MARSBUGS: The Electronic Exobiology Newsletter Volume 3, Number 14, 31 October, 1996. Editors: David Thomas, Department of Biological Sciences, University of Idaho, Moscow, ID, 83844-3051, USA, thoma457@uidaho.edu. 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. ------------------------------------------------------------------------------ 1) LIFE IN THE UNIVERSE WHAT IS THE MESSAGE FROM MARTIAN FOSSILS? 2) THREE MARS MISSIONS TO LAUNCH IN LATE 1996 NASA release 96-207 3) 1996 MARS MISSIONS PRESS KIT AVAILABLE ONLINE 4) LIVE WEATHER REPORTS FROM MARS 5) EXPERTS TO DETAIL FUTURE MOON & MARS EXPLORATION PLANS 6) TELEMEDICINE SERIES UNITES U.S. AND RUSSIAN MEDICAL SCHOOLS NASA release 96-214 7) JUPITER'S LARGEST MOON HAS THIN OXYGEN ATMOSPHERE NASA release 8) SFSU RESEARCHERS DISCOVER NEW PLANET WITH OBLONG ORBIT SFSU Public Affairs Press Release 9) NEW MARS WEB PAGES by Geoffrey A. Landis 10) MARS PATHFINDER STATUS 11) 1996 ANTARCTIC OZONE HOLE BELOW RECORD AVERAGE SIZE NASA release 96-217 ------------------------------------------------------------------------------ LIFE IN THE UNIVERSE WHAT IS THE MESSAGE FROM MARTIAN FOSSILS? The Space Policy Institute of George Washington University's Elliott School of International Affairs, in cooperation with The Planetary Society and the National Space Society, is organizing on November 22, 1996 a major symposium discussing the cultural, intellectual, theological, and policy implications of the recent announcement of evidence of long-ago life on Mars and the public's reactions to those findings. Reacting to the August 7 announcement, President Clinton asked Vice President Gore to convene a "space summit on the future of America's space program." The "Life in the Universe" symposium will provide a way for the public to express its views on the appropriate government response to the Mars findings prior to the White House summit. The all-day symposium will be held at the Dorothy Betts Marvin Theatre located at 800 21st Street, NW on the campus of The George Washington University. Admission is free: however, advance registration is required. Funding for the symposium is being provided by the sponsors and the District of Columbia Space Grant Consortium. REGISTRATION IN ADVANCE IS REQUIRED To register, please provide the following information: 1) Name 2) Organization 3) Phone 4) Fax 5) Email address via: email: marssymp@gwis2.circ.gwu.edu OR fax: (202) 994-1639 OR mail: Space Policy Institute George Washington University 2013 G Street, NW, Suite 201 Washington, DC 20052 For up to date information on the symposium, visit home pages of: Space Policy Institute - http://www.gwu.edu/~spi/ National Space Society - http://www.nss.org The Planetary Society - http://planetary.org/tps/ PRELIMINARY AGENDA 9:00-9:15 Opening Remarks 9:15-9:45 What Did We Find? Briefing by Kathie L. Thomas-Keprta, ALH84001 team 9:45-10:15 How Will We Know the Findings are Valid? From the perspective of a working scientist - John Grotzinger, Department of Earth, Atmosphere and Planetary Sciences, MIT From the perspective of a philosopher of science - Peter Caws, University Professor of Philosophy, GW 10:15-10:30 Break 10:30-11:45 Alien Life in Fiction and Fact Alien life in science fiction - Kim Stanley Robinson, author, Red Mars, Green Mars, and Blue Mars Humanity's long-time fascination with extraterrestrial life - Steven Dick, Naval Observatory, author, The Biological Universe 11:45-12:15 Critical Factors in New Space Endeavors Bruce Murray, Vice-President, The Planetary Society 12:15-1:30 Lunch Break 1:15-2:30 Putting the Findings in Broad Perspective Panel composed of: Father John Minogue, President, DePaul University Abdel-Monem Al-Mashat, Cultural & Education Attache, Embassy of Egypt John Noble Wilford, The New York Times (Invited) Molly McCauley, economist, Resources for the Future Richard Berendzen, astrophysicist, American University 2:30-3:00 International Interest and Response Roald Sagdeev, University of Maryland, former Director, Space Research Institute, Moscow 3:00-3:15 Break 3:15-4:30 What Response? Public Interest Perspectives Robert Zubrin, Chair, Executive Committee, National Space Society Louis Friedman, Executive Director, The Planetary Society Results of an Internet Survey - Space Policy Institute Other views 4:30-5:00 Next Steps: Reflecting the Public Interest NASA Administrator Dan Goldin ------------------------------------------------------------------------------ THREE MARS MISSIONS TO LAUNCH IN LATE 1996 NASA release 96-207 The United States and Russia return to Mars this fall with the launch of three missions destined to explore Earth's planetary neighbor in greater detail than has ever before been accomplished. NASA's Mars Global Surveyor and Mars Pathfinder and Russia's Mars '96 mission are scheduled for three separate launches in November and December 1996. Mars Global Surveyor, an orbiter carrying six scientific instruments to study the atmosphere, surface and interior of Mars, will be launched Nov. 6. It will be followed by Russia's Mars '96, an orbiter carrying 12 instruments plus two small landers and two penetrators, which will lift off Nov. 16. Mars Pathfinder will carry a lander and small rover robot when it is lofted into space Dec. 2. Launch of the NASA spacecraft marks the beginning of a new era in Mars exploration and an ambitious new initiative by the United States to send pairs of spacecraft to the red planet every 26 months through the year 2005. NASA's new decade-long program of robotic exploration--known as the Mars Surveyor program--takes the next step in expanding scientists' knowledge of Mars. The program is focused on three major areas of investigation: the search for evidence of past life on Mars; understanding the Martian climate and its lessons for the past and future of Earth's climate; and understanding the geology and resources that could be used to support future human missions to Mars. The unifying theme of the Mars exploration program is the search for water, which is a key requirement for life, a driver of climate and a vital resource. Early missions will thus focus partially on finding and understanding the past and present state of water on Mars. Mars Global Surveyor and Mars Pathfinder will be the forerunners in this quest, becoming the precursors to a series of missions that may culminate in the first few years of the next century with robotic return of a Martian soil sample to Earth, followed by eventual human exploration. Continuing Exploration Program NASA's 1996 missions to Mars further the global explorations of the planet begun in 1965 with the Mariner 4 mission to Mars and continued in the mid-'70s by the Viking lander missions. From earlier investigations, scientists have compiled a portrait of Mars full of stark contrasts. Mars' surface features range from ancient, cratered terrain like Earth's Moon to immense volcanoes that would dwarf Mt. Everest and a canyon that would stretch across the United States. Mars' atmosphere is less than 1 percent as thick as Earth's, but there are permanent polar caps with reservoirs of water ice. Closeup shots of Mars' terrain resemble that of an Earthly desert, with surface features that look like river channels carved long ago by flowing water. The next step in Mars exploration, according to scientists, is to obtain an overview of the entire planet and to verify remote observations with measurements taken from the ground. Mars Global Surveyor is designed to study the atmosphere, surface and interior systematically over a full Martian year. The Russian Mars '96 orbiter has similar objectives, but will also characterize the uppermost atmosphere and its interactions with the solar wind. To obtain "ground truth"--observations on the surface verifying those made from space--the Russian Mars '96 spacecraft will deploy two landers that will touch down in the northern hemisphere in a region called Amazonis Planitia and two penetrators that will impact and lodge themselves anywhere from 3 to 20 feet (1 to 6 meters) underground. These probes will furnish details of the atmosphere and surface at the specific locations in which they land. NASA is contributing two experiments to Mars '96: the Mars Oxidation Experiment, which will measure the oxidation rate of the Martian environment, and the Tissue-Equivalent Proportional Counter, which will study the radiation environment in interplanetary space and near Mars. Mars Pathfinder will deploy a mobile rover that will characterize rocks and soil in a landing area over hundreds of square meters (yards) on Mars. Pathfinder's instruments and mobile rover are designed to provide an in-depth portrait of Martian rocks and surface materials over a relatively large landing area, thereby giving scientists an immediate look at the crustal materials that make up the red planet. Pathfinder Arrival in July 1997 Although the last to leave Earth, Mars Pathfinder takes a shorter flight path and will be the first of the three spacecraft to arrive at Mars, touching down in Ares Vallis on July 4, 1997. Pathfinder is designed to demonstrate an innovative approach to landing a spacecraft and rover on the surface of Mars. Pathfinder will dive through the upper atmosphere of Mars on a parachute, then inflate a huge cocoon of airbags to cushion its impact. The spacecraft will collect engineering and atmospheric science data along its descent to the ground. The primary objective of the mission is to test this low-cost method of delivering a spacecraft, science payload and free-ranging rover to the surface of the red planet. Landers and rovers of the future will share the heritage of spacecraft designs and technologies that evolve from this pathfinding mission. Once on the surface, the lander's first task will be to transmit engineering and science data collected during descent through the thin atmosphere of Mars. Then its camera will take a panoramic image of its surroundings and begin transmitting the data directly to Earth at a few thousand bits per second. Much of Pathfinder's mission after this will be focused on collecting atmospheric and surface composition data, and supporting the rover by storing and transmitting images captured by its cameras. Pathfinder's nominal mission lifetime is approximately 30 "sols," or Martian days (about the same number of Earth days). Pathfinder's rover, Sojourner, will be carried to Mars in a stowed configuration with its chassis and wheels folded up like an accordion. Once its solar cells are exposed to the Sun, the rover will power up and stand to its full height before leaving the lander. Driving off onto the floor of an ancient flood plain believed to contain a wide variety of rocks, Sojourner will explore the surface independently, relying on the lander primarily for communications with Earth. Mars Global Surveyor and Mars '96 Two months later, NASA's Mars Global Surveyor and Russia's Mars '96 orbiter will arrive at Mars on September 11 and 12, 1997, respectively. At first, Mars Global Surveyor will be in a highly elliptical orbit and spend four months dipping lower and lower into Mars' upper atmosphere using a technique called aerobraking to bring it into a low-altitude, nearly circular mapping orbit over the poles. By March 1998, Surveyor will be ready to begin data collection, compiling a systematic database as it surveys the Martian landscape and photographs unique features, such as the polar caps and Mars' network of sinuous, intertwining river channels. Mars '96 carries a dozen instruments and a dozen smaller devices designed to study the evolution of the Martian atmosphere, surface and interior. In addition to meteorological and seismic instruments, the spacecraft carries instruments to image the Martian surface, explore the chemistry and water content of rocks and attempt to detect and measure the Martian magnetic field. The Jet Propulsion Laboratory manages the Mars Pathfinder and Mars Global Surveyor missions for NASA's Office of Space Science, Washington, DC. Lockheed Martin Astronautics Inc., Denver, CO, is NASA's industrial partner for development and operation of the Mars Global Surveyor spacecraft. Russia's Mars '96 is managed by the Russian Space Agency. The Russian Academy of Sciences, Moscow, Russia, is responsible for the Mars '96 science payload. ------------------------------------------------------------------------------ 1996 MARS MISSIONS PRESS KIT AVAILABLE ONLINE NASA's 1996 Mars Missions Press Kit, highlighting the United States' and Russia's return to Mars this fall, is available online to Internet users. The press kit details the scientific goals of the two U.S. missions--the Mars Global Surveyor orbiter and Mars Pathfinder lander and rover--to be launched to the red planet in November and December, as well as Russia's Mars '96 orbiter, to be launched in mid-November. The press kit includes line-drawings of the three spacecraft, spacecraft flight trajectories to Mars, a map of Mars pinpointing the landing sites, including those of the 1976 Viking landers, and a line-drawing of the entry, descent and landing sequence of the Pathfinder spacecraft. Internet users may access the press kit on the World Wide Web at the following URL: http://www.jpl.nasa.gov/files/misc/m96pkt.pdf (Please note the file is a 1.6 megabyte Adobe Acrobat pdf file.) Further information on NASA's plans for robotic exploration of Mars, including live shots of both the Mars Global Surveyor and Mars Pathfinder spacecraft in their respective clean rooms at NASA's Kennedy Space Center, FL, can be accessed on the Internet at: http://www.jpl.nasa.gov/mars/ Mars Global Surveyor is set for launch on November 6, followed by Mars Pathfinder on December 2, both on Delta II launch vehicles. If the launch is on time, Mars Pathfinder will land in the Ares Vallis region of Mars on July 4, 1997. Assuming Mars Global Surveyor launches on time, the spacecraft will arrive at Mars in September 1997 and, after several months of aerobraking in the upper atmosphere of Mars, will begin its primary mapping mission in March 1998. Russia's Mars '96 orbiter will be launched on a Russian Proton launch vehicle on November 16 from Baikonur Cosmodrome in Kazakstan. An on-time launch will put the spacecraft in orbit around Mars in mid-September 1997. ------------------------------------------------------------------------------ LIVE WEATHER REPORTS FROM MARS CAPE CANAVERAL, Florida (AP) Come next summer, it will be all Mars, all the time. NASA plans to issue Mars news and weather updates on the Internet and take World Wide Web browsers along for rides in a Mars rover once the Pathfinder spacecraft arrives at the Red Planet. The probe is to be launched December 2 and land July 4, 1997. "Every day on the Internet, we're going to post the weather report on Mars--a little different than Earth--and there will be a virtual presence on Mars, so everybody in America and for that matter around the world can participate," NASA Administrator Daniel Goldin said Wednesday. Web users will be able to see what the Mars rover sees as it ambles along the surface and scrutinizes rocks. Expect a 20- to 40-minute lag, though, for the time it takes the signals to reach Earth. Mars Pathfinder will be the first spacecraft to land on Mars since NASA's twin Viking landers in 1976. Back then, there was no way to share such wonders with so many people. Even with the more recent planetary probes, there's never been anything like this. "I would definitely term this the first planetary mission in the full-blown Internet era," said NASA spokesman Douglas Isbell. "It's vicarious exploration." Cold and colder If all goes well, the rover, named Sojourner, will study Martian rocks and soil for at least a week, possibly months, with scientists and Internet browsers following along. As for the Martian weather forecast, make it cold and colder. At its equator, Mars is a brisk minus-70 degrees Fahrenheit and gets colder the closer one gets to the poles. "I would hope that every newspaper would show the weather in Timbuktu -- and why not on Mars, too?" asked Matthew Golombek, project scientist for the Mars Pathfinder. "It's a little chilly, but a nice place to be." In addition to Pathfinder, NASA plans to launch a Mars orbiter called the Mars Global Surveyor on November 6. It will take 10 months for the spacecraft to reach its destination. Once there, it will map the planet from a circular orbit for two years. The color images will be posted on the Internet within a day or two. Neither of the Mars probes will carry messages from Earthlings like Pioneers 10 and 11 and Voyagers 1 and 2, all launched in the 1970s. NASA is gathering signatures, however, to put on one or two CD-ROMs that will be attached to the Cassini probe, to be launched next year to Saturn. So far, some 500,000 signatures have been collected, Isbell said. Stay tuned for Saturn weather reports. ------------------------------------------------------------------------------ EXPERTS TO DETAIL FUTURE MOON & MARS EXPLORATION PLANS Will a 21st century Moon become a site for business, tourism, as well as scientific study? What plans are now being drawn to explore the planet Mars for martian life, but also transform the Red Planet into a second home for humanity? International Space Enterprises (ISE) and the National Space Society (NSS) announce the Third Annual International Lunar and Mars Exploration Conference, to be held in San Diego, California on November 17-20. Focused on lunar exploration the previous two years, this year's conference will feature a special session on the possibility of life on Mars. Aerospace entrepreneurs will present innovative plans for corporate sponsorship of low cost Moon and Mars missions, commercial space tourism, and beaming solar energy to Earth from space. Details on the 1997 launch of the Lunar Prospector robotic craft to the Moon and the X-33 reusable launch vehicle, a stepping stone to affordable access to Earth orbit will also be presented. Experts from industry, entrepreneurial firms, universities and NASA will review the promise of a rejuvenated space agenda for the 21st century in up- to-the-minute talks and discussion. A special feature of this year's event will be a half day session entitled Life on Mars: Past, Present and Future, offering several lectures and dramatic presentations addressing NASA's recent discovery of indications of possible life on Mars. The session will be led by Dr. Robert Zubrin, Chairman of the NSS Executive Committee and noted advocate of human voyages to the Red Planet. Dr. Zubrin will speak on the need to send humans to Mars and will sign copies of his just-released book, The Case for Mars - The Plan to Settle The Red Planet and Why We Must. The conference, to be held at the beautiful Hyatt Islandia Hotel on San Diego's Mission Bay, will convene many of the world's leading lunar and planetary scientists and engineers. In a unique public demonstration, ISE will invite conference participants to view and operate the robotic Mars Seeker, a new prototype of a rover ISE hopes to deliver to Mars on a commercially financed, international voyage. The Mars Seeker prototype will be the centerpiece of a permanent interactive exhibit at NASA's Kennedy Space Center beginning in December. For registration details about the conference, or other information, please contact: Greg Nemitz of ISE [phone: (619) 637-5773, fax: (619) 637-5776]; via e-mail: isehq@aol.com] or call the National Space Society at (202) 543- 1900. ------------------------------------------------------------------------------ TELEMEDICINE SERIES UNITES U.S. AND RUSSIAN MEDICAL SCHOOLS NASA release 96-214 The first in a series of NASA-sponsored telemedicine education conferences began today at 9 a.m. EDT, with a linkup between Baylor College of Medicine in Houston and Moscow State University. Dr. Arnauld Nicogossian, Associate Administrator for Life and Microgravity Sciences and Applications at NASA Headquarters, said, "It is NASA's hope that this telemedicine program will provide a valuable and ongoing series of international medical education presentations between Russian and American medical schools. This is an important activity. It brings our two communities together and will help us promote joint research in space biology and medicine, both on the ground and in orbit aboard the International Space Station." NASA began its telemedicine experience with the former Soviet Union in 1989 when it created the Spacebridge to Armenia and Ufa. NASA used its telecommunications and telemedicine capabilities to help provide humanitarian assistance to the victims of the Armenian earthquake and the Ufa natural gas explosion. Nicogossian said, "In the years following Spacebridge, we came to recognize the value of the Internet for its global communications capabilities while maintaining and working with the telemedicine infrastructure we had created. One of the greatest potential dividends of the telemedicine program is the great strides we expect to see in medical education both in the United States and abroad." The topic of today's program, "Recent Advancements in the Management of Heart Disease," included presentations on aneurysm surgery, coronary angioplasty, new cholesterol reducing drugs, cryopreservation of organs and molecular genetics of cardiovascular disease. ------------------------------------------------------------------------------ JUPITER'S LARGEST MOON HAS THIN OXYGEN ATMOSPHERE NASA release Astronomers using the Hubble Space Telescope have found evidence for a thin oxygen atmosphere on Jupiter's moon Ganymede, the largest of the Jovian satellites. The same team of scientists had previously found a tenuous veil of oxygen around another Jupiter moon, Europa. The observations also suggest that Ganymede, like Earth and Jupiter itself, has polar aurorae--light displays created when charged particles collide with atmospheric gases. The findings will be presented as a poster paper on display throughout a meeting of the American Astronomical Society's Division of Planetary Sciences, from Oct. 23 to Oct. 26 at the Tucson Convention Center in Tucson, Ariz. A team of astronomers used the Hubble telescope's Goddard High Resolution Spectrograph on June 21 to make ultraviolet observations of Ganymede. The astronomers were excited when they saw the spectrum had the characteristic fingerprint that indicates the presence of oxygen gas. But they were puzzled because the spectrograph had detected two peaks, where the astronomers were expecting to see at most a single spike. They soon realized, however, that the two spikes could be explained by the existence of light emitted from two regions near Ganymede's north and south poles. "The bright spikes correspond nicely to the poles of Ganymede," said Doyle Hall, the Johns Hopkins University astronomer who led the team making the oxygen discovery. Hall called the data "very tentative evidence for the existence of polar aurorae." Ganymede and Europa are both at least partially covered with water ice. The scientists believe that the atmospheric oxygen comes from the icy surfaces, where oxygen atoms are split off from water molecules that are bombarded by charged particles; exposure to sunlight and meteor impacts also could create some of the gas, Hall said. The atmosphere on Ganymede is likely to be as thin as the gas previously detected on Europa, comparable in pressure to Earth's atmosphere at an altitude of several hundred kilometers, roughly as high as the space shuttle orbits. "I want to emphasize that all of the results that we have seen related to oxygen do not require nor imply the presence of life," Hall said. This is in contrast to the oxygen in Earth's atmosphere, which is generated by biological activity. "In fact, the surfaces of these moons, as far as we can tell, are completely inhospitable to any life form that we can imagine." The other members of the research team were Paul Feldman, a professor in the Johns Hopkins Department of Physics and Astronomy; Darrell Strobel, a professor in the Department of Earth and Planetary Sciences; and astronomer Melissa McGrath from the Space Telescope Science Institute in Baltimore -- the same scientists who used the Hubble telescope to detect an oxygen atmosphere on Europa about two years ago. Polar aurorae are created when charged particles are guided by a planet's magnetic field toward its poles. As the charged particles collide with atmospheric gases they create brilliant and colorful emissions, which on Earth are known as the Northern and Southern lights. Earth, Jupiter, Saturn, Uranus and Neptune are known to have polar aurorae. If confirmed, the Ganymede findings "would be the first detection of polar aurorae on any planetary satellite," Hall said. The astronomers observed ultraviolet light from Ganymede because in the visible spectrum the faint oxygen emissions would have been overwhelmed by bright sunlight reflecting off the moon's surface. Scientists believe there are three prerequisites for the existence of polar aurorae on a planet or satellite: an atmosphere, a magnetic field, and a population of charged particles. At nearly the same time that the astronomers were using the Hubble telescope to detect the atmospheric oxygen, scientists operating NASA's Galileo spacecraft discovered both a magnetic field and charged particles around Ganymede. The research is being funded by a two-year grant from the Space Telescope Science Institute totaling $76,000. ------------------------------------------------------------------------------ SFSU RESEARCHERS DISCOVER NEW PLANET WITH OBLONG ORBIT SFSU Public Affairs Press Release "Eccentric" orbit shatters long-held theory of circular orbits A remarkable new planet around a Solar-like star (16 Cygni B) has been discovered by Drs. Geoff Marcy and Paul Butler of SFSU, and Drs. Bill Cochran and Artie Hatzes of the University of Texas--two teams working independently. This planet orbits its star with the most extreme "eccentricity" (i.e., oblong shape) ever found for any planet, e = 0.6, on a scale of 0 to 1. All of the planets in our Solar System reside in nearly circular orbits, having eccentricities less than 0.2. This new planet dismantles the long-held theory that other planets in the universe would all have nearly circular orbits. The discovery was made by measurements of the Doppler shift of the light from the Solar-type Star, 16 Cyg B, (spectral type = G2.5) which is 85 light years from Earth. The star exhibits a periodic Doppler variation, with a period of 804 days (= 2.2 years). The star changes its velocity by ±46.5 meters/sec every 2.2 years, in a pattern that is NOT a perfect sine wave. This wobble implies that a planet orbits the star with an orbital period of 2.2 years and has a mass of at least 1.5 Jupiter masses. The actual mass of the planet may be slightly greater than 1.5 Jupiter masses, the uncertainty being due to the unknown tilt of the orbit plane which enters into the orbital physics (as the trigonometric sine of inclination). Of extreme importance is the unprecedented eccentricity of the orbit, unlike that for any other planet. Its orbit carries the planet from a closest distance of 0.6 Earth-Sun distances to 2.7 Earth-Sun distances at its farthest from its host star, 16 Cyg B. The planet would experience extreme variations in the heat energy it receives from its star, as it varies from Venus-like distances to Mars-like distances. The oblong shape of the orbit is easily determined from the graph of Doppler- shift versus time. This graph is not a sine wave, which occurs for circular orbits. The departure from a sine wave is due to the speeding-up of the planet as it rounds the star at closest approach, much as the sound of a car engine changes pitch (also by the Doppler effect) as it rounds a sharp curve. This planet adds to the mystery of a previously discovered planet around the star, 70 Virginis (discovered by the SFSU Marcy and Butler team). Its planet also has a large eccentricity of 0.4, the previous record holder. But that non-circular orbit was so discordant with the expected circular orbits from theory, that some theorists hoped it could be dismissed as a failed star (i.e., a "brown dwarf"), thereby ignoring the problem of how a planet (or any object) might become so eccentric. Now, new theories must be found to explain these two eccentric planets. Proposed theories involve collisions of two planets that scatter them into wacky orbits (Doug Lin, UC Santa Cruz and Fred Rasio MIT) , or gravitational perturbations from the disk of gas and dust out of which the planets formed (Pat Cassen of NASA Ames Research Center, and Pawel rtymovicz of Stockholm Observatory). This new planet was discovered completely independently by two teams: Drs. Bill Cochran and Artie Hatzes from the University of Texas and Drs. Paul Butler and Geoff Marcy of San Francisco State University and U.C. Berkeley. Each team has an ongoing, extremely sensitive technique for measuring the Doppler shifts of stars, designed explicitly to detect the perturbations imposed on the stars due to the gravitational force exerted on it by orbiting planets. This planet represents the sixth planet discovered by the team of Butler and Marcy, and brings the total of known planets outside our Solar System to eight. Technical solution Formally, this is the solution for 16 Cyg B from the COMBINED measurements of both teams. The San Francisco State team provides Doppler measurements that have better precision (8 m/s compared with 27 m/s). But both teams detect virtually the same orbit. Orbital elements P= 804.4 days s.e. = 12.4 T (JD)= 48941.508 J.D. s.e. = 10.523 K = 46.592 m/sec s.e. = 8.219 e = 0.666 s.e. = 0.091 w (omega) = 86.807 degrees s.e. = 12.908 Physical elements a*sin(i) = 3.84328E+08 meters s.e. = 6.21915E+07 f(m) = 3.49068E-09 solar masses s.e. = 1.69798E-09 One deduces that 16 Cyg B is about 1.0 solar mass, as it's spectrum (G2.5 V) is nearly the same as the Sun's (including age and metalicity). Indeed, it is often deemed a "Solar Twin" This gives a companion mass of : M_comp = 1.52/sin i Jupiter masses. The semimajor axis of the planet about the star is: a = 1.7 AU (1.7 earth-sun distances) coming directly from Kepler's 3rd Law. ------------------------------------------------------------------------------ NEW MARS WEB PAGES by Geoffrey A. Landis For anybody interested, I have just posted two new web pages about Mars. http://powerweb.lerc.nasa.gov/pv/SolarMars.html discusses Lewis work on solar energy on Mars http://powerweb.lerc.nasa.gov/pv/lightning.html is a look at the question "Is there lightning on Mars?" ------------------------------------------------------------------------------ MARS PATHFINDER STATUS For week of October 17, 1996 From the Mars Pathfinder home page: http://mpfwww.jpl.nasa.gov/ Mars Pathfinder launch date is December 2, 1996. Spacecraft Status at KSC: As you can see from the live KSC image, quite a lot has been accomplished over the last two weeks. The petals have been closed for the final time, the lander bolted (using separation nuts) to the "backshell interface plate" inside the backshell. Most recently, the heatshield has been bolted to the aeroshell. These accomplishments come as a great relief to the entire team. As we and other spacecraft builders have discovered, the flight hardware is often more in danger of being damaged inadvertently by human hands than from anything the rigors of outer space could dish out! For example we had to repair a broken wind sensor in the MET mast after a ground wrist strap brushed past it, damaging a very tiny element. During the mission, nothing will come near this sensor. Fortunately, it was fixed without much trouble. Now that the bulk of the system is neatly packaged inside the backshell, at least we can breathe a partial sigh of relief. The next step in this delicate process will be to turn the entry vehicle upside down and spin balance it at 70 rpm using a spin table in the facility. This process will remove any wobble from the mass properties. (For the technically inclined, this process aligns the principle axis of inertia with the axis of symmetry.) Once done later this week, we will flip the vehicle over again (a tricky process all by itself) and then mount the cruise stage. We will then do yet another spin balance in the launch configuration. When we started this assembly sequence at KSC two months ago we had about 14 days of schedule "pad" in case anything slowed us down. Well of course, things did slow us down and we now have about 5 days of schedule margin left until we place the spacecraft on top of the upper stage in November. However that isn't bad considering the complexity of this operation. And we had expected to use the margin up. We are all very happy with the progress so far. Mission Operations Status at JPL: For the past two weeks those of us on the team working at JPL have been focused on operations. We have a "testbed" at in Pasadena that has a complete duplicate set of all of the flight electronics that are on the spacecraft (including a "sim" rover when needed). In addition to testing flight software on this testbed, we also use it in an operational mode: essentially "flying" the testbed in a simulated mission to Mars! Early last week we "launched" the testbed using the same people, procedures and software that we will use on launch day. We even used the launch team at the Cape who have been doing the electronics integration testing. Afterward we performed the instrument and rover health checks that we will perform in the weeks after launch. This week, we performed two TCMs (trajectory correction maneuvers--or "burns"). Later this week and this weekend we will "land" the testbed: actually running the "EDL" (entry descent and landing) flight software in the "testbed spacecraft." Saturday we will simulate the first day on Mars. We are currently in the process of building up a "Mars Room" adjacent to the testbed near our operations area. This room is filled with sand and rocks and will eventually be the home of a test lander and the sim rover. Although most of the electronics will reside in the testbed a few feet away (so we can more easily access it), the lander's sensors and actuators will reside on the lander in the room. This lander will include the petals, camera, high gain antenna, airbags and rover communication antenna. The rover ramps will also be installed. In the coming months, we will use this room to simulate the first days and weeks on Mars. These simulations help us learn the finer points of operating this complex little lander and rover. ------------------------------------------------------------------------------ 1996 ANTARCTIC OZONE HOLE BELOW RECORD AVERAGE SIZE NASA release 96-217 Two NASA instruments again have detected substantial depletion of ozone levels over Antarctica, commonly referred to as the Antarctic ozone hole. The average size of the Antarctic ozone hole during 1996 has been almost as large as in the peak year of 1993, although ozone values are higher than the record lows seen in September 1994, according to preliminary analysis of satellite data by scientists at NASA's Goddard Space Flight Center in Greenbelt, MD. During the current year, the ozone hole covered a surface area over the South Pole roughly equal in size to the North American continent. These data were recorded by two of NASA's Total Ozone Mapping Spectrometer instruments (TOMS) launched this year, one on board the NASA Earth Probe satellite and another on the Japanese Advanced Earth-Observing Satellite (ADEOS) satellite. Low ozone amounts over the Antarctic continent consistent with these TOMS data also have been validated by ground-based instruments and other satellite-based instruments. The average size of the ozone hole during this year was 8.3 million square miles, similar to observations in the last four years. The largest observed average size of the ozone hole was in 1993, at 8.5 million square miles. The hole started to form in mid-August of this year and reached a one-day peak size on Sept. 7, 1996, of about 10 million square miles, then quickly shrunk to values of less than 8.5 million square miles. The previous largest one-day peak size hole was 9.4 million square-miles on Sept. 27, 1992. In comparison, the surface area of North America is 8.1 million square-miles while Antarctica has a surface area of 5.4 million square-miles. Since the mid-1980s, the region covered by low total ozone begins to grow each year in early August. This region reaches its maximum extent in September, while the lowest ozone values are typically seen in late September and early October. The ozone hole usually disappears by early December. The ozone hole in 1996 opened up slightly earlier than in previous years, but had begun to decrease in surface area below 7.7 million square-miles by Oct. 16, 1996. "This ozone hole is very similar to those seen in recent years," said Dr. Paul Newman, research scientist in the Laboratory for Atmospheres at Goddard. "Although its area climbed briefly over that of the previous peak, that is not as great a concern as the average size, because meteorological conditions can cause large day-to-day fluctuations. This is similar to winter temperatures, where one really cold day is not as important as the average temperature over the whole winter season." The ozone amounts measured by TOMS/ADEOS and TOMS/Earth Probe dropped to 111 Dobson units on Oct. 5 near the center of the Antarctic continent, with values below 220 Dobson units measured over a wide area. Total ozone values less than 100 Dobson units were measured in both 1993 and 1994, with the record low value of 88 Dobson units measured on Sept. 28, 1994. Ozone, a molecule made up of three atoms of oxygen, comprises a thin layer of the atmosphere which absorbs harmful ultraviolet radiation from the Sun. A Dobson unit is related to the physical thickness of the ozone layer if it were brought to the Earth's surface. The global average ozone layer thickness is 300 Dobson units, which equals 1/8th of an inch, approximately the thickness of two stacked pennies. In contrast, the ozone layer thickness in the ozone hole is about 100 Dobson units (1/25th of an inch), approximately the thickness of a single dime. Scientists at the South Pole from the National Oceanic and Atmospheric Administration (NOAA), working with balloon-borne measurements, have found low total ozone values similar to those seen in 1995. "However, in the central region of the ozone hole, from 7.5 to 12.5 miles altitude, ozone depletion was more severe than in the past," said Dr. Dave Hofmann of the NOAA Climate Monitoring and Diagnostics Lab in Boulder, CO. The NOAA measurements showed that complete destruction of ozone at an altitude of 10 miles was observed over the period from Sept. 24 to Oct. 14. "Total ozone did not reach record lows because of unusually high ozone above the ozone hole at 15 miles which compensated for the low values in the ozone hole," Hofmann said. "These deep and large ozone holes are likely to continue to form annually until the stratospheric chlorine amount drops to its pre-ozone hole values," said Dr. Richard Stolarski, also a research scientist at Goddard. "The slightly earlier ozone hole this year probably resulted from the continued increase of Antarctic stratospheric total chlorine levels." Since the discovery of the ozone hole in 1985, TOMS has been a key instrument for monitoring ozone levels throughout the southern hemisphere. The first TOMS aboard NASA's Nimbus-7 satellite measured Antarctic ozone levels from November 1978 to May 1993, and it helped make ozone a household word through pictures of the Antarctic ozone hole. It was followed by a TOMS sensor on a Russian satellite. TOMS data also provided part of the scientific underpinning for the Montreal Protocol, under which many of the world's nations have agreed to phase out the use of ozone-depleting chemicals. As a result of restrictions in the Montreal Protocol, chlorine levels have already peaked in the lower atmosphere, and should peak in the Antarctic stratosphere in about three to five years. The size and depth of the ozone hole, and global ozone levels, depend on meteorological conditions and on the amount of chlorine present in the atmosphere, and may be affected by the presence of sulfate aerosols produced by volcanic eruptions. Scientists speculate that ozone values over Antarctica were low in 1993 and 1994 because of the enhanced presence of sulfuric acid aerosols in the stratosphere due to the June 1991 Mount Pinatubo eruption in the Philippines. TOMS-Earth Probe, launched in July of this year, is the third in the series of TOMS instruments. Operating from a 312-mile orbit, TOMS-Earth Probe is principally dedicated to collecting ozone and aerosol data in the lower atmosphere. The fourth TOMS instrument was launched in August aboard ADEOS into a 500-mile orbit. ADEOS is an international climate change research mission that includes instruments from the U.S., Japan, and France, with investigators from many countries around the world. Both TOMS-EP and ADEOS are key parts of a global environmental effort which includes NASA's Mission to Planet Earth, a long term, coordinated research effort to study the Earth as a global environmental system. TOMS ozone data and pictures are available to anyone with a computer connection to the Internet World Wide Web at: http://jwocky.gsfc.nasa.gov The TOMS instruments are managed by the Goddard Space Flight Center for NASA's Office of Mission to Planet Earth, Washington, DC. ------------------------------------------------------------------------------ End Marsbugs Vol. 3, No. 14.