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Marsbugs: The Electronic Astrobiology Newsletter, Volume 11, Number 13, 23 March 2004
Marsbugs: The Electronic Astrobiology Newsletter
Volume 11, Number 13, 23 March 2004
Editor/Publisher: David J. Thomas, Ph.D., Science Division, Lyon College, Batesville, Arkansas 72503-2317, 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, except for specific articles, in which instance copyright exists with the author/authors. 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 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.
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Marsbugs: The Electronic Astrobiology Newsletter, Volume 11, Number 13, 23 March 2004
Articles and News
Page 1CREATURE FEATURES: FOSSIL HUNTING ON MARS
By Leonard David
Page 1SURVIVING WITH—AND WITHOUT—OXYGEN: AN INTERVIEW WITH CHRISTOPHER CHYBA
By Henry Bortman
Page 2PAUL G. ALLEN CHARITABLE FOUNDATION FUNDS NEXT PHASE IN CONSTRUCTION OF THE WORLD'S NEWEST RADIO TELESCOPE ARRAY
SETI Institute release
Page 4FROM LAVA LAKES ON JUPITER'S MOON, IO, COME IDEAS ABOUT WHAT EARTH MAY HAVE LOOKED LIKE AS A NEWBORN PLANET
University at Buffalo release
Page 4ASTEROID SCARE PROMPTS NASA TO FORMALIZE RESPONSE
By Robert Roy Britt
Page 5OCEANS' ACIDITY INFLUENCES EARLY CARBON DIOXIDE AND TEMPERATURE LINK ESTIMATES
Pennsylvania State University release
Page 5ANTIFREEZE IN COMET HALE-BOPP
Paris Observatory release
Announcements
Page 6NASA ANNOUNCES NEW MARS INTERACTIVE WEB FEATURE
NASA release 04-097
Page 6NEW ADDITIONS TO THE ASTROBIOLOGY INDEX
By David J. Thomas
Mission Reports
Page 6CASSINI SIGNIFICANT EVENTS
NASA/JPL release
Page 8MARS EXPLORATION ROVERS UPDATES
NASA/JPL releases
Page 9MARS EXPRESS: WATER AT MARTIAN SOUTH POLE
ESA release
Page 10MARS GLOBAL SURVEYOR IMAGES
NASA/JPL/MSSS release
Page 11MARS ODYSSEY THEMIS IMAGES
NASA/JPL/ASU release
Page 11STARDUST: COMPOSITE AND STEREO IMAGES OF COMET WILD 2
NASA/JPL release
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Marsbugs: The Electronic Astrobiology Newsletter, Volume 11, Number 13, 23 March 2004
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Marsbugs: The Electronic Astrobiology Newsletter, Volume 11, Number 13, 23 March 2004
CREATURE FEATURES: FOSSIL HUNTING ON MARS
By Leonard David
From Space.com
16 March 2004
Those on-the-prowl Mars robots—Spirit and Opportunity—are sending back extraordinary images and science data about the red planet and its history of climate and water. Both rovers have found evidence of water at their respective landing sites. But the question remains open as to whether Mars was, or is today, a planet capable of supporting life.
The tell-tale clues of water left behind hint that some spots on Mars did have a persistent wet look that might have been sociable to extraterrestrial creatures. While Mars scientists have their eyes focused on finding tiny microbes, the question remains: just how far along could martian biology, if any, have evolved? Yet answering this question is a difficult task to answer robotically and it might take rock-splitting fossil hunters, hammer in hand, to chronicle the true life on Mars saga.
Read the full article at
SURVIVING WITH—AND WITHOUT—OXYGEN: AN INTERVIEW WITH CHRISTOPHER CHYBA
By Henry Bortman
From Astrobiology Magazine
17 March 2004
Christopher Chyba is the principal investigator for The SETI Institute lead team of the NASA Astrobiology Institute. Chyba formerly headed the SETIInstitute's Center for the Study of Life in the Universe. His NAI team is pursuing a wide range of research activities, looking at both life's beginningson Earth and the possibility of life on other worlds. Astrobiology Magazine's managing editor, Henry Bortman, spoke recently with Chyba aboutseveral of his team's projects that will explore the origin and significance of oxygen in Earth's atmosphere.
Astrobiology Magazine: Many of the projects that members of your team will be working on have to do with oxygen in Earth's atmosphere. Today oxygen is a significant component of the air we breathe. But on early Earth, there was very little oxygen in the atmosphere. There is a great dealof debate about just how and when the planet's atmosphere became oxygenated. Can you explain how your team's research will approach thisquestion?
Christopher Chyba: The usual story, with which you're probably familiar, is that after oxygenic photosynthesis evolved, there was then a hugebiological source of oxygen on early Earth. That's the usual view. It may be right, and what's usually the case in these kinds of arguments is not whetherone effect is right or not. Probably many effects were active. It's a question of what was the dominant effect, or whether there were several effects ofcomparable importance.
SETI Institute researcher Friedemann Freund has a completely non-biological hypothesis about the rise of oxygen, which has some experimentalsupport from laboratory work that he's done. The hypothesis is that, when rocks solidify from magma, they incorporate small amounts of water. Cooling and subsequent reactions leads to the production of peroxy links (consisting of oxygen and silicon atoms) and molecular hydrogen in therocks.
Left: Freund's hypothesis suggests that when rocks solidify from magma, they incorporate small amounts of water. Image credit: UC Berkeley. Right: Saturn's moon Titan is composed of methane and nitrogen. Image credit: NASA.
Then, when the igneous rock is subsequently weathered, the peroxy links produce hydrogen peroxide, which decomposes into water andoxygen. So, if this is right, simply weathering igneous rocks is going to be a source of free oxygen into the atmosphere. And if you look at some ofthe quantities of oxygen that Friedemann is able to release from rocks in well-controlled situations in his initial experiments, it might be that thiswas a substantial and significant source of oxygen on early Earth.
So even apart from photosynthesis, there might be a kind of natural source of oxygen on any Earth-like world that had igneous activity andliquid water available. This would suggest that the oxidation of the surface might be something that you expect to occur, whether photosynthesis happens early or late. (Ofcourse, the timing of this depends on oxygen sinks as well.) I emphasize that's all a hypothesis, at this point, for much more careful investigation. Friedemann's done only pilotexperiments so far.
One of the interesting things about Friedemann's idea is that it suggests there might be an important source of oxygen on planets completely independent of biological evolution. So there might be a natural driver towards the oxidation of the surface of a world, with all the ensuing consequences for evolution. Or maybe not. The point is to do the workand find out.
Another component of his work, which Friedemann will do with the microbiolologist Lynn Rothschild of NASA Ames Research Center, has to dowith this question of whether in environments associated with weathered igneous rocks and the production of oxygen, you could have createdmicro-environments that would have allowed certain microorganisms living in those environments to have pre-adapted to an oxygen-richenvironment. They'll be doing work with microorganisms to try to address that question.
AM: Emma Banks will be looking at chemical interactions in the atmosphere of Saturn's moon Titan. How does that tie into understandingoxygen on early Earth?
CC: Emma's looking at another abiotic way that might be important in oxidizing a world's surface. Emma does chemical computational models, allthe way down to the quantum mechanical level. She does them in a number of contexts, but what's relevant to this proposal has to do with hazeformation.
On Titan—and possibly on the early Earth as well, depending on your model for the atmosphere of the early Earth—there's a polymerization of methane [the combination ofmethane molecules into larger hydrocarbon-chain molecules] in the upper atmosphere. Titan's atmosphere is several percent methane; almost all the rest of it is molecularnitrogen. It's bombarded with ultraviolet light from the sun. It's also bombarded with charged particles from Saturn's magnetosphere. The effect of that, acting on the methane,CH4, is to break the methane up and polymerize it into longer-chain hydrocarbons.
If you start polymerizing methane into longer and longer carbon chains, each time you add another carbon onto the chain, you've got to get rid ofsome hydrogen. For example, to go from CH4 (methane) to C2H6, (ethane) you have to get rid of two hydrogens. Hydrogen is an extremelylight atom. Even if it makes H2, that's an extremely light molecule, and that molecule's lost off the top of Titan's atmosphere, just as it's lost off thetop of the Earth's atmosphere. If you bleed hydrogen off the top of your atmosphere, the net effect is to oxidize the surface. So it's another waythat gives you a net oxidation of a world's surface.
Emma's interested in this primarily with respect to what takes place on Titan. But it's also potentially relevant as a kind of global oxidizingmechanism for the early Earth. And, bringing nitrogen into the picture, she's interested in the potential production of amino acids out of theseconditions.
AM: One of the mysteries about early life on Earth is how it survived the damaging effects of ultraviolet (UV) radiation before there was enoughoxygen in the atmosphere to provide an ozone shield. Janice Bishop, Nathalie Cabrol and Edmond Grin, all of whom are with the SETI Institute,are exploring some of these strategies.
CC: And there are a lot of potential strategies there. One is just being deep enough below the surface, whether you're talking about the land orthe sea, to be completely shielded. Another is to be shielded by minerals within the water itself. Janice and Lynn Rothschild are working on a project that is examining the role offerric oxide minerals in water as a kind of UV shield.
In the absence of oxygen the iron in water would be present as ferric oxide. (When you have more oxygen, the iron oxidizes further; it becomesferrous and drops out.) Ferric oxide could potentially have played the role of an ultraviolet shield in the early oceans, or in early ponds or lakes. To investigate how good it is as a potential UV shield, there are some measurements you might want to make, including measurements in naturalenvironments, such as in Yellowstone. And once again there's a microbiological component to the work, with Lynn's involvement.
This is related to the project that Nathalie Cabrol and Edmond Grin are pursuing, from a different perspective. Nathalie and Edmond are veryinterested in Mars. They are both on the Mars Exploration Rover science team. In addition to their Mars work, Nathalie and Edmond exploreenvironments on Earth as Mars analog sites. One of their topics of investigation is strategies for survival in high-UV environments. There's a lakesix kilometers high on Licancabur (a dormant volcano in the Andes). We now know there's microscopic life in that lake. And we'd like to knowwhat are its strategies for surviving in the high-UV environment there? And that's a different, very empirical way of getting at this question of howlife survived in the high-UV environment that existed on early Earth.
These four projects are all coupled, because they have to do with the rise of oxygen on early Earth, how organisms survived before there was substantial oxygen in theatmosphere, and then, how all this relates to Mars.
Read the original article at
An additional article on this subject is available at
PAUL G. ALLEN CHARITABLE FOUNDATION FUNDS NEXTPHASE IN CONSTRUCTION OF THE WORLD'S NEWEST RADIO TELESCOPE ARRAY
SETI Institute release
18 March 2004
Investor and philanthropist Paul G. Allen has committed $13.5 million to support the construction of the first andsecond phases of the Allen Telescope Array (the ATA-32 and ATA-206), theworld's newest multiple use radio telescope array. The ATA will eventuallyconsist of 350 6.1-meter dishes (ATA-350), when construction is completedlate in the decade. The announcement was made today by Thomas Pierson,chief executive officer for the SETI Institute, a leading astrobiology institutionwith the mission of exploring the origin, nature and prevalence of life in theuniverse. The ATA is a partnership between the SETI Institute and the RadioAstronomy Laboratory of the University of California, Berkeley (RAL).
Today's announcement follows the successful completion of a three-yearresearch and development phase which was originally funded by an $11.5million gift from the Allen Foundation. The R & D proved that one of the primaryadvantages of the array design—its scalability—makes it possible for the ATAto conduct scientific investigations as soon as the first 32 dishes are installed. Pierson also announced that the ATA-32 is scheduled to begin conductingscientific investigations by the end of 2004, significantly earlier than the 350element array can be completed.
The ATA will be a general-purpose radio telescope that will providefundamentally new measurements and insights into the density of the very earlyuniverse, the formation of stars, the magnetic fields in the interstellar medium,and a host of other applications of deep interest to astronomers. At the sametime, this 21st Century radio telescope will also have the capability to searchfor possible signals from technologically advanced civilizations elsewhere in thegalaxy.
"I am very excited to be supporting one of the world's most visionary efforts toseek basic answers to some of the fundamental question about our universeand what other civilizations may exist elsewhere," said Paul G. Allen, primaryfunder of the ATA. "I am a big proponent of leveraging revolutionary technologyand design and applying it to important problems in science. The developmentstaking place with this new instrument will not only enables us to realize a lot ofbang for our research and development buck, but it will also change thelandscape of how telescopes will be built in the future. An instrument of thismagnitude, which will result in the expansion of our understanding of how theuniverse was formed, and how it has evolved, and our place therein, is thereason I am the primary supporter of its development, design and construction."
ATA prototype currently being installed at Hat Creek Observatory. Image credit: SETI Institute.
Allen's $13.5 million funding, structured as a challenge grant, will allowconstruction and operation of the first phase of 32-dishes by the end of theyear. It will also support construction of the second phase of 174 additionaldishes (the ATA-206), which is contingent upon fulfilling the Foundations'challenge grant, in response to which the Institute will raise $16 million inadditional support.
It is especially thrilling to see the Allen Telescope Array approach its firstsignificant milestone,said SETI Institute CEO Tom Pierson. We are gratefulfor the additional support from the Allen Foundation that is making this newfacility—and further discovery—possible. Mr. Allen and his Foundation haveset the bar high. Mr. Allen's support of this worthwhile project, when matchedby other supporters of radio astronomy and SETI, will quickly bring this projectto fruition.
The ATA is the result of a multi-faceted private-public partnership between theSETI Institute and the RAL. It differs in practice, appearance, and cost fromtraditional radio telescopes currently in use. When completed, the ATA-350 willbe among the world's largest and fastest observing instruments. Rather than a single enormous dish or several large dishes, the ATA will beconstructed using hundreds of specially produced small dishes. The telescopewill incorporate innovative technologies and modern, miniaturized electronics inconcert with increasingly affordable computer processing. These newtechnologies, combined with the ability to conduct continuous observations, willincrease SETI search speed by 300 times over previous efforts andsimultaneously allow astronomers to conduct complex radio astronomy projectsrequiring long-term observations. And the instrument will achieve these goals atone-fifth the cost of traditional radio telescopes of comparable collecting areaand complexity.
In its first phase, the ATA-32 will have more antennas than any of the world'sother centimeter-wavelength radio telescopes. The individual antennas will belinked by fiber optics. The fiber, power, and air distribution systems will beinstalled in ten-antenna "nodes," an efficient way to maintain the cooloperating temperature required by the equipment.
The ATA-32 will observe in the direction of the galactic anti-center to detectprimordial deuterium, study dark matter in nearby dwarf galaxies, generatemaps of polyatomic molecules in molecular clouds, and conduct a SETI survey ofthe inner galaxy.
"I am eager to begin observing on the ATA," commented Dr. Jill C. Tarter, ATAproject leader and Director of the Center for SETI Research at the Institute. "Conducting observations 24/7 is a dream come true for any astronomer, and itis particularly exciting for the Institute's astronomers, who have beenconstrained by limited time on other large centimeter wavelength telescopes. Finally, our tools are becoming commensurate with the size of our task."
First truckload of dishes for the Allen Telescope Array arrive at Hat Creek Observatory on March 18. Image credit: David DeBoer.
Scientists believe that radio waves, such as those commonly produced by avariety of technologies on Earth and traveling at light-speed through interstellarspace, may offer the easiest way to detect evidence of a technologicallysophisticated civilization elsewhere in the galaxy. With sufficient collecting area,it is possible to detect signals from a distant technology that are no morepowerful than those produced on Earth today.