Marsbugs: The Electronic Astrobiology Newsletter Volume 12, Number 2, 19 January 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. [http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=36378] This image was returned yesterday, 14 January 2005, by ESA's Huygens probe during its successful descent to land on Titan. This is the colored view, following processing to add reflection spectra data, gives a better indication of the actual color of the surface. Initially thought to be rocks or ice blocks, they are more pebble-sized. The two rock-like objects just below the middle of the image are about 15 centimeters (left) and 4 centimeters (center) across respectively, at a distance of about 85 centimeters from Huygens. The surface is darker than originally expected, consisting of a mixture of water and hydrocarbon ice. There is also evidence of erosion at the base of these objects, indicating possible fluvial activity. Image credit: ESA/NASA/University of Arizona. __________________________________________________________________________ Articles and News 1) ORGANIC MOLECULES TRANSPORT STRONGEST SPECTRAL SIGNATURE OF INTERPLANETARY DUST PARTICLES Lawrence Livermore National Laboratory release 05-01-02 2) TITAN CLOSE UP By Henry Bortman 3) KECK TELESCOPE CAPTURES TITAN BUT MISSES HUYGENS By Robert Sanders 4) DID FLUID ONCE FLOW ON TITAN? (INTERVIEW WITH CAROLYN PORCO) By Helen Matsos 5) LAKEFRONT LANDING IN CRÈME BRULÉ By Henry Bortman 6) MEDIA LEFT LOST ON TITAN By Simon Mansfield 7) TARGETING TITAN (INTERVIEW WITH TOBY OWENS, PART 1) By Henry Bortman 8) METHANE WORLD (INTERVIEW WITH TOBY OWENS, PART 2) By Henry Bortman Mission Reports 9) CASSINI-HUYGENS UPDATES NASA/ESA releases 10) MARS EXPLORATION ROVERS UPDATES NASA/JPL releases 11) MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release __________________________________________________________________________ ORGANIC MOLECULES TRANSPORT STRONGEST SPECTRAL SIGNATURE OF INTERPLANETARY DUST PARTICLES Lawrence Livermore National Laboratory release 05-01-02 13 January 2005 Carbon and silicate grains in interplanetary dust particles are helping scientists solve a 40-year-old astronomical mystery. Using a transmission electron microscope, researchers from Lawrence Livermore National Laboratory have detected a 5.7-electron volt or 2175 Å (angstrom) wavelength feature in interstellar grains that were embedded within interplanetary dust particles (IDPs). They found that this feature is carried by carbon and amorphous silicate grains that are abundant in IDPs and may help explain how some IDPs formed from interstellar materials. The research appears in the January 14 edition of the research journal, Science. Interplanetary dust particles gathered from the Earth's stratosphere are complex collections of primitive solar system and presolar grains from the interstellar medium. The strongest ultraviolet spectral signature of dust in the interstellar medium (the gas and dust between stars, which fills the plane of a galaxy) is the astronomical 2175 angstrom feature or "2175 Å bump." Production of this interstellar feature is generally believed to originate from electronic transitions associated with the surfaces of very small grains. The carbon and silicate grains may have been produced by irradiation of dust in the interstellar medium. The measurements may help explain how interstellar organic matter was incorporated into the solar system. In addition, they provide new information for computational modeling, laboratory synthesis of similar grains and laboratory ultraviolet photo-absorption measurements. "Our finding potentially breaks a log-jam in the search for the carrier of the astronomical 2175 Å feature," said John Bradley, director of Livermore's Institute for Geophysics and Planetary Physics and lead author of the paper. "Over the past 40 years, a whole variety of exotic materials have been proposed, including nano-diamonds, fullerenes, carbon 'onions' and even interstellar organisms. Our findings suggest that organic carbonaceous matter and silicates, the 'common stuff' of interstellar space, may be responsible for the 2175 Å feature." Other Livermore scientists on the project include Zu Rong Dai, Giles Graham, Peter Weber, Julie Smith, Ian Hutcheon, Hope Ishii and Sasa Bajt. Outside collaborators include researchers from UC Davis, Lawrence Berkeley National Laboratory, Washington University and NASA-Ames Research Center. Founded in 1952, Lawrence Livermore National Laboratory is a national security laboratory, with a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by the University of California for the U.S. Department of Energy's National Nuclear Security Administration. Contact: Anne Stark Phone: 925-422-9799 E-mail: stark8@llnl.gov Read the original news release at http://www.llnl.gov/pao/news/news_releases/2005/NR-05-01-02.html. An additional article on this subject is available at http://www.spacedaily.com/news/stellar-chemistry-05d.html. __________________________________________________________________________ TITAN CLOSE UP By Henry Bortman From Astrobiology Magazine 14 January 2005 The European Space Agency has released the first 3 of several hundred images captured by the Huygens probe during its descent through the atmosphere of Saturn's giant moon Titan. Although the images have not yet been cleaned up - they were released in their raw form--they reveal a world of diverse landforms, shaped at least in part by fluid erosion. Two of the images are reminiscent of early photographs of Mars. The left half of the first image, taken from a height of 16 kilometers (10 miles) above Titan's surface, shows a pattern of branching channels that look like canyons on Earth cut by water. It's unlikely that water was responsible in Titan's case, though; Titan is far too cold for liquid water to flow on its surface. Scientists say it's too early to speculate about what the fluid might be. On the right side of the image is a large flat dark area that is being interpreted initially as a large body of liquid with a visible shoreline. This is the first image of Titan that seems to confirm scientists' speculation that Huygens would find large pools of liquid hydrocarbons, methane or ethane, on the moon's surface. The second image, taken from 8 kilometers (5 miles) above the surface, shows a hodge-podge of light and dark areas that are more difficult to interpret. The darker areas may be bodies of liquid as well. More work is needed to be certain. In the coming hours and days, image-processing teams will enhance the contrast of this and other images and clean up artifacts in attempt to extract more detail. This will then be combined with spectroscopic data that will tell scientists how reflective various areas of the image are. Combining imaging and reflectance data will help scientists figure out what they are looking at. The third image is perhaps the most stunning of all. It was taken from the surface of Titan, and shows a plain of what appear to be boulders stretching to the horizon. At first glance, it resembles a martian landscape. "The amazing thing to me is how familiar this kind of scene seems. All of us on Earth see scenes not so different from this all the time. We see boulders strewn around. We've seen things that kind of look like this on Mars. We've seen things that look like this everywhere," said Marty Tomasko, the principal investigator for Huygens' camera, the Descent Imager/Spectral Radiometer (DISR). "These probably are not really rocks of silicate. These are probably blocks of ice, perhaps water ice frozen solid. The temperatures on Titan are so cold that water would be as stiff and as hard as a boulder would be on the Earth." "But there are questions that come to mind, too. How did this scene get produced? What physical processes happened on the surface to produce this? What kinds of motion, and the uplift, and the breaking of the rocks and the migration of the rocks--there are lots of questions that people will be debating." That debate has already begun, as the Huygens image-processing team and data-processing teams from Huygen's other instruments hunker down to work through the night in an effort to turn the billions of bits of raw data returned by Huygens into meaningful information. There is one sour note to the day's events. Only one of Huygens' two communications channels functioned properly, resulting in a significant loss of data. One set of missing data was designed to help scientists learn about wind speeds in Titan's atmosphere. Fortunately, scientists will be able partially to reconstruct the wind-speed information by studying variations in the frequency of the Huygens carrier signal detected on Earth by a global network of large radio telescopes. Also lost, however, were half of the images captured by Huygens. This may make it difficult to construct the panoramic mosaic images that Tomasko's team was hoping to produce. Read the original article at http://www.astrobio.net/news/article1393.html. __________________________________________________________________________ KECK TELESCOPE CAPTURES TITAN BUT MISSES HUYGENS By Robert Sanders University of California, Berkeley release 14 January 2005 Despite real though faint hopes, ground-based astronomers failed to see any sign of the Huygens probe's plunge into Titan's atmosphere today (Friday, January 14), but they did obtain some near-infrared images of Saturn's largest moon at the moment of impact. The images were captured by the world's largest telescope, the 10-meter Keck telescope seated atop Mauna Kea in Hawaii. The bright and dark patches on the surface were the only detail visible of the surface, with most features obscured by the moon's dense hydrocarbon haze. "We did observe, as through a miracle we opened up (the telescope dome) in 40 to 50 mile-per-hour winds," said Imke de Pater, professor of astronomy at the University of California, Berkeley. "We didn't see anything, but just got context images--the only ones taken, I believe--during probe entry." De Pater was one of a team of astronomers training the Keck telescope on Titan, just after midnight in Hawaii, to view Huygens pierce the atmosphere to start its two and a half hour descent to the surface. Near- infrared images were taken from the W. M. Keck Observatory with the near infrared camera (NIRC2) and the adaptive optics system at the time of probe entry. The team had planned imaging sequences to look for thermal emissions or condensates at the probe entry site. The probe, launched late last year by the Cassini mother ship, did send back photos from 10 miles above the surface that showed channels running through hilly terrain. And it apparently survived a landing, at least long enough to send back signals from the surface. Titan is of particular interest to scientists because it is the only moon in our solar system with a dense, methane-rich, nitrogen atmosphere, reminiscent of our own atmosphere here on Earth. The moon is cloaked in a thick, smog-like haze produced by the breakup of methane by sunlight. Further study of this moon could provide clues to planetary formation and evolution and, perhaps, about the early days of Earth as well. "Although no disturbances in Titan's atmosphere were detected, the observations provide the best images that characterize the satellite at the moment of probe entry," said Antonin Bouchez, a staff member at the Keck observatory who was leading the observing effort. "It was worth getting up in the middle of the night for this historic moment," said Fred Chaffee, director of the Keck Observatory, "despite the bad weather on the mountain". Winds were blowing at 40-50 M.P.H., while the mountaintop itself was still cloaked with snow and ice from a recent storm. Other team members that participated in the observations were David LeMignant from the Keck Observatory and Michael Brown, a professor at Caltech. For more on Keck observations of Titan before the arrival of Cassini and Huygens, see the story at http://www.berkeley.edu/news/media/releases/2004/10/13_Huygens.shtml. Read the original news release at http://www.berkeley.edu/news/media/releases/2005/01/14_huygens2.shtml. An additional article on this subject is available at http://spaceflightnow.com/cassini/050116kecktitan.html. __________________________________________________________________________ DID FLUID ONCE FLOW ON TITAN? (INTERVIEW WITH CAROLYN PORCO) By Helen Matsos From Astrobiology Magazine 14 January 2005 Carolyn Porco of the Space Science Institute (Boulder, Colorado) heads Cassini's imaging science team. She sat down with Astrobiology Magazine's Chief Editor, Helen Matsos, to give a scientist's first look at Titan from the European Space Agency's Darmstadt, Germany mission control room. Porco, also a University of Arizona adjunct professor of planetary sciences, describes her excitement and surprise when the Mars-like imagery first beamed down to Earth from Titan's surface. Porco speculates what might elementally comprise those mysteriously smooth boulders in the foreground. Helen Matsos (HM): What is your reaction to the stunning photos from Titan today? Carolyn Porco (CP): I sound like a broken record, but I am so shocked! I really didn't expect Titan to look this way. I really didn't expect the images to be so easily interpretable. HM: What did you think they'd look like? CP: I thought we'd see patterns like we're seeing only in finer details and I thought they'd still be mysterious to us. But the images that we've seen, one of them is clearly a drainage pattern. I mean, what else could it be, it doesn't take a rocket scientist, right? Secondly the other one looks like Mars! I totally didn't expect it, it looks like Mars! So I'm thinking it can't be silicon rocks--it's not Mars really--it can't be silicon rocks. Because if Titan is a differentiated body, and it's got to be differentiated because it's big, it would be ice on the outside and all the rocky material would have fallen to the inside. So it can't be silicon rocks--it has to be ice. So it's ice rocks, but the ice rocks, you see them, they look flattened, they look for all the world like normal rocks except they can't be silicate rocks. So what could they be? They are ice rocks; maybe they got tumbled in a river of some sort, who knows? Maybe there was a flood plain like we see on Mars, but it's just unexpected, very unexpected. I'm still having a hard time absorbing it. I can't wait to see what they have tomorrow. HM: In terms of the quality we are getting back, what kind of resolution can we expect for future images that have been more heavily processed? Will they change in terms of refinement? CP: These first pictures we've seen, they are not going to improve any more. They have put out their best in terms of a sample. But I would imagine that to put together the kind of mosaic they want to put together it takes a lot of work. That's why we're not seeing that tonight. Those poor people, I'm just glad it's not me! I'm just enjoying this and they are having to do all the work! They will probably stay up all night long and be beat by press time tomorrow. But boy are they going to have a story to tell! It is going to be one hell of a day. It sounds trite, but this is way more than I expected. I was hoping for some glimmer of a chance that their data were going to help us interpret ours. But I think now some of the things that we are seeing make a lot more sense to me. HM: Such as? CP: Such as these features that we see in the South Polar region which look long and meandering... And my first impression, and I'm not a geologist, was it looked like a meandering stream. But as a scientist you don't say that unless you have ample evidence--because it just looks like a curvy line, right? But this thing that we've seen today looks so much like a drainage pattern, now that we've got the fine details. It can't be tectonic so almost by default it has to be something that flowed to cause those channels. HM: So what fluid do you think it was that created those patterns? CP: I suppose lava tubes could do this. If there were vulcanism you could get lava tubes--because you see meandering things like this on the moon, and they are not depressions, they're more raised tubes. In fact you see this even in Hawaii, where you can see collapsed lava tubes --there was a big vacant tube and then it just collapsed. That's because the stuff on the outside cools faster than the stuff on the inside, so the stuff on the inside keeps flowing until there is no more, but the stuff on the outside forms a crust--that's called a lava tube. I suppose these meandering patterns could be those too now that I think about it, but again, what would be the lava? You'd expect the outside of Titan to be icy. HM: Are you saying it is seemingly not icy? CP: No, no, I can't say--seemingly not, the pattern could be carved in ice. This is not new. People have theorized that there would be stuff falling out of the atmosphere and there would be liquid ethane-methane combos falling out of the atmosphere carving channels and gullies. I did a little captain's log on my web site about this, which is just a synopsis of what people have been saying for years--so it looks like maybe that's what we're seeing? I just didn't think it was going to be so clear. I said the same thing during Saturn orbit insertion about the ring images--I mean, I'm batting zero! I thought we were going to see a lot of squishy kind of patterns and still not really know what they were. Again, I guess it could be a lava tube. It is a drainage pattern of some sort, but given what people suspect about the atmosphere it's probably a fluid. But the question is, is it a fluid flowing right now? Or something from long ago? Who knows? Read the original article at http://www.astrobio.net/news/article1394.html. __________________________________________________________________________ LAKEFRONT LANDING IN CRÈME BRULÉ By Henry Bortman From Astrobiology Magazine 14 January 2005 The European Space Agency's Huygens probe has lifted the veil on the bizarre world of Titan. For the first time, humans have gotten a close-up look at this planet-sized moon. Previous attempts to get a glimpse of the ground on Titan have been frustrated by the thick layer of smog that shrouds the giant moon. Huygens, scientists say, has landed in soil with the consistency of wet sand or clay--or, as John Zarnecki, the principal investigator for Huygens' Surface Science Package, said one team member had suggested, "crème brulé." The scenery surrounding the landing site resembles a postcard panorama of undeveloped lakefront property, hand-tinted in pastel shades of orange. It's hardly a typical lakefront, though--and not just because everything, including the sky, is orange. For starters, the temperature on Titan averages about minus 180° Celsius (minus 292° Fahrenheit). It makes the shore of Lake Michigan on a windy night in January seem balmy by comparison. Then there's the composition of the liquid in the "lake." It's not water. On the surface of Titan, water is frozen as solid as granite. It's more likely liquid methane or ethane, perhaps a mixture of the two. In other words, it's a lake of liquid natural gas. Researchers expected that, because of the high concentration of methane in Titan's atmosphere, they would find bodies of liquid methane on the surface. Some even proposed the possibility that Titan could be covered by a global methane ocean. The latter possibility can now be crossed off the list, although it's important to note that Huygens examined only one tiny spot on Titan. And Cassini, the orbiting spacecraft that delivered Huygens to Titan, has only made three passes by the giant moon and has looked in detail at only a few small strips of the surface. More than 40 additional flybys are planned during the 4 years of Cassini's primary mission. It's still possible that some other location on Titan will reveal the presence of an ocean-sized body of liquid. The landform adjoining the lake where Huygens landed is criss-crossed with drainage channels that appear to have been cut by erosion, through the action of flowing liquid. Again, the liquid in question could not be water or even ice; more likely it is methane or ethane. The surface at the point of impact appears to be coated with organic sludge. A measurement taken of the surface material by one of Huygens' instruments just after it landed showed a high concentration of methane. A puffy band of white can be seen along the shoreline in images taken by Huygens as it neared the ground, although it doesn't appear in images taken from higher elevations. In describing this white material, Marty Tomasko, principal investigator for Huygens' imaging camera, suggested that it was "pehaps a thin ground fog, possibly of methane or ethane." Other scientists look at the same scene and see the white material as surf crashing along the shore. All of these impressions, though, are preliminary. Huygens' science teams have had less than 24 hours to process the vast quantity of data returned by Huygens. As ESA Director of Science David Southwood put it, "You have to understand, the science is going to be done in the future, over many years. What we see is the potential." Read the original article at http://www.astrobio.net/news/article1397.html. __________________________________________________________________________ MEDIA LEFT LOST ON TITAN By Simon Mansfield From SpaceDaily 18 January 2005 The money shot is what they call it. While usually applied to less salubrious sectors of "film making," in this case we are talking about a mostly static 98 frame view of the surface of Titan. How much this actually cost is hard to pin down. Do we include the total cost of getting to Saturn. Or do we assign a strict dollar per pound ratio for the transport segment and then add on the cost of the Huygens probe, mission control, and eventually the science work done back on Earth. Whatever the exact amount is, it's a lot of money. The pursuit of science is never easy and rarely cheap. It takes a certain amount of raw guts for public officials to plonk down hundreds of millions of dollars, or in this case euros, to send a probe billions of kilometers across the solar system and then have only a limited chance of success. But that's what makes space science so exciting. Massive bets against massive odds, all in the hope of extending the knowledge of humanity that little bit further. Read the full article at http://www.spacedaily.com/news/oped-05i.html. __________________________________________________________________________ TARGETING TITAN (INTERVIEW WITH TOBY OWENS, PART 1) By Henry Bortman From Astrobiology Magazine 18 January 2005 University of Hawaii astronomer Toby Owens is one of the original planners of the Cassini-Huygens mission to Saturn and its moon Titan. Astrobiology Magazine's editor Henry Bortman spoke with Owens shortly after the successful Huygens mission had completed. In this part of the interview, Owens talks about the history of the mission and the reasons scientists were interested in exploring Titan. Astrobiology Magazine (AM): How long have you been working on this Cassini-Huygens mission? Toby Owens (TO): From the beginning, 1982. Well, actually we started thinking about it, discussing it, even earlier, right when the Voyager encounter occurred with Titan in 1980. When we saw how interesting it was, a number of us began thinking, "Gee, wouldn't it be nice to go back there?" Then the opportunity came, on the American side, to plan the next 10 years of NASA missions, and I was made the chairman of the outer planets group, and this was certainly one thing that I was trying to promote. I was very much aware that the Europeans were also interested in this because Daniel Gautier was a good friend of mine and so we were in close communication. And he was in parallel getting ESA interested in this. So we were then able to get both agencies involved. It started with a joint working group. AM: Did it take a lot of convincing in the scientific community to get this idea off the ground, or was everybody pretty enthusiastic about it? TO: There was a lot of enthusiasm for it, because one of our ideas was to make it a big mission. In those days, it was still possible to think in those terms. We realized that the only way to do that was to have both Europe and the United States involved, because neither country by itself, neither organization by itself, would have the finances to do it. We then tried to involve as many different kinds of scientists as we could who would be interested in going to Saturn. And indeed they were. And so we have a full range of scientific activity. You're seeing here with the [Huygens] probe only a small fraction of what the whole program is like. And especially in these days, I'm just delighted that we were able to make such a big mission come together. AM: What was it about Titan that made people want to explore it further? TO: I guess there were a number of things. One was the fact that we couldn't see the surface. And there was a sense of frustration about that. Here's this really big object, bigger than the planet Mercury, and we can't see the surface. We don't know what's down there. And, of course, that gave some impetus to just the sense of exploration. But, more than that, the fact that Titan had this thick atmosphere. And it was an atmosphere dominated by nitrogen, like ours. It's the only other world in the solar system with a thick nitrogen atmosphere. And that in that atmosphere, we saw chemical reactions taking place with fragments of nitrogen and methane coming together, that resembled some of the reactions people have talked about that must have preceded the origin of life on Earth. Saying that, it must be very different on Titan, because it's much colder, you don't have access to the ready supply of oxygen, because of the water. You don't have the liquid water. AM: Do you think it ever had liquid water? TO: There may have been liquid water at isolated instances. In fact there may still be, if you have an impact or some kind of cryovolcanism (which is like ordinary volcanism, but you have water instead of magma). And it looks like that kind of thing is happening. We're just beginning to see the indications of that in the data from the spacecraft. So you may still have it. But the main history of Titan has been a low-temperature environment, very low temperature. Read the original article at http://www.astrobio.net/news/article1401.html. __________________________________________________________________________ METHANE WORLD (INTERVIEW WITH TOBY OWENS, PART 2) By Henry Bortman From Astrobiology Magazine 19 January 2005 University of Hawaii astronomer Toby Owens is one of the original planners of the Cassini-Huygens mission to Saturn and its moon Titan. Astrobiology Magazine's editor Henry Bortman spoke with Owens shortly after the successful Huygens mission had completed. In this part of the interview, Owens talks about the significance of methane in Titan's atmosphere. Astrobiology Magazine (AM): You said that one thing that was particularly intriguing about Titan was its thick nitrogen-methane atmosphere. Do you think that the data that Huygens has collected going through that atmosphere is going to enable the science community to figure out how and why Titan got its atmosphere, and why other bodies didn't? Toby Owens (TO): I hope it will. That was one of our major goals. But it's not going to be easy. In other words, it's going to be one of those studies where you don't get a single data point that suddenly illuminates the landscape for you. You have to put together all the different results that you get. And we're just in the early stages of doing that. For example, one of the clues to the history of any small-body atmosphere, including the Earth, is the amount of noble gases in the atmosphere-- argon, krypton, xenon--and their relative abundances. Because they're very heavy, so they don't escape easily, and they're inert, so they don't combine chemically with what's in the rocks. Once you get them in the atmosphere they stay there. So they give you a kind of record of what sort of volatiles have come out of the ground or have been brought to the planet. We're very eager to see what that record is on Titan. AM: Will the data from the Huygens GCMS (Gas Chromatograph/Mass Spectrometer) be able to tell you that? TO: That's one of the main goals of the GCMS, yes. Another goal is to look at the isotopes: nitrogen, carbon, and oxygen. We have some indications already from the so-called INMS, the ion neutral mass spectrometer on the Cassini spacecraft, which went through the upper atmosphere [of Titan], and we'll get more data because [Huygens went] down inside where the densities are higher. So we already know that there's been quite a lot of escape. Some gases have escaped; others have not. The difference suggests that methane, for example, must be continually resupplied to the atmosphere--which we were pretty sure was the case already, because you can calculate that it's disappearing as a result of photochemical reactions. The lifetime of what's there, the amount of methane there, is only 10 or 20 million years. It might be that we just happened to come along just before it disappears, but nobody liked that idea very much. Now that we have the isotopes, it shows us that the carbon isotopes are completely normal, whereas the oxygen and the nitrogen show the escape. So, again, the methane couldn't have been there a long time. It must have been resupplied relatively recently. AM: Methane seems to be a key to Titan. But it's been somewhat puzzling that methane clouds appear to be concentrated at the south pole of Titan, which is not what most researchers expected. TO: That whole issue came up from ground-based observations just in the last five years. When people began to see these clouds over the south pole, and only over the south pole. And that was very strange, because nobody could understand why that should be. We still don't. Now we're seeing clouds in other places as well. But still there's this tendency for more clouds at the south pole. It is odd. AM: Now that you have these images from the landing site and the initial methane data from the descent, to what extent is the picture fitting together, and to what extent is it still a little odd? TO: Well, initially, as I guess you're aware, there was some talk that the whole surface of Titan might be covered by a global ocean. Then we came to realize that was not the case. Ground-based observations showed that there was a big bright area on one hemisphere that didn't exist on the other, so it could only be half-covered by oceans. Then we got better ground-based data that showed that there are dark and light areas, and the best you could hope for was some seas. And now we're getting down to lakes, maybe. It's getting tough. But what we're seeing so far is that in these images we don't have a clear indication of open bodies of liquid hydrocarbons--yet. We see some intriguing possibilities, things that look like lakes or seas. But we don't know that they're liquid. They're just very dark and very smooth. So we don't yet have the evidence we want. But assuming that they are, or even without that, we do see these river channels, which indicate that liquids have been flowing over the surface. And those liquids must be the hydrocarbons. AM: The channels couldn't be formed by ice? It couldn't be glaciation? TO: No. It's much too cold for that. It won't make these little channels. You could get a massive movement of ice, but at these temperatures I don't think you'd even get that. You have to warm it up somehow to do that. And there seem to be places where that has happened. The equivalent of hot springs or something like that. It's not a passive world. There is some internal energy that's being dissipated and causing these geological formations. It's not rivers of water running around. But it's rivers. And it looks like it's liquid hydrocarbons, which is what we expected. AM: I know it's a little early in the process, and I know it's difficult to interpret things right off the bat, but when you see the panoramic mosaic of the Huygens landing site, what do you see? TO: Well, I'm from Hawaii, and what I see is surf. It really looks to me as if there is a shoreline, with waves along it. But that's just a visual impression, and my impression is no better than yours. AM: That's what I saw, too, actually. But then it got described as ground fog, so I thought, "Okay, maybe it isn't surf." Will it be possible to distinguish between those two by studying the data? TO: Yes. Eventually it will. But I think it could well be a combination of the two. That's what we have on Earth, frequently. AM: So this would be a hydrocarbon fog? TO: Yeah. You just have to get used to the idea of methane and ethane being liquids--which, of course, we do on the Earth all the time. I was just reading about how people are now shipping gas as a liquid. They cool it down to condense it, and they put it in these big refrigerated tankers- -my god!--and they ship it across the ocean. So Titan does it for us. All we have to do is get a hose out there. Read the original article at http://www.astrobio.net/news/article1402.html. __________________________________________________________________________ CASSINI-HUYGENS UPDATES NASA/ESA releases NASA Salutes Successful Huygens Probe NASA release 05-021 14 January 2005 NASA Administrator Sean O'Keefe today offered congratulations to the European Space Agency (ESA) on the successful touchdown of its Huygens probe on Saturn's moon Titan. "The descent through Titan's atmosphere and down to its surface appeared to be perfect," Administrator O'Keefe said. "We congratulate ESA for their spectacular success. We're very proud of the Cassini-Huygens teams that helped to make this both an engineering and scientific victory, and we appreciate the dedication and support from our international partners," the Administrator noted. The probe entered Titan's upper atmosphere at about 5:15 AM EST January 14. During its two and one-half hour descent to the surface of the moon, it sampled the chemical composition of the atmosphere. The probe continued transmitting data for more than 90 minutes after reaching the surface. The data was sent to NASA's Cassini spacecraft, and recorded and relayed through NASA's Deep Space Network to the Jet Propulsion Laboratory (JPL), Pasadena, CA, and to ESA's Space Operations Center in Darmstadt, Germany. The ESA facility is the operations center for the Huygens probe mission. Data was received over one of two channels designed to be mostly redundant. Cassini-Huygens is a joint mission of NASA, ESA and the Italian Space Agency (ISA). ESA's Huygens probe was carried to Saturn's orbit aboard Cassini, and sent on its way to Titan on December 24, 2004. Cassini continues to orbit Saturn on a four-year prime mission to study the planet, its rings, moons and magnetosphere. JPL Director Charles Elachi said, "We congratulate our colleagues at ESA on the splendid performance of the Huygens probe and look forward to the science results of this effort." "Our ESA colleagues have every reason to be very proud of the excellent manner in which the Huygens probe performed," said Robert T. Mitchell, Cassini program manager at JPL. "We are also proud of our support for this endeavor," he said. First Results from Huygens ESA releases 15-17 January 2005 DISR: Composite images show three dimensional structure and possible methane or ethane ground fog on surface. Wind speed is 7 meters per second at altitudes of 10 to 20 km. [http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=36378] This image was returned yesterday, 14 January 2005, by ESA's Huygens probe during its successful descent to land on Titan. This is the colored view, following processing to add reflection spectra data, gives a better indication of the actual color of the surface. Initially thought to be rocks or ice blocks, they are more pebble-sized. The two rock-like objects just below the middle of the image are about 15 centimeters (left) and 4 centimeters (center) across respectively, at a distance of about 85 centimeters from Huygens. The surface is darker than originally expected, consisting of a mixture of water and hydrocarbon ice. There is also evidence of erosion at the base of these objects, indicating possible fluvial activity. Image credit: ESA/NASA/University of Arizona. [http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=36381] A composite image showing a full 360-degree view around Huygens. The left-hand side, behind Huygens, shows a boundary between light and dark areas. These images were taken from an altitude of about 8 kilometers with a resolution of about 20 meters per pixel. Image credit: ESA/NASA/University of Arizona. [http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=36382] This picture is a composite of 30 images from ESA's Huygens probe. They were taken from an altitude varying from 13 kilometers down to 8 kilometers when the probe was descending towards its landing site. The images have a resolution of about 20 meters per pixel and cover an area extending out to 30 kilometers. Image credit: ESA/NASA/University of Arizona. GCMS: Detailed analysis of methane in the stratosphere indicates uniform mixing. 90 minutes into descent, the methane mixing ratio (relative to nitrogen) changes indicating the possible presence of clouds. The methane mixing ratio is higher at the surface. HASI: Data was collected from entry covering the full deceleration of the probe. A full analysis of the atmospheric structure is underway. Measurements of pressure and temperature against altitude were achieved. The surface temperature was estimated at 93.8 K. The microphone recorded sounds in the Titan atmosphere as the probe descended (http://www.esa.int/SPECIALS/Cassini-Huygens/SEM85Q71Y3E_0.html). SSP: 3 hours 37 minutes of data were recovered, including 1 hour 10 minutes on the surface. No data from any of the nine sensors were lost. Deceleration of about 15 g in 40 milliseconds occurred when Huygens touched down. Touchdown took place 2 hours 27 minutes 57 seconds after atmosphere interface. Penetrometer measurements suggest a thin crust of over the surface. The penetrometer extended 15 cm into the surface. Sonar measurements recorded data until about 12 meters above surface. Impact speed on the surface was 4.5 meters per second. Radio experiments: By using VLBI techniques, 18 radio observatories around the world were able to track the descent of the Huygens probe. This will allow scientist to determine the position of Huygens to within a few kilometers and wind speed to a few meters per second. Read the original news release at http://sci.esa.int/science- e/www/object/index.cfm?fobjectid=36370. Huygens Lands in Titanian Mud ESA release, 18 January 2005 Although Huygens landed on Titan's surface on 14 January, activity at ESA's European Space Operations Centre (ESOC) in Darmstadt, Germany, continues at a furious pace. Scientists are still working to refine the exact location of the probe's landing site, seen above. While Huygens rests frozen at -180 degrees Celsius on Titan's landscape, a symbolic finale to the engineering and flight phase of this historic mission, scientists have taken little time off to eat or sleep. They have been processing, examining and analyzing data, and sometimes even dreaming about it when they sleep. There's enough data to keep Huygens scientists busy for months and even years to come. Recreating Huygens' descent profile One of the most interesting early results is the descent profile. Some 30 scientists in the Descent Trajectory Working Group are working to recreate the trajectory of the probe as it parachuted down to Titan's surface. The descent profile provides the important link between measurements made by instruments on the Huygens probe and the Cassini orbiter. It is also needed to understand where the probe landed on Titan. Having a profile of a probe entering an atmosphere on a Solar System body is important for future space missions. After Huygens' main parachute unfurled in the upper atmosphere, the probe slowed to a little over 50 meters per second, or about the speed you might drive on a motorway. In the lower atmosphere, the probe decelerated to approximately 5.4 meters per second, and drifted sideways at about 1.5 meters per second, a leisurely walking pace. "The ride was bumpier than we thought it would be," said Martin Tomasko, Principal Investigator for the Descent Imager/Spectral Radiometer (DISR), the instrument that provided Huygens' stunning images among other data. The probe rocked more than expected in the upper atmosphere. During its descent through high-altitude haze, it tilted at least 10 to 20 degrees. Below the haze layer, the probe was more stable, tilting less than 3 degrees. Tomasko and others are still investigating the reason for the bumpy ride and are focusing on a suspected change in wind profile at about 25 kilometers altitude. The bumpy ride was not the only surprise during the descent. Landing with a splat Scientists had theorized that the probe would drop out of the haze at between 70 and 50 kilometers. In fact, Huygens began to emerge from the haze only at 30 kilometers above the surface. When the probe landed, it was not with a thud, or a splash, but a splat. It landed in Titanian "mud". "I think the biggest surprise is that we survived landing and that we lasted so long," said DISR team member Charles See. "There wasn't even a glitch at impact. That landing was a lot friendlier than we anticipated." DISR's downward-looking High Resolution Imager camera lens apparently accumulated some material, which suggests the probe may have settled into the surface. "Either that, or we steamed hydrocarbons off the surface and they collected onto the lens," said See. "The probe's parachute disappeared from sight on landing, so the probe probably isn't pointing east, or we would have seen the parachute," said DISR team member Mike Bushroe. When the mission was designed, it was decided that the DISR's 20-Watt landing lamp should turn on 700 meters above the surface and illuminate the landing site for as long as 15 minutes after touchdown. "In fact, not only did the landing lamp turn on at exactly 700 meters, but also it was still shining more than an hour later, when Cassini moved beyond Titan's horizon for its ongoing exploratory tour of the giant moon and the Saturnian system," said Tomasko. All Huygens raw images are now available at http://esamultimedia.esa.int/docs/titanraw/index.htm (image credits: ESA/NASA/JPL/University of Arizona). Read the original news release at http://www.esa.int/SPECIALS/Cassini- Huygens/SEM5YW71Y3E_0.html. JPL, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Science Mission Directorate, Washington, DC. JPL designed, developed and assembled the Cassini orbiter. ESA built and managed the development of the Huygens probe and is in charge of the probe operations. ISA provided the high-gain antenna, much of the radio system and elements of several of Cassini's science instruments. More information about the Cassini-Huygens mission is available on the Web, at http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov. For information about NASA and agency programs on the Web, visit http://www.nasa.gov. Contacts: Dolores Beasley NASA Headquarters, Washington, DC Phone: 202-358-1753 Veronica McGregor/Nancy Lovato Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-5011 Additional articles on this subject are available at: http://www.astrobio.net/news/article1396.html http://www.astrobio.net/news/article1400.html http://science.nasa.gov/headlines/y2005/16jan_titan.htm http://www.space.com/missionlaunches/huygens_images_050114.html http://www.space.com/missionlaunches/huygens_update_050115.html http://www.spacedaily.com/news/cassini-05o.html http://spaceflightnow.com/cassini/050114science.html http://spaceflightnow.com/cassini/050115pic3.html http://spaceflightnow.com/cassini/050115science.html http://spaceflightnow.com/cassini/images/050115montage.jpg http://www.universetoday.com/am/publish/huygens_landed_mud.html __________________________________________________________________________ MARS EXPLORATION ROVERS UPDATES NASA/JPL releases Spirit Close to the Crest NASA/JPL release, 14 January 2005 Currently Spirit is approximately 50 meters (164 feet) from a target called "Larry's Lookout" on a ridge line in the "Columbia Hills." During the period from sol 360 through sol 366, engineers focused on maximizing the amount of time Spirit could drive every sol with limited power. The driving is slow and difficult; Spirit is encountering many rock obstacles and patches of soft sand that are causing Spirit to either slip or dig in. Just when it looked like Spirit might not be able to reach Larry's Lookout, the rover had three successful drive sols. Spirit is in excellent health as the team looks forward to celebrating the anniversary of Opportunity's landing on January 24. More Heat Shield Observations NASA/JPL release, 14 January 2005 The week saw Earthlings celebrate a new year and Spirit's first birthday on Mars (one Earth year) while Opportunity continued its trek around its own heat shield. On Earth, the operations team experienced a few tool problems, but the support team was in position to fix most problems as soon as they were discovered. A dust storm that affected Opportunity the previous week has slowly receded, allowing increasing solar exposure. To conserve energy, Opportunity has been going into the deep-sleep mode every night, but as power continues to improve, the team is planning to resume using some early-morning Mars Odyssey communication passes to reduce a backlog of unsent telemetry. Opportunity continues to be in excellent health as the rover team looks forward to the January 24 anniversary of Opportunity's landing. Hovering Near Heat Shield and a Holey Rock NASA/JPL release, 14 January 2005 Opportunity is healthy. It acquired microscopic images of the fractured edge of the heat-shield wreckage and began a detailed investigation of an intriguing, pitted rock a few meters to the north, called "Heat Shield Rock." The team continues to closely monitor orbital images for dust storms. The opacity of the atmosphere above Opportunity has averaged 0.75 with a slight downward (clearing) trend over the past week. Additional information is available at http://marsrovers.jpl.nasa.gov/home/index.html. Additional articles on this subject are available at: http://www.astrobio.net/news/article1395.html http://www.space.com/missionlaunches/mars_rock_050117.html __________________________________________________________________________ MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 10-14 January 2005 Channel Wall Landslides (Released 10 January 2005) http://themis.la.asu.edu/zoom-20050110a.html Tharsis Landslide (Released 11 January 2005) http://themis.la.asu.edu/zoom-20050111a.html Landslide in A Crater (Released 12 January 2005) http://themis.la.asu.edu/zoom-20050112a.html Terra Cimmeria Crater Landslide (Released 13 January 2005) http://themis.la.asu.edu/zoom-20050113a.html Isidis Crater Landslide (Released 14 January 2005) http://themis.la.asu.edu/zoom-20050114a.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 2.