MARSBUGS: The Electronic Astrobiology Newsletter Volume 9, Number 36, 30 September 2002. Editor/Publisher: David J. Thomas, Ph.D., Science Division, Lyon College, Batesville, AR 72503-2317, USA. dthomas@lyon.edu Contributing Editor: Julian A. Hiscox, Ph.D., 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 effectively 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/. _____________________________________________________________________ CONTENTS 1) AVOIDING THE FATE OF THE DINOSAURS ESA release 60-2002 2) AMATEURS INVITED TO JOIN PLANET SEARCH By Robert Roy Britt 3) CLIMATE MODEL FOR EARTH ALSO DESCRIBES CHANGES ON MARS Brown University Release 4) MICROBES COULD BE IN VENUS ATMOSPHERE From Reuters and CNN 5) FUTURE SCIENTISTS AND ENGINEERS ENCOURAGED TO SUBMIT MICROGRAVITY PROPOSALS NOW NASA/GRC release 6) NASA REVEALS NEW PLAN FOR THE MOON, MARS & OUTWARD By Leonard David 7) SEX, IQ & ET: HOW WE GOT BIG BRAINS By Seth Shostak 8) RUSSIA MULLS MOTHBALLING SPACE STATION From Reuters and CNN 9) WATER WORLDS By Leslie Mullen 10) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 11) CASSINI-HUYGENS MISSION STATUS NASA/JPL release 12) MARS GLOBAL SURVEYOR STATUS REPORT NASA/JPL release 13) MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 14) STARDUST STATUS REPORT NASA/JPL release _____________________________________________________________________ AVOIDING THE FATE OF THE DINOSAURS ESA release 60-2002 24 September 2002 Tales of asteroids or comets in a collision course with the Earth are always good to fill space in newspapers during the quiet summer months. Is there any truth in these tales of impending doom and if so, what is ESA doing about it? Certainly if a large comet or asteroid were to collide with the Earth the result could be apocalyptic. But, the possibilities of this happening are remote. The latest asteroid scare story to hit the press was that of 2002NT7, believed to be about 2 km in diameter. First reports said that 2002NT7 could collide with the Earth on 1 February 2019 at a speed of 28 km/s. The result would be widespread devastation, if not the end of the world, predicted in some papers. Fortunately for those of us who will be around in 2019 the possibility of this happening is now reported to be negligible. Although first estimates gave odds of about 1 in 100,000, now that scientists have had more time to study this "new" asteroid and its orbit--only discovered in July--the odds have lengthened considerably. Asteroids and comets whose orbits bring them close to the Earth are referred to as Near Earth Objects (NEOs). NEOs less than 50 m in size burn up on entry into the Earth's atmosphere. It is estimated that around 50,000 fragments of NEOs fall to Earth as meteorites each year, most far too small to do any damage. Fortunately, the larger the NEO the less likely it is to collide with the Earth, as even a NEO 300 m in diameter could wipe out an entire country if it hit land, and cause even more damage if it struck an ocean, as it would trigger the enormous waves known as tsunamis that could devastate many coastal cities. According to astronomers, a NEO of around 50 m in diameter collides with the Earth every 100 to 300 years and a NEO with a diameter of 1 km occurs every few hundred thousand years. Very large collisions, that could threaten the existence of all large land species, occur once every hundred million years. To date, astronomers have identified 600 NEOs bigger than 1 km but believe that there are possibly half as many again still waiting to be tracked. But, even if the odds are on our side, the fact remains that at some time or other the Earth will again be hit by a large NEO, such as that thought to have wiped out the dinosaur population 65 million years ago. So to return to the second question, what is ESA doing about it? ESA and NEOs ESA has been supporting activities to monitor and investigate NEOs for a number of years. In ESA's view, these are activities that surpass national boundaries and which it considers to be a service to the international community. ESA's space research institute outside Rome in Italy, ESRIN, also hosts the Spaceguard Central Node. This private non-profit scientific organization aims to support and coordinate NEO research throughout the world. Now ESA has launched a new project to seek the best ideas from industry and academia on how to protect the Earth from NEOs and in particular, to learn more about them. The damage an NEO causes depends on the speed at which it hits the Earth, its size and what it is made of. So, the more we know about them the easier it will be to decide which are potentially dangerous and what is the best action to take. In June a panel of NEO experts met to select the best six proposals. Andrés Gálvez, one of ESA's representatives on the panel reports, "the six winning proposals were selected because the mission concepts would help to answer essential questions on the NEO threat such as: how many are there, what is their size and mass, are they compact bodies or loose rock aggregates? This information, as well as other data, is needed before adequate mitigation procedures can be developed." The winning six are: Don Quijote: This proposal is for a spacecraft named "Hidalgo" to hit a target asteroid at high speed while the other, "Sancho", observes what happens from a safe distance before, during and after the impact, to gather information on the NEO's internal structure. This will also test possible future mitigation techniques, such as whether "Hidalgo" could be programmed to hit the asteroid to change its orbit so that it avoids collision with the Earth. Earthguard 1: A spacecraft using propulsion technology such as solar sails or electric propulsion, or "hitching a ride" on a future launch, would be placed in a heliocentric orbit to observe NEOs from a more favorable viewpoint. ISHTAR: This would probe the interior of an NEO to study its structure and assess the danger with radar tomography, a new technology that uses ground penetrating radar to make images of the interior of a solid body. SIMONE: A fleet of low-cost small satellites would fly by and/or rendezvous with a number of NEOs to characterize the population and obtain first hand information on the hazardous objects. EUNEOS: A space survey would be undertaken from an inner solar system orbit to find the most dangerous NEOs. These are often the most difficult to observe from ground-based observatories as very often these faint objects only appear in the daytime sky or very close to the horizon. Remote observation of NEOs from Space: A space-based observatory to carry out remote sensing and detect physical characteristics of NEOs, such as size, composition and surface properties. Andrea Carusi, President of the Spaceguard Foundation, believes, "it is very important that ESA, one of the largest space agencies, and one that is already deeply involved in support of NEO studies, has decided to take a further step in this direction". Preliminary studies, funded by the Agency's General Studies Programme, are now under way for the six proposals. Once these are submitted in 2003, ESA will judge whether one or more of the proposed missions is feasible and merits further development. Contact: ESA Media Relations Service Phone: +33(0)1.53.69.7155 Fax: +33(0)1.53.69.7690 _____________________________________________________________________ AMATEURS INVITED TO JOIN PLANET SEARCH By Robert Roy Britt From Space.com 25 September 2002 With the tally of planets around other stars hovering around 100 and growing rapidly, amateurs are being invited to join the search for other worlds in an effort to confirm detections of presumed planets and improve understanding of their sizes and other characteristics. A new Web-based initiative could mark the re-entry of amateurs into the ranks of planet hunters--a heady group that has long exhibited the resourcefulness unique to backyard stargazers. In 1781, William Herschel found Uranus using an amateur telescope at home. Clyde Tombaugh found Pluto in 1930 at the age of 23 after his amateur efforts got him a real job as a professional astronomer. Get the full story at http://www.space.com/scienceastronomy/astronomy/planet_hunting_020925 .html. _____________________________________________________________________ CLIMATE MODEL FOR EARTH ALSO DESCRIBES CHANGES ON MARS Brown University Release http://www.brown.edu/Administration/News_Bureau/2002-03/02-019.html 25 September 2002 Orbit affects climate on Mars similar to the way it affects climate on Earth, say three scientists, who used a model of climate change on Earth to explain the layers of deposits in the polar regions of the Red Planet. Their study appears in the September 26 issue of Nature, and suggests that a climate change theory for Earth can also be applied to Mars and possibly to other Earth-like planets. "The orbital theory of climate change has been successful in explaining changes in the Earth's climate, and we have used cores of the Greenland and Antarctic ice caps to reconstruct past climates and atmospheres on Earth," said author Jack Mustard, associate professor of geological sciences at Brown University. "This means that we can now use the Mars caps in a similar way." The study also produced "a much better constraint on the time required to form the layers on the polar cap of Mars," he said. "This has importance in understanding the martian climate, and also the water cycles and history. We have so little information on the rates of change on Mars, but this gives us a solid marker." Besides Mustard, the other two authors of the study are Jacques Laskar and Benjamin Levrard of the Astronomie et Systèmes Dynamiques in Paris. The trio used orbital calculations and rotational [bands] parameters of Mars, new high-resolution images of its north pole terrain, and high-resolution topography data to correlate exposed layers of ice and dust with changes in climate, particularly the sum of solar radiation reaching the terrain. Their techniques mirrored those used for orbital-based climate studies on Earth. Changes in the ratio of dust and ice over time are visible in the variations of brightness seen in the layers of polar deposits on Mars. First noticed in the earliest Mars missions, the layers were thought to be related to changes in climate possibly linked with the evolution of Mars' orbit such as the tilt of the axis and deviations in circularity. But the image resolution of past data was insufficient to resolve such key details. High-resolution images from the Mars Global Surveyor allowed Mustard to resolve the fine detail and analyze the patterns. "After correcting the observations for topography, we produced a measure of the brightness of the layers as a function of depth," he said. "We assume that depth equals time and thus can peer into the past. We then compared this record with the predicted amount of sunlight received at the pole over the last 10 million years, which varies with orbital evolution involving tilt and circularity." The researchers' goal was to determine whether the sunlight record at the north polar cap of Mars correlated with the brightness-depth profile, and over what time frame. If the record correlated, that would solidify their hypothesis that the layers are due to climate changes related to orbit and allow the researchers to determine the formation rate of the layers. "Indeed we find an excellent correlation and show that the 350-meter thick package of layers formed within the last 1 million years or so," Mustard said. For the most recent 250-meter thick deposit of the north ice polar cap, the researchers found an average deposition rate of 0.05 cm/yr. "For the first time, we showed that the orbital theory of climate change has a record in the polar deposits on Mars." In orbit, Earth tilts about 23-25 degrees. In contrast, Mars tilts as little as 15 degrees and as much as 40 degrees, which is enough to redistribute moisture from polar caps to equatorial regions, Mustard said. In the 1970s, research by geologists at Brown first showed an orbital effect on climate change for Earth. "This study further ties Mars and Earth as similar planets and strengthens the foundations to compare their climates and orbital evolutions," Mustard said. "Showing that a planet with as strange an orbit as Mars has climate changes recorded in its surface means we have a tool in this orbital driver to explore what happens on the surface of planets with differences and similarities to Earth. And as we learn more about deposits on Mars we can compare what we find with what we know about Earth." The Centre Nationale de la Recherche Scientifique Programme Nationale de Planétologie and NASA's Solar System Exploration programs supported the research. _____________________________________________________________________ MICROBES COULD BE IN VENUS ATMOSPHERE From Reuters and CNN 26 September 2002 Dirk Schulze-Makuch and his colleague Louis Irwin at the University of Texas at El Paso have been studying conditions in a region of the atmosphere of the planet that has a high concentration of water droplets. Using data from the Russian Venera space missions and the U.S. Pioneer Venus and Magellan probes, they noticed oddities in its chemical composition that they think could be explained by the presence of microbes. Get the full story at http://www.cnn.com/2002/TECH/space/09/26/venus.bugs.reut/index.html. An additional article on this subject is available at http://www.spacedaily.com/news/020925180028.rwauurvt.html. _____________________________________________________________________ FUTURE SCIENTISTS AND ENGINEERS ENCOURAGED TO SUBMIT MICROGRAVITY PROPOSALS NOW NASA/GRC release 26 September 2002 NASA's Glenn Research Center, Cleveland, wants to find those high school students that have what it takes to create a science experiment that can be tested in one of its drop towers. Glenn is currently accepting proposals for its annual Dropping In a Microgravity Environment (DIME) competition, which allows students to be scientists and engineers by experiencing the scientific process from inception to end. DIME is a project-oriented educational program consisting of investigations and design challenges that lasts one school year. DIME links students directly to NASA's diverse and exciting missions of research, exploration and discovery. By participating in this competition, students develop a hypothesis that can be tested through experimentation and prepare a scientific research proposal. The program is open throughout the fifty United States, the District of Columbia and Puerto Rico to student teams in grades 9--12 comprised of groups such as science classes, clubs, or scout troops, and their advisors. To participate, each group must develop an experiment concept that shows a significant effect of gravity to be reduced via a microgravity environment, prepare a proposal and submit it to Glenn. Proposals are judged on criteria including scientific objectives, technical plan, team organization, creativity, attention to detail and originality. Proposals should be postmarked no later than November 1, 2002. A panel of Glenn microgravity experts will select the top four proposals for further experiment design and development before sending them to Glenn. Four students and one adult advisor from each selected team will travel, at NASA's expense, to Glenn in April 2003 to attend the DIME Drop Days. For three days, teams will operate the experiments in Glenn's 2.2 Second Drop Tower and participate in workshops and Center tours. Each team's drop tower activities will be webcast on the Internet. More information on the DIME competition, including official rules, is available online at http://microgravity.grc.nasa.gov/DIME.html. Contacts: Barbara L. Kakiris, InDyne, Inc. Media Relations Office Phone: 216-433-2513 E-mail: barbara.l.kakiris@grc.nasa.gov Lori J. Rachul Media Relations Office Phone: 216-433-8806 E-mail: lori.j.rachul@grc.nasa.gov _____________________________________________________________________ NASA REVEALS NEW PLAN FOR THE MOON, MARS & OUTWARD By Leonard David From Space.com 26 September 2002 To boldly go, the timeless and optimistic Space Age theme, looks to have been reclaimed from a NASA lost-and-found drawer as long-range planners prepare to reveal next month a new roadmap for robotic and human missions to deep space, SPACE.com has learned. The 21st Century, science-driven agenda is designed to propel exploration beyond the International Space Station and involves a new habitation complex that would be built between Earth and the Moon, serving as a portal to Mars and other solar system targets. Somewhat secretive, this behind-the-scenes stratagem has been years in the making. A NASA Exploration Team (NExT) is prepared to showcase their springboard vision for returning to the Moon, visiting asteroids, and trekking on to Mars and beyond. At the upcoming World Space Congress to be held October 10-19, an expected throng of some 13,000 officials from various nations will descend on Houston, Texas. This once-a- decade gathering provides a status report on global space prowess. Get the full story at http://www.space.com/news/beyond_iss_020926- 1.html. _____________________________________________________________________ SEX, IQ & ET: HOW WE GOT BIG BRAINS By Seth Shostak From Space.com 26 September 2002 Relative to their size, humans have the biggest brains on the planet. Check out the guy sitting next to you on the bus: hunkered beneath a fringe of moussed hair and a few millimeters of skull are three crinkly pounds of brain--the only substantive difference between you and species you regard as food or pets. But how did this happen? What special circumstance, what unperceived evolutionary force, nudged our hulking, hairy ancestors toward intelligence, and silently trebled the size of their brains in two million years or less? This question is seductive not only because it tells us something exquisitely interesting about ourselves, but also because the answer could give us insight into whether other intelligent beings really exist. Get the full story at http://www.space.com/searchforlife/seti_bigbrains_020926.html. _____________________________________________________________________ RUSSIA MULLS MOTHBALLING SPACE STATION From Reuters and CNN 27 September 2002 Manned missions to the International Space Station may have to be suspended because Russia cannot afford to build new craft to carry crews there, a Russian space official said Thursday. "The situation is desperate," Valery Ryumin, director of the Russian section of the ISS, said by telephone. Ryumin, also a top designer for rocket-builder Energiya--which supplies the Soyuz craft--said the company had no money beyond next year to build the vehicles. "It takes two years to build the spaceship. Unless we place an order today, we will have nothing to fly on in 2004," he said. Get the full story at http://www.cnn.com/2002/TECH/space/09/26/russia.station.reut/index.ht ml. _____________________________________________________________________ WATER WORLDS By Leslie Mullen From Astrobiology Magazine 30 September 2002 Some extrasolar planets have water in their atmospheres, an Italian astronomer announced at the Second European Workshop on Exo/Astrobiology in Austria. At least, that's one interpretation of the data obtained by Cristiano Cosmovici and his team from the Institute for Cosmic and Planetary Sciences in Rome. Using the 32- meter Medicina radio telescope to receive water MASER emissions, Cosmovici and his team looked at 17 stars that are thought to have planetary systems. MASER stands for Microwave Amplification by Stimulation Emission of Radiation. Like a LASER, which is an amplified beam of ultraviolet, visible, or infrared light, a MASER is a beam of amplified microwave radiation. Natural MASERs develop in regions of space where the normal balance of atoms absorbing and releasing energy is altered. For instance, MASERs can form from the disk of gas and dust that surrounds a young star. As the star emits electromagnetic radiation, the densely packed atoms and molecules in the disk absorb some of these photons. The frequency of the photon absorbed depends on the type of atom or molecule. This absorption pushes the atoms and molecules into a higher, "excited" state. Atoms don't remain in this state for long, and they soon emit photons in order to relax back to the lower energy, "ground" state. The MASER beam arises when groups of atoms or molecules are stimulated to simultaneously make a transition to the ground state, all releasing their energy at the same wavelength. Since the photons are the same wavelength, the MASER beams are extremely focused. Scientists can use radio telescopes to receive these beams, and then determine which type of atom or molecule is responsible based on the frequency of the emission. The water MASER line is approximately 22 gigahertz (GHz). For radio astronomers, this is one of the brightest spectral lines in the radio universe. Water production is a common result of star formation, as newly ignited stars send huge shock waves into the surrounding cloud of material. This energy blast causes some hydrogen and oxygen molecules to bind together, creating excited water molecules that relax by emitting microwaves at the 22 GHz wavelength. Over the years, many water MASERs have been detected from the regions around newborn stars as well as from the circumstellar disks of young stars. But for older stars, the shock waves have long since subsided and the circumstellar disks have dissipated. Another explanation for the presence of water near such stars must be found. The Italian astronomers found three stars with the signature water MASER emissions: Upsilon Andromedae, Epsilon Eridani, and Lalande 21185. The Italian team suggests these water MASER beams might arise as water molecules in a planet's atmosphere become excited by the infrared light of its star. According to Cosmovici, such water MASER signals are "a powerful diagnostic tool for planetary searches outside the solar system." "This result is astonishing if it's true," says Geoff Marcy, a planet hunter from the University of California at Berkeley. "It definitely needs to be checked by other observers." The stars Upsilon Andromedae is about 44 light-years away. The star is about 3 billion years old, and a little more massive and just slightly hotter than the Sun. Doppler measurements of Upsilon Andromedae indicate three gas giant planets orbit the star. The most massive planet is 4.6 Jupiter masses, although astrometry measurements suggest it may be as much as 10 Jupiter masses. This planet orbits at 2.5 AU and completes an orbit in 1,267 days. Another planet is about twice as massive as Jupiter, orbits at 0.83 AU and completes an orbit in 241 days. The third planet is 0.71 Jupiter masses and orbits at a mere 0.059 AU, completing an orbit in only 4 days. The star Epsilon Eridani is located 10.5 light-years away. Somewhat smaller and cooler than our own Sun, Epsilon Eridani is also less luminous. This may be because the star is so young: Epsilon Eridani is believed to be only 500 million to 1 billion years old. The existence of a planet near Epsilon Eridani is still under debate because, like other young stars, Epsilon Eridani is magnetically very active. The California planet hunting team led by Geoff Marcy says, "The Doppler behavior of magnetically active stars remains poorly explored, because so few stars are as active as Epsilon Eridani. Thus, [the] interpretation of a planet remains controversial." If the planet orbiting Epsilon Eridani does exist, it is very much like Jupiter, with a similar mass and an orbit of 3.3 AU from its star (Jupiter orbits our Sun at 5 AU). Other scientists have commented that the Epsilon Eridani system probably resembles what our own solar system may have looked like 4 billion years ago. The planets around Lalande 21185 are also controversial. Rather than the Doppler measurements normally used to detect planets, these were found by optical astrometry. This observational method relies on the fact that a planet and its star orbit a common center of mass, making the star appear to move back and forth in the sky. University of Pittsburgh astronomer George Gatewood analyzed photographic plates taken between 1930 and 1984 that tracked the movement of Lalande 21185. He also followed the star's motion for eight years using a photoelectric detector. His measurements indicated the presence of at least one, and possibly three, Jupiter-mass planets. Only 8.1 light-years away, Lalande 21185 is one of our closest neighbors. The star is a red dwarf--a relatively cool, low-mass star--and it is believed to be between 5 to 10 billion years old. (Interestingly, water MASER emissions have been detected from the outer atmospheres of red giants and supergiants--older stars approaching the end of their lifetimes. On Earth, liquid water is essential to life. By searching for liquid water elsewhere, we may find "life as we know it," increasing the odds that we will recognize alien life if we ever come across it. Because Lalande 21185 is such a dim star, any worlds orbiting it will be cold and dark, and water could not exist there in a liquid state. Nor can water remain liquid on Jupiter-mass bodies due to temperature and pressure conditions. Thus, all of the supposed planets in these three star systems would only be able to retain water as a vapor in their atmospheres. But water MASER emissions from these distant star systems also could be due to other water sources, such as cometary clouds. Still, knowing that other stars have water in their solar systems gives astronomers hope that Earth-like worlds could be out there. Additional information on this article is available at http://www.astrobio.net/news/article283.html. _____________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.h tml 30 September 2002 Astrobiology, exobiology and terraformation articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s1.html R. L. Crawford, A. Paszczynski, Q. Lang, D. P. Erwin, L. Allenbach, G. Corti, T. J. Anderson, I. F. Cheng, C. Wai, B. Barnes, R. Wells, T. Assefi and M. Mojarradi, 2002. Measurement of microbial activity in soil by colorimetric observation of in situ dye reduction: an approach to detection of extraterrestrial life. BMC Microbiology, 2:22. Reuters, 2002. Microbes could be in Venus' atmosphere. CNN. Terrestrial extreme environments articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s2.html C. E. Blank, S. L. Cady and N. R. Pace, 2002. Microbial composition of near-boiling silica-depositing thermal springs throughout Yellowstone National Park. Applied and Environmental Microbiology, 68(10):5123-5135. Human space exploration and microgravity effects articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s3.html L. David, 2002. NASA reveals new plan for the Moon, Mars & outward. Space.com. Search for extraterrestrial intelligence (SETI) articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s4.html S. Shostak, 2002. Sex, IQ & ET: how we got big brains. Space.com. Evolutionary biology and chemistry articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s5.html S. B. Hedges, H. Chen, S. Kumar, D. Y.-C. Wang, A. S. Thompson and H. Watanabe, 2001. A genomic timescale for the origin of eukaryotes. BMC Evolutionary Biology, 1:4. G. A. Wray, 2001. Dating branches on the Tree of Life using DNA. Genome Biology, 3. K. Wong, 2002. Study hints at how genetic mutations led to macroevolutionary change. Scientific American. Planetary protection articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s6.html This is a new subject page that contains articles concerning planetary protection, including: forward- and back-contamination of Earth and other planets, and asteroid/comet impacts and other planetary catastrophes. _____________________________________________________________________ CASSINI-HUYGENS MISSION STATUS NASA/JPL release 26 September 2002 The Huygens probe, riding aboard the Saturn-bound Cassini spacecraft, stepped flawlessly through a test run last week of the activities it will perform when it descends through the soupy atmosphere of Titan less than 28 months from now. "All the probe subsystems and probe instruments did just what they are supposed to do," said European Space Agency systems engineer Shaun Standley, stationed at NASA's Jet Propulsion Laboratory, Pasadena, CA. For the multinational Cassini-Huygens mission, NASA provided the large Cassini spacecraft, which will begin orbiting Saturn July 1, 2004, and the European Space Agency provided the Huygens probe, which will parachute into the atmosphere of Titan, Saturn's largest moon, on January 14, 2005. Last week's Huygens checkout was the 10th since launch on October 15, 1997. The probe is sleeping for most of the seven-year journey. About every six months, though, engineers wake it up to check its health and exercise the moving parts in its valves and pumps. "As nearly as possible, we put the probe through all the stages of the real descent sequence," Standley said. The sequence lasts about five hours. Since Huygens remains inside a protective shell, the simulation can't include every instrument activity nor, of course, one-time events such as parachute deployment. The checkout does turn on each instrument for the periods they will be used as the probe descends, take data from each, and send the data to Cassini for transmission to Earth. That allows evaluation of the subsystems, such as power, computers and transmitter, as well as each instrument. Results of the checkout have been evaluated by engineers and scientists at the Huygens Probe Operations Center in Darmstadt, Germany, and at the home institutions for each of the probe's instruments in France, United Kingdom, Germany, and the United States. The Huygens atmospheric structure instrument will analyze features such as temperature, pressure and lightning at different layers of Titan's atmosphere. Instruments named the gas chromatograph mass spectrometer and the aerosol collector and pyrolyser will work in tandem to collect, break down and identify particles and gases, including organic chemicals in the atmosphere. The descent imager/spectral radiometer will take pictures and spectra of the atmosphere and surface. The Doppler wind experiment will track how winds carry the probe. And the surface science package will investigate physical properties of Titan's surface. Additional information about the Cassini-Huygens mission is available online at http://saturn.jpl.nasa.gov. The mission is a cooperative effort of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Office of Space Science, Washington, DC. An additional article on this subject is available at http://spaceflightnow.com/news/n0209/28huygens/. _____________________________________________________________________ MARS GLOBAL SURVEYOR STATUS REPORT NASA/JPL release 18 September 2002 Launch / Days since Launch = November 7, 1996 / 2142 days Start of Mapping / Days since Start of Mapping = April 1, 1999 / 1267 days Total Mapping Orbits = 15,779 Total Orbits = 17,462 Recent events The spacecraft is operating nominally in performing the beta- supplement daily recording and transmission of science data. The mm209 sequence executed successfully from 02-255 (9/12/02) through 02-257 (9/14/02). The mm210 sequence has performed well since it started on 02-258 (9/15/02). It terminates on 02-261 (9/18/02). The mm211 sequence, successfully uplinked on 02-260 (9/17/02), begins executing near the end of day on 02-261 (9/18/02). The three Roll Only Targeted Observations (ROTOs) reported as successful last week were in fact not successful. The images taken during those ROTOs and the first two ROTOs in mz200 were distorted because the spacecraft was slewing slowly while the images were being taken. The relative slew rate parameter had been set to orbital rate while the equator-crossing software patch was being loaded on 02-248 (9/05/02). The parameter was not reset to zero following the patch update. The problem was discovered on 02-255 (9/12/02) and corrected on 02-256 (9/13/02). The following four ROTOs in mz200 and six ROTOs in mz201 were performed successfully. MGS has successfully completed 306 ROTOs to date. Spacecraft health Spacecraft subsystems report good health and status. Uplinks There have been 23 uplinks to the spacecraft during the past week, including new star catalog and ephemeris files; instrument command loads; the mi0654 slew-rate parameter update; the mz200, mz201 & mz202 ROTO mini-sequences; and the mm210 & mm211 background sequences. 7,040 command files have been radiated to the spacecraft since launch. Upcoming events ROTOs are planned for next week in the mz201, mz202, & mz203 mini- sequences. Radio Science Occultation Egress Scans will be performed on 02-273 (9/30/02) and 02-274 (10/01/02). A DDOR experiment is scheduled for 02-276 (10/03/03). _____________________________________________________________________ MARS ODYSSEY THEMIS IMAGES NASA/JPL/ASU release 24-26 September 2002 Acidalia Planitia (Released 24 September 2002) http://themis.la.asu.edu/zoom-20020924a.html Bread Loaf' Mesa East of Phlegra Montes (Released 24 September 2002) http://themis.la.asu.edu/zoom-20020924b.html Tithonium Chasma (Released 26 September 2002) http://themis.la.asu.edu/zoom-20020926a.html All of the THEMIS images are archived at http://themis.la.asu.edu/latest.html. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, DC. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey 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. _____________________________________________________________________ STARDUST STATUS REPORT NASA/JPL release 26 September 2002 All of Stardust's subsystems are performing normally. The spacecraft is continuing to collect interstellar particles. There was one period of radio contact through JPL's Deep Space Network this week. Heaters for the Navigation Camera's light-sensing electronics and mirror motor will be turned on for two days to remove a small amount of contamination that has reappeared on the camera. Similar treatments removed past contamination. Performance of the periscope appears to have improved, exhibiting less contamination. 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 36.