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Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 2, 19 January 2005
Marsbugs: The Electronic Astrobiology Newsletter
Volume 12, Number 2, 19 January 2005
Editor/Publisher: David J. Thomas, Ph.D., Science Division, LyonCollege, Batesville, Arkansas72503-2317, USA.
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 LyonCollege. 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 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 image (right) 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. [
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Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 2, 19 January 2005
Articles and News
Page 1ORGANIC MOLECULES TRANSPORT STRONGEST SPECTRAL SIGNATURE OF INTERPLANETARY DUST PARTICLES
Lawrence Livermore National Laboratory release 05-01-02
Page 2TITAN CLOSE UP
By Henry Bortman
Page 3KECK TELESCOPE CAPTURES TITAN BUT MISSES HUYGENS
By Robert Sanders
Page 3DID FLUID ONCE FLOW ON TITAN? (INTERVIEW WITH CAROLYN PORCO)
By Helen Matsos
Page 4LAKEFRONT LANDING IN CRÈME BRULÉ
By Henry Bortman
Page 5MEDIA LEFT LOST ON TITAN
By Simon Mansfield
Page 5TARGETING TITAN (INTERVIEW WITH TOBY OWENS, PART 1)
By Henry Bortman
Page 5METHANE WORLD (INTERVIEW WITH TOBY OWENS, PART 2)
By Henry Bortman
Mission Reports
Page 6CASSINI-HUYGENS UPDATES
NASA/ESA releases
Page 9MARS EXPLORATION ROVERS UPDATES
NASA/JPL releases
Page 9MARS ODYSSEY THEMIS IMAGES
NASA/JPL/ASU release
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Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 2, 19 January 2005
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Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 2, 19 January 2005
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.
A secondary electron image of a typical chondritic Interplanetary Dust Particle (IDP).
"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, WashingtonUniversity and NASA-AmesResearchCenter.
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:
Read the original news release at
An additional article on this subject is available at
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.
Channel-like landscape from 16 kilometers, at 40 meters per pixel resolution during descent. Image credit: ESA.
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.
Titan image from Huygens probe January 14, 2005—8 kilometer altitude, 20 m/pixel resolution. Image credit: ESA.
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."
Surface image from Titan shows ice blocks strewn around. Image credit: ESA.
"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
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."
Near-infrared surface image of Titan captured with Keck adaptive optics system moments after the Huygens probe reached its target at 09:06 GMT January 14, 2005. The bright and dark patterns on Titan's surface may be regions of solid ice and of liquid hydrocarbons. No atmospheric disturbance was detected. The arrow indicates the estimated landing area of the Huygens probe. Image credit: W. M. Keck Observatory.
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
Read the original news release at
An additional article on this subject is available at
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.
Carolyn Porco, Imaging Team Lead. Titan is unlike Mars and the icy moons of Jupiter, which have little or no atmosphere. So the "techniques that we've used for interpreting airless bodies, all those methods of examining solid surfaces from planetary spacecraft that we have learned over the last half century," don't apply, says Porco. "We can't use that on Titan, because it's a very different environment." Image credit: NASA/JPL.
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.
The very bright features near Titan's south pole are clouds similar to those observed during the distant Cassini flyby on July 2, 2004. Image credit: NASA/JPL.
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.