl.arizona.edu

Additional articles on this subject are available at:http://spaceflightnow.com/news/n0502/21titan/http://www.universetoday.com/am/publish/ammonia_key_titan.html.

NASA STATEMENT ON FALSE CLAIM OF EVIDENCE OF LIFE ON MARSNASA release 05-05218 February 2005

News reports on February 16, 2005, that NASA scientists from Ames Research Center, Moffett Field, CA, have found strong evidence that life may exist on Mars are incorrect. NASA does not have any observational data from any current Mars missions that supports this claim. The work by the scientists mentioned in the reports cannot be used to directly infer anything about life on Mars, but may help formulate the strategy for how to search for martian life. Their research concerns extreme environments on Earth as analogs of possible environments on Mars. No research paper has been submitted by them to any scientific journal asserting martian life.

For information about NASA and agency programs on the Web, visit http://www.nasa.gov. For more information about NASA's Mars programs on the Web, visit http://mars.jpl.nasa.gov/.

Read the news articles in question at:http://www.space.com/scienceastronomy/mars_life_050216.html.http://msnbc.msn.com/id/6981361/http://www.marsdaily.com/news/mars-life-05a.html

Contacts:Dolores Beasley/Gretchen Cook-AndersonNASA Headquarters, Washington, DCPhone: 202-358-1753/0836)

EVIDENCE FOR LARGE WATER RESOURCES FOUND NEAR MARS EQUATOR Mars Society release21 February 2005

An article in the New Scientist reports that a team of scientists working on the European Mars Express orbiter have found evidence of large amounts of pack ice lying within a few centimeters of the martian surface in parts of the planet's equatorial regions. The evidence was judged to be "fairly plausible" by Dr. Michael Carr. Carr is the former head of NASA's Mars Science Working Group, the author of the books, The Surface of Mars, and Water on Mars" and is widely considered to be the dean of martian geology.

The Mars Express team's discovery, if confirmed, is of extraordinary importance. Up until now, the only pure water resources known to exist on Mars have been found in its polar regions. Water is known to exist in significant percentages the soil and in hydrates all over Mars, but processing these involves solid handling procedures of significantly greater complexity and power requirements greater than those needed to deal with ice. The availability of pure ice easily accessible from the surface would be of enormous benefit to future martian explorers and settlers, as combined with the known plentiful carbon dioxide resources of the martian atmosphere, would allow synthesis of hydrocarbon fuels and oxidizers, the production of food, fiber, fabrics, plastics, and innumerable other necessary items. Water is also needed for many other essential industrial processes involving the production of metals and other chemicals.

This is a vastly more favorable resource prospect that exists on the impoverished Moon, where water is only present in parts per million quantities in deeply frozen permanently shadowed craters near the lunar poles, and carbon is absent entirely. In addition, frozen bodies of water in the martian tropics may hold enormous scientific value, as they could contain preserved, or even dormant but viable, microbial martian life forms. The detection and analysis of such life could provide the Rosetta Stone for human understanding of the nature, prevalence, and potential diversity of life in the cosmos.

A complete discussion of the breaking discoveries from the American and European Mars probes will be held at the 8th International Mars Society Convention, August 11-14, 2005, University of Colorado, Boulder. Registration is now open at www.marssociety.org.

The New Scientist article may be found at http://www.newscientist.com/article.ns?id=dn7039.

OPEN UNIVERSITY SCIENTIST HELPS DISCOVER FROZEN SEA OF WATER ON MARSOpen University release22 February 2005

The discovery of a frozen sea close to the equator of Mars has brought the possibility of life on Mars one step closer. Open University scientist, Dr. John Murray, is among the scientists who made the discovery from the High Resolution Stereo Camera images on board the Mars Express probe—the first European mission to another planet. Dr. Murray, of the Department of Earth Sciences, said, "The fact that there have been warm and wet places beneath the surface of Mars since before life began on Earth, and that some are probably still there, means that there is a possibility that primitive micro-organisms survive on Mars today. This mission has changed many of my long-held opinions about Mars—we now have to go there and check it out".

The water that formed the sea appears to have originated beneath the surface of Mars, and to have erupted from a series of fractures known as the Cerberus Fossae, from where it flowed down in a catastrophic flood, and collected in a vast area 800 x 900 km about 5 million years ago. It initially averaged 45 meters deep, making it about the same size and depth as the North Sea. It was the pack-ice which formed on the surface of the sea that drew the attention of Mars Express scientists.

The young age of this feature has caused excitement among scientists. Although formed at the time when early hominids on Earth were evolving from apes, this is very young in geological terms, and suggests that vast flooding events, which are known to have occurred from beneath Mars' surface throughout its geological history, are still continuing to happen. The presence of liquid water for thousands of millions of years, even beneath the surface, is a possible habitat in which primitive life may have developed, and

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might still be surviving now. Clearly this must now be considered as a prime site for future missions looking for life.

The fractured plate-like features on Mars range in size from 30 m to greater than 30 km. Image credit: ESA/DLR/F. U. Berlin/G. Neukum.

The discovery was made by Dr. Murray, Jan-Peter Muller (University College London), Gerhard Neukum (Free University, Berlin & Principal Investigator) and a team of international scientists working on the pictures sent back from Mars, and is to appear in the scientific journal Nature.

Mars Express, Europe's first ever space mission to another planet, entered the orbit of Mars successfully on Christmas Day 2003, and since January 2004 the high resolution stereo camera on board has been taking a massive number of stereo images of the surface from altitudes as low as 270 km, showing details down to 10 meters.

Read the original news release at http://www3.open.ac.uk/events/9/2005222_52769_nr.doc.

An additional article on this subject is available at http://www.universetoday.com/am/publish/frozen_sea_water_mars.html.

LIFE AT THE LIMITS: EARTH, MARS, AND BEYONDLunar and Planetary Institute release18 February 2005

The Lunar and Planetary Institute invites you to join an Earth-bound exploration of astrobiology on July 10-17, 2005!

"Life at the Limits: Earth, Mars, and Beyond" is a NASA-sponsored training workshop for middle-and high-school science teachers (others welcome, including pre-service teachers, informal educators, education specialists, early college instructors, and junior college instructors). At field sites in Nevada and California participants will investigate some extreme geological and chemical conditions in which life on Earth can thrive. This hands-on, real-world experience will enhance classroom teaching about earth and space science, especially about what organisms need to survive and the search for past and present extraterrestrial life.

Astrobiologists and planetary scientists will lead the field and laboratory experiences, helping to connect the field observations with the search for life in our solar system and beyond through discussions and proven, hands-on, standards-based classroom and laboratory activities that are ready to share with students! For more information and to access the on-line application, please visit http://www.lpi.usra.edu/education/fieldtrips/2005/. Applications are due March 23, 2005.

CASSINI UPDATESNASA/JPL releases

NASA Spacecraft Help Solve Saturn's Mysterious AurorasNASA/JPL release 2005-028, 16 February 2005

Scientists studying data from NASA's Cassini spacecraft and Hubble Space Telescope have found that Saturn's auroras behave differently than scientists have believed for the last 25 years. The researchers, led by John Clarke of Boston University, found the planet's auroras, long thought of as a cross between those of Earth and Jupiter, are fundamentally unlike those observed on either of the other two planets. The team analyzing Cassini data includes Dr. Frank Crary, a research scientist at Southwest Research Institute in San Antonio, Texas, and Dr. William Kurth, a research scientist at the University of Iowa, Iowa City.

These images of Saturn's polar aurora were taken by NASA's Hubble Space Telescope on January 24, 26, and 28. Each of the three images of Saturn combines ultraviolet images of the south polar region (to show the auroral emissions) with visible wavelength images of the planet and rings. The Hubble images were obtained during a joint campaign with NASA's Cassini spacecraft to measure the solar wind approaching Saturn and the Saturn kilometric radio emissions. The strong brightening of the aurora on January 26 corresponded with the recent arrival of a large disturbance in the solar wind. These results are presented in three papers, which appear in the February 17 issue of the journal, Nature. Image credit: NASA/Hubble/Z. Levay and J. Clarke. Hubble snapped ultraviolet pictures of Saturn's auroras over several weeks, while Cassini's radio and plasma wave science instrument recorded the boost in radio emissions from the same regions, and the Cassini plasma spectrometer and magnetometer instruments measured the intensity of the aurora with the pressure of the solar wind. These sets of measurements were combined to yield the most accurate glimpse yet of Saturn's auroras and the role of the solar wind in generating them. The results will be published in the February 17 issue of the journal, Nature. The findings show that Saturn's auroras vary from day to day, as they do on Earth, moving around on some days and remaining stationary on others. But compared to Earth, where dramatic brightening of the auroras lasts only about 10 minutes, Saturn's can last for days. The observations also show that the Sun's magnetic field and solar wind may play a much larger role in Saturn's auroras than previously suspected. Hubble images show that auroras sometimes stay still as the planet rotates beneath, like on Earth, but also show that the auroras sometimes move along with Saturn as it spins on its axis, like on Jupiter. This difference suggests that Saturn's auroras are driven in an unexpected manner by the Sun's magnetic field and the solar wind, not by the direction of the solar wind's magnetic field.

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"Both Earth's and Saturn's auroras are driven by shock waves in the solar wind and induced electric fields," said Crary. "One big surprise was that the magnetic field imbedded in the solar wind plays a smaller role at Saturn."

At Earth, when the solar wind's magnetic field points southward (opposite to the direction of the Earth's magnetic field), the magnetic fields partially cancel out, and the magnetosphere is "open". This lets the solar wind pressure and electric fields in, and allows them to have a strong effect on the aurora. If the solar wind's magnetic field isn't southward, the magnetosphere is "closed" and solar wind pressure and electric fields can't get in. "Near Saturn, we saw a solar wind magnetic field that was never strongly north or south. The direction of the solar wind magnetic field didn't have much effect on the aurora. Despite this, the solar wind pressure and electric field were still strongly affecting auroral activity," added Crary.

Seen from space, an aurora appears as a ring of energy circling a planet's polar region. Auroral displays are spurred when charged particles in space interact with a planet's magnetosphere and stream into the upper atmosphere. Collisions with atoms and molecules produce flashes of radiant energy in the form of light. Radio waves are generated by electrons as they fall toward the planet. The team observed that even though Saturn's auroras do share characteristics with the other planets, they are fundamentally unlike those on either Earth or Jupiter. When Saturn's auroras become brighter and thus more powerful, the ring of energy encircling the pole shrinks in diameter. At Saturn, unlike either of the other two planets, auroras become brighter on the day-night boundary of the planet which is also where magnetic storms increase in intensity. At certain times, Saturn's auroral ring is more like a spiral, its ends not connected as the magnetic storm circles the pole.

The new results do show some similarities between Saturn's and Earth's auroras. Radio waves appear to be tied to the brightest auroral spots. "We know that at Earth, similar radio waves come from bright auroral arcs, and the same appears to be true at Saturn," said Kurth. "This similarity tells us that, on the smallest scales, the physics that generate these radio waves are just like what goes on at Earth, in spite of the differences in the location and behavior of the aurora."

Now with Cassini in orbit around Saturn, the team will be able to take a more direct look at the how the planet's auroras are generated. They will next probe how the Sun's magnetic field may fuel Saturn's auroras and learn more details about what role the solar wind may play. Understanding Saturn's magnetosphere is one of the major science goals of the Cassini mission.

Cassini's Radar Spots Giant Crater on TitanNASA/JPL release 2005-029, 16 February 2005

A giant impact crater the size of Iowa was spotted on Saturn's moon Titan by NASA's Cassini radar instrument during Tuesday's Titan flyby. Cassini flew within 1,577 kilometers (980 miles) of Titan's surface and its radar instrument took detailed images of the surface. This is the third close Titan flyby of the mission, which began in July 2004, and only the second time the radar instrument has examined Titan. Scientists see some things that look familiar, along with scenes that are completely new. The new radar images are available at http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini. "It's reassuring to look at two parts of Titan and see similar things," said Dr. Jonathan Lunine, Cassini interdisciplinary scientist from the University of Arizona, Tucson. "At the same time, there are new and strange things." This flyby is the first time that Cassini's radar and the imaging camera overlapped. This overlap in coverage should be able to provide more information about the surface features than either technique alone. The 440-kilometer-wide (273-mile) crater identified by the radar instrument was seen before with Cassini's imaging cameras, but not in this detail. A second radar image released today shows features nicknamed "cat scratches". These parallel linear features are intriguing, and may be formed by winds, like sand dunes, or by other geological processes. On Thursday, Cassini will conduct its first close flyby of Saturn's icy moon Enceladus (en-SELL-uh-duss) at a distance of approximately 1,180 kilometers (730 miles). Enceladus is one of the most reflective objects in the solar system, so bright that its surface resembles freshly fallen snow.

This image shows a crater, approximately 60 kilometers (37 miles) in diameter, on the very eastern end of the radar image strip taken by the Cassini orbiter on its third close flyby of Titan on February 15. The appearance of the crater and the extremely bright (hence rough) blanket of material surrounding it is indicative of an origin by impact, in which a hypervelocity comet or asteroid, in this case, roughly 5-10 kilometers (3-6 miles) in size, slammed into the surface of Titan. The bright surrounding blanket is debris, or ejecta, thrown out of the crater. The asymmetric appearance of this ejecta blanket could be an effect of atmospheric winds associated with the impact itself. Although clearly formed by impact, the feature lacks a central peak, suggesting that it has been eroded or otherwise modified after formation. Rainfall, wind erosion, and softening of the solid material in which the crater formed are all possible processes that might have altered this impact feature.

Saturn's Moons Titan and Enceladus Seen by CassiniNASA/JPL release 2005-03018 February 2005 NASA's Cassini spacecraft has had a busy week, snapping stunning new images of two of Saturn's moons—smoggy Titan on February 15 and wrinkled Enceladus on February 16. Visible in radar images released today are a crater, channels, and terrain similar to the area where the European Space Agency's Huygens probe landed on January 14. The crater is approximately 60 kilometers (37 miles) in diameter. Earlier this week, the radar team released an image of a giant impact crater dubbed "Circus Maximus," about 440 kilometers wide (273 miles). "The appearance of the small crater and the extremely bright, hence rough, blanket of material surrounding it is indicative of an origin by impact," said Dr. Jonathan Lunine, Cassini interdisciplinary scientist from the University of Arizona, Tucson. From the crater's size, scientists estimate that it was created when a comet or asteroid roughly 5 to 10 kilometers (3 to 6 miles) in size slammed into the surface of Titan. The feature lacks a central peak, suggesting that it has been eroded or otherwise modified since formation.Rainfall, wind erosion, and softening of the solid material in which the crater formed are all possible processes that might have altered this impact feature. Also visible in the radar images are channels located just east of Circus Maximus, the large impact crater. The longest channel is approximately 200 kilometers long (124 miles). The channels appear to flow from the slopes of the crater. The fluid was most likely liquid methane, given the extremely cold ambient conditions at the surface of Titan. The area somewhat resembles the rubble-strewn plains in the region where the Huygens probe landed. Just one day after the Titan flyby, Cassini turned its sights on Saturn's moon Enceladus, revealing a fascinating, tortured world of ice. The spacecraft swept within 1,180 kilometers (730 miles) of the moon's wrinkled surface, providing the first-ever high resolution images of this world with the brightest, most reflective surface in the solar system. Since NASA's Voyager spacecraft flew past Enceladus in 1980 and 1981, planetary scientists have been intrigued by the moon's wrinkled terrain and smooth plains, some of

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which appeared to be relatively free of impact craters. Smooth, crater-free surfaces on moons and planets indicate geologically young ages, while wrinkles may indicate tectonic activity or volcanism.

NASA's Cassini spacecraft has had a busy week, snapping stunning new images of two of Saturn's moons—smoggy Titan on February 15 and wrinkled Enceladus on February 16.

"Cassini has now viewed these terrains at almost 10 times better resolution than Voyager," said Dr. Carolyn Porco, Cassini imaging team leader based at the Space Science Institute in Boulder, CO. "Interestingly, the icy surface of Enceladus appears to have similarities to both Europa and Ganymede—two prominent icy satellites of Jupiter—and topographic relief of about 1 kilometer (0.6 mile). Both Europa and Ganymede are thought to have subsurface water layers, or 'oceans,' so the similarities with Enceladus are intriguing." One view released today is a high-resolution mosaic showing complex systems of fractures and resurfaced terrain. Among the most intriguing features in the images are a series of small, dark spots, which in many places seem to be aligned in chains parallel to narrow fractures. A false-color view shows some linear features on Enceladus with a slightly different color from their surroundings. Different colors of ice may be caused by varying compositions or varying ice crystal sizes. Either one can indicate different formation mechanisms or different ages. Another early highlight from the flyby is a high-resolution stereo view of Enceladus. Stereo views are helpful in interpreting the moon's complex topography. Other preliminary results from the visual and infrared mapping spectrometer show a surface composed of only pure water ice, with no other compounds detected. Ammonia or ammonium compounds and carbon dioxide were expected, but not seen in the data. Further analysis may find trace amounts. "The spectra look like laboratory fabricated water ice, indicating the ice is quite pure," said Dr. Roger N. Clark, Cassini science team member at the U.S. Geological Survey in Denver. During the latest flybys, Cassini was 1,577 kilometers (980 miles) above Titan, and 1,180 kilometers (730 miles) above Enceladus. Cassini will conduct an even closer flyby of Enceladus on March 9, coming within approximately 500 kilometers (310 miles) of its surface. More than 40 additional Titan flybys are planned. The pictures are available at http://saturn.jpl.nasa.gov, http://www.nasa.gov/cassini and http://ciclops.org.

Cassini Significant Events for 10-16 February 2005NASA/JPL release19 February 2005

The most recent spacecraft telemetry was acquired today from the Goldstone tracking station. 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 fourth week of S08 began with the ongoing Visible and Infrared Mapping Spectrometer (VIMS) observations of the Saturn atmosphere, focusing on the detection of methane fluorescence. The Imaging Science Subsystem (ISS) observed Titan and looked for shepherding satellites of the C-Ring. On Friday the first of the special events for this week occurred. Orbital Trim Maneuver 13 successfully executed and was followed by a Titan targeted

encounter. This very busy week wrapped up with some CIRS F-Ring observations and ISS observations of Enceladus as Cassini approaches for next week's non-targeted flyby.

Cassini took this image of the ropy, taffy-like topography on Saturn's moon Enceladus as it soared above the icy moon on February 17, 2005. This view, about 60 kilometers across (37 miles), shows several different kinds of ridge-and-trough topography, indicative of a variety of horizontal forces near the surface of this 505-kilometer (314-mile) diameter satellite. Several different kinds of deformation are visible, and a small population of impact craters shows that this is some of the younger terrain on Enceladus. Sunlight illuminates the scene from the bottom. Interestingly, the topographic relief is only about one kilometer, which is quite low for a small, low gravity satellite. However, this is consistent with other evidence that points to interior melting and resurfacing in Enceladus' history. This view was obtained in visible light with the Cassini spacecraft narrow angle camera. Image scale is 60 meters (197 feet) per pixel. The image has been contrast-enhanced to aid visibility.

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Thursday, February 10:

The Project succeeded in providing another astronomy picture of the day. The image of Blue Saturn (with Mimas) can be found on the Cassini Web site. The rings are, as usual, gorgeous, but the detail that can be seen in Mimas is outstanding.

The Radio Science Subsystem (RSS) team performed another operational readiness test (ORT) today. The tests are being performed to prepare the instrument and the DSN for an occultation during Titan-3 and for the Enceladus mass determination observations.

The S08 sequence leads uplinked a number of files to the spacecraft today.Among them were an ACS S08 telemetry schedule overlay for February 15, a RADAR instrument expanded block trigger for the Titan flyby, a Magnetospheric Imaging Instrument (MIMI) power cycle command for the Low Energy Magnetospheric Measurement Subsystem, and commands for the Cosmic Dust Analyzer (CDA) involving data rate handling, uplink of the real time activity for the ring plane crossing on February 16, and threshold level adjustments for the Enceladus flyby.

Mission Assurance convened a risk team meeting to re-assess risks identified for orbital tour operations. The outcome of this risk team meeting was not only to re-assess existing risks, but also each risk item was re-assessed for placement into a 5X5 risk matrix. This is significant in that Cassini has used a 3X4 risk matrix since the inception of the risk management program for mission operations. The team met and reassessed a portion of the remaining open risk items. A follow-up meeting has been scheduled to complete the risk assessment activity.

Friday, February 11:

Orbit trim maneuver #13 (OTM-13) was successfully completed on the spacecraft tonight. This maneuver, also called the "T3 minus 3 day maneuver," refines Cassini's trajectory for the 1,577 km flyby of Titan on February 14.

The reaction control system maneuver began at 11:15 p.m. Pacific Time. A "quick look" immediately after the maneuver showed the burn duration was 220.5 seconds, giving a delta-V of approximately 207.2 mm/s. ACS reported the burn termination was a "nominal complete" with a "virtual accelerometer" cutoff. All spacecraft subsystems are nominal.

Preliminary port 2 of the Science Operations Plan Update process for tour sequence S11 was achieved today. The products were merged and output reports published.

Monday, February 14:

Early today RSS performed their final ORT in preparation for the Titan flyby. Titan 3 (T3), Cassini's third close flyby of Saturn's largest moon, occurred today. During the flyby, the Composite and Infrared Spectrometer (CIRS) made two full-hemisphere temperature maps, inbound and outbound, to measure dynamics and atmospheric circulation. CIRS also conducted composition integrations in the far Infrared of the south tropical nadir, and mid-Infrared at the north polar limb, which should produce a great chance to detect new species. In particular, the mid-Infrared integration over the north pole gave CIRS a glimpse of stratospheric chemistry over the winter pole. This CIRS data will fold into the Huygens Titan atmospheric model effort.

The Imaging Science Subsystem (ISS) took movies to look for cloud motion and make wind measurements. The Ultraviolet Imaging Spectrograph performed a series of Extreme Ultraviolet and Far Ultraviolet scans across Titan to create spectral images. The Radio and Plasma Wave Science (RPWS) instrument measured the density and temperature of the thermal electrons near Titan and in its ionosphere, searched for evidence of atmospheric lightning, looked for evidence of the ion pickup process, and studied the interaction of Titan with Saturn's magnetosphere. The Cassini Plasma Spectrometer measured the plasma environment of Titan and searched for pickup ions resulting from atmospheric loss. The Dual Technique Magnetometer also studied the magnetic environment of Titan, its interactions and plasma environment.

During closest approach the RADAR instrument performed Synthetic Aperture Radar imaging, including the first real bright terrain, which includes part of Xanadu, to be the subject of a joint Optical Remote Sensing/RADAR

investigation. RADAR altimetry measurements taken during the flyby will establish whether the lack of topography identified during an earlier Titan flyby was atypical.

Processing of the downlinks for T3 was accelerated by running off the real-time Telemetry Delivery Subsystem data stream. DSMS-provided image display capabilities were used within the Project for real-time presentation of the ISS data. In English, this means we got to watch the images as they came down from the spacecraft.

Tuesday, February 15:

A beautiful picture of Rhea taken by Cassini is today's Astronomy Picture of the Day.

"The stars come out for Founders' Day" was the theme for the Santa Fe Middle School annual PTA Founders' Day celebration held tonight. Despite a 60% chance of rain, Saturn Observation Campaign and Cassini Outreach brought three easy-to-pack-up-in-the-rain telescopes to the school's annual PTA Founders' Day celebration. The first quarter moon, Pleiades star cluster, and of course Saturn, emerged from the clouds as if by magic. Over 300 parents, teachers and students attended. A bonus for the event was a closing talk given by a Cassini ITL member who graduated from the school. While a student at Santa Fe, she had listened to a visiting JPL engineer give a talk about the Viking mission, and this inspired her to pursue education leading to a career at JPL.

Today Science Planning dusted off the S13 sequence that had been archived in January of 2003 and began the Aftermarket process. An assessment meeting was held to review all of the requested changes to the sequence. It appears that all of the requested changes can fit within the available resources. A final waiver and sequence change request meeting was held as part of development for S09.

Wednesday, February 16:

Today Cassini again passed through Saturn's ring plane. The CDA team members are tremendously excited about the science they will gain with this opportunity.

The wrap-up meeting for the Science Operations Plan (SOP) Implementation for S41 was held today. This sequence is now in the process of being archived. This completes the development of the SOP for the entire prime mission out to 2008. This task required 2 years and 9 months of intense effort to complete and resulted in 41 tour sequences being developed down to the command level. The S09 Final Sequence Integration and Validation products were released today for review by participating teams.

ISS personnel at JPL conducted two tests in the Integrated Test Lab (ITL) using the ISS Engineering Models. The first test exercised the 1.4 flight software checkout sequence. The second test simulated instrument error conditions and exercised failure recovery. Analysis of the results is underway.

VIMS personnel have resolved a long-standing flight software issue that resulted in lost science data unless a workaround was performed. The issue involved the compounding of the effects of two different software errors dating back to the original code. The resolution led to the prediction of potential lost data at T3. A precisely timed VIMS configuration command was sent to eliminate the risk. This command will need to be sent after every other sleep/wake cycle through the S09 sequence. S10 and subsequent sequences will be protected by a ground software change.

JPL put out a news release today regarding a giant crater the size of Iowa on Titan that was spotted by the RADAR instrument during Tuesday's Titan flyby. News Release: 2005-029

Friday and Saturday nights, February 18 and 19, weather permitting, the Saturn Observation Campaign will have a couple telescopes out in old town Pasadena and Monrovia for Saturn and moon viewing. It's definitely Saturn time right now. The jewel of the Solar System is overhead, offering the best views of the season. You can use the star chart on the Saturn Observation Campaign web site to see where to look—Saturn is near the Gemini Twins, Castor and Pollux right now. It's on the "Viewing Saturn" page, all freshly updated for 2005. Scroll down to see the star chart (http://soc.jpl.nasa.gov/viewing.cfm).

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Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 7, 22 February 2005

For the latest images and information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini. 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, CAPhone: 818-354-9382 Ann Marie Menting Boston University, MAPhone: 617-353-2240 Donna WeaverSpace Telescope Science Institute, Baltimore, MDPhone: 410-338-4493 Dolores BeasleyNASA Headquarters, Washington, DCPhone: 202-358-1753

Additional articles on this subject are available at:http://www.astrobio.net/news/article1448.htmlhttp://www.astrobio.net/news/article1449.htmlhttp://www.astrobio.net/news/article1451.htmlhttp://science.nasa.gov/headlines/y2005/17feb_bluesaturn.htmhttp://www.space.com/scienceastronomy/050216_saturn_aurora.htmlhttp://www.space.com/scienceastronomy/ap_050218_titan.htmlhttp://www.spacedaily.com/news/cassini-05x.htmlhttp://www.spacedaily.com/news/cassini-05y.htmlhttp://www.spacedaily.com/news/cassini-05z.htmlhttp://www.spacedaily.com/news/cassini-05za.htmlhttp://spaceflightnow.com/cassini/050218enceladus.htmlhttp://spaceflightnow.com/cassini/050219faults.htmlhttp://www.universetoday.com/am/publish/titan_fourth_flyby.htmlhttp://www.universetoday.com/am/publish/close_up_enceladus.htmlhttp://www.universetoday.com/am/publish/saturn_auroras_explained.htmlhttp://www.universetoday.com/am/publish/giant_crater_titan.html

MARS EXPLORATION ROVERS UPDATESAdapted from NASA/JPL releases11-15 February 2005

NASA's Mars Exploration Rover Spirit used its panoramic camera to take the images combined into this mosaic view of the rover. The downward-looking view omits the mast on which the camera is mounted. It shows dust accumulation on Spirit's solar panels. The images were taken through the camera's 600-, 530- and 480-nanometer filters during Spirit's 329th and 330th martian days, or sols (December 7 and 7, 2004). Image credit: NASA/JPL/Cornell.

Spirit's solar panels are collecting a fine layer of dust, which has reduced energy levels, but Spirit keeps on keeping on. Spirit completed an approximately 13-meter (43-foot) drive toward the "Cumberland Ridge" on sol 388. Spirit spent sol 389 performing the usual set of remote-sensing observations. As of sol 393, Spirit's total odometry is 4,108 meters (2.55 miles).

Opportunity is in good health after more than a year on the martian surface. The rover completed its investigation of a trench and soil materials on sol 373 and is ready for a software patch, which will be uploaded over next few sols. There have been no recent dust storm events, and tau—a measurement of atmospheric opacity—has remained close to 0.9 for the past two weeks.

NASA's Mars Exploration Rover Opportunity used its panoramic camera to take the images combined into this mosaic view of the rover. The downward-looking view omits the mast on which the camera is mounted. It shows Opportunity's solar panels to be relatively dust-free. The images were taken through the camera's 600-, 530- and 480-nanometer filters during Opportunity's 322nd and 323rd martian days, or sols (December 19 and 20, 2004). Image credit: NASA/JPL/Cornell.

Complete MER updates are available at http://marsrovers.jpl.nasa.gov/mission/status.html.

An additional article on this subject is available at http://www.marsdaily.com/news/mars-mers-05r.html.

SCIENCE FROM MARS EXPRESS AFTER ONE YEAR IN ORBITESA release 10-200516 February 2005

After reaching its observational orbit around Mars a year ago, ESA's Mars Express has already delivered an avalanche of scientific data of unprecedented quality that have completely changed the way in which we think about the Red Planet. In order to compare views and discuss the implications of the new discoveries, over two hundred scientists will be attending the first Mars Express science conference, taking place from 21 to 25 February at ESA's European Space Research and Technology Centre (ESTEC), Noordwijk, the Netherlands.

With over a hundred presentations from scientists from Europe, the United States, Japan, Russia and other countries, the discussions will cover all aspects of this ground-breaking investigation, from an historical perspective to the latest surprising findings. The topics addressed include results from the interior and subsurface of Mars; its geology, mineralogical composition and surface chemistry; the polar regions and their ice caps; the climate and atmosphere of Mars and the interactions between surface and atmosphere; the space environment around Mars and its moons. A special session on exobiology and the search for life on Mars is being held on the afternoon of Thursday, 24 February.

Members of the media are invited to attend all sessions, but may be particularly interested in the conference summary on Friday 25 February, at 14:00 CET. During the briefing, lasting about an hour, the Principal Investigators of all active experiments on board Mars Express will summarize the major scientific achievements of the first year in orbit and outline the

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Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 7, 22 February 2005

plans for future research. The briefing will include a summary of the discussions on exobiology and the search for life on Mars, and an overview of European plans for future exploration of Mars. A question-and-answer session will follow and ample time is set aside for one-on-one interviews. A detailed program of the conference can be found at http://www.congrex.nl/05C05 .

MARS GLOBAL SURVEYOR IMAGESNASA/JPL/MSSS release10-16 February 2005

The following new images taken by the Mars Orbiter Camera (MOC) on the Mars Global Surveyor spacecraft are now available.

Dunes in Noachis (Released 10 February 2005)http://www.msss.com/mars_images/moc/2005/02/10/

Sedimentary Rock in Candor (Released 11 February 2005)http://www.msss.com/mars_images/moc/2005/02/11/

MOC 1000th Release! (Released 12 February 2005)http://www.msss.com/mars_images/moc/2005/02/12/

Polar Polygons (Released 13 February 2005)http://www.msss.com/mars_images/moc/2005/02/13/

Martian Valentine's Day (Released 14 February 2005)http://www.msss.com/mars_images/moc/2005/02/14/

Mars at Ls 160 Degrees (Released 15 February 2005)http://www.msss.com/mars_images/moc/2005/02/15/

Antoniadi's Floor (Released 16 February 2005)http://www.msss.com/mars_images/moc/2005/02/16/

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 IMAGESNASA/JPL/ASU release14-18 February 2005

THEMIS Images as Art #36 (Released 14 February 2005)http://themis.la.asu.edu/zoom-20050214A.html

THEMIS Images as Art #37 (Released 15 February 2005)http://themis.la.asu.edu/zoom-20050214A.html

THEMIS Images as Art #38 (Released 16 February 2005)http://themis.la.asu.edu/zoom-20050214A.html

THEMIS Images as Art #39 (Released 17 February 2005)http://themis.la.asu.edu/zoom-20050214A.html

THEMIS Images as Art #40 (Released 18 February 2005)http://themis.la.asu.edu/zoom-20050214A.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.

End Marsbugs, Volume 12, Number 7.

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