MARSBUGS: The Electronic Astrobiology Newsletter Volume 9, Number 6, 11 February 2002. 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. Information concerning the scope of this newsletter, subscription formats and availability of back-issues is available from the Marsbugs web page at http://welcome.to/marsbugs or http://www.lyon.edu/webdata/users/dthomas/marsbugs/marsbugs.html. _____________________________________________________________________ CONTENTS 1) DIGITAL ZOOKEEPERS TAKE A CENSUS From the NASA Astrobiology Institute 2) PUBLIC TELLS NASA WHERE TO GO: MARS By Robert Roy Britt 3) SATELLITES VS. MOSQUITOES: TRACKING WEST NILE VIRUS IN THE U.S. NASA release 02-029 4) FORMER ASTRONAUT ALDRIN, PURDUE ENGINEERS PLANNING MARS HOTELS By Emil Venere 5) HYDROGEN-DRIVEN ACTUATORS MAY REPLACE DAMAGED MUSCLES From NASA Tech Briefs Insider 6) FIRST GENETIC EVIDENCE UNCOVERED OF HOW MAJOR CHANGES IN BODY SHAPES OCCURRED DURING EARLY ANIMAL EVOLUTION University of California, San Diego release 7) EUROPAN TIDES MIGHT FOSTER LIFE, SAYS UA MEMBER OF GALILEO IMAGING TEAM University of Arizona release 8) DETECTING OTHER WORLDS VII: DIRECT IMAGING By Laurance Doyle 9) MARS INFRARED SPECTROSCOPY: FROM THEORY AND THE LABORATORY TO FIELD OBSERVATIONS Lunar and Planetary Institute workshop announcement 10) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 11) CASSINI WEEKLY SIGNIFICANT EVENTS NASA/JPL release 12) INTERNATIONAL SPACE STATION STATUS REPORT NASA/JSC release 13) MARS ODYSSEY MISSION STATUS NASA/JPL release 14) STARDUST STATUS REPORT NASA/JPL release _____________________________________________________________________ DIGITAL ZOOKEEPERS TAKE A CENSUS From the NASA Astrobiology Institute 1 February 2002 If the name of each species on Earth were put on a single recipe card, the box containing them all would stretch for over 6 miles. There are approximately 1.4 million species that have been named by researchers, but the true number of species on earth may be anywhere between 5 and 30 million species. If just keeping those animal names straight wasn't challenging enough, the shuffling of cards over time has captured the combined interest of a 25 member scientific team, first organized by Dr. Charles Marshall (now at Harvard). In reporting some of their analysis of the timelines for fossil records, the team has created a kind of digital zoo. Cataloguing the taxonomy of an entire planet's history, their database holds great promise for resolving century-old debates about how the Earth got to be such a rich spawning ground for life's diversity. That history of life is buried in the rocks: "Our goal is quite literally to provide a reasonable sampling of the entire fossil record", says Professor Arnold Miller, a team member of the database project and geologist at the University of Cincinnati. Miller and four of his graduate students are all catalog contributors. The National Center for Ecological Analysis and Synthesis (NCEAS) houses the mammoth database in Santa Barbara, California. So far, the team’s fossil catalog comprises 8,500 collections and over 110,000 taxonomic occurrences, with an initial emphasis on the rich collections of marine invertebrates. Including 90% of all the animals on the planet, invertebrates encompass worms, sponges, mollusks and other species without a backbone. The analysis of the catalog spans 300 million years, an era that geologists classify as Middle Ordovician-Carboniferous (approximately 450 Million years ago) and Late Jurassic-Paleogene (approximately 150 Million years ago). Evolution: smooth or bumpy? As recently published in the Proceedings of the National Academy of Sciences (PNAS), one key question the research team has pondered statistically dates back to the earliest fossil collectors. Has biodiversity in the oceans increased dramatically throughout the history of animal life, or moved erratically to an average plateau? Does a curve or flat-line best describe the type and frequency as new species arise or die off? No doubt, during past periods life has simply sprouted wildly, in what some paleobiologists enthusiastically refer to as the "explosive radiation of animals." Buried in the sedimentary layers on both land and sea, previous fossil records show distinctly these innovative bursts. But such unbounded biological optimism contrasts markedly with sharp disturbances and interruptions, including seven mass extinction peaks in the last 250 million years, each spaced 20 to 60 million years apart. Untangling these competing forces may help the team resolve the limitations of the simplest model of slow expansion and diversification, called logistic growth (a gradual upward exponential curve). Primarily attributed to two factors--the favorable geographic niches (e.g. islands, desert, mountains) and cooperative interactions (e.g. predator-prey relations)-- life's diversity has been commonly assumed to be an expansion, or radiation of animals. Self-evidently drawing a straight line from the first appearance of life on Earth to as many as 30 million species shows expansion. But the journey itself seems less smooth, particularly when peering into the sometimes sporadic fossil records. Proving exactly how steady this diversification has gone has required a detective's insight into the fossil record. The researcher’s particular attention to the bin sizes is new, and as past progress has burst forward in fits and starts, their recent analyses account for exactly "when" and "how much". In general, the newer the fossil, the higher the chance it has preserved whatever evidence might point to a more diverse taxonomy. Miller says, "The discovery of more taxa during a given interval may imply that the world genuinely contained more taxa at that time (i.e., the increase is biologically meaningful). However, it is also possible that the fossil record is simply better--more 'complete' or more extensive--for that interval, leaving open the possibility that the apparent increase in biodiversity during the interval may not be biologically meaningful, but might, instead, be tied simply to the increased availability of fossils--and taxa--from the interval." Therefore, according to the researchers, diversity may indeed increase or may alternatively--as an artifact--just appear better because of a more extensive database of rocks and recognized species’ taxonomy. Clearly, before a digital zoo reveals deeper patterns of change, more data needed cataloguing. Miller notes, "This issue has been debated back and forth over the years, but has not been resolved, partly because the data have not been available to resolve it." Data sampling: does size matter? One particularly promising statistical method used so far has been to adjust for what may appear as more diversity, but which in truth may just arise from better fossils. "If it works, this overcomes the problem because we can 'adjust down' the intervals with larger samples," says Miller. An immediate conclusion from the researchers' compendium was evident. "Interval size matters! All else being equal, a longer interval should contain a larger sample," says Miller. In addition to picking which time interval to sample, or bin size for the number of species to classify as a genuine growth spurt, a second and formidable challenge remains--to go to more remote places to get fossils. For sheer numbers and variety however, some of the richest biological areas on the globe, like the Amazon, haven't been charted equally in depth with those found in North America and Europe. This regional selection may introduce an added bias. "In assembling the data, it is much easier to acquire information from some parts of the world than it is from others," says Miller. "One of the real challenges for us is to ensure that our data are truly global in scope." A large chunk of the database now represents mainly northern industrialized areas, and also tends to capture more marine fossils than land samples. In pulling together such a large and accomplished group of scientists, a common purpose and unity was found between them about the importance of looking at global diversity. "One of the reasons we were able to get off the ground and gain momentum on what has now turned into a large project," says Miller, "is that several of us were like-minded in the first place with respect to the analysis of global diversity." Getting older fossils from more remote venues remains one of their top research goals. The research group has already highlighted a number of intriguing initial conclusions. As anticipated, the older the rocks, the less they reveal about biological diversification. This bias indeed does make for more of a plateau than previously thought, and flattens some expectations for radiative explosion of animal species. For example, in the most recent geological time periods, instead of a sharp increase in biodiversity, there was very little change in overall diversity over time. Younger rocks mean more fossils, but, in reality, not necessarily more biodiversity. If that conclusion continues to gain support as more remote geography and land species get catalogued, then the team will have moved closer to resolving one of the grand debates of paleobiology--the pace and scope of species leaping forward on evolutionary branches. However that debate settles itself, one summary seems clear. Tapping the historical record has predictable pitfalls in comparing together young and old rocks. "We are reliant on the efforts of paleontologists over the past centuries to catalogue the known fossil record," concludes Miller. What's next? As the current collection expands beyond the 8,500 fossil catalogs so far, more biological diversity will be sought out to include in the database. For the number of species studied statistically in the database so far, "there is nothing magical about the 110,000 figure," says Miller. "It simply represented where we were at the time we did our first set of analysis last winter. The database has grown since then." But more revealing than just the quality of their initial data records, richer comparisons across different venues and epochs can approach a standard kind of encyclopedic compendium of life. "It certainly is our hope that these data will be useful for other purposes, " says Miller, "in addition to sampling standardization, given that we are collecting a variety of ancillary information on each occurrence (e.g., rock type and paleoenvironment, when available) that should enable all sorts of investigations in which diversification is compared and contrasted among different environmental or geographic regimes." Additional information on this article is available at http://web99.arc.nasa.gov/NAI/stories/database.cfm. Additional articles on this subject are available at: http://www.pnas.org/cgi/content/abstract/98/11/6261 http://www.spacedaily.com/news/life-02e.html _____________________________________________________________________ PUBLIC TELLS NASA WHERE TO GO: MARS By Robert Roy Britt From Space.com 2 February 2002 A public survey conducted for NASA shows overwhelming support for Mars missions. Of the more than 54,000 people who responded to the online survey run by the Planetary Society, more than 90 percent ranked Mars exploration among the top five missions priorities. Missions to the Moon and Jupiter's moon Europa were the next most popular, were both ranked in the top five by more than 60 percent of respondents. The next closest contender for favorite destination was Pluto, along with its neighboring objects, at 37 percent. Get the full story at http://www.space.com/scienceastronomy/survey_says_020204.html. _____________________________________________________________________ SATELLITES VS. MOSQUITOES: TRACKING WEST NILE VIRUS IN THE U.S. NASA release 02-029 5 February 2002 A NASA-funded study uses temperature and vegetation data from satellites to help track and predict where West Nile Virus is spreading in North America. Scientists and public health officials hope one day to use near real-time maps to focus resources and stave off the disease more efficiently. The disease, first reported in the U.S. in 1999, causes flu-like symptoms that can lead to fatal encephalitis in people with compromised immune systems, like the elderly. Though not yet proven, scientists believe the West Nile Virus may be spread across the country by infected birds traveling along their migration routes. Mosquitoes that act as a vector carry the virus, and pass it on when feeding on hosts like birds, livestock, other animals and people. The satellite maps show nation-wide temperatures, distributions of vegetation, bird migration routes and areas pinpointing reported cases. The combined data helps scientists predict disease outbreaks by showing where conditions are right for the insects to thrive and where the disease appears to be spreading. "The images are derived from satellite data that capture a number of variables that are crucial for detecting whether a habitat is suitable for a vector, like a mosquito that carries West Nile Virus," said David Rogers, the lead author of the study. Rogers is Professor of Ecology at Oxford University in the United Kingdom and a member of the International Research Partnership for Infectious Diseases (INTREPID) group, based at NASA's Goddard Space Flight Center. This paper is the cover story in the most recent issue of Photogrammatic Engineering and Remote Sensing. "It's not a single variable that tends to determine whether a disease will occur, but rather a combination of variables," Rogers said. Satellite sensors, like the National Oceanic and Atmospheric Administration's Advanced Very High Resolution Radiometer (AVHRR), provide information on vegetation and peak and average annual temperatures. Mosquito populations are constrained by different factors in different places. In the North, colder temperatures hold mosquito populations back. In the south, where temperatures are higher, the insects are more dependent on the availability of moisture for survival. Lush vegetation provides a good indicator of areas with increased levels of moisture. Mosquitoes tend to thrive in warmer, wetter areas. Satellites let researchers see which areas have these conditions, allowing for better prediction of disease transmission. Similarly, satellites also help plot patterns like the timing of when temperatures peak during a year. Mosquito populations appear to increase during the first half of the year but only reach sufficient levels to transmit the disease during the second half of each year. "The timing of a seasonal peak of temperatures determines the increase of vector populations in that place," said Rogers. "An early rise in spring temperature is likely to get the mosquito off to a flying start." The idea is to let the satellite capture where the disease is spreading from year to year and make some predictions about where the disease is going. Computer models can determine which areas have the right combinations of temperatures and moisture levels most suitable for mosquitoes and transmission. Then, efforts and resources can target those high-risk areas. The study suggests that a mild winter in 1998 to 1999 may have provided favorable conditions for mosquitoes to survive the winter, leading to a greater number of carriers in 1999. In that first year reported cases were found in three states. The number grew to 12 states in 2000, and more than 20 in 2001, despite the fact that the winters preceding these years were either average or slightly below average. "Once a disease like West Nile Virus establishes a foothold, and spreads, it will be very difficult to eradicate," said Rogers. The methods used in this research may be modified and applied to study a variety of other diseases like malaria, dengue fever, Lyme disease, influenza and even asthma. For more information, see http://www.gsfc.nasa.gov/topstory/20020204westnile.html. Contact: Cynthia O'Carroll NASA Goddard Space Flight Center, Greenbelt, MD Phone: 301-286-5017 E-mail: cocarrol@pop100.gsfc.nasa.gov An additional article on this subject is available at http://www.spacedaily.com/news/earth-02b.html. _____________________________________________________________________ FORMER ASTRONAUT ALDRIN, PURDUE ENGINEERS PLANNING MARS HOTELS By Emil Venere Purdue University release 5 February 2002 Buzz Aldrin, the second man to walk on the moon, is leading a team of researchers, including engineers at Purdue University, to design a new class of spacecraft that would serve as orbiting hotels perpetually cruising between Earth and Mars. The "cycler" spacecraft would constantly ferry people and materials between the two planets, enabling earthlings to explore, commercially develop and eventually colonize the Red Planet. "We believe these regular planetary flybys would create an entirely new economic and philosophic approach to space exploration," the researchers wrote in a December report prepared for NASA's Jet Propulsion Laboratory. "Reliable, reusable and dependable cycler transportation can be the key to carry humanity into the next great age of exploration, expansion, settlement and multi-planetary commerce." Aldrin is working with a team of researchers, including professors and engineering graduate students at Purdue, the Massachusetts Institute of Technology and the University of Texas. The former astronaut is an engineer by training and holds a doctorate from MIT. "We are going to put in a proposal for a more detailed study to narrow down some of the choices of the different kinds of cyclers and decide which ones seem to fit into a very nice operational mission," Aldrin said. Modified versions of the space shuttle's external fuel tank might be used as building units for cyclers. The tank ordinarily is jettisoned during shuttle flights, and it burns up in the atmosphere. However, the shuttle's external fuel tank could be modified, adding two additional empty tanks atop the existing fuel tank. Instead of being jettisoned, the modified external tank assembly could then be carried by the shuttle all the way to low-earth orbit, where the dry tanks could be separated from the main tank and used to construct the spacecraft. Cyclers would take advantage of the gravitational forces that are exerted by the sun, the planets and their moons, which provide "gravity assists" to passing spacecraft. As a spacecraft travels close to a planet, its flight path is bent, causing it to whip around the planet while boosting its speed. The path is commonly called a "slingshot" trajectory, which enables a spacecraft to achieve the proper speed and heading. "The cycler essentially is in orbit around the sun and makes regular flybys of Earth and Mars," said team member James Longuski, a professor of aeronautics and astronautics at Purdue. "Once you put your vehicle into a cycler orbit, it continues on its own momentum, going back and forth between Earth and Mars. You may need to carry some propellant for an occasional boost, but it's pretty much a free trip after that." In their report to JPL, researchers said a cycler would practically fly itself and "become a permanent, man-made inner solar system companion of Earth and Mars, tapping the free and inexhaustible 'fuel supply' of gravitational forces to maintain orbit. Like an ocean liner on a regular trade route, a cycler will glide perpetually along its beautifully predictable orbit." However, it is difficult to precisely design cycler trajectories because of the complex orbital relationship between Earth and Mars as the planets travel around the sun. While the Earth orbits the sun in a nearly circular route, Mars' orbit is oblong, or elliptical. That means the distance between Mars and the Earth varies dramatically depending on Mars' orbital position around the sun, complicating the design of spacecraft trajectories between the two planets. "If they were both in circular orbits, any cycler that you would design would repeat perfectly over and over again," Longuski said. "Mars' orbit is somewhat eccentric. That throws a curve ball into the whole design." Determining the precise path for cyclers requires engineers highly skilled in celestial mechanics who use mathematical techniques to create and evaluate numerous possible trajectories, eventually arriving at the best choice. Longuski and his students have previously designed trajectories for an unmanned spacecraft to Jupiter's moon Europa, which is tentatively scheduled for launch in 2006. The team also designed trajectories for a hypothetical manned mission to Mars. "Some day, people will be going to Mars on a regular basis," Longuski said. "Most people are convinced that we are going to do this; the only question is when." The cycler spacecraft would have to encounter Mars and Earth at precisely the right distance and speed. If a cycler approached Mars too fast or at the wrong distance, too much fuel would be needed for steering rockets and it would be more difficult for "taxi" spacecraft to dock with the cyclers as they sped by. A cycler might fly past the Earth at about 21,000 kilometers per hour, or roughly 13,000 miles per hour. Small taxi spacecraft carrying people and supplies would have to rendezvous with the speeding cycler. "This is sort of like a bus that doesn't stop," Longuski said. "When it comes by, you have to run alongside of it and grab on. " The outbound trip to Mars would take six to eight months. "Then, when you get to Mars, you get in the taxi and de-orbit down to the planet," said Longuski, who is working with Purdue graduate students to design "outbound" and "inbound" trajectories, or the trips from Earth to Mars and from Mars to Earth. "These cyclers would be like space hotels," Longuski said. "They would provide the usual creature comforts." Cyclers would rotate slowly to create artificial gravity and prevent the debilitating effects of weightlessness on its passengers. The spacecraft also would be roomy enough to make the trip tolerable. The earliest versions of the space hotels might accommodate up to 50 passengers. One cycler would not be sufficient: by the time that craft arrived at Mars, the two planets would have moved much farther apart, making a return trip impractically long. Rather, a family of perhaps three cyclers, continuously providing outbound and inbound flights, would ensure that passengers could get to Earth and Mars within a reasonable amount of time, Longuski said. While the Purdue engineers are working on the interplanetary celestial mechanics of getting back and forth between Earth and Mars, researchers at the University of Texas and MIT are helping with other critical aspects of the trip, such as getting a cycler into the proper position to begin its trip to Mars and learning how to design the taxis. "We have to look at the configuration of those taxis and how much energy will be needed to intercept the cyclers," Aldrin said. Perhaps the first cyclers could fly around 2018, he said. "The first mission will be more conservative, and it will have more safety supports until we are sure we know what we are doing," Aldrin said. Contacts: Emil Venere, 765-494-4709, venere@purdue.edu James Longuski, 765-494-5139, longuski@ecn.purdue.edu Buzz Aldrin, 310-278-0384, starbuzz1@aol.com Purdue News Service, 765-494-2096, purduenews@purdue.edu Additional information on this article is available at http://news.uns.purdue.edu/UNS/html4ever/020205.Longuski.Aldrin.html. Additional articles on this subject are available at: http://www.cnn.com/2002/TECH/space/02/06/aldrin.hotel.reut/index.html http://spaceflightnow.com/news/n0202/07marshotels/ _____________________________________________________________________ HYDROGEN-DRIVEN ACTUATORS MAY REPLACE DAMAGED MUSCLES From NASA Tech Briefs Insider 5 February 2002 Actuators are at the forefront of motion control technology as more and more manufacturers look to replace the venerable piston. One reason for this activity is the wide range of uses for actuators--in robotics, simulators, positioning systems, and opening devices, to name but a few. The latest entry, designed by Japanese firm Sensor Control Group, incorporates a metal-hydride (MH) alloy that absorbs and desorbs 1,000 times its own volume in hydrogen, creating gas pressure to drive the actuator. Hydrogen was chosen because of the favorable features of a hydrogen reaction: it is completely reversible, occurs quickly, and generates a lot of heat, which aids absorption and enables quicker motions. Some of the most promising applications of the MH actuator are in the field of human rehabilitation. MH actuators are being tested in wheelchairs/lifters and other medical equipment. They eliminate the need for bulky pumps, compressors, or reduction gears, and their output power per weight is 2-2.5 times that of traditional hydraulic and pneumatic systems, according to the designer. More intriguing is the potential of using MH actuators to aid or even replace damaged muscles. A flexible polymer film that is being designed into an MH actuator for robotic applications may be adapted to create artificial muscles for humans. Because they run off batteries and are lighter and smaller than traditional actuators, MH actuators also offer many uses in emergency equipment. They could stabilize earthquake-damaged structures and possibly even help jack up vehicles using muffler heat to create the hydrogen reaction. Get the complete report at http://link.abpi.net/l.php?20020205A2. _____________________________________________________________________ FIRST GENETIC EVIDENCE UNCOVERED OF HOW MAJOR CHANGES IN BODY SHAPES OCCURRED DURING EARLY ANIMAL EVOLUTION University of California, San Diego release 6 February 2002 Biologists at the University of California, San Diego have uncovered the first genetic evidence that explains how large-scale alterations to body plans were accomplished during the early evolution of animals. In an advance online publication February 6 by Nature of a paper scheduled to appear in Nature, the scientists show how mutations in regulatory genes that guide the embryonic development of crustaceans and fruit flies allowed aquatic crustacean-like arthropods, with limbs on every segment of their bodies, to evolve 400 million years ago into a radically different body plan: the terrestrial six-legged insects. The achievement is a landmark in evolutionary biology, not only because it shows how new animal body plans could arise from a simple genetic mutation, but because it effectively answers a major criticism creationists had long leveled against evolution--the absence of a genetic mechanism that could permit animals to introduce radical new body designs. "The problem for a long time has been over this issue of macroevolution," says William McGinnis, a professor in UCSD's Division of Biology who headed the study. "How can evolution possibly introduce big changes into an animal's body shape and still generate a living animal? Creationists have argued that any big jump would result in a dead animal that wouldn't be able to perpetuate itself. And until now, no one's been to demonstrate how you could do that at the genetic level with specific instructions in the genome." The UCSD team, which included Matthew Ronshaugen and Nadine McGinnis, showed in its experiments that this could be accomplished with relatively simple mutations in a class of regulatory genes, known as Hox, that act as master switches by turning on and off other genes during embryonic development. Using laboratory fruit flies and a crustacean known as Artemia, or brine shrimp, the scientists showed how modifications in the Hox gene Ubx--which suppresses 100 percent of the limb development in the thoracic region of fruit flies, but only 15 percent in Artemia--would have allowed the crustacean-like ancestors of Artemia, with limbs on every segment, to lose their hind legs and diverge 400 million years ago into the six-legged insects. "This kind of gene is one that turns on and off lots of other genes in order to make complex structures," says Ronshaugen, a graduate student working in William McGinnis' laboratory and the first author of the paper. "What we've done is to show that this change alters the way it turns on and off other genes. That's due to the change in the way the protein produced by this gene functions." "The change in the mutated protein allows it to turn off other genes," says William McGinnis, who discovered with two other scientists in 1983 that the same Hox genes in fruit flies that control the placement of the head, thorax and abdomen during development are a generalized feature of all animals, including humans. "Before the evolution of insects, the Ubx protein didn't turn off genes required for leg formation. And during the early evolution of insects, this gene and the protein it encoded changed so that they now turned off those genes required to make legs, essentially removing those legs from what would be the abdomen in insects." The UCSD team's demonstration of how a mutation in the Ubx gene and changes in the corresponding Ubx protein can lead to such a major change in body design undercuts a primary argument creationists have used against the theory of evolution in debates and biology textbooks. Their specific objection to the idea of macroevolutionary change in animals is summed up in a disclaimer that the Oklahoma State Textbook Committee voted in November, 1999 to include in that state's biology textbooks: "The word evolution may refer to many types of change. Evolution describes changes that occur within a species. (White moths, for example, may evolve into gray moths). This process is microevolution, which can be observed and described as fact. Evolution may also refer to the change of one living thing into another, such as reptiles and birds. This process, called macroevolution, has never been observed and should be considered a theory." "The creationists' argument rests in part on the fact that animals have two sets of chromosomes and that in order to get big changes, you'd need to mutate the same genes in both sets of chromosomes," explains McGinnis. "It's incredibly unlikely that you would get mutations in the same gene in two chromosomes in a single organism. But in our particular case, the kind of mutation that's in this gene is a so-called dominant mutation, so you only need to mutate one of the chromosomes to get a big change in body plan." The discovery of this general mechanism for producing major leaps in evolutionary change has other implications for scientists. It may provide biologists with insights into the roles of other regulatory genes involved in more evolutionarily recent changes in body designs. In addition, the discovery in the UCSD study, which was financed by the National Institute of Child Health and Human Development, of how this particular Hox gene regulates limb development also may have an application in improving the understanding human disease and genetic deformities. "If you compare this gene to many other related genes, you can see that they share certain regions in their sequences, which suggests that their function might be regulated like this gene," says Ronshaugen. "This may establish how, not only this gene, but relatives of this gene in many, many different organisms actually work. A lot of these genes are involved in the development of cancers and many different genetic abnormalities, such as syndactyly and polydactyly, and they may explain how some of these conditions came to be." Contacts: William McGinnis Phone: 858-822-0458 E-mail: wmcginnis@ucsd.edu Matthew Ronshaugen Phone: 858-822-0461, E-mail: mronshau@biomail.ucsd.edu Media contact: Kim McDonald Phone: 858-534-7572 E-mail: kimmcdonald@ucsd.edu Graphic and image of Artemia at http://ucsdnews.ucsd.edu/newsrel/science/mchox.htm. Image credit: Matthew Ronshaugen, UCSD. Additional information on this article is available at http://ucsdnews.ucsd.edu/newsrel/science/mchox.htm. Visit UCSD news on the web at http://ucsdnews.ucsd.edu. An additional article on this subject is available at http://www.spacedaily.com/news/life-02g.html. _____________________________________________________________________ EUROPAN TIDES MIGHT FOSTER LIFE, SAYS UA MEMBER OF GALILEO IMAGING TEAM University of Arizona release 7 February 2002 Europa, Jupiter's smallest moon, might not only sustain but foster life according to the research of a University of Arizona professor. Richard Greenberg, a professor of planetary sciences and member of the Imaging Team for NASA's Galileo Jupiter-orbiter spacecraft, reported in the February issue of American Scientist that a combination of several factors could create habitable niches. Europa, similar in size to Earth's moon, has been imaged by Galileo for the last 4 years. Its surface, a frozen crust of water, was previously thought to be tens of kilometers thick, denying the oceans below any exposure. The combination of tidal processes, warm waters and periodic surface exposure may be enough to not only warrant life but also encourage evolution, Greenberg said. "The implication is that these settings would actually be hospitable to life," he said. Since late 1997, Greenberg and his team, consisting of fellow professors to undergraduates, have been studying the images sent from the Galileo. High-resolution images of the surface along with knowledge of Earth's geology have helped to reveal the environment of Europa. One factor contributing to a habitable environment is the presence of liquid water, Greenberg said. With Jupiter being the largest planet in the solar system, its tidal stresses on Europa create enough heat to keep the water on Europa in a liquid state. This "opened the door to speculation about life," Greenberg said. However, Greenberg points out that more than just water is needed to support life. Tides also play a role in providing for life. Ocean tides on Europa are much greater in size than Earth's with heights reaching 500 meters (more than 1,600 feet). Even the shape of the moon is stretched along the equator due to Jupiter's pull on the waters below the icy surface. "Everything on and under the surface is driven by the tides," Greenberg said. The mixing of substances needed to support life is also driven by tides, he added. "Stable environments are also necessary for life to flourish," he said. Europa, whose orbit around Jupiter is in-synch with its rotation, is able to keep the same face towards the gas giant for thousands of years. But over longer periods of time, any given niche freezes, Greenberg said. "That would require an organism to adapt in some way," he said. The surface of Europa was previously thought to be tens kilometers thick, never exposing the oceans. Greenberg said the geologic structures are evidence that exposure occurs more commonly that ever thought. "The ocean is interacting with the surface," Greenberg said. "There is a possible biosphere that extends from way below the surface to just above the crust." Tides have created the two types of surface features seen on Europa: cracks/ridges and chaotic areas, Greenberg said. The ridges are thought to be built over thousands of years by water seeping up the edges of cracks and re-freezing to form higher and higher edges until the cracks close to form a new ridge. The chaotic areas are thought to be evidence of the melt-through necessary for exposure to the oceans. The tidal heat, created by internal friction, could be enough to melt the ice, he said. [Also], Undersea volcanoes are also a possible explanation for large melt-throughs. Greenberg said [that] this combination of factors would give organisms a stable but changing environment -exactly the type that would encourage evolution. "Necessity drives change," Greenberg said. The melted-through ice provides light and surface chemicals to the oceans, Greenberg said. Life on Europa could resemble that of simple sea-dwelling organisms of Earth, Greenberg said, possibly utilizing photosynthesis for energy. "Plenty of Earth's organisms live at 32 degrees (Fahrenheit) or below," he said. Microbes, recently discovered in the Antarctic, can hibernate for up to a million years in the ice. Europan organisms, trapped in the ice, could be thawed out when the next warm tide flowed through, effectively releasing them, Greenberg said. While the Galileo spacecraft is almost finished with its mission, Greenberg is already poised for future missions. His team has two proposals on the table with NASA for the next orbiter to Jupiter and its moons, which is slated for sometime this decade. The decade after holds plans for a lander to Europa, if timetables hold. Contact: Aaron Farnsworth University of Arizona News Services Phone: 520-621-1877 Additional information on this article is available at http://uanews.opi.arizona.edu/cgi- bin/WebObjects/UANews.woa/wa/SRStoryDetails?ArticleID=4950. Additional articles on this subject are available at: http://www.spacedaily.com/news/jupiter-europa-02b.html http://www.space.com/scienceastronomy/solarsystem/europa_life_020208. html _____________________________________________________________________ DETECTING OTHER WORLDS VII: DIRECT IMAGING By Laurance Doyle From Space.com 7 February 2002 Everyone would like to see an image of an extrasolar planet. So far, the radial velocity detection method has only detected giant planets indirectly by measuring the wobble of the planet's parent star toward or away from us. Astrometry also measures the wobble of the star in the other two directions not covered by the radial velocity method. The pulsar and eclipsing binary methods also measure the offset of stars by timing the "clocks" of pulsar pulses or binary eclipses at minimum, respectively. While the phase variation method measures light directly from a planet, the light is mixed in with the much greater light contribution from the planet’s star. Finally, though the photometric transit method also is an indirect detection technique, it actually measures the shadow of the planet. Direct imaging of extrasolar planets, then, is highly desirable because one could separate the light from the star and the planet. One could then spectroscopically measure the chemical constituents of the planet by itself, independent of its star's light... Get the full story at http://www.space.com/searchforlife/seti_doyle_020207.html. _____________________________________________________________________ MARS INFRARED SPECTROSCOPY: FROM THEORY AND THE LABORATORY TO FIELD OBSERVATIONS Lunar and Planetary Institute workshop announcement 7 February 2002 Workshop dates and place: 18-20 June 2002, Houston, Texas. Sponsor: Lunar and Planetary Institute Contact information: For further information regarding the format and scientific objectives please contact one of the conveners: Laurel Kirkland, E-mail: kirkland@lpi.usra.edu, Phone: 281-486-2112 John Mustard, E-mail: John_Mustard@brown.edu, Phone: 401-863-1264 Questions concerning meeting logistics should be addressed to the LPI meeting coordinator, Paula Walley, E-mail: walley@lpi.usra.edu, Phone: 281-486-2144. Purpose and scope The current Mars exploration strategy relies heavily on the productivity of visible/infrared spectral studies. Spectral interpretations are based on theoretical, laboratory, and field studies, so the successful interpretation of these data sets is intimately tied to the strength of the supporting spectroscopy research programs. In light of that, we are convening a focused workshop for the spectroscopy community to address the following. Given the current and planned spectral datasets (1996 TES, 2001 THEMIS, 2003 Mini-TES, 2003 Mars Express OMEGA, 2005 CRISM) and the current priorities of the Mars Program, what terrestrial laboratory and field analog studies are most needed to best support interpretations of these dat asets and the goals of the Mars exploration program? Goals The end result of the workshop will be to produce a report with detailed recommendations of what laboratory and field analog studies are most needed to best support interpretations of visible/infrared data sets in light of the goals of the Mars Program. The workshop goals are to: 1) Summarize past and current laboratory and field analog visible/infrared spectral studies as they relate to studies of Mars, with an assessment of their significance for the current scientific goals of NASA's Mars Exploration Program, and an assessment of critical unanswered questions. 2) Briefly review current and future spectroscopic instruments to lay a foundation for workshop discussions (including 1996 TES, 2001 THEMIS, 2003 Mini-TES, 2003 Mars Express OMEGA, 2005 CRISM). 3) Discuss what theoretical laboratory, and field spectral analog studies are most needed to attain the critical goals of the Mars Exploration Program, especially as they relate to supporting interpretations of the data sets for: a) Contributing to the search for possible mineral biomarkers and environments that could preserve signatures of life. b) Answering basic questions in geology and volatile budget. c) Contingency plans: In the event that a currently slated spectral dataset is not returned, would requirements or priorities change? 4) Discuss what laboratory and field instrumentation or improvements to current instruments are needed, if any, to support needed analog studies. Workshop format The workshop will be held at the Lunar and Planetary Institute in Houston, Texas on June 18-20, 2002, and is limited to 30 participants. The format will consist of scheduled morning talks, afternoon discussion, and a continuous poster display. The wrap-up discussion on the last day will form the basis for the workshop report Abstract submission Abstracts should not exceed two pages and should be submitted via e- mail to walley@lpi.usra.edu. Abstracts can be submitted in PDF or Microsoft Word format, and must be received no later than May 15, 2002. Registration A registration fee of $15.00 will be collected on the first day of the workshop (cash or check only, no credit cards will be accepted) and space is limited to the first 30 participants, so register by June 3, 2002 at www.lpi.usra.edu/meetings/marsspec. _____________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.h tml 11 February 2002 Articles about astrobiology, exobiology and terraformation http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s1.html L. Doyle, 2002. Detecting other worlds VII: direct imaging. Space.com. A. Farnsworth, 2002. Jovian tidings may stir and heat up life on Europa. SpaceDaily. Space.com, 2002. Wrenching tides on Europa could force life to evolve. Space.com. Articles about human space exploration and the microgravity environment http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s3.html Purdue University, 2002. Buzz Aldrin, Purdue engineers plan Mars hotels. Spaceflight Now. Reuters, 2002. Space 'hotels' to slingshot between Earth and Mars. CNN. Articles about evolutionary biology and chemistry http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s5.html NASA Astrobiology Institute, 2002. Digital zookeepers take a census. SpaceDaily. SpaceDaily, 2002. Genetic archeology uncovers early animal evolution. SpaceDaily. _____________________________________________________________________ CASSINI WEEKLY SIGNIFICANT EVENTS NASA/JPL release 31 January - 6 February 2002 The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Wednesday, February 6. The Cassini spacecraft is in an excellent state of health and is operating normally. See the "Present Position" web page at http://www.jpl.nasa.gov/cassini/english/where/. The C30 sequence continues to execute as planned. Science activities include commanding for the Magnetometer Subsystem (MAG) to set the Vector Helium Magnetometers bit to OFF state, and the conclusion of the Imaging Science Subsystem (ISS) decontamination and Visual and Infrared Mapping Spectrometer Image/Occultation mini-sequences. Preliminary results from the ISS decontamination mini-sequence show a significant improvement for the Narrow Angle Camera. The C30 decontamination cycle lasted approximately 7½ days and reached about +4 degrees C. This was several degrees above the C28 cycle as the replacement heaters were also powered on. Final results should be available next week and will be followed by discussions of further decontamination activities. Other spacecraft activities included clearing of the AACS high water marks, an autonomous Command & Data Subsystem Solid State Recorder Memory Load Partition repair, and an attitude control reaction wheel friction test. Results from the test were normal. The C31 preliminary Sequence Integration & Validation (SI&V) products were released this week. Members of the Sequence Team reviewed the package and submitted desired Sequence Change Requests (SCR). The SCRs will be dispositioned in the C31 SI&V SCR approval meeting to be held next week. Science Planning (SP) reported the publication of a final report for the Satellite Orbiter Science Team (SOST) Science Uplink Verification (SUPV) activity. SP activities included a full set of TWT meetings to continue the integration of the orbits associated with the next delivery milestone, which includes orbits 10 through 15, and a Titan Orbiter Science Team (TOST) meeting to refine the integration details associated with the recent T6/T7 trade. The Spacecraft Office reported the Attitude Control flight software team delivered version 8.5.0. This is the first version containing the energy cutoff algorithm for the Saturn orbit insertion burn and will be used for system mode testing. In addition, the Attitude Control ground software developers delivered the preliminary set of target options to Spacecraft Operations and Uplink Operations for early test and evaluation. These comprise the full set of options for the Mission Sequence System D8 delivery. The Cassini Program conducted a NASA Quarterly Review on Monday, February 4. UVIS 1.3.0 instrument flight software was delivered to the Program Software Library. Significant progress has been made in the Risk Management area, following a Program wide review of the Significant Risk List. The overall risk posture of the Program has been reduced due to effective mitigation efforts. Redundancy in several risk statements has been eliminated to create a crisp list for Risk Management during Mission Operations. A review and redesign of the proposed Telemetry Delivery System architecture for tour support has been implemented due to changing storage system costs, and lack of adequate existing expertise with complex storage array systems. The Cassini-Huygens outreach and education web site, currently hosted at http://www.jpl.nasa.gov/cassini, has been relocated to a new, enhanced environment. In conjunction with the move a new domain name has been established for the Cassini-Huygens site. The new address is http://saturn.jpl.nasa.gov. This change will take effect on February 5, 2002. 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. _____________________________________________________________________ INTERNATIONAL SPACE STATION STATUS REPORT NASA/JSC release 8 February 2002 This week the Expedition Four crew--Commander Yury Onufrienko and Flight Engineers Carl Walz and Dan Bursch--worked with several of the science experiments aboard the International Space Station. They tested the ultrasound instrument in the Human Research Facility rack, activated the EarthKam experiment and the seventh sample cylinder in the Protein Crystal Growth--Single-locker Thermal Enclosure System, and tested the Zeolite Crystal Growth Furnace, which will be used to grow crystals beginning in April. The crew also completed their periodic physical fitness tests. In addition, Walz and Bursh prepared a set of three dosimeters each that will be used to measure any radiation they might receive during their scheduled February 20 spacewalk. The dosimeters are part of the EVARM experiment, which is studying the amount of radiation astronauts receive during spacewalks to better design future radiation shielding in spacesuits. Today, the crew spent their 64th day in space doing an inventory of the supplies aboard the station. The inventory will help planners determine how much and what kind of supplies the next station crew will need. The crew began the inventory process today and will complete it as time permits. On Monday, the crew's normal work was interrupted for a few hours when a main computer in the station's Zvezda module unexpectedly went off-line, disrupting the system that controls the spacecraft's orientation. The computer was quickly brought back on-line and all station systems have operated normally since then. Russian controllers are still working to determine the cause of the disruption. On Wednesday, Onufrienko celebrated his 41st birthday. He and his crewmates have been in space since December 5. The crew has a light weekend of planned activities ahead, but usually takes time to complete a variety of odd jobs on their task list, a list of work aboard the station that does not need to be done at any specific time. Information on the crew's activities aboard the space station, future launch dates and times, as well as station sighting opportunities from anywhere on the Earth, is available on the internet at http://spaceflight.nasa.gov. Details on station science operations can be found on an Internet site administered by the Payload Operations Center at NASA's Marshall Space Flight Center in Huntsville, AL, at http://www.scipoc.msfc.nasa.gov. The next ISS status report will be issued February 15, or sooner, if developments warrant. _____________________________________________________________________ MARS ODYSSEY MISSION STATUS NASA/JPL release 6 February 2002 NASA's Mars Odyssey spacecraft deployed its high-gain communications antenna last night, marking a major technical milestone prior to the beginning of the science mapping mission. At 7:29 PM Pacific Time, Tuesday, February 5, mission controllers monitored changes in the radio signal from Odyssey, indicating that the release and deployment of the antenna boom were proceeding as planned. The antenna boom was deployed to its latched position with a motor-driven hinge and locked into place as expected. The antenna's position is controlled with a two-axis gimbal assembly that allows the spacecraft to communicate with Earth while the science instruments are simultaneously collecting data of Mars. Overnight, flight controllers checked out the gimbals, which allow the antenna to be pointed in a variety of positions to track Earth. "Successful deployment of the high gain antenna paves the way for Odyssey to achieve the real payoff of the mission, the science data return," said David A. Spencer, Odyssey's mission manager at NASA's Jet Propulsion Laboratory, Pasadena, CA. The science instruments are expected to begin collecting data later this month. Flight controllers first need to test the mapping orientation of the spacecraft, in which the instruments are pointed at Mars while the antenna tracks Earth. The high-gain antenna is 1.3 meters (4.3 feet) in diameter, with a parabolic shape. The antenna can transmit at data rates as high as 110 thousand bits per second. JPL manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, DC. Principal investigators at Arizona State University in Tempe, the University of Arizona in Tucson, and NASA's Johnson Space Center, Houston, Texas, operate the science instruments. Additional science investigators are located at the Russian Space Research Institute and Los Alamos National Laboratories, New Mexico. Lockheed Martin Astronautics, Denver, CO, is the prime contractor for the 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. An additional article on this subject is available at http://www.spacedaily.com/news/mars-odyssey-02c.html. _____________________________________________________________________ STARDUST STATUS REPORT NASA/JPL release 8 February 2002 There were two Deep Space Network (DSN) tracking passes in the past week, and all subsystems are normal. Activities are in progress to predict the power margin at aphelion, when the spacecraft reaches the furthest point in its orbit from the Sun. Since Stardust is the first spacecraft to operate so far away from the Sun, there [are] no data for solar powered spacecraft at this distance, so we will take a conservative approach in regards to power usage. It is expected that the DSN passes will decrease from the current time, about 4 hours, to approximately 1.5 hours by late March. This will ensure that the spacecraft's power demand does not exceed the solar arrays' ability to provide current to re-charge the battery. The Education and Public Outreach team gave a presentation on Stardust and the NASA plan to explore comets at the NASA Educators Resource Center in Pomona, California. For more information on the Stardust mission--the first ever comet sample return mission--please visit the Stardust home page at http://stardust.jpl.nasa.gov. _____________________________________________________________________ End Marsbugs, Volume 9, Number 6.