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Дата: 09 апреля 1998 (1998-04-09) От: Alexander Bondugin Тема: Space Station Media Workshop Scheduled For May 12-14 At JSC Привет всем! Вот, свалилось из Internet... Michael Braukus Headquarters, Washington, DC April 8, 1998 (Phone: 202/358-1979) James Hartsfield Johnson Space Center, Houston, TX (Phone: 281/483-5111) NOTE TO EDITORS: N98-26 SPACE STATION MEDIA WORKSHOP SCHEDULED FOR MAY 12-14 AT JSC Members of the news media are invited to attend press briefings and hands-on demonstrations at training and simulation facilities May 12-14 at NASA's Johnson Space Center, Houston, TX. The activities will provide information about the International Space Station and its five-year assembly in orbit that will begin with launches this year. The workshop will follow a day of standard preflight media briefings -- on the last Shuttle-Mir docking mission, STS-91 -- that are currently planned for May 11 at Johnson. On May 12, a series of briefings will describe the International Space Station, its current status and its assembly in orbit. On May 13 and 14, media representatives can visit a variety of facilities at Johnson for demonstrations and activities that will provide familiarity with the station and assembly operations. Media planning to attend the workshop must fax a written request for press accreditation to the Johnson Space Center newsroom at (281) 483-2000 before April 30. Because of limited capacity in some facilities, attendance at the demonstrations may be limited to one reporter and/or camera crew per news media organization. The briefings will be carried live on NASA Television, available on GE-2, transponder 9C at 85 degrees West longitude, with vertical polarization. Frequency is on 3880.0 megahertz, with audio on 6.8 megahertz. Planned briefings for May 12 include: (all times EDT) 9 a.m. International Space Station: Overview and Status 10:30 a.m. International Space Station: Research and Exploration 1 p.m. International Space Station: Assembly in Orbit 2:30 p.m. Flight Control of the International Space Station News media at Johnson also will receive details and logistical information concerning coverage of the launch of the first International Space Station component, the Control Module or Functional Cargo Block (FGB), from Russia later this year. Media demonstrations on May 13-14 will include an opportunity for hands-on activities and briefings by experts in station engineering, training and operations. Several sessions of each demonstration will be held each day, and media will be able to attend in small groups to allow individual attention and participation. The planned demonstrations include: * Space Station Training Facility -- viewing and demonstrations in the U.S. Segment and Russian Segment International Space Station trainers under development at Johnson, including a new Soyuz emergency egress trainer. * Neutral Buoyancy Laboratory -- Adjacent to Johnson's new 6.4- million gallon spacewalk training pool, high-fidelity mockups of the first two components, the Control Module and the Node 1 connecting module, will be displayed, along with demonstrations of spacewalking tools, suits and equipment developed and flight-tested by NASA in preparation for station assembly. * Shuttle Cockpit Rendezvous Simulators -- Demonstrations of the rendezvous and capture activities that will be required to join the Control Module and Node 1 during Shuttle mission STS- 88 will be viewed in a domed Space Shuttle aft cockpit simulator, as well as on a desktop rendezvous simulation. * Virtual Reality Training and Station Mockups -- Demonstrations of Johnson's Virtual Reality Laboratory used by astronauts to train for upcoming assembly spacewalks will be performed. Media also will have an opportunity to tour nearby trainers for the Shuttle and station robotic arms; the International Space Station full-scale mockups and trainers; and the X-38 crew return vehicle development facility. In addition, throughout the three-day workshop, Johnson personnel with expertise on all aspects of the International Space Station program and assembly operations will accommodate as many individual interview requests as possible. Facilities with International Space Station mockups and backgrounds will be available for such interviews. - end - Hа сегодня все, пока! =SANA=

Дата: 09 апреля 1998 (1998-04-09) От: Alexander Bondugin Тема: Increasing Greenhouse Gases May Be Worsening Arctic Ozone Depletion Привет всем! Вот, свалилось из Internet... David E. Steitz Headquarters, Washington, DC April 8, 1998 (Phone: 202/358-1730) Lynn Chandler Goddard Space Flight Center, Greenbelt, MD (Phone: 301/286-9016) RELEASE: 98-58 INCREASING GREENHOUSE GASES MAY BE WORSENING ARCTIC OZONE DEPLETION AND MAY DELAY OZONE RECOVERY In late 1997, larger levels of ozone depletion were observed over the Arctic than in any previous year on record. Now, using climate models, a team of scientists reports why this may be related to greenhouse gases, according to a paper published in the April 9 issue of Nature. The study suggests the increase in greenhouse gas emissions is one possible cause of the observed trends in Arctic ozone losses and that this may delay recovery of the ozone layer. The research team, consisting of researchers from NASA's Goddard Institute for Space Studies (GISS) and Columbia University, New York, investigated the response of ozone to projected future emissions of greenhouse gases and ozone- depleting halogens over time, using the GISS climate model. This is the first time ever that the interaction between ozone chemistry and the gradual buildup of greenhouse gases has been studied in a climate model. "Buildup of greenhouse gases leads to global warming at the Earth's surface, but cools the stratosphere. Since ozone chemistry is very sensitive to temperature, this cooling results in more ozone depletion in the polar regions," said Dr. Drew Shindell of Columbia University, the lead author of the study. NASA will continue research in this area to determine if these models are accurate. The "greenhouse effect" is defined as the warming of climate that results when the atmosphere traps heat radiating from Earth toward space. Certain gases in the atmosphere -- such as water vapor, carbon dioxide, nitrous oxides and chlorofluorocarbons -- act like glass in a greenhouse, allowing sunlight to pass into the "greenhouse," but blocking Earth's heat from escaping into space. Ozone, a molecule made up of three atoms of oxygen, comprises a thin layer of the upper atmosphere which absorbs harmful ultraviolet radiation from the Sun and protects people, animals and plants from too much ultraviolet sunlight. Distribution and concentration of stratospheric ozone are influenced in two ways by human-driven activity in addition to natural, seasonal variations. Of first importance is the direct impact of industrially produced chlorofluorocarbons. Although ozone levels around the globe are expected to continue to decline over the next several years, NASA is now detecting decreasing growth rates of ozone-depleting compounds in the upper part of the atmosphere, indicating that international treaties to protect the ozone layer are working. The second influence on stratospheric ozone levels is the indirect impact of "greenhouse gases" on atmospheric temperatures. Ozone destruction is quite sensitive to temperature increases in the atmosphere. Since upper atmospheric temperatures in the Northern Hemisphere during winter and spring generally are warmer than those in the Southern Hemisphere, ozone depletion over the Arctic has been much smaller than over the Antarctic during the 1980s and early 1990s. The Arctic stratosphere, however, gradually has cooled over the past few decades resulting in very large ozone depletion, especially during 1996-97. In the simulations performed by Shindell and his team, temperature and wind changes, induced by increasing greenhouse gases, clearly alter the dynamics of the atmosphere. According to this model, as the abundance of greenhouse gases gradually increases, the frequency of Northern Hemisphere sudden stratospheric warming is reduced, leading to significantly colder lower stratospheric temperatures. If proven correct, this dynamic effect would add to the greenhouse cooling of the stratosphere. "Results suggest that the combination of these two cooling effects causes dramatically increased ozone depletion so that ozone loss in the Arctic by the year 2020 roughly is double what it would be without greenhouse gas increases," said Dr. David Rind of GISS, a co-author of the paper. Increasing greenhouse gases therefore may be at least partially responsible for the very large Arctic ozone losses in recent winters. The authors caution, however, that though the model predicts a general trend towards increasing ozone depletion, the year-to-year variability is quite large, especially in the Arctic. For example, several years in the late 1990s and early 2000s show very little Arctic ozone depletion, while others show record losses. In fact, the 1997-98 winter that just occurred was characterized by significantly less ozone loss than the preceding six winters. A factor that should be considered, however, is the consistency in model predictions, i.e. whether the same results can be reproduced by other models. According to this model, the severity and duration of the Antarctic ozone depletion also may increase due to greenhouse gas-induced stratospheric cooling over the coming decades. However, ozone in the Antarctic is already so depleted that any additional losses may be relatively small, Rind added. The research was conducted by scientists at GISS, The Center for Climate Systems Research, Columbia University, and Science Systems and Applications Inc., New York. The GISS research is part of NASA's Earth Science Enterprise, a long-term coordinated research effort to study the Earth as a global system. -end- Hа сегодня все, пока! =SANA=

Дата: 09 апреля 1998 (1998-04-09) От: Alexander Bondugin Тема: JPL Evening Lectures Highlight Earth Exploration Missions Привет всем! Вот, свалилось из Internet... MEDIA RELATIONS OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011 http://www.jpl.nasa.gov Contact: Stephanie R. Zeluck FOR IMMEDIATE RELEASE April 7, 1998 JPL EVENING LECTURES HIGHLIGHT EARTH EXPLORATION MISSIONS "The Earth Observer: Understanding Our Planet from 400 Miles Up" will be the theme for two free public lectures, one on Thursday, April 16 at 7 p.m. in JPL's von Karman Auditorium, the other on Friday, April 17 at 7 p.m. in The Forum at Pasadena City College. Seating is limited and will be on a first-come, first- served basis. The lectures will be presented by Marguerite Syvertson, outreach coordinator for the Earth Science Flight Experiments Program and the Earth and Space Sciences Division. She has been involved as an engineer, scientist and outreach specialist in the development of the Earth Observing System (EOS). Over the next decade, NASA is preparing to launch a suite of missions that will greatly aid in a more comprehensive understanding of Earth and its processes. The Earth Observing System AM-1 satellite, scheduled for launch this summer, is the first of these missions and will provide unprecedented amounts of data about Earth's surface, oceans and atmosphere that will allow scientists to study and eventually model changes in Earth's environment and climate. EOS AM-1 will carry two instruments onboard: the Multi-Angle Imaging Spectroradiometer (MISR) and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), which is provided by Japan's Ministry of International Trade and Industry with scientific support provided by JPL. These instruments will monitor Earth's biosphere, volcanoes, oceans and clouds. Two more spacecraft, one carrying the Atmospheric Infrared Sounder (AIRS), which will study weather and climate, and the other carrying the Microwave Limb Sounder (MLS) and the Tropospheric Emission Specrometer (TES), will study atmospheric composition and will be launched in 2000 and 2002 respectively. This lecture is part of the von Karman Lecture Series sponsored monthly by the JPL Media Relations Office. A web site on the lecture series is located at http://www.jpl.nasa.gov/lecture. For directions and other information, call the Media Relations Office at (818) 354-5011. ##### Hа сегодня все, пока! =SANA=

Дата: 09 апреля 1998 (1998-04-09) От: Alexander Bondugin Тема: 25 years of Spacelab -- Go for Space Station [1/2] Привет всем! Вот, свалилось из Internet... European Space Agency Press Information Note Nr 10-98 Paris, France 7 April 1998 25 years of Spacelab -- Go for Space Station A live videotransmission of the Space Shuttle/Neurolab launch On Thursday 16 April, the Space Shuttle will lift off from the Kennedy Space Center in Florida, on the Neurolab/STS-90 mission. The flight will bring together two of the last great frontiers of human exploration -- outer space and inner space -- as it delves into the effects of weightlessness on the nervous system, one of the most complex and least understood parts of the human body. Research will be carried out in Spacelab, the laboratory carried in the Shuttle's cargo bay. Developed by ESA and built by European industry between the 1970s and early 1980s, Spacelab heralded a new approach to the utilisation of space. Now it will be making its final scheduled flight after 15 years of service. Later this year, the International Space Station will take over. The permanently inhabited research facility will begin to be assembled in space. As of next year, it will provide scientists from around the world with unique opportunities to research new solutions to Earth-bound challenges. To mark the occasion, press are invited to an evening at Noordwijk Space Expo, next door to ESA/ESTEC in Noordwijk, The Netherlands. Events will focus on a one-hour, live videotransmission, looking back at the 25 years of the Spacelab programme and looking forward to the beginning of the Space Station era. The programme will culminate in the countdown to the launch from Cape Canaveral, with live images of launch preparations and the lift-off. Wubbo Ockels, the second ESA astronaut to fly on a Spacelab mission will be the presenter. Key people from government, industry and the science community will tell how it was at the beginning, the successes that Spacelab has encouraged, and their hopes for the future as Europe prepares for the next step, the Space Station. Press wishing to take part in the evening should complete the attached form and return it by fax to ESA/ESTEC Public Relations, fax: (31) 71.565.5728. 25 years of Spacelab -- Go for Space Station Live videotransmission from Noordwijk Space Expo Thursday, 16 April 1998 - 8:30-22:00 Programme 18:30 Opening of guest centre at Noordwijk Space Expo 19:00 Welcome 19:40 Live videotransmission broadcast from the future International Space Station Station European User Information Centre 20:15 Countdown to launch begins, with live feed from Cape Canaveral 20:19 Scheduled lift-off of Columbia (launch window is open for 2.5 hours) 21:40 Conclusions 21:00 Opportunities for interviews Noordwijk Space Expo Keplerlaan 3 2201 AZ Noordwijk The Netherlands Tel: (31) 71.364.6446 Fax: (31) 71.364.6453 Note to Editors Neurolab (STS-90) mission The European Space Agency (ESA) and European scientists are playing a key role in the next Space Shuttle research mission that will bring together two of the last great frontiers of human exploration -- outer space and inner space. The 16-day international Neurolab flight -- NASA's contribution to the 'decade of the brain' -- will focus on the effects of weightlessness on the nervous system, one of the most complex and least understood parts of the human body. After almost 40 years of manned space flight, the effects of weightlessness on the brain, spinal cord, peripheral nerves and sensory organs remain largely unknown. The Neurolab mission is designed to tackle questions like how the absence of gravity affects the nervous system and how astronauts gain their 'space legs', but the research will also have many applications back on Earth. A seven-member crew, including three medical doctors, will carry out a series of neurological studies in Spacelab, the pressurised scientific laboratory which rides in the Space Shuttle's payload bay. One of the main items of equipment onboard is an ESA-developed rotating chair, known officially as the 'off-axis rotator' and part of the VVIS (Visual and Vestibular Investigation System). This 'human centrifuge' will be used as a way of investigating the role of the inner ear in detecting changes in motion and orientation. Exploiting biomedical techniques and new combinations of sophisticated measurement and recording devices, the goals of Neurolab are to: * Use the unique environment of space flight to study fundamental neurobiological processes. * Increase understanding of the mechanisms responsible for neurologic and behavioural changes that occur in space flight. * Gain knowledge that will help understand how space flight affects human biology. * Apply results from space studies to the health, well-being and economic benefit of people on Earth. Scientists from France, Germany and Italy are leading seven of the 26 experiments that will take place during the flight, ranging from the study of the inner ear and sleep patterns to a study of how well astronauts can catch a ball in microgravity. Crew members will serve as both subjects and operators in carrying out the investigations coordinated by scientific teams back on Earth. STS-90 is scheduled for launch from the Kennedy Space Center on 16 April at 20.19 European time. For more about the Neurolab mission, visit the ESA web site http://www.esa.int or http://neurolab.jsc.nasa.gov/ Hа сегодня все, пока! =SANA=

Дата: 09 апреля 1998 (1998-04-09) От: Alexander Bondugin Тема: Science Team Chosen For Mars Microprobes Mission (DS-2) Привет всем! Вот, свалилось из Internet... Douglas Isbell Headquarters, Washington, DC April 8, 1998 (Phone: 202/358-1547) John Watson Jet Propulsion Laboratory, Pasadena, CA (Phone: 818/354-5011) RELEASE: 98-59 SCIENCE TEAM CHOSEN FOR TECHNOLOGY VALIDATION MISSION TO EXPLORE THE SUBSURFACE OF MARS Nine researchers have been selected to be the Science Team for the Mars Microprobes, a technology validation mission that will hitchhike to the red planet aboard NASA's 1998 Mars Polar Lander mission. Two identical probes will be carried as a secondary payload on the lander, due for launch in January 1999. Following an 11- month cruise, the Microprobes will separate from the lander before it enters the Martian atmosphere, and then hit the ground at approximately 400 mph. During the impact, each microprobe will separate into two sections: the forebody and its instruments will penetrate up to six feet (two meters) below the surface, while the aftbody will remain near the surface to communicate with a radio relay on NASA's Mars Global Surveyor orbiter while making meteorological measurements. The nine selected scientists are: * David Catling, NASA Ames Research Center, Moffett Field, CA * Ralph Lorenz, University of Arizona, Tucson * Julio Magalhaes, NASA Ames Research Center * Jeffrey Moersch, NASA Ames Research Center * Paul Morgan, Northern Arizona Univ., Flagstaff * James Murphy, NASA Ames Research Center * Bruce Murray, California Institute of Technology, Pasadena * Marsha Presley, Arizona State Univ., Phoenix * Aaron Zent, NASA Ames Research Center The scientific objectives of the Mars Microprobes include searching for the presence of water ice in the soil and characterizing its thermal and physical properties. A small drill will bring a soil sample inside the probe, heat it, and look for the presence of water vapor using a tunable diode laser. An impact accelerometer will measure the rate at which the probes come to rest, giving an indication of the hardness of the soil and any layers present. Temperature sensors will estimate how well the Martian soil conducts heat, a property sensitive to different soil properties such as grain size and water content. A sensor at the surface will measure atmospheric pressure in tandem with a sensor on the Mars Polar Lander. The Mars Microprobes mission, also known as Deep Space-2 (DS- 2), is scheduled to be the second launch in NASA's New Millennium Program of technology validation flights, designed to enable advanced science missions in the 21st century. "I'm delighted with the selection of this excellent group of investigators. The Mars Microprobe will give us a glimpse of the subsurface of Mars, which in many ways is a window into the planet's history," said Dr. Suzanne Smrekar, the DS-2 project scientist at NASA's Jet Propulsion Laboratory, Pasadena, CA. "The region of Mars we will explore is similar to Earth's polar regions in that it is believed to collect ice and dust over many millions of years. By studying the history of Mars and its climate, we are likely to better understand the more complex system on our own planet." In addition to the miniaturized science instruments capable of surviving high velocity impact, technologies to be tested on DS-2 include a non-erosive, lightweight, single-stage atmospheric entry system or aeroshell; power microelectronics with mixed digital/analog advanced integrated circuits; an ultra-low temperature lithium battery; an advanced three-dimensional microcontroller; and flexible interconnects for system cabling. "The combination of a single-stage entry vehicle with electronics and instrumentation that can survive very high impact loads will enable us to design a whole new class of very small, rugged spacecraft for the in-situ exploration of the planets," explained Sarah Gavit, DS-2 project manager at JPL. "Slamming high-precision science instruments into the surface of Mars at 400 mph is very challenging, no doubt about it! But once this type of technology is demonstrated, we can envision future missions that could sample numerous regions on Mars or make network measurements of global weather and possible Marsquakes," said DS-2 program scientist Dr. Michael Meyer of NASA Headquarters, Washington, DC. Further information on DS-2 is available on the Internet at the following URL: http://nmp.jpl.nasa.gov/ds2/ The New Millennium Program is managed by JPL for NASA's Office of Space Science in Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. -end- Hа сегодня все, пока! =SANA=

Дата: 09 апреля 1998 (1998-04-09) От: Alexander Bondugin Тема: Water Vapor On Titan And Remote Galaxies ... [1/2] Привет всем! Вот, свалилось из Internet... European Space Agency Press Information Note No. 09-98 Paris, France 7 April 1998 New water and remote galaxies complete ISO's observations Water vapour detected on Saturn's largest moon, Titan, and infrared galaxies identified at immense distances are among the latest results from the European Space Agency's Infrared Space Observatory, ISO. At a press briefing in London today (7 April) ESA's director of science, Roger Bonnet, said "ISO is one of the most successful space observatories, and in the infrared it has had no rival." Its discoveries will change our views on the Universe. ISO's operational teams at ESA's ground station at Villafranca near Madrid have been hurrying to provide the world's astronomers with as many observations as possible. They have long anticipated the exhaustion of ISO's vital supply of liquid helium, which cooled the infrared telescope and its instruments to their operating temperatures, close to absolute zero. Two weeks after ISO was put into orbit on 17 November 1995 by an Ariane 44P launcher, the external parts of the cooling system had settled to the operating temperature. The specification required that ISO should then operate for at least 18 months -- implying that operations might have to end in May 1997. Thanks to superb engineering by European industry, which built the spacecraft and its super-cool telescope, ISO has given astronomers almost a year longer than that. During the extra time the count of ISO's observations of cosmic objects has risen from 16,000 to about 26,000. Among the benefits of ISO's longevity has been the chance to examine an important region of the sky, in and around the constellation of Orion. This was not accessible in the nominal mission but has now been observed in two periods. Four international teams, supported by national funding agencies, supplied the instruments to analyse the infrared rays received by ISO's telescope. The principal investigators leading the teams are Dietrich Lemke (Heidelberg, Germany) for the versatile photometer ISOPHOT, Catherine Cesarsky (Saclay, France) for the camera ISOCAM, Thijs de Graauw (Groningen, the Netherlands) for the Short Wavelength Spectrometer SWS, and Peter Clegg (London, UK) for the Long Wavelength Spectrometer LWS. Water vapour on Titan A big difference between ISO and the only previous infrared astronomy satellite (IRAS 1983) has been its ability to examine individual objects across a wide range of accurately defined infrared wavelengths. Many spectra showing patterns of intensities at the different wavelengths have enabled astronomers to deduce the presence of diverse materials in interstellar space, in the surroundings of stars, and in other galaxies. As previously reported, ISO has identified stony materials, tarry compounds of carbon, and vapours and ices like water and carbon monoxide. Together they give the first clear picture of how Mother Nature prepares, from elements manufactured in stars, the ingredients needed for planets and for life itself. Particularly striking for the human imagination are ISO's repeated discoveries of water in the deserts of space. They encourage expectations of life elsewhere in the Universe. Water has turned up around dying stars, newborn stars, in the general interstellar medium, in the atmospheres of the outer planets and in other galaxies too. A link to the Earth's oceans and the water we live by comes in the water-ice long known to be a major ingredient of comets, which are relics from the era of planet-building. A further link to the investigation of the origin of life is the apparent detection of water vapour in the mysterious atmosphere of Saturn's largest moon, Titan. A preliminary announcement comes from an international team headed by Athena Coustenis of Paris Observatory and Alberto Salama of the ISO Science Operations Center at Villafranca. The team used ISO's Short Wavelength Spectrometer during several hours of observations last December, when Titan was at its farthest from Saturn as seen by ISO. Emissions at wavelengths of 39 and 44 microns showed up, as an expected signature of water vapour. The news will excite the scientists involved in ESA's probe Huygens, launched last year aboard NASA's Cassini spacecraft. It will parachute into Titan's atmosphere to see what the chemistry of the Earth may have been like before life began. "Water vapour makes Titan much richer," comments Athena Coustenis. "We knew there was carbon monoxide and carbon dioxide in Titan's atmosphere, so we expected water vapour too. Now that we believe we've found it, we can expect to better understand the organic chemistry taking place on Titan and also the sources of oxygen in the Saturnian System. After ISO, the Huygens probe will reveal the actual degree of complexity in a mixture of elaborate organic molecules closely resembling the chemical soup on the young Earth." Ballet corps of young stars Infrared images of the spectacular Orion star-forming regions, at a distance of approximately 1500 light years, are bonuses from ISO's extended life. In the Horsehead Nebula, visible light shows a large dark dust cloud from which a black wisp shaped like a horse's head protrudes into a luminous cloud of gas. When seen by ISO's camera ISOCAM, dense parts of the dusty region appear as shiny filaments and the horse's head almost disappears. Young stars are detected in the horse's forehead and in the nearby nebula NGC 2023. Other well-known nebulae in the Orion region include NGC 2068 and NGC 2071. Emission by carbon compounds (polycyclic aromatic hydrocarbons or PAH) makes the infrared nebulae spectacular, as seen by ISOCAM. And thanks to ISOCAM's sensitivity and the ability of infrared rays to penetrate a dust cloud better than visible light, ballet corps of young stars appear on the stage, seen as spots in the centre of these two nebulae. This is not surprising, because the dense, dusty regions called molecular clouds are often the breeding grounds of new stars, but ISOCAM detects fainter and more obscured objects. "We have used ISOCAM to make a census of families of young stars," comment Lennart Nordh and Goran Olofsson of Stockholm University, who lead a team of astronomers from Sweden, France, Italy, the UK and ESA. "By comparing the intensities of the point-like objects at different infrared wavelengths we can efficiently identify the ensemble of young stars still embedded in its parental molecular clouds." >From their study of ISO's early observations of four star-forming clouds, the astronomers report the detection of small stars. "Almost 300 young stars have been identified to date, many of which were previously not recognized," Nordh and Olofsson say. "Most of the latter objects have luminosities 10-100 times lower than revealed by earlier observations. Our preliminary analysis indicates that at least ten per cent of the embedded young stars will become small brown dwarfs, or ownerless super-planets, less than one-tenth of the mass of the Sun." Hа сегодня все, пока! =SANA=

Дата: 09 апреля 1998 (1998-04-09) От: Alexander Bondugin Тема: Water Vapor On Titan And Remote Galaxies ... [2/2] Привет всем! Вот, свалилось из Internet... Colliding galaxies Some galaxies are unusually bright in the infrared because of cosmic traffic accidents that bring them into collision with other galaxies. The result is a frenzy of star formation called a starburst. The explosion of short-lived stars then creates a pall of warm dust which ISO observes in the infrared. The relative intensities of different wavelengths enable astronomers to distinguish starburst events from other sources of strong infrared rays, such as the environment of a black hole in the nucleus of a galaxy. Collisions and starbursts play an important part in the evolution of galaxies. A famous pair of colliding galaxies called the Antennae was one of the first objects to be examined by ISO. Continuing study of the Antennae over the past two years has revealed a clear picture of a starburst occurring exactly where the dense disks of the galaxies intersect. The nuclei of the two galaxies are plainly distinguished too. Centaurus A is a galaxy that first attracted the attention of astronomers by its strong of radio emissions. In its visible appearance, a large, round (elliptical) galaxy has a dark band across its face. This too turns out to be the result of a galactic collision. The dark band is a flat, disk-shaped galaxy seen almost edge-on. Centaurus A is the nearest case of a phenomenon seen elsewhere by ISO, in which a flat galaxy has merged with an elliptical galaxy while preserving its flat configuration. ISOCAM gives an image of Centaurus A in which the disk galaxy is the more conspicuous object. The orientation of the disk becomes clear. It is at right angles to the axis of the radio-emitting regions, which are powered by jets of electrons driven by a black hole in the centre of the galaxy. Excited emissions detected by ISO's Short Wavelength Spectrometer also indicate the presence of an active black hole. "Centaurus A is an example of ISO's magic," says Catherine Cesarsky of CEA Saclay in France, leader of the ISOCAM instrument team. "It transforms opaque clouds seen by visible light into glowing scenes in the infrared. The same thing happens in dust clouds hiding newborn stars, and on a huge scale in dusty starburst galaxies -- which become infrared beacons lighting our way deep into the Universe." Distant galaxies seen through the holes in the sky When ISO was launched, one of the hopes for the space observatory was that it would detect galaxies made luminous by starburst events, or by black-hole activity, very far away in space and therefore far back in time. Dust in our own Milky Way Galaxy usually obscures the remotest and faintest galaxies. But when they look northwards and southwards, at right-angles to the disk of the Milky Way, astronomers find holes in the dust clouds through which distant galaxies are discernible. Both for ISO and the Hubble Space Telescope these holes have been special targets for observations with long exposures, to reveal faint galaxies. ISOCAM results through the northern hole, by a Japanese-led team, were reported last year in an ESA Information Note (25.97) and a picture release (ESA/ISO 97:8/1). They revealed many infrared-luminous galaxies billions of light-years away, from an era corresponding with about half the present age of the Universe. Even more distant and earlier galaxies may be present in ISO's observations, including some objects not yet seen by visible light. Results released at the London press briefing on ISO include "deep field" examinations by groups of astronomers led by Catherine Cesarsky of CEA Saclay and Michael Rowan Robinson of Imperial College, London, analysing the northern and southern images respectively. In the northern deep field, when ISOCAM observations are superimposed on a Hubble picture of the same region, they pick out spiral galaxies experiencing starbursts. A different signature comes from large elliptical galaxies whose visible light has been shifted into the infrared by the expansion of the Universe. The astronomers estimate that some of the objects seen by ISOCAM are so far away that the Universe was only one-third of its present age when they emitted the radiation seen today. The first ISO images from the opposite direction in the sky, in the southern deep field, show similar objects, again at great distances. A preliminary analysis indicates the presence of of 30-40 remote galaxies seen at a wavelength of 7 microns and 22-30 at 15 microns. One interesting source, bright in the infrared, is not seen by visible light even in a prolonged examination by the CTIO 4-metre telescope in Chile (A. Walker). Astronomers suspect that this object is undergoing an especially violent period of star formation. The interpretation can be checked when Hubble and other telescopes have a chance to examine this scene. Besides illuminating the evolution of the galaxies, ISO's deep field results are encouraging for scientists planning another of ESA's astronomical space projects, FIRST. Its longer wavelengths will penetrate even deeper into the unknown. Non-stop discoveries The extended life was not the only outcome that made ISO a triumph for ESA, European industry and those responsible for its operations. The pointing accuracy of the telescope turned out to be ten times better than required in the specification and its jitter was one-fifth of what was considered tolerable. Stray light in the optical system was too small to measure. The scheduling systems achieved science observations for 90-95 per cent of the available time. Much of the rest of the time, when ISO was turning to new targets, was spent in mapping parts of the sky at a wavelength of 200 microns. Activity concerning ISO will continue at the Villafranca ground station until the year 2001, long after the completion of the observational phase of the mission. During the space operations, the main objective was to make as many observations as possible. Thorough analysis and interpretation of the results will take several years. "We still have plenty to do," says Martin Kessler, ESA's project scientist for ISO. "Our team at Villafranca is preparing a complete archive of ISO data on 500-1000 compact disks, after reprocessing with improved software. We'll release part of this archive to the world-wide astronomical community in the autumn of this year, and the rest in 1999. We shall also advise the astronomers who have used ISO, about the particular requirements for handling the data from each instrument, and we'll be doing some astronomy ourselves. There are far more results still to come from ISO." Europe's infrared astronomers are already busy preparing ESA's FIRST and Planck missions, due for launch early in the new century. FIRST will observe long infrared wavelengths in the sub-millimetre range, while Planck will map the cosmic microwave background far more accurately than NASA's COBE mission did, to reveal the clumps of matter from which galaxies evolved. Also under study by ESA is a possible interferometer mission using a combination of infrared telescopes. In principle it might observe and characterize planets in orbit around other stars. Meanwhile, Europe's space astronomy programme continues apace in other directions. ESA's participation in the Hubble Space Telescope and its eventual successor assures access to those important instruments for Europe's astronomers. The release in 1997 of the catalogues from ESA's unique star-mapping mission Hipparcos provided all astronomer with amazingly precise data for sizing up the stars and the wider Universe. Next year will see the launch of ESA's XMM satellite to observe X-rays from the Universe with the most ingenious and sensitive X-ray telescopes ever made. It will be followed by Integral in 2001, which will investigate cosmic gamma-rays with clever imaging devices called coded masks, and ultra-sensitive detectors. "Our aim in space astronomy is that every ESA mission should be the best in the world at the time of its launch," says Roger Bonnet, ESA's director of science. "ISO is a shining example. It has revolutionized infrared astronomy. It has given us wonderful insights into cool and hidden places in the Universe, and into the origins of water and other materials to which we owe our very existence. A mission of this scale and complexity was feasible for Europe only through the multinational collaboration coordinated by ESA." See ISO's results on the World Wide Web, or on a CD Immediate access to information about ISO and its results, including a picture gallery, is available via the Internet: http://isowww.estec.esa.nl For the assistance of journalists, ESA's ISO team has also prepared a compact disk containing the same information as the website, together with previously published information about ISO and its results. For further information, contact ESA Public Relations Division Tel: +33.(0)1.53.69.71.55 Fax: +33(0)1.53.69.76.90 Hа сегодня все, пока! =SANA=

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