MARSBUGS: The Electronic Exobiology Newsletter Volume 4, Number 5, 18 March, 1997. Editors: David Thomas, Department of Biological Sciences, University of Idaho, Moscow, ID, 83844-3051, USA, thoma457@uidaho.edu or Marsbugs@aol.com. Julian Hiscox, Microbiology Department, BBRB 17, Room 361, University of Alabama at Birmingham, Birmingham, AL 35294-2170, USA, Julian_hiscox@micro.microbio.uab.edu. MARSBUGS is published on a weekly to quarterly 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. E-mail subscriptions are free, and may be obtained by contacting either of the editors. 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 may be obtained via anonymous FTP at: ftp.uidaho.edu/pub/mmbb/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. Exobiology is still a relatively young field, and new ideas may come out of the most unexpected places. Subjects may include, but are not limited to: exobiology proper (life on other planets), the search for extraterrestrial intelligence (SETI), ecopoeisis/ terraformation, Earth from space, planetary biology, primordial evolution, space physiology, biological life support systems, and human habitation of space and other planets. ----------------------------------------------------------------- INDEX 1) MARS GLOBAL SURVEYOR FLIGHT STATUS REPORTS JPL releases 2) MARS PATHFINDER MISSION STATUS REPORTS JPL releases 3) SMALL FIRE EXTINGUISHED ON MIR NASA release 97-30 4) PLANET THEORY 'EXPLODED' BY NEW RESEARCH University of Western Ontario release 5) MARTIAN SAMPLES POSE LITTLE RISK, BUT STILL WILL REQUIRE CAREFUL HANDLING NAS publication announcement 6) IMPACT! BOOK REVIEW by Julian Hiscox 7) THE PLANETARY SOCIETY'S NEAR-EARTH OBJECT GRANT PROGRAM 8) NASA-ESA AGREEMENT ENHANCES STATION WITH ADDITIONAL NODE NASA release 97-36 9) MARS ROCK COOLS DOWN, LIFE DEBATE HEATS UP From the Science website 10) NEW STUDY BOOSTS IDEA OF PAST LIFE ON MARS University of Wisconsin-Madison release 11) WHEN MODELS AND SATELLITES MISLEAD: NCAR SCIENTISTS PRESCRIBE CAUTION IN MARCH 13 NATURE National Center for Atmospheric Research release by Bob Henson 12) GLOBAL CLIMATE MONITORING: THE ACCURACY OF SATELLITE DATA NASA/Marshall Space Sciences Lab release by Roy Spencer, John Christy, John Horack 13) TRW DELIVERS TWO CERES INSTRUMENTS TO NASA; CERES TO STUDY ROLE OF CLOUDS AND RADIATION TRW release 14) NASA SELECTS INSTITUTION FOR LIFE SCIENCES RESEARCH NASA release 97-37 15) NASA ESTABLISHES NEW NATIONAL MICROGRAVITY CENTER NASA release 97-40 16) PRESS BRIEFING TO PRESENT NEW DATA AND STATUS OF 'PAST LIFE ON MARS' DEBATE SCHEDULED FOR MARCH 19 NASA release 17) NASA NAMES A NEW NATIONAL BIOMEDICAL RESEARCH INSTITUTE NASA release 97-43 18) (FAIRLY) RECENT PUBLICATIONS OF INTEREST TO EXOBIOLOGISTS Compiled by Julian Hiscox ---------------------------------------------------------------- MARS GLOBAL SURVEYOR FLIGHT STATUS REPORTS JPL releases Friday, 14 February 1997 On Tuesday, the Surveyor spacecraft rotated to a position that pointed the Mars Orbiter Camera at a cluster of stars called the Pleiades. Over the course of an hour, the camera imaged stars within the cluster. These images were used by the camera team to determine the focus of the narrow-angle camera following the bakeout period that ended two weeks ago. During that five-day bakeout period, a 53-Watt heater was used to remove residual moisture from the camera's graphite epoxy structure. This moisture affects the camera's focus. Preliminary results from this week's activity indicates that additional bakeout will not be necessary. Over the next two weeks, the camera will image the Pleiades on four separate opportunities to allow the camera team to make adjustments to the focus settings. Friday, 21 February 1997 Today, in an activity similar to the one that occurred last week, the Surveyor spacecraft rotated to a position that pointed the Mars Orbiter Camera at a cluster of stars called the Pleiades. Over the course of an hour, the camera imaged stars within the cluster. Images from today's opportunity, combined with three image sets that will be taken between February 24th and February 28th, will allow the camera team to determine settings to control the instrument's focus. Other major events this week included a complete memory read-out of Surveyor's on-board flight computers on Monday. During this activity, the flight team commanded the spacecraft's computers to transmit the contents of its memory banks back to Earth. The read-out was performed to allow the flight team to verify the values of critical flight software parameters that control the spacecraft. Because some of these parameters are periodically updated, the results of the memory read-out were entered into a tracking system that provides a historical record of the changes. Monday's activity was only the second time during the mission that the memory has been completely read out. After a mission elapsed time of 106 days from launch, Surveyor is 27.71 million kilometers from the Earth, 90.93 million kilometers from Mars, and is moving in an orbit around the Sun with a velocity of 28.25 kilometers per second. This orbit will intercept Mars on September 12th, 1997. The spacecraft is currently executing the C5 command sequence, and all systems continue to be in excellent condition. Friday, 28 February 1997 On Monday, Wednesday, and Friday of the week that began on February 24th, the Surveyor spacecraft rotated to a position that allowed the Mars Orbiter Camera to obtain images within a cluster of stars called the Pleiades. Images were gathered over the course of one hour on each day's opportunity. These images, combined with the images obtained on February 21st, will allow the camera team to determine settings to control the instrument's focus. Late in the afternoon on Friday, the spacecraft experienced a minor glitch with the star scanner. Normally, this device constantly scans a set of reference stars in deep space. These distant stars serve as fixed reference points that allow the spacecraft to determine its proper pointing orientation relative to the Earth and Sun. This process is called attitude control and is not related to the camera's star imaging for focus determination purposes. This glitch occurred during Friday's playback of Mars Orbiter Camera data from Surveyor's recorders. At that time, the star scanner began misidentifying stars. As a consequence, the flight team transmitted a command to the flight software to reset the portion of the attitude control software that controls the star scanner. After several hours, all conditions returned to normal. Although the cause of the glitch has not yet been determined, the flight team suspects that the star scanner was fooled by sunlight reflecting off of dust particles in the vicinity of the spacecraft. In order to further investigate this event, a playback of spacecraft engineering data recorded during the glitch will occur later this week. After a mission elapsed time of 113 days from launch, Surveyor is 31.76 million kilometers from the Earth, 83.40 million kilometers from Mars, and is moving in an orbit around the Sun with a velocity of 27.74 kilometers per second. This orbit will intercept Mars on September 12th, 1997. The spacecraft is currently executing the C5 command sequence, and all systems continue to be in excellent condition. Friday, 7 March 1997 On Monday, the on-board command sequence controlling Surveyor executed a test called the "Solar Array Feather." During the several-hour test, the solar arrays were rotated back and forth several times in a similar fashion to the motion that a person makes when rotating the wrist joint. This activity was performed for the benefit of the Magnetometer science team. The test simulated the rotation of the solar arrays that will occur as the arrays automatically track the Sun during Mars mapping operations. Because the Magnetometer sensors sit at the end of the solar arrays, the data collected from the test will allow the science team to determine the effect of the solar array rotation on the quality of their data. On Tuesday, the flight team loaded new parameters to Surveyor's attitude control software. These parameters deal with the performance of the star scanner that controls the spacecraft's ability to point at targets in space. With this parameter update, the spacecraft will be able to point its science instruments at objects with better accuracy than previously possible. Later on Tuesday, the Ka-band communications team accomplished a major milestone in their experiment. Over a several hour time period, an antenna at the Goldstone tracking station recorded data transmitted simultaneously from Surveyor's X-band and Ka- band transmitters. Normally, the spacecraft utilizes the 25- Watt, X-band transmitter for communicating with the Earth. The main difference between the two signals is that the 1-Watt, Ka- band transmitter operates at a frequency near 32 gigaHertz versus 8 gigaHertz for X-band. An analysis of the experiment indicated that no disagreements existed between the X-band and Ka-band data for all 12 million data bits observed on Tuesday. This positive result marks the first verified data transmission by an interplanetary spacecraft using a Ka-band signal. The result affirms a long-held belief that the use of Ka-band signals can allow a spacecraft to transmit information at faster data rates with transmitters that consume much less power. After a mission elapsed time of 120 days from launch, Surveyor is 36.46 million kilometers from the Earth, 76.39 million kilometers from Mars, and is moving in an orbit around the Sun with a velocity of 27.23 kilometers per second. This orbit will intercept Mars on September 12th, 1997. The spacecraft is currently executing the C5 command sequence, and all systems continue to be in excellent condition. Friday, 14 March 1997 On Monday of this week, the flight team loaded new parameters to Surveyor's attitude control software. These parameters deal with the alignment of the Inertial Measurement Unit. This device contains three gyroscopes that provide the flight computers with critical information regarding the spacecraft's pointing orientation in space. The new parameters, combined with the new parameters for the star scanner that were loaded last week, will enable Surveyor to point its science instruments at objects with better accuracy than previously possible. Today marked the first day since the launch of both Mars Pathfinder and Mars Global Surveyor that Pathfinder's distance to Mars was less than Surveyor's. However, because the two spacecraft are on different types of flight paths to Mars, they did not physically fly past each other. At the time of closest approach, Pathfinder and Surveyor were separated by 4.7 million kilometers. Pathfinder was launched after Surveyor, but will reach Mars first because it is traveling on a shorter, more direct flight path. This week was a relatively quiet week as the flight team prepared for next week's trajectory correction maneuver. This engine firing will refine Surveyor's flight path to Mars and will take place on Thursday, March 20th at 10:00 a.m. PST. After a mission elapsed time of 127 days from launch, Surveyor is 41.78 million kilometers from the Earth, 69.86 million kilometers from Mars, and is moving in an orbit around the Sun with a velocity of 26.74 kilometers per second. This orbit will intercept Mars on September 12th, 1997. The spacecraft is currently executing the C5 command sequence, and all systems continue to be in excellent condition. ----------------------------------------------------------------- MARS PATHFINDER MISSION STATUS REPORTS JPL releases 28 February 1997 The spacecraft remains in excellent health and is currently about 32 million kilometers from Earth. No significant operational activities were conducted this week. Continued investigation of the recent reset and attitude control software problems now indicates that they are related to the Command Detector Unit erroneous lock problem. A bug was found in the codeblock error detection software which causes a corruption to the floating point registers. The reset and attitude control problems were caused by floating point error conditions and can be tied directly to this corruption. We are currently in the process of developing a patch to correct this problem. Congratulations to Steve Stolper and Glenn Reeves for quickly identifying the problem and developing the required fix. A combined Project Science Group meeting involving Mars Pathfinder, Mars Global Surveyor, and Mars Surveyor '98 was held on Thursday and Friday, February 27-28. Although there is not a great deal of overlap between Pathfinder and these other projects, there are some synergistic investigations that can be performed. The Rover Operations Team completed a Rover Operational Readiness Test in the Mars Yard this week. Preparations are proceeding for next week's project wide surface Operations Readiness Test in the Pathfinder Sandbox. The current plan is to conduct nominal Sol 1 and 2 operations. For further information, please visit our website at http://mpfwww.jpl.nasa.gov. ----------------------------------------------------------------- SMALL FIRE EXTINGUISHED ON MIR NASA release 97-30 A problem with an oxygen-generating device on the Mir space station last night set off fire alarms and caused minor damage to some hardware on the station. No injuries to any of the six crewmembers on board were reported. The fire was located in the Kvant 1 module. The fire, which began at 10:35 p.m. Sunday, Moscow time, burned for about 90 seconds. The crew was exposed to heavy smoke for five to seven minutes and donned masks in response. After completing physical exams of everyone on board, U.S. astronaut Jerry Linenger, a physician, reported that all crewmembers are in good health. Medical personnel have directed them to wear goggles and masks until an analysis of the Mir atmosphere has been completed. Lithium perchlorate candles are burned to generate supplemental oxygen when more than three people are on board the space station. ----------------------------------------------------------------- PLANET THEORY 'EXPLODED' BY NEW RESEARCH University of Western Ontario release February 26, 1997 A new planet, discovered and announced to much excitement two years ago, probably doesn't exist at all, indicates research by a University of Western Ontario astronomer. In an article being published in the Feb. 27 issue of the international science journal Nature, astronomy professor David Gray reports that the likelihood of a planet being next to the 51st star in the Pegasus constellation is "vanishingly small." The detection of the planet was first reported by researchers in Nature in late 1995. Although the researchers had not observed the planet directly, they based their conclusion on the periodic movements in the position of lines in the spectrum of light surrounding the star, 51 Pegasi (pronounced Peg-a-see). The movements, it was proposed, could have been caused by the presence of a nearby planet. Gray's examination of the lines around 51 Pegasi ÐÐ called spectral lines ÐÐ indicates that they are not only moving, but changing shape. "While the presence of nearby planets can make spectral lines move, it is well established in astronomy that they cannot make them change shape," says Gray. "This new research explodes the theory that there must be a planet near 51 Pegasi. A planet could not produce the phenomena that I observed and recorded around the star," he says "Spectral lines are known to change shape when a star pulsates or has spots on its surface. That may be all that's happening in this case," he says. Since the original discovery in 1995, approximately 10 other planets outside our solar system have been reported using the same research and data collection techniques. Four of them are similar to 51 Pegasi. "They may be hot telescope subjects in the next year," says Gray. Gray's report in Nature was based on work conducted between 1989 and 1996 in the University's Elginfield Observatory near Lucan, Ont. Although faint, the Pegasus constellation is visible to the human eye and is about the size of the Big Dipper. For more information, please contact David Gray, professor of astronomy, at (519) 679-2111 ext. 6715 (E:mail: dfgray@uwovax.uwo.ca) or Judy Noordermeer, public affairs officer, at (519) 661-2046 (E-mail: jnoorder@julian.uwo.ca). ----------------------------------------------------------------- MARTIAN SAMPLES POSE LITTLE RISK, BUT STILL WILL REQUIRE CAREFUL HANDLING NAS publication announcement With NASA's plan to bring back samples of material from the Martian surface early in the next century, the need has arisen to examine the potential for contamination of Earth by microscopic organisms from another world. A new report from a task group of the National Research Council says that samples from Mars pose little risk to life on Earth but will still require special handling. Life as we know it is unlikely to exist on the surface of Mars, the task group said. Even if microorganisms do exist and were somehow brought here in a sample, it is doubtful that they could adapt to Earth's environment or cause significant harm. The task group cautioned, however, that uncertainties are involved in any assessment of the potential for harm, and the risk is not zero. It is possible that life developed on Mars when the planet was young, and may have survived in more hospitable oases on or near the surface of the planet. Because there are plausible scenarios in which samples taken from Mars could contain either active or dormant organisms, these samples should be isolated physically and biologically and regarded as hazardous until proved otherwise. If instruments cannot verify the isolation of a sample while en route to Earth, the sample and any spacecraft components that may have been exposed to it should be either sterilized in space or not returned to Earth. Further research and testing are needed to develop sterilization technologies, possibly using heat, chemical, or radiation treatment. Once a spacecraft has returned to Earth, samples should be contained and processed at a special receiving facility. This facility should be established as soon as possible once serious planning for a sample return mission has begun, the report says. The facility should be operational at least two years prior to launch to allow sufficient time for developing the necessary technologies for life-detection, sample containment, and sterilization. NASA also should ensure that an administrative structure is in place to verify that protection requirements are fulfilled at each critical stage of a mission, including launch, reentry, and sample distribution. Distribution of unsterilized samples from NASA's special receiving facility to researchers should be allowed only after rigorous analysis to determine that no biological entities are present, the report says. In addition, the public's interest in planetary protection issues should be acknowledged; the public should be fully informed about sample return and handling decisions. The study was funded by NASA. The National Research Council is the principal operating agency of the National Academy of Sciences and the National Academy of Engineering. It is a private, non-profit institution that provides science and technology advice under a congressional charter. A task-group roster follows. Copies of Mars Sample Return: Issues and Recommendations are available from the National Academy Press for $15.00 (prepaid) including shipping; tel. (202) 334-3313 or 1-800-624-6242. Reporters may obtain copies from the Office of News and Public Information (contacts listed above). [This announcement is available on the World Wide Web at .] ----------------------------------------------------------------- IMPACT! BOOK REVIEW by Julian Hiscox Title: Impact! Subtitle: The threat of comets & asteroids. Author: Gerrit L. Verschuur. Publisher: Oxford University Press. Year: 1996. ISBN: 0-19-510105-7. Pages: 237, illustrated throughout. Price: $25.00. A couple of years ago, in the October 1995 issue of Astronomy, I learnt a worrying statistic. According to David Morrison (whose article "Target Earth" was featured on the front cover) there were more people working in a medium sized burger joint than there were on detecting and plotting the orbits of near-Earth asteroids -- those most likely to impact with the Earth. Before the impact of Comet Shoemaker-Levy 9 into Jupiter in July 1994, the public at large was not really concerned with the very real threat of extinction caused by an asteroid hitting the Earth. Not even the fact that the dinosaurs and about 60% of all life was wiped out by an asteroid impacting with the Earth 65 million years ago, caused too much of a stir. Prior to this time the subject was perhaps treated some what in jest. But nothing stirred the public imagination and galvanised those in charge into action as the 1994 Jupiter impact. With the advent of the World Wide Web, data gathered from the Hubble Space Telescope, Galileo, and Voyager space probes (amongst others) was widely distributed to the public (who after all fund the research). Since this time a number of books, riding on the crest of publicity, have reached the high street shelves about this topic. One of the latest is Impact!: The threat of comets & asteroids, by Gerrit L. Verschuur. Verschuur is a radio astronomer and author of many articles and books popularising astronomy and one can see why after reading this book. Impact! was very hard to put down as Verschuur's writing style is so readable. The book is divided into eighteen chapters, with black and white photographs and illustrations throughout, and comprehensively indexed with an excellent bibliography. The book contains a wealth of information on asteroids and comets, charting their formation and their sometimes devastating affects if they strike the Earth and other planets. All of the content is impressive and obviously the K/T impact and Jupiter impact are featured in great detail. The saga of these events is recounted from both the perspective of the personalities involved and from a science point of view. Apart from the modern day perspective of asteroids and comets I also liked the historical treatment of the topic that Verschuur provides. Verschuur ends Impact! by arguing passionately that humanity must address the issue that asteroids and comets can, do, and have impacted with the Earth and thus present a very real threat. He describes the on going efforts in this direction and concludes that the establishment of some type of defence mechanism should be conceived if we as a species are ultimately to avoid extinction. ----------------------------------------------------------------- THE PLANETARY SOCIETY'S NEAR-EARTH OBJECT GRANT PROGRAM Objectives The Planetary Society Near-Earth Object (NEO) Grant Program seeks to encourage the discovery and exploration of NEOs by supporting observation projects and related research around the world. The Society intends these grants to accelerate the NEO discovery rate, to improve and increase observations, and to encourage international cooperation in this field. Categories The Planetary Society invites applications in one or more of the following categories: 1. NEO Observational Programs. Projects in this category could include discovery programs and those projects that might increase the rate of discovery. For example, an observation program by an amateur or at a small observatory could provide follow-up to discoveries, and thereby free observers at larger telescopes for more discovery work. Such a program would qualify for a Planetary Society grant. 2. NEO Research Programs. The category will include all those fields relating to understanding NEOs and their roles in the evolution of Earth and the solar system. Spectroscopy measurements and analysis would be an example of a project in this category. 3. International Collaboration in NEO Observations. Projects in this category include those that develop international collaboration through cooperative research, or those that enable amateurs and researchers at smaller observatories to participate in NEO observations and data analysis. Selection criteria The selection committee will consider how a project enables discoveries, advances knowledge, and/or enhances international scientific collaboration. Projects will also be judged on their feasibility, creativity, originality, significance and likelihood of completion. The committee will give special consideration to "seed" grants -- where a little help now can generate high leverage for future work. Amateurs and scientists and observers from developing countries will be given special consideration. Amounts of grants The average grant will be $5,000 to $10,000, although the selection committee will consider a range from $1,000 to $25,000, depending on need and expected results. The amount available is made possible by the donations of Planetary Society members. Eligibility Anyone anywhere may submit an application for a Planetary Society Near-Earth Object grant. We will accept only one application per individual or group. An application submitted on behalf of a group must clearly indicate the person acting as the group's representative or principal investigator. That person must sign the application form. Should a group project be chosen, the grant will be presented to the group's representative or principal investigator. The Planetary Society will have no obligation to any other member of the group. Applications Applications may be submitted at anytime. To be considered, an application must be neatly printed in English by letter, no more than three pages in length. Supporting documentation may be submitted or referenced. Send your application to: NEO Grant Program The Planetary Society 65 North Catalina Avenue Pasadena, CA 91106-2301 USA Applicants should send copies, not originals, of supporting documents, figures or photographs. No applications will be returned. Supporting materials must arrive with the application form unless prior arrangements are made. Notification Grant recipients will be notified of their award as soon as a decision is made. No other notification will be sent by The Planetary Society before this date, except for requests by the selection committee for supplementary information. Selection advisory committee The selection advisory committee for the NEO grants will be composed of internationally renowned scientists. The final selection will be made by the Board of Directors of The Planetary Society. The committee's procedures and deliberations will be kept confidential. Publication of awards Winners of the Planetary Society NEO grants will be published in The Planetary Report and The NEO News. The Society reserves the right to publish summaries of the most interesting projects in either publication. The Society also encourages professional publications and other popular promotion and articles, so long as proper credit is given for any support. ----------------------------------------------------------------- NASA-ESA AGREEMENT ENHANCES STATION WITH ADDITIONAL NODE NASA release 97-36 The planned final configuration of the International Space Station has been enhanced under a recent agreement signed by NASA with the European Space Agency (ESA) that will have ESA construct two station docking nodes, one of which is a new addition, in exchange for the planned NASA launch of the station's ESA- supplied Columbus laboratory module. The launch-offset barter agreement, a type of agreement common within the International Space Station Program, exchanges ESA services to construct the nodes as payment to NASA for the launch of the Columbus module. Under the agreement, ESA will supply Node 2, a docking node planned to be launched in mid-2000 and connected to the United States Laboratory Module, and Node 3, a new addition to the station planned to be launched after station assembly is completed in the current assembly sequence. Node 3 will attach to the station's habitation module and provide valuable additional docking ports to the orbital outpost. Construction of the two nodes will be delegated to the Italian Space Agency. Plans to convert the Node 1 structural test article, located at Boeing's facilities at the Marshall Space Flight Center, Huntsville, AL, into the Node 2 flight article will be revised accordingly. Although the construction of the two nodes by ESA is the primary service supplied to NASA under the barter agreement, the agreement also includes requirements for ESA to supply a crew refrigerator/freezer unit for the station's habitation module; a cryogenic freezer unit for the U.S. laboratory module; and a variety of other minor hardware. The next step is for NASA and ESA to negotiate an implementing arrangement for this activity. ----------------------------------------------------------------- MARS ROCK COOLS DOWN, LIFE DEBATE HEATS UP From the Science website Thursday, 13 March 1997, 7:00 p.m. The famous martian meteorite, ALH84001, may be cool enough for life again. After NASA scientists claimed last August to have found evidence of past life in carbonate intrusions in the rock, skeptics argued that the chemical composition of the carbonate could only have formed at temperatures of 650 degrees Celsius or above--too high for life. But in tomorrow's issue of Science, two papers fuel the argument with new evidence that the rock formed at comfortably low temperatures. Both groups see abrupt changes in the properties of the carbonates that would have been washed out at high temperatures, they say. In one study, John Valley, a petrologist at the University of Wisconsin, and his colleagues found that isotopic ratios of several elements vary widely throughout the rock. "The gradients are very steep," he says. "[At high temperatures], these sorts of gradients diffuse away in hours to days," leaving the rock rather uniform in isotopic composition. He concludes that the carbonates must have formed at relatively low temperatures, perhaps less than 100 degrees Celsius. Similarly, geologist Joseph Kirschvink and his colleagues at the California Institute of Technology looked at a tiny inclusion in the carbonate, composed of two separate mineral crystals that had been crushed together. After sawing the crystals apart, the team measured their magnetic fields and found that each had a field pointing in a different direction, presumably because the crystals were reoriented when they were crushed. If the rock had ever been heated above about 320 degrees Celsius, its magnetization would have been wiped out. If it had been remagnetized, the fields would have been aligned in the same direction, says Altair Maine, a member of the team. The pattern of the meteorite's magnetic signals thus indicates that it "has a cool history," he concludes. Ralph Harvey, a geologist at Case Western Reserve University in Cleveland who has argued that the carbonates formed at high temperatures, isn't convinced by either finding. For one, he says, if the carbonate formed rapidly at high temperatures and then cooled, steep isotopic gradients could have been frozen in. As for the magnetic data, he argues that the crystals might have been magnetized and then crushed into different orientations long after the carbonate formed. The heat is still on the life-on-Mars claim, it seems. "Isotope people think it was formed at low temperature, and chemical- composition people high temperature," says Robert Clayton, a geologist at the University of Chicago. "Will anybody budge?" © 1997 by the American Association for the Advancement of Science ----------------------------------------------------------------- NEW STUDY BOOSTS IDEA OF PAST LIFE ON MARS University of Wisconsin-Madison release 13 March, 1997 New isotopic analyses of the meteorite that provided hints of past life on Mars reveal a low-temperature origin, boosting the idea that features of the meteorite may have been formed by living organisms. The study, published March 14 in the journal Science by a team led by University of Wisconsin-Madison geochemist John W. Valley, lends powerful new support to the notion that the carbonate globules found within the meteorite, dubbed ALH84001, were formed on the Red Planet under conditions consistent with life. The isotopic procedures employed by Valley and his colleagues were developed specifically for the Mars rock. Results contradict claims that the carbonate globules found in the rock were formed at blistering temperatures too hot to support life, or were formed on Earth, two primary arguments advanced against the meteorite as evidence of past life on Mars. "Everything we see is consistent with biological activity, but I still wouldn't rule out low-temperature inorganic processes as an alternative explanation" said Valley. "We have not proven that this represents life on Mars, but we have disproven the high- temperature hypothesis." Valley said the high-temperature origin hypothesis relies on a set of thermodynamic assumptions that don't measure up on Earth, and therefore don't apply to an ancient Mars that may have had conditions more conducive to life. "If the same assumptions are applied to the carbonates found in the Earth's oceans, one would erroneously conclude that the water temperatures are over 1,000 degrees Fahrenheit and the surface pressures are several thousand atmospheres," Valley said. "These carbonates in the meteorite are easily explained by low- temperature processes similar to those commonly found on Earth," he said. The meteorite at the center of the scientific controversy was blasted off the surface of Mars about 15 million years ago and fell to Earth about 13,000 years ago. There is also widespread agreement that the rock is very old, probably 4.5 billion years, and that it formed in the Martian crust. The age of the rock sparked interest, because it formed at a time when the Red Planet was warmer, wetter and potentially more hospitable to life. The new study was conducted by a team that includes Valley, John M. Eiler and Edward M. Stolper of the California Institute of Technology, Colin M. Graham of the University of Edinburgh, Everett K. Gibson of NASA's Johnson Space Center, and Christopher S. Romanek of the University of Georgia. The analysis was made with a device designed to analyze minute samples of material gleaned from spots less than one-quarter of the diameter of a human hair. Known as an ion microprobe, it uses a beam of high-energy plasma to burn tiny craters on the surface of a sample, in this case a polished sample no bigger than a grain of rice. The vaporized material is held in a vacuum and drawn into a mass spectrometer for isotopic analysis. The advantage of the ion microprobe, said Valley, is that it allows for minuscule amounts of material to be sampled, one million times less than would typically be necessary. Employing the microprobe, Valley and his colleagues were able to look deep within the carbonates themselves and make the first in situ measurements of the controversial globules. "Making these analyses in situ has never been done before," he said. "For the first time, we can actually see what we analyze." He described the carbonates as "pancakes within pancakes" having a distinct chemistry in each. "We can go in and look for differences or similarities within the carbonates themselves." "Without the ion microprobe, one doesn't really know what's being analyzed. We found that the globules are different. There is a very intricate concentric mineral, chemical and isotopic zonation (within the globules)." Valley's team measured the ratios of two different isotopic species of oxygen and two of carbon. They found that the carbon ratios in the meteorite are high, higher than in Earthbound rocks. "This rules out the idea that these features formed while the meteorite was lodged in the Antarctic ice," said Valley. "Such ratios have never been measured in a terrestrial sample." Oxygen isotope ratios are also high, Valley said, but he noted that the significant discovery is that the oxygen isotopes are not evenly distributed within the sample. "The ion microprobe allows us to determine which parts of the meteorite have more of a particular oxygen isotope." The life on Mars hypothesis has been challenged on the grounds that the carbonates formed in chemical equilibrium above 1200 degrees Fahrenheit. The new data prove that the meteorite is not in isotopic or chemical equilibrium. "There is no self-consistent evidence to suggest such a high- temperature genesis," said Valley. "All of the chemical, mineralogical and isotopic evidence that we present is consistent with a low-temperature origin." The upshot of the analysis is that the carbonates most likely precipitated at temperatures below 200 degrees Fahrenheit, under conditions hospitable to some forms of microscopic life. ----------------------------------------------------------------- WHEN MODELS AND SATELLITES MISLEAD: NCAR SCIENTISTS PRESCRIBE CAUTION IN MARCH 13 NATURE National Center for Atmospheric Research release by Bob Henson March 11, 1997 BOULDER -- Computer models and temperature-gleaning satellites are useful tools in the quest to diagnose global change, but only when their limitations are well understood. This is the message conveyed by two scientists from the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, in two articles appearing in the journal Nature on March 13. One article provides new findings on an ongoing controversy involving the reliability of global temperature trends obtained via satellite. The other provides an overview of how to use -- and how not to use -- computer models that mimic the earth's atmosphere for research on climate change. NCAR is managed by the University Corporation for Atmospheric Research under sponsorship by the National Science Foundation. Satellite- versus surface-derived temperatures: Why the disagreement? A puzzling discrepancy between global temperature trends ascertained by surface instruments versus satellites is analyzed by NCAR's James Hurrell and Kevin Trenberth in the article "Spurious trends in satellite MSU temperatures from merging different satellite records." Since 1979, microwave sounder units (MSUs) have been deployed aboard polar-orbiting satellites of the National Oceanic and Atmospheric Administration. MSUs measure the brightness of oxygen in the earth's atmosphere and thus infer the temperature across the globe at various heights. MSU readings for the lowest several kilometers have been averaged and yearly trends calculated since 1989. These show a drop in global temperature of -0.03 to -0.05 degree Celsius per decade since 1979. More traditional global temperature averages taken near the ground show a rise of about 0.1 degree C/decade over the same period. The difference in trends has been a subject of spirited debate because of its implications for the projection and measurement of global warming. (The projected rate of warming is typically around 0.2 degree C/decade.) In their Nature article, Hurrell and Trenberth argue that the MSU data, while useful for many purposes, are poorly suited for gauging long-term surface temperature trends. MSUs monitor the globe more thoroughly than surface reports, which are concentrated over land and approximated over oceans. However, each MSU lasts only a few years, to be replaced by another deployment on a different satellite. According to the NCAR scientists, the transitions between satellites may be producing spurious temperature drops that mask an actual rise in global readings. "The surface and MSU records measure different physical quantities," write Hurrell and Trenberth, "so that decadal trends should not be expected to be the same." However, they add, "unreconciled discrepancies among the different records remain." To study the matter further, the scientists focused on the tropics between 20 degrees N and S, where "noise" from short-term weather variations is lower than it is in temperate and polar zones. Hurrell and Trenberth compared simultaneous MSU records to each other, to sea-surface temperatures (SSTs), and to air temperatures simulated by an NCAR climate model using SSTs. They found that most of the difference between MSU and surface trends could be explained by two significant drops in MSU data for 1981 and 1991, years when satellite transitions took place. Some newspaper and magazine articles now cite only the MSU or only the surface data in reporting on global temperature trends, without noting the counterpart to each. Hurrell and Trenberth stress that both data sets are needed to unravel the mysteries of global climate. "The MSU data are excellent for analyzing year- to-year changes, but not necessarily for longer-term trends," says Hurrell. Thoughts on interpreting climate models and their results Trenberth provides an overview of the strengths and weaknesses of global atmospheric models in his article "The use and abuse of climate models." He points out that humankind is now "performing a great geophysical experiment" by modifying the environment in a way that threatens to change the climate. Lacking a spare earth on which to run a true experiment, "we have to do the next best thing -- try to understand the climate system well enough to build a good model of the planet earth system ... a virtual model of the earth in a computer." However, Trenberth notes, a climate model is only as realistic as the theoretical understanding behind it and the complexity allowed in it. Computer resources, while growing rapidly, still restrict the detail and sophistication of current models. NCAR's climate system model, for example, requires weeks of actual time for a single 100- or 200-year climate simulation. "Computing power is one key to future progress," says Trenberth. Another is to improve the representation of common processes such as cloud formation and ocean circulation in order to minimize the number of "flux adjustments" -- shifts in energy, water, and momentum exchange that are artificially prescribed in order to make a model more stable. These adjustments run the risk of causing unforeseen and unrealistic side effects in the modeled climate. In his article, Trenberth describes a strategy for carrying out climate experiments that removes much of the impact of flux adjustments and other potential sources of error. However, this strategy does not eliminate the possibility of complicated feedback effects. Among other sources of difficulty, clouds represent "probably the single greatest uncertainty in climate models," notes Trenberth. "The enormous variety of cloud types, their variability on all space scales... and time scales (microseconds to weeks) poses a special challenge." To help gain confidence in model results, Trenberth advocates the use of such tools as sensitivity tests, to see how much a result varies with small changes in the input conditions or model procedures, and simplified models, which require less computer time, to check approximations and assumptions. He also suggests that the burden of proof for claims that model results are incorrect should be on the critic, not the modeler. For policymakers hoping for guidance from computer models, Trenberth emphasizes the value of using pooled knowledge and results from a number of different models, such as those used in the estimates from the Intergovernmental Panel on Climate Change of a projected global warming from 1.3 to 2.9 degrees C by the year 2100. "Statements such as these, given with appropriate caveats, are likely to be the best that can be made because they factor in the substantial understanding of many processes included in climate models. Such projections cannot offer certainty, but they are far better than declaring ignorance and saying nothing at all." ----------------------------------------------------------------- GLOBAL CLIMATE MONITORING: THE ACCURACY OF SATELLITE DATA NASA/Marshall Space Sciences Lab by Roy Spencer, John Christy, John Horack [Rebuttal to previous article] March 12, 1997 Recently, much scientific debate has focused on the global temperature of the Earth's lower atmosphere as measured by orbiting satellites. And while these data are exceedingly precise, verified by multiple satellite observations, and balloon measurements taken in-situ, they reveal no discernable warming trend in the Earth's lower atmosphere over the last 18+ years. Dr. Roy W. Spencer (NASA Marshall Space Flight Center) and Dr. John Christy (The University of Alabama in Huntsville) have used the Microwave Sounding Units (MSUs) flying aboard NOAA's TIROS-N weather satellites to construct a continuous record of lower tropospheric (from the surface to about 4 miles) temperatures since the first MSU was launched in late 1978. The lower tropospheric temperature trend has been calculated to be -0.04 degrees C/decade. In the latest (March 13, 1997) edition of Nature, two scientists, James Hurrell and Kevin Trenberth, report that sea-surface temperatures monitored by buoys and ships at various locations in the tropics show, for the same period as the satellite record, a warming trend of +0.12 deg. C/decade, in apparent disagreement with the satellites. This so-called "disagreement" between satellite and surface temperature measurements is not new. Despite the fact that Hurrell and Trenberth begin with a measurement of sea-water temperature and make an estimate of the temperature of the atmosphere from a linear regression model, while the MSU data actually measure the temperature of the free atmosphere, Hurrell and Trenberth conclude that the satellite data must be wrong. The recent paper's conclusion is based on two apparent "breaks" in the satellite versus sea-water temperature record, one in late 1981 and the other in late 1991. "During the first period, we had two separate satellites, operating simultaneously, and agreeing with each other to about 0.02 degrees C. So their estimate of the late 1981 break is inconsistent with these observations," observed Dr. Spencer, an atmospheric scientist at NASA. "There isn't a problem with the measurements that we can find," Spencer explained. "In fact, balloon measurements of the temperature in the same regions of the atmosphere we measure from space are in excellent agreement with the satellite results." Dr. Christy explained further, "In particular, we've examined these two `breaks' claimed by Hurrell and Trenberth. Even in these disputed intervals, we find excellent agreement between the two independent, direct atmospheric temperature measurements from balloons and satellites." The disagreement between satellites and surface-based thermometers, furthermore, is not geographically uniform. "Over Northern Hemisphere land areas, where the best surface thermometer data exist, the satellites and thermometers agree almost perfectly", said Dr. Christy of UAH. "It is primarily over the oceans where they disagree by a couple of tenths of a degree C. This is most likely a well-known phenomenon in which the temperature in the deep atmosphere is not as strongly linked to the surface temperature as it is over land." While Hurrell and Trenberth attempt to account for possible differences between the surface and deep-layer measurements by forcing a computerized atmospheric general circulation model (GCM) with the observed sea-water temperatures, this methodology is likely flawed. "It is well known that GCMs will produce atmospheric temperatures that vary in lock-step with the surface temperatures. In addition, the GCM did not include the direct forcing on the atmosphere from this century's two largest volcanoes," noted Spencer. "The physics in these models is not refined enough to do anything else. The satellite measurements provide the first observational evidence that the surface and deep layer temperatures can vary slightly differently (a couple of tenths of a degree) over a decade or so." Spencer and Christy point out that the surface versus satellite temperature controversy will likely not die away soon. Through NASA's Earth Observing System, researchers will continue to improve our ability to monitor the Earth system so that we may understand the subtleties of variations in the global atmosphere as noted in the current discussion. It is only with direct observations of the earth that we will be able to sort out the issues of climate variability and change that affect the planet. ----------------------------------------------------------------- TRW DELIVERS TWO CERES INSTRUMENTS TO NASA; CERES TO STUDY ROLE OF CLOUDS AND RADIATION TRW release REDONDO BEACH, Calif. -- March 13, 1997 -- TRW Inc. is delivering next week to NASA Langley Research Center, Hampton, Va., two instruments that will be used to study the role of clouds and radiation on the environment. The Clouds and the Earth's Radiant Energy System (CERES) instruments will measure reflected solar and emitted thermal radiation from the Earth's surface to determine the influence of clouds on the Earth's temperature. CERES will be integrated onto the Earth Observing System AM-1 (EOS AM-1) satellite, which is set for launch in June 1998. The CERES instruments are part of NASA's Mission to Planet Earth (MTPE), an ambitious, long-term program that includes the development of instruments and spacecraft to monitor natural and human-induced changes to Earth's climate and environment. As part of the CERES contract, TRW is also providing two instruments for the EOS PM-1 spacecraft -- which will be built by TRW. These instruments are currently beginning fabrication and assembly. "Clouds are still a mystery to scientists," said Steve Carman, CERES program manager at TRW's Space & Electronics Group in Redondo Beach. "We know that clouds act as an umbrella to shield the Earth against the sun's radiation and as a blanket to warm the Earth, but clouds remain the single largest area of uncertainty in climate models today." "CERES will gather data to help scientists build more accurate models to forecast long-range climatic trends, and to better understand the effects of clouds on the climate," he said. These instruments represent two of six units that TRW is under contract to build and deliver by 2001. The first instrument, set for launch on the Tropical Rainfall Measuring Mission satellite, was delivered to NASA Langley in October 1995. The remaining three instruments will be delivered for integration on the EOS PM-1 satellite and the EOS AM-2 mission. CERES is a scanning broadband radiometer that measures reflected sunlight and emitted thermal energy from the surface of the Earth and the atmosphere. The radiometer is made up of three sensors, each with its own telescope mounted on a gimbaled platform that continuously scans across the Earth in a 6.6-second cycle. The two CERES instruments will operate in different scan modes (one, cross-track scanning and the other, biaxial scanning), allowing scientists to view the Earth's surface and atmosphere from different angles simultaneously. The additional data will enable scientists to build better models of the Earth and make more accurate predictions. CERES radiometric measurement accuracy requirements are at the state-of-the-art level of greater than 99 percent. To meet this requirement, CERES sensors have been precisely calibrated using standards from the National Institute of Standards and Technology at TRW's absolute radiometric calibration facility. In recent tests, the instruments have demonstrated accuracy better than specifications. CERES data will be combined with data from supporting imaging instruments that identify cloud conditions. NASA Langley is responsible for CERES data reduction. The CERES science investigation will be conducted by an international team of scientists, led by Co-Principal Investigators Bruce Barkstrom and Bruce Wielicki of NASA Langley Research Center. ----------------------------------------------------------------- NASA SELECTS INSTITUTION FOR LIFE SCIENCES RESEARCH NASA release 97-37 NASA has selected the Lawrence Berkeley National Laboratory, Berkeley, CA, to serve as a NASA Specialized Center of Research and Training (NSCORT) to conduct research into the biological effects of exposures to galactic and cosmic radiation. The research will help define the radiation risks experienced by space travelers. The selection was made on the basis of merit as judged by a peer review panel assembled under the supervision of NASAÕs Office of Life and Microgravity Sciences and Applications, Washington, DC. NASA plans to award the center approximately $1 million a year for five years. The selection is a competitive renewal award for the NSCORT at Lawrence Berkeley, after an initial and very successful five-year period. The Colorado State University in Fort Collins, CO, is a collaborating partner. The NSCORT radiation health program is an integral part of NASA's research and analysis activities to understand the hazards associated with radiation exposures in humans and to develop effective methods to limit the associated risks in space. This program is established exclusively to support ground research and analysis, including education and training of future scientists. In addition to the NSCORT in radiation health, there are six other NASA-funded NSCORTs. The other previously selected institutions and their specialties include: * Northwestern University Medical School, Chicago, IL (funded jointly by National Institutes of Health) -- Vestibular Research * Ohio State University, Columbus (funded jointly by National Science Foundation) -- Plant Biology * University of Texas, Southwestern Medical Center, Austin -- Integrated Physiology * Purdue University, Lafayette, IN -- Bioregenerative Life Support: Biomass Productivity and Sustainability Of Bioregenerative Life Support Systems; and * Kansas State University, Manhattan -- Gravitational Studies in Cellular and Developmental Biology. ----------------------------------------------------------------- NASA ESTABLISHES NEW NATIONAL MICROGRAVITY CENTER NASA release 97-40 Case Western Reserve University (CWRU), Cleveland, OH, and the Universities Space Research Association (USRA) will partner with NASA's Lewis Research Center, Cleveland, OH, to advance microgravity research in fluid physics and combustion science through a new National Center for Microgravity Research on Fluids and Combustion, according to NASA Administrator Daniel S. Goldin. Administrator Goldin was at CWRU to sign a cooperative agreement among the three parties. The new center, located at CWRU's Case School of Engineering, is the first national center dedicated to microgravity research. This research is critical for carrying the space program into the next century and achieving the promised scientific and economic payoffs from the International Space Station. NASA will provide $17.8 million in funding over the next five years to support the center. The university-based science community will own and operate the center through USRA, a consortium of 80 colleges and universities which includes CWRU. The center's principal responsibilities can be grouped into five areas -- fundamental research and technology development, science program outreach and development, scientific support to principal investigators, technology transfer to industry, and public education initiatives. "The National Center for Microgravity Research on Fluids and Combustion represents a commitment to our goal to strengthen the partnership between NASA and our nation's research community in universities and industry so that together we can increase the scientific and economic payoffs from NASA's Microgravity Science Program," Goldin said. The center will enhance the value of the nation's investment in microgravity fluid and combustion research. This research is essential for developing the knowledge base to generate technology for long-term space missions and human space exploration. It is also expected to lead to applications of new technologies that can be used on Earth to advance such things as more efficient power generation, pollution abatement, improved manufacturing processes, and biomedical innovations. Simon Ostrach, the Wilbert J. Austin Distinguished Professor of Engineering at CWRU, and the recently named Director of the National Center, said "the center will be a catalyst for creating a knowledge base to advance our basic understanding of many of natureÕs processes. It also will provide a better way to get that knowledge into the hands of those who can really apply it in order to benefit us all." "Most industrial systems are empirically derived and a chasm exists between existing industrial systems and what the laws of nature dictate," he noted. "While we keep talking about the rubric of design, manufacturing, and marketing, we donÕt have the basic knowledge needed to design better products and processes to operate in microgravity or on Earth." In its effort to enhance the value of microgravity research, the center will: identify and nurture new research areas; transfer information, data, and technology to industry; provide technology for NASA's Enterprise for the Human Exploration and Development of Space program; and spur interest among tomorrow's young scientists through programs designed for students in kindergarten through grade 12. The center also will develop a pool of highly-skilled microgravity investigators who can exploit the unique capabilities of the International Space Station to conduct world- class research that is impossible to study in ground-based laboratories. Ostrach will direct a team of over 30 people consisting of senior staff scientists who will be members of the CWRU faculty, visiting professors, staff scientists located at Lewis, CWRU graduate students, and an administrative staff. They also will extend outreach efforts to the community to generate new research ideas and proposals. Through their participation in the center, the researchers will have access to unique equipment and facilities, such as the drop towers at Lewis which test the effects of short-term microgravity on experiments. They also will establish an interactive network with other universities and industry to encourage their use of Lewis's capabilities and facilities. Center researchers will provide scientific and engineering support to principal investigators conducting microgravity research. They also will contribute on-site scientific support to principal investigators and flight hardware developers during the design, development, and operation of flight experiments, and later during analysis and dissemination of their flight research results. The Cooperative Agreement establishes a formal, long-term partnership between CWRU, USRA, and NASA which builds on the unique experience, expertise, and capabilities of each partner to achieve success, a success which is critical to seizing the vast opportunities and benefits made possible by microgravity research. ----------------------------------------------------------------- PRESS BRIEFING TO PRESENT NEW DATA AND STATUS OF 'PAST LIFE ON MARS' DEBATE SCHEDULED FOR MARCH 19 NASA release Seven months after NASA's initial announcement suggesting that a Martian meteorite shows life may have existed on ancient Mars, a panel of science experts will present new data and deliver a progress report on the continuing "Past Life on Mars" discussion at a press briefing scheduled for 1 p.m. EST, Wednesday, March 19, in the media briefing room at the Johnson Space Center (JSC), Houston, TX. Douglas P. Blanchard, Ph.D., Chief of JSC's Earth Science and Solar System Exploration Division, will moderate a six-person panel of co-authors of each of the six abstracts on the Mars issue that are scheduled for presentation later that day during a special plenary session of the Lunar and Planetary Science Conference in the adjacent Teague auditorium at JSC. The briefing will be carried live on NASA Select TV. ----------------------------------------------------------------- NASA NAMES A NEW NATIONAL BIOMEDICAL RESEARCH INSTITUTE NASA release 97-43 NASA has selected Baylor College of Medicine, Houston, TX, to lead the consortium for its new National Space Biomedical Research Institute. In its role as an Institute, Baylor will conduct the focused biomedical research necessary to support human health in the exploration and development of space. Following a 60-day cooperative agreement for detailed definition, a five year agreement with three, five-year extensions will be awarded on June 1, 1997. The total value of the 20-year agreement is approximately $145 million. The Johnson Space Center, Houston, TX, will sponsor the Institute. NASA identified the concept of a science institute as a means of maintaining the scientific excellence of its applied biomedical research through a greater involvement of the scientific community in NASA's overall research program. NASA believes this pilot program will be a national consortium of premier academic and research organizations, developing the solutions to medical risks associated with extended human space flight. The members of the National Space Biomedical Research Institute consortium are: Harvard Medical School, Cambridge, MA; Johns Hopkins University¹s Applied Physics Laboratory, Laurel, MD; Massachusetts Institute of Technology, Cambridge, MA; Morehouse School of Medicine, Atlanta, GA; Rice University, Houston, TX; and Texas A & M University, College Station, TX. The specific objectives of the Institute include: --Implementation of a research plan that will leadto the knowledge and technologies required for long-duration space flight, including specific countermeasures; --Ensure the dissemination of knowledge to the scientific community; --Facilitate science community access to NASA¹s space biomedical research expertise and facilities; --Ensure that technology development and knowledge are transferred to the private sector. As the Institute's sponsor, the Johnson Space Center will make available to Baylor, NASA's considerable knowledge and expertise in the area of biomedical research in general and human space flight in particular, and the associated facilities and assets which were developed in more than 30 years of human space flight. ----------------------------------------------------------------- (FAIRLY) RECENT PUBLICATIONS OF INTEREST TO EXOBIOLOGISTS Compiled by Julian Hiscox Benaroya. 1997. An engineering perspective on terraforming. Journal of the British Interplanetary Society. v50, 105-108. Cabrol et al. 1996. Ma'adim Vallis revisited through new topographic data: evidence for an ancient intravalley lake. Icarus. v123, 269-283. Cathcart. 1997. Seeing is believing: Planetographic data display on a spherical TV. Journal of the British Interplanetary Society. v50, 103-104. Chyba. 1997. Life on other moons. Nature. v385, 201. Cregg and Williams. 1996. Explosive mafic volcanoes on Mars and Earth: Deep magma sources and rapid rise rate. Icarus. v122, 397-405. Fogg. 1997. Planetary engineering bibliography. Journal of the British Interplanetary Society. v50, 117-119. Fogg. 1997. Book review of: The Case for Mars by Zubrin and Wagner. Journal of the British Interplanetary Society. v50, 120. Gray. 1997. Absence of a planetary signature in the spectra of the star 51 Pegasi. Nature. v385, 795-796. Hiscox and Lindner. 1997. Ozone and the habitability of Mars. Journal of the British Interplanetary Society. v50, 109-114. Holland. 1997. Evidence for life on Earth more than 3850 million years ago. Science. v275, 38-39. Johnson and Liu. 1997. The loss of atmosphere on Mars. Science. v274, 1932-1933. Mautner. 1997. Directed panspermia. 3. Strategies and motivation for seeding star-forming clouds. Journal of the British Interplanetary Society. v50, 93-102. McDonald et al. 1996. Production and chemical analysis of cometary ice tholins. Icarus. v122, 107-117. Reichhardt. 1997. Russian space module "in need of more protection". Nature. v385, 190. Walker. 1997. One of our planets is missing. Nature. v385, 775-776. Williams et al. 1997. Habitable moons around extrasolar giant planets. Nature. v385, 234-236. Zubrin and McKay. 1997. Technological requirements for terraforming Mars. Journal of the British Interplanetary Society. v50, 83-92. ----------------------------------------------------------------- End Marsbugs, Vol. 4, No. 5.