MARSBUGS: The Electronic Astrobiology Newsletter Volume 8, Number 35, 17 September 2001. Editors: Dr. David J. Thomas, Science Division, Lyon College, Batesville, AR 72503-2317, USA. dthomas@lyon.edu Dr. Julian A. Hiscox, School of Animal and Microbial Sciences, University of Reading, Reading, RG6 6AJ, United Kingdom. J.A.Hiscox@reading.ac.uk 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 editors, except for specific articles, in which instance copyright exists with the author/authors. While we cannot copyright our mailing list, our readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing list. The editors do not condone "spamming" of our subscribers. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editors. E-mail subscriptions are free, and may be obtained by contacting either of the editors. Article contributions are welcome, and should be submitted to either of the two editors. Contributions should include a short biographical statement about the author(s) along with the author(s)' correspondence address. Subscribers are advised to make appropriate inquiries before joining societies, ordering goods etc. Back issues and Adobe Acrobat PDF files suitable for printing may be obtained from the official Marsbugs web page at http://welcome.to/marsbugs. The purpose of this newsletter is to provide a channel of information for scientists, educators and other persons interested in exobiology and related fields. This newsletter is not intended to replace peer- reviewed journals, but to supplement them. We, the editors, envision Marsbugs as a medium in which people can informally present ideas for investigation, questions about exobiology, and announcements of upcoming events. Astrobiology is still a relatively young field, and new ideas may come from the most unexpected places. Subjects may include, but are not limited to: exobiology and astrobiology (life on other planets), the search for extraterrestrial intelligence (SETI), ecopoeisis and terraformation, Earth from space, the biology of terrestrial extreme environments, planetary biology, primordial evolution, space physiology, biological life support systems, and human habitation of space and other planets. _____________________________________________________________________ CONTENTS 1) "GOLD BUG" SHEDS LIGHT ON HOW SOME GOLD DEPOSITS FORMED University of Massachusetts Amherst release 2) QUASI VON NEUMANN MACHINES COULD BE BUILT WITH NEAR-TERM TECHNOLOGIES By Robert Clements 3) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 4) CASSINI WEEKLY SIGNIFICANT EVENTS NASA/JPL release 5) THIS WEEK ON GALILEO NASA/JPL release 6) ISS STATUS REPORT NASA/JSC release _____________________________________________________________________ "GOLD BUG" SHEDS LIGHT ON HOW SOME GOLD DEPOSITS FORMED University of Massachusetts Amherst release 6 August 2001 For centuries, scientists have wondered why gold is found in two forms--as a solid in deposits close to the Earth's crust, and in solution, often far removed from gold-ore deposits. A fairly simple lab experiment conducted at the University of Massachusetts may lead to an understanding of how the precious metal came to be available in disparate forms, and how some gold-ore deposits might have been formed. In research related to pollution clean-up, a team of UMass microbiologists led by noted researcher Derek Lovley has extracted gold solids from water containing dissolved gold. The work uses technology Lovley developed 10 years ago to clean up heavily polluted water and soil around the U.S. using bacteria and archaea, or ancient microorganisms, to break down heavy metals in affected environments. Like uranium, cadmium, and other heavy metals, gold is precious and useful to humans. Lovley notes that dissolved gold, however, is useless because it can't be manipulated and formed into objects of value or beauty. He says when either solid or liquid gold is ingested, it is toxic to most life forms. On the other hand, liquid gold and many other heavy metals are not toxic to a group of microbes called extremophiles, or simple life forms known to thrive in environments where others cannot live. With this in mind, the UMass researchers asked if extremophiles might have ingested the liquid gold found in hydrothermal vents, hot springs, and other hot places, and left it scattered as deposits of solid gold in places that now are below the surface of the Earth. This would explain how the metal came to be in two different forms in very different environments. If that is the case, the team wondered if microbes could duplicate the process in the laboratory and extract valuable solids from liquid containing dissolved gold. "A vast number of bacteria and archaea have the ability to transfer electrons to iron through a reduction process," explained Lovley. "In other words, they digest one form of a metal and excrete it as another form. This transfer leaves behind deposits of solid metal in unlikely places on Earth or maybe even on Mars. What's left behind is often more useful, or more accessible to humans, than the original form of the same substance." Lovley's lab has previously published evidence that iron-reducing microorganisms are involved in the formation of uranium ores, changing uranium to a form that precipitates out of water. Massive accumulations of magnetite created by iron-reducing microbes during the Precambrian period of the earth's development now are important deposits of iron ore, according to Lovley. In the laboratory, postdoctoral research associate, Kazem Kashefi, and graduate students Jason M. Tor, and Kelly P. Nevin studied dissolved gold in an oxidized form in an environment similar to that found in a hydrothermal vent, where dissolved gold can sometimes be found. The team wanted to see what would happen if they put iron- reducing microbes into the gold solution under those conditions. As they suspected, the microbes rapidly converted the gold from the useless, oxidized, dissolved form to a more valuable, insoluble, metal form. Essentially, the microbes had eaten the solution, and left behind a precious by-product. "There's a significant amount of gold found in solution in some thermal springs, and hydrothermal vents on the ocean floor," Lovley said. "The problem is that the gold is extremely diluted, so only a teeny amount is dispersed in a very large volume of water." "There are waste streams from gold processing where this same reduction process might work on a larger scale, but the goal of this study was to offer an explanation of how gold deposits are formed, more than it was to produce any profitable or useful application on a larger scale," explained Lovley. The research was presented in the July issue of the journal Applied and Environmental Microbiology. It was funded in part by a grant from the National Science Foundation, through the Life in Extreme Environments Program. Derek Lovley can be reached at 413-545-9651 or dlovley@microbio.umass.edu. An additional article on this subject is available at http://www.spacedaily.com/news/early-earth-01j.html. _____________________________________________________________________ QUASI VON NEUMANN MACHINES COULD BE BUILT WITH NEAR-TERM TECHNOLOGIES By Robert Clements 11 September 2001 [This article is a response to Ivo Renkema's article in last month's Marsbugs (Vol. 8, No. 34).] You don't need to invoke biological systems to make von Neumann-style technologies feasible. There are several quasi-von Neumann design scenarios, which could almost be built with existing technologies. In this scenario, instead of launching a system that can reconstruct itself completely, a quasi-von Neumann needs only to carry the technology that can use in situ materials to build a part (or a whole) of the construction system, which will eventually create the final product. Such a unit might, for example, begin by building a communication system capable of linking to the nearest data node to receive what are effectively the latest systems schematics; then begin to create the tools required to create the next stage(s) in technology construction, eventually--through multiple generations of intermediary systems--building what is effectively a quasi-von Neumann factory, which launches a new generation of these probes outwards and onwards. While still suitably mind-boggling, this scenario is philosophically rather simpler than Dr. von Neumann's original conception, and takes advantage of the fact that any technology capable of spanning interstellar distances at relativistic velocities is unlikely to be in much of a hurry. Proving that such a scenario has taken place historically is rather difficult, of course. Although it does raise the currently untestable possibility that defunct--and possibly large--construction systems may be found in parts of the solar system rich in easily accessible in situ materials: in particular, asteroid And/or cometary zones like the main asteroid or the Edgeworth-Kuiper belts. I've never seen any reason for invoking extraterrestrial seeding to explain the appearance of life on Earth, though. Contact: Robert Clements E-mail: Robert.Clements@dva.gov.au Endeavour 2 project http://www.geocities.com/robtclements/endeavour2.html _____________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.h tml 17 September 2001 Articles about the biology of extreme environments (on Earth) http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s2.html SpaceDaily, 2001. 'Gold bug' sheds light on how some gold deposits formed. SpaceDaily. Articles about human space exploration and the microgravity environment http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s3.html National Research Council, 2001. Readiness Issues Related to Research in the Biological and Physical Sciences on the International Space Station. National Academy Press, Washington, DC. Astrobiology and extreme environments book list http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology_b ooks.html National Research Council, 2001. Readiness Issues Related to Research in the Biological and Physical Sciences on the International Space Station. National Academy Press, Washington, DC. _____________________________________________________________________ CASSINI WEEKLY SIGNIFICANT EVENTS NASA/JPL release 6-12 September 2001 The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Saturday, September 8. The Cassini spacecraft is in an excellent state of health and is operating normally. Information on the spacecraft's position and speed can be viewed on the "Present Position" web page at http://www.jpl.nasa.gov/cassini/english/where/. The next scheduled tracking pass is Friday, September 14. The rather long gap between passes is indicative of the fact that Cassini is now in a quiescent cruise phase, and was not influenced by the other events of the week. Recent spacecraft activities include initiation of the C28 sequence on board the spacecraft, the beginning of a detailed solar wind study by the Cassini Plasma Spectrometer, and a Radio and Plasma Wave Science High Frequency Receiver calibration. Real-time commands were uplinked to the spacecraft to power off the Visual and Infrared Mapping Spectrometer and turn on the replacement and remote sensing pallet heaters. Cassini 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, CA, manages the Cassini mission for NASA's Office of Space Science, Washington, DC. _____________________________________________________________________ THIS WEEK ON GALILEO NASA/JPL release 10-16 September 2001 This week's focus for the Galileo spacecraft is again playback of the recorded data that was acquired during the August 5 flyby of Io and Jupiter. A variety of observations are planned for return this week, from the Photopolarimeter Radiometer (PPR), the Near Infrared Mapping Spectrometer (NIMS), and the Solid State Imaging camera (SSI). PPR will first see data from Io, with a global day-side map of temperatures across the surface. This observation represents the first-ever global view of day-side temperatures by PPR. A second global map of the satellite's surface will examine the polarization of the light reflected from the surface. This will provide insight into the fine structure of the surface materials. In addition, two observations of Callisto will provide polarization data from that body at different angles of reflected sunlight. NIMS is returning a regional map of a portion of Io, looking for thermal variations and sulfur dioxide distribution on the surface. An observation of Jupiter, looking in the wake of the Great Red Spot, rounds out the NIMS data this week. The SSI science team is expecting a global color mosaic of the face of Io that faces Jupiter. This observation was recorded approximately 32 hours after Io closest approach. We will also begin to play back a series of pictures that track the evolution of a portion of Jupiter's atmosphere as the giant planet rotates beneath the spacecraft. On Wednesday, at the Goldstone tracking station in the Southern California desert, the spacecraft appears to pass close to Earth's moon. Although Galileo is not blocked by the moon, enough thermal energy reflected by the moon is received in the ground communications antenna to raise the temperature of the radio receivers. This adds enough noise to the signal we are trying to receive from the spacecraft that the data can be corrupted. To protect against this, a special, non-critical data type is transmitted during this time, so that the high-priority playback data from the encounter are not jeopardized. For more information on the Galileo spacecraft and its mission to Jupiter, please visit the Galileo home page at one of the following URL's: http://galileo.jpl.nasa.gov http://www.jpl.nasa.gov/galileo _____________________________________________________________________ ISS STATUS REPORT NASA/JSC release 14 September 2001 On its way to provide additional capabilities to the International Space Station, the Russian Docking Compartment lifted off from the Baikonour Cosmodrome in Kazakhstan today. Pirs, the Russian word for pier, was successfully launched atop a Russian Soyuz rocket at 6:35 PM CDT. Expedition Three Commander Frank Culbertson reported that he was able to see the rocket climbing into orbit as the station was orbiting 250 miles up, southwest of the Caspian Sea. He said it was the first time he had witnessed such an event from orbit. Using its Progess-style instrumentation and propulsion stage, Pirs will navigate its way to the ISS for a fully automatic docking planned at 8:08 PM CDT on Sunday, September 16. Culbertson and crewmates Pilot Vladimir Dezhurov and Flight Engineer Mikhail Tyurin spent some time this week preparing for the arrival of Pirs. Preparation tasks included checking out the automated and manual docking systems and configuring the outside cameras to view the Docking Compartment's approach. The crew also practiced using the manual docking system to complete the rendezvous, which would occur only if there were a problem with the automatic system. Thursday night, flight controllers in Houston and Moscow completed a ground-controlled docking test. In that test, Mission Control in Houston handed over attitude control authority to the Zvezda module's motion control system. Russian flight controllers commanded the Zvezda control thrusters to fire and rotate the station to the docking attitude. After going into a free drift mode, the Russian control system then moved the station back to its normal attitude and handed control back to the U.S. control moment gyroscopes. The new Russian component will serve as an additional docking port for future Russian vehicles arriving at the station, an added stowage area and also as an airlock for the Russian segment. Three spacewalks are to be conducted in October from Pirs by the Expedition Three crew--two by Dezhurov and Tyurin and one by Culbertson and Dezhurov--to electrically mate the Docking Compartment to Zvezda and install more equipment on the outside of the module. The crew will be shifting its sleep period, going to bed at 7:30 AM CDT Sunday, just six and a half hours after awakening. The crew will awaken again at 4:00 PM CDT and immediately begin final preparations for the docking about four hours later. In addition to preparing for the arrival of the new component, crewmembers have been monitoring many science activities. Oversight of science investigations on the station from the ground is handled by the Payload Operations Center at NASA's Marshall Space Flight Center in Huntsville, AL. Johnson Space Center manages the Human Research Facility. Details on station science operations can be found at the center's web site at http://www.scipoc.msfc.nasa.gov. The International Space Station (ISS) is orbiting at an average altitude of 240 statute miles (385 km). Sighting opportunities from the ground for many cities around the world can be viewed at http://spaceflight.nasa.gov/realdata/sightings/. The next ISS status report will be issued Sunday, September 16, or earlier if events warrant. _____________________________________________________________________ End Marsbugs, Volume 8, Number 35.