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Дата: 23 апреля 1998 (1998-04-23) От: Alexander Bondugin Тема: Mission Prepares To Collect Pieces of Stardust Привет всем! Вот, свалилось из Internet... From The Planetary Society Home Page: http://planetary.org/articlearchive/headlines/1998/headln-041698.html Mission Prepares To Collect Pieces of Stardust April 16, 1998 Earth's First Cometary Dust Sample Return Mission Will Fly Planetary Society Member Names to a Comet and Back Scientists and engineers continue to prepare the Stardust spacecraft for its February 1999 launch. Earlier this month, Stardust Project Manager Ken Atkins reported that mission planners continue to make impressive progress in piecing together the spacecraft's flight system. Set for launch in February 1999, Stardust will be the first US mission dedicated solely to a comet and the first robotic return of extraterrestrial material from outside the orbit of the Moon. Its primary goal is to collect comet dust and volatile samples during a planned close encounter with comet Wild-2 in January of 2004. Aboard the spacecraft will be a microchip that carries the name of thousands of planetary exploration supporters -- including all Planetary Society members as of November 1997. These names are now posted on line on the Stardust web site (http://stardust.jpl.nasa.gov/microchip/names.html). The Stardust spacecraft will also bring back samples of interstellar dust, including the recently discovered dust streaming into the solar system from the direction of Sagittarius. These materials consist of ancient pre-solar interstellar grains and nebular condensates including remnants left over from the formation of the solar system. Their analysis is expected to yield important insights into the evolution of the Sun and planets and possibly into the origin of life itself. Preparing Stardust for Flight Earlier this month, the team from Germany's Max Planck Institute delivered the flight cometary and interstellar dust analyzer (CIDA). Mission engineers completed setting up the analyzer and checking it out, testing the instrument's ability to transmit examples of the kind of data it will collect in flight. The navigation camera team also made some important progress as they completed testing and calibrating the camera at the Jet Propulsion Laboratory in preparation for delivery to Lockheed Martin Astronautics in Denver, Colorado. This camera will be used to provide pictures to the navigators as they make the final course corrections for the cometary flythrough. It will also be the instrument for taking the "up-close-and-personal" images of Comet Wild 2 as the spacecraft cruises some 150 miles (about 240 kilometers) above the now-unknown surface of the comet's nucleus. The team at Lockheed Martin Astronautics also completed some deployment testing on the spacecraft's solar array. These tests demonstrated how Stardust will "spread its wings" following launch and separation from the launch rocket. Finally, engineers reviewed a test unit of the aerogel collector in preparation for using it to test how we will keep it extremely clean during its installation and launch. It is partially loaded with examples of flight-quality aerogel. Hа сегодня все, пока! =SANA=

Дата: 23 апреля 1998 (1998-04-23) От: Alexander Bondugin Тема: Mission to Asteroid, Mars, and Comet Delayed Привет всем! Вот, свалилось из Internet... From The Planetary Society Home Page: http://planetary.org/articlearchive/headlines/1998/headln-042098.html Mission to Asteroid, Mars, and Comet Delayed April 20, 1998 Software Troubles and Late Electronics System Force NASA To Postpone Deep Space 1 The planned July 1998 launch of NASA's Deep Space 1 technology validation mission from Cape Canaveral, Florida, has been rescheduled for October. The delay is due to a combination of late delivery of the spacecraft's power electronics system and an ambitious flight software development schedule, which together leave insufficient time to test the spacecraft thoroughly for a July launch. The power electronics system regulates and distributes power produced by not only the solar concentrator array, a pair of experimental solar panels composed of 720 cylindrical Fresnel lenses, but also by an on-board battery. Among many other functions, it helps the solar array to operate at peak efficiency, and ensures that the battery is able to cover temporary surges in power needed so that the ion propulsion system (which needs electricity for its basic operations) receives a steady power supply. "With a new launch date for this bold mission, we can be more confident that we will be ready to fully exercise our payload of important technologies," explained Chief Mission Engineer Marc Rayman of NASA's Jet Propulsion Laboratory in Pasadena, California. "The entire DS1 team looks forward to this opportunity to make a significant contribution to science missions of the future through the capabilities we are testing on DS1." Deep Space 1 is the first launch in NASA's New Millennium program, a series of missions designed to test new technologies so that they can be confidently used on science missions of the 21st century. Among the 12 technologies the mission is designed to validate are ion propulsion, autonomous optical navigation, a solar power concentrator array and an integrated camera and imaging spectrometer. The earlier July launch period for DS1 allowed it to fly a trajectory encompassing flybys of an asteroid, Mars, and a comet. By the end of May, the mission design team is scheduled to finalize new target bodies in the solar system for DS1 to encounter based on an October launch date. Editor's note: Deep Space 1 will no longer visit asteroid 3352 McAuliffe, Mars, and comet West-Kohoutek-lkemura. The launch delay was announced after this article went to press. Mission planners will announce the new targets for this mission by the end of May. The full text and graphics for this article will appear in the May/June 1998 issue of The Planetary Report. This publication goes out to all members of the Planetary Society. If you're not already a member, we encourage you to join. Deep Space 1: Exploration Technology for the 21st Century by Robert M. Nelson and Marc D. Rayman This summer NASA takes a revolutionary step when it launches Deep Space 1 (DS1). During its flight, the spacecraft will visit asteroid 3352 McAuliffe, the planet Mars, and comet West-Kohoutek-lkemura. But its primary goal is not to study these fascinating bodies; rather, as a member of the New Millennium program, its job is to pave the way for future, even more exciting, space science missions. NASA has already flown missions to asteroids, comets, and Mars, so what makes DS1 unusual? It will demonstrate a dozen technical innovations that will serve as foundation technologies for the next generation of deep-space missions. Foremost among these new technologies will be solar electric propulsion (SEP), which will enable a whole class of ambitious missions that are simply impractical or unaffordable, with the standard chemical propulsion available today. A Test Drive DS1 will be launched from Cape Canaveral on the first Delta 7326 rocket, a low-cost member of the Delta 11 family. DS1 is so small that even this economy-class launch vehicle will be able to carry a second spacecraft -- SEDSAT-1, an Earth orbiter built at the same time by students at the University of Alabama in Huntsville. Once in space, DS1 will be checked out and certified by the mission operations team, and then the SEP system will begin thrusting. Instead of burning a strong, short pulse of chemical propellant, followed by a long interplanetary cruise, the SEP system will sustain a tenuous but very high-velocity stream of ionized xenon. This stream will create a gentle, steady thrust that will propel the spacecraft almost continuously during interplanetary cruise. Although the thrust of SEP is small, its advantage accrues because the exhaust velocity of the ion rocket is many times greater than the exhaust velocity of a conventional chemical system. The bottom line is that SEP requires far less propellant than a chemical rocket to deliver the same payload mass to a target, It takes time for the gentle thrust to build up high spacecraft velocity, so SEP is appropriate only for missions requiring high energy or long trips. Within a month of launch, DS1 will have accomplished most of its major objectives, and we will have assessed its payload of advanced technologies. If a technology fails during the flight, even if it causes the loss of the spacecraft, we may still regard the mission as a success if it achieves the program goal of reducing the risk for future science missions. It is in these future missions that the real science return of DS1 will be found. But this high-risk project will attempt to return science during its test flight.... The flight of DS1 will test new autonomy technologies, solar concentrator arrays, and a variety of telecommunications and microelectronics devices. Autonomy, which in this case means the ability of the spacecraft to make its own decisions, can help reduce the heavy burden on NASA's Deep Space Network (DSN). As more and more probes are sent into space in the coming years, it will be harder for the DSN to communicate with all of them as frequently as it has done in the past. With autonomy technologies allowing spacecraft to operate for longer times without detailed instructions from Earth, the precious resources of the DSN can go further. In addition, by placing more responsibility on the spacecraft, we reduce delays caused by signal travel times and limited communications rates. Despite the potential advantages, it is easy to see that onboard decision-making systems entail risk for the first user. If the autonomy systems on DS1 perform as planned, future mission teams can be more confident about leaving important decisions to the spacecraft. One of the powerful autonomy technologies on DS1 is the navigation system. It uses images of main-belt asteroids viewed against the background stars to compute the spacecraft's position. As the spacecraft travels, foreground objects (the asteroids) will appear to move relative to the background stars. The apparent shift, or parallax, gives the navigation system information from which to triangulate the spacecraft position. The navigation system then uses positions calculated at earlier times to determine trajectory, making allowances for SEP thrusting, gravitational pulls of the Sun and planets, and other forces. If the navigation system finds that it is off course, it can make a course correction by adjusting the direction or duration of SEP thrusting.... Hа сегодня все, пока! =SANA=

Дата: 23 апреля 1998 (1998-04-23) От: Alexander Bondugin Тема: Washington Reins in NASA's Budget Привет всем! Вот, свалилось из Internet... From the Planetary Society home page: http://planetary.org/articlearchive/headlines/1998/headln-042198.html Washington Reins in NASA's Budget April 21, 1998 Search for Extraterrestrial Life and Human Exploration of Mars May Be in Jeopardy While the Clinton administration's overall budget for NASA in fiscal year 1999 once again declines, it does contain a modest increase in funding for space science -- from $1.983 billion in fiscal year 1998 to $2.058 in fiscal year 1999 -- that must be safeguarded, according to Louis Friedman, Executive Director of The Planetary Society. "The budget allows NASA to meet its obligations and fund a new mission start to explore Europa, the moon of Jupiter that may have an ocean capable of supporting life," Friedman said in testimony to a house appropriations subcommittee. "The slight increase is minimal considering the extraordinary results and opportunities in space science." The orbiter to Europa is scheduled for launch in 2003. It will measure the thickness of the moon's surface ice and seek to determine whether a liquid ocean exists below. Other instruments will examine the interior processes. In our solar system, Europa and Mars are the best candidates for having conditions that might be conducive to life. As a consequence, they are a priority in the search for evidence of extraterrestrial life. Robotic and Human Exploration The Planetary Society also urges members of Congress to appropriate an additional $42 million in new funding so NASA's Office of Space Flight can participate in the Mars 2001 lander mission as originally planned. Budget pressures within NASA recently forced the office of space flight to withdraw its participation in the mission. It earlier had agreed to provide $57 million for several experiments. But because of a shortfall in available funding, the office cannot now afford the financial contribution. The office of space science is now managing the experiments, although its budget was augmented by only $15 million, introducing severe technical constraints in the mission. Having the office of space flight participate in robotic missions is important for many reasons, Friedman said. Working together cross-fertilizes engineering and operations to promote innovative designs. The advanced technologies for robotic spacecraft have applications for human exploration missions and vice versa. The integration also will enhance scientific objectives. "It is critical for engineers to better understand the separate capabilities of humans and robotic technology," Friedman said. "As now envisioned, a future crew on Mars will rely heavily on robotic tools to explore the planet and collect scientific data. Building bridges between the two offices will ensure future success." Public Supports Exploration Sixty-eight percent of the public believe it was "worth it" to send humans to explore the Moon in the Apollo Program, according to a July 1997 poll by CBS News. Fifty-four percent favor "sending astronauts to explore Mars." In a Roper poll (7/11/97), 62 percent of the public said they would support "the United States sending astronauts to explore Mars." "Clearly, a human Mars mission on some time scale is a goal backed by a large majority of Americans," Friedman said. The Clinton Administration recently attempted to restrict investments in research for human exploration beyond low Earth orbit. Members of Congress and space organizations, including The Planetary Society, voiced opposition to the new directive and it was rescinded. Until 1996, the National Space Policy contained language establishing as a goal of America the human exploration of the Moon, then Mars. But this provision was removed by the Clinton Administration. As a consequence, activities at NASA in support of eventual human exploration beyond low Earth orbit are being challenged. "If the United States is not preparing to explore the Moon and Mars," Friedman said, "why then are we building the space station in the first place? When the space station is completed early in the next century, astronauts will be all dressed up with no place to go." Friedman said our nation cannot afford to sit on its hands until the station's assembly is completed before determining our next step in space. "We must not build fences at low Earth orbit, fearing to venture beyond," Friedman said. "Americans rise to great challenges. They want to be emboldened to have their spirit enlivened. By stabilizing NASA's budget, the agency can focus all its attention on managing programs, not budget cuts. NASA must have the wherewithal to make investments in future technology. We must begin now to establish a coherent vision for our nation following the completion of the space station." Overall Budget Every year since 1992, NASA's budget has been cut. The Clinton Administration is seeking to reduce spending in fiscal year 1999 by another $173 million. The rollback, when accounting for inflation, totals $445 million. Friedman said NASA deserves better. The space agency has enacted far-reaching reforms. It is innovating advanced technologies in aeronautics, space transportation, human exploration, and space science, which are being transferred to the marketplace to maintain America's economic health. "There is a limit to what NASA can withstand and still remain successful," Friedman said in Congressional testimony. "Budgets are now being squeezed to a breaking point, sapping vitality. The time is long past to stabilize NASA's funding. Our nation's space program merits no less." Hа сегодня все, пока! =SANA=

Дата: 23 апреля 1998 (1998-04-23) От: Alexander Bondugin Тема: Irakli Simonia, Tsitsino Simonia, Abastumani Astrophysical Observatory Subject: Irakli Simonia, Tsitsino Simonia, Abastumani Astrophysical Observatory Привет всем! Вот, свалилось из Internet... IRAKLI SIMONIA, TSITSINO SIMONIA ABASTUMANI ASTROPHYSICAL OBSERVATORY REPUBLIC OF GEORGIA E-mail: irsim@nilc.org.ge The Dust Around Cool Stars The cosmic dust, as a form of the matter, a carrier of relic information, and information on the cosmic environment, keeps causing growing interest among specialists working in different areas of research. The dust in the solar system, the interstellar medium surrounding stars of different types, has become an object of regular and, frequently, coordinated research. Theoretical and practical studies have provided us with fundamental knowledge of the cosmic dust. Meanwhile, the recent research results, including those obtained from cosmic missions to Halley=92s comet, have demonstrated that the dust observed in various shapes, forms and types in the universe possesses common, universal features. Better and deeper understanding of those properties of the dust will require more intensive comparative studies, with the results of terrestrial laboratory experiments, cosmic sounding of the solar system bodies and astronomical observations of distant stars and nebulas being compared and summed up. Considering the physical, chemical and biological aspects of the problem, the pride of place is to be given to more intensive comparative studies of the dust that contains organic components, in particular, C2, CH, CN. In this work we made an attempt to define some properties of cool crystalline hydrocarbons from the dust shell around stars of the late types, on the basis of laboratory investigations of terrestrial crystalline hydrocarbons. It is common knowledge that both carbon stars and M-type stars are rich in hydrocarbon and other carbon-containing substances including CH. According to S.Pickelner (1959), S.Kaplan, S.Pickelner (1959) and M.Grinberg (1970) and some other authors, the stellar wind molecules, carried to a certain distance away from the carbon stars, turn into a material providing solid particles, is grains of dust. In this way, solid particles of silicon =96 carbide, graphite, etc., can= form in the vicinity of the carbon stars. Taking into consideration the chemical composition of carbon stars, on the one hand, and the complex structure of the "star"-dust shell" system on the other one can suggest that the dust around stars of the mentioned types may contain solid carbon particles formed as separate, equally dispersed crystals, as well as complex unequally dispersed polycreistals. Investigation of the dust around cool stars, using radio and IR methods, will certainly give some information on its character, but the results thus obtained ought to be compared with those of the terrestrial laboratory experiments. One of the most interesting properties of solid crystalline hydrocarbons is their ability to luminance when being exited by UV radiation. Solid crystalline hydrocarbons become luminescent under the action of UV radiation in the visible spectrum. The phenomenon of luminescence of hydrocarbon has been sufficiently well studied by specialists of photochemistry. As far as the luminescence of crystalline hydrocarbons in the cosmic medium is concerned, it has hardly been studied, so far. We find it possible to identify some luminescence properties of crystalline hydrocarbons contained in the dust around cool stars, using laboratory investigation results of luminescence properties revealed in terrestrial hydrocarbons. It is common knowledge that luminescence of organic substances can be categorized as metastable or induced luminescence. The hydrocarbons discussed in this paper produced metastable luminescence. Cold crystalline hydrocarbons produce two basic luminescence spectra at negative temperatures: I.A striped spectrum of wide bands in the visible area. II. A striped spectrum of very narrow bands in the visible area. This type of spectrum is also called quasilinear. The luminescence spectra of such hydrocarbons as C23.3 H19.3, C24 H18.4, C36 H27.8 are sets of wide bands (see the Table for maximum wavelengths) at negative temperatures. Hydrocarbon of the C14H10 type at negative temperature produces a quasilinear luminescence spectrum of very narrow bands in a 4000-5000 Ao range. Speaking of specific features of the cold crystalline hydrocarbon luminescence spectra, the following should be pointed out. a) as the hydrocarbon molecules become more complex, their luminescence spectra shift towards longer waves; b) as the temperature of cold crystalline hydrocarbon decreases, the wide bands in the luminescence spectra grow narrower. At 20oK the spectra appear as quasilinear ones. In our view, the feature described in (B) should, in principle enable evaluation of the proper temperature of cold crystalline hydrocarbons by their luminescence spectra. This can be performed, for instance, by comparing the observed band widths with standard bands. An important characteristic of luminescence is its energy output: ? =3D h c/? where h is the Planck's constant and ? is the wavelength of the exciting radiation. Assuming that cold crystalline hydrocarbon luminescence is induced by UV radiation of ?=3D3600 Ao wavelength, the energy output of the luminescence is ? =3D 5,6 x 10-19J It actually means that every quantum of UV radiation induces luminescence of hydrocarbon with the energy output of 5,6 x 10-19J. This fact provides corresponding information on the energetics of the phenomenon in question. Solid crystalline hydrocarbons obtained from various grades of petroleum were studied by L.Melikadze, T.Eliava (1958) and L.Melikadze, D.Varfolomeev (1980), who demonstrated that luminescence of hydrocarbons of the aromatic series occured only under UV radiation of 3600-3800 Ao, with Stokes' Law ?lum>?absorb being permanently in effect. No anti-Stokes lines were observed. The crystalline hydrocarbons under study luminesced under UV radiation in the yellow-green visible spectrum, with the maximum wavelength of 5500 Ao. It was experimentally proved that at the intrinsic temperature of the studied hydrocarbons of 270oK and more, the UV radiation excited luminescence of those hydrocarbons was of the fluorescence type. The after-glow period was equal to zero. When, however, the intrinsic temperature was below 270oK the UV-excited luminescence was of the phosphorescence type. The after-glow time at 230oK was as a rule, equal to several seconds. The table gives the most important results of laboratory investigations of some crystalline hydrocarbons of the aromatic series. Luminescence was excited by UV radiation in the indicated range. Column I presents the characteristics and colour of the substance; Column 2 gives the basic colour of luminescence; Column 3 gives the wavelengths of energy distribution maximums in the fluorescence =96 type luminescence spectrum (T=3D270oK); Column 4 gives the wavelengths of energy distribution maximums= in the phosphorescence =96 type luminescence spectrum (T=3D250oK); Column 5= shows the component composition; Column 6, the empirical equations; and Column 7, the molecular weight. As the laboratory experiments revealed, some properties of solid crystalline hydrocarbons change as a result of heating up to 310oK and higher. In particular, the hydrocarbons completely lost their luminescence at 310oK. Such heated hydrocarbons appeared to be incapable of luminescence under UV radiation. Presumably, as the hydrocarbons were heated, the probability of nonradiative transition in the hydrocarbon atoms increased. Solid crystalline hydrocarbons present in the cosmic medium in the form of separate dust particles, grains, dust clusters, clouds and dust shells, will be, probably, capable of UV =96 excited luminescence. This kind of luminescence could possess corresponding characteristics, and, to a certain extent, differ from luminescence of terrestrial hydrocarbons in their spectral characteristics, intensity, stability, etc. Basic regularities of luminescent processes of the comet crystalline hydrocarbon were studied by I.Simonia in 1991. However, crystalline hydrocarbon found in the dust around cool stars are bound to be in specific conditions, such as: a) high density of the dust masses around cool stars; b) permanent presence of the dust in the area of redundant infra-red radiation. Conditions (a) and (b) will impose noticeable restrictions on luminescence possible in solid crystalline hydrocarbons contained in the dust shells. Penetration and propagation of short-wave radiation from an external source into dense dust masses is somewhat questionable. On the other hand, constant heating of crystalline hydrocarbon by the central star will, apparently, result in an abrupt increase of probability of non-radiative transitions in the atoms of those hydrocarbons. It appear, there for that in the inner layers of a dust shell, closer to the cool star crystalline hydrocarbons art devoided of any luminescence ability. In the outer dust layers, remote from the cool star, crystal hydrocarbons are heated to moderate temperature levels. If UV radiation from some distant foreign source happens to fall upon such slightly heated crystalline hydrocarbons, it will excite luminescence in the corresponding spectrum. Such luminescence may occur under the following concurrent conditions: 1.Presence of considerable amounts of solid crystalline hydrocarbon in the outer layers of the dust shells. 2.Failure of solid crystalline hydrocarbons to be heated to 250oK and higher (from the moment of dust grains formation). 3.Radiation of crystal hydrocarbons from some distant foreign source emitting a corresponding UV-radiation spectrum. As it was shown above, terrestrial solid crystalline hydrocarbons revealed bright and steady luminescence at T?270oK. A distant foreign source of UV radiation located at a certain distance away from the cool star surrounded by dust, may be a cosmic body undergoing some rapid catastrophic changes, accompanied by emission of UV radiation. UV radiation can also be provided by such foreight sources as stars or nebulas and others, i.e., those bodies that are hardly ever subject to rapid catastrophic transformation. In case of all the above listed three conditions being present simultaneously, weak episodic phosphorescence will appear in the outer layers of the dust shells. We have chosen this definition for this phenomenon, because luminescence of the phosphorescence type is bound to be weak and hardly visible. If, at least, one of those conditions fails to be observed, there will be no phenomenon of weak episodic phosphorescence to be found. Considering all the above statements and the results of laboratory experiments (see Table), one can make a conclusion that weak episodic phosphorescence will occur mainly as blue or violet glow. The phosphorescence intensity will probably change, depending on the changes of the UV radiation intensity. The phosphorescence will be of a specific spectrum with its maximum at the corresponding wave length. Observability or recordability of such a phenomenon depends on two basic paints: first, on the spatial configuration of the conventional system "UV-source" =96 "cocoon star" =96 "Earth"; second, on the sensibility of our instruments,= photoplates of photoelectric receivers, etc. It should be mentioned that weak episodic phosphorescence can be observed only in the coolest IR bodies. Study of physico-chemical characteristics of crystalline hydrocarbons around the stars is on extremely difficult task; therefore, detection and investigation of weak episodic phosphorescence may help to clear up many points in this field. It is doubtless that luminescence spectrum of hydrocarbons depends on the structure of their molecules. Laboratory investigations have demonstrated that as the hydrocarbon molecular weight grows, the bands in the luminescence spectra shift towards longer waves. For instance, several additionally introduced atoms cause a 150-200 cm-1 change of frequency change by 600 cm or more. Proceeding from the above said and considering possible variety of molecules in stellar hydrocarbons one could hardly expect an apriori quantitative evolution of characteristics of such hydrocarbons to be possible. First, weak episodic phosphorescence has to be detected and its spectrum precisely recorded to be then compared with standard luminescence spectra of a number of terrestrial hydrocarbons. Differences between the compared spectra (line intensity, relative displacement) will indicate unambiguously to the main physicochemical characteristics of the distant stellar hydrocarbons. In the effort to discover and identify weak episodic phosphorescence one should keep in mind that luminescence as produce not by separate atoms or molecules but their combinations. Consequently, only bodies of certain shape and size produce luminescence in nature. The boundary of luminescence in such circumstances will be clearly visible and identifiable wherever the given body (or a combination of bodies such as dust particles) ends/begins. The phenomenon of weak episodic phosphorescence seems to be widely common in the univerce. In particular, it can occur in dark dust clouds or clusters rich in solid crystalline hydrocarbons. Recording of this kind of phosphorescence can be considered as a sort of a tool, an instrument for revealing the dark dust matter. The Earth's atmosphere is transparent for crystalline hydrocarbon phosphorescence owing to the dust shells around the cold stars. We believe that it is quite possible nowdays to observe and record However, extra-atmospheric observations seem to be more favourable in view of recording very weakly luminescing bodies. It could be concluded that we have considered the most general aspects of the problem. The luminescence properties of hydrocarbons of star dust shells can be also identified according to laboratory analysis of the cosmic matter samples to the earth. We hope that our work will attract attention and be properly appreciated and criticized. TABLE Laboratory Investigations Results of Crystalline Hydrocarbons of the Aromatic Serie 1 2 3 4 5 6 7 CH = =20 =20 White crystalline =20 Substance Blue 3980,4180,4450, 4870,5230 5050,5440 93.66 6.45 C23:3 H19.3 29 White crystalline Substance Violet 4130,4360,4650 4800,5070, 5470 92.98 7.00 ---------- ----- White crystalline Substance Violet 4030,4210,4480, 4900,5250 4850,5050, 5440 94.28 5.80 C24 H18.4 316 White crystalline Substance Yellow- green 4780,5050,5290 4820,5040, 5090,5460 93.97 6.02 C36 H27.8 459 REFERENCE 1.S.Pickelner. Physics of the Interstellar Medium. Moscow. 1959 (in Russian) 2.S.Kaplan. S.Pickelner. The Interstellar Medium. Moscow. 1963 (in Russian) 3.M.Grinberg. The Interstellar Dust. Moscow. 1970 (in Russian) 4.L.Melikadze, T.Eliava, et al. On the knowledge of the Nature of Petroleum Fluorescent Components. Tbilisi. 1958 (in Georgian) 5.L.Melikadze, D.Varfolomeev, et al. The Study of the Carbon Composition of Residual Fractions of Samgori Petroleum. Ac.Sci. Georgian SSR. V.98, N.2, 1980, p.349-352 (in Georgian) 6.I.Simonia. On Carbon Molecules in Comets. Astronomic-Geodetic Society, N.52, Moscow 1991 (in Russian) Hа сегодня все, пока! =SANA=

Дата: 23 апреля 1998 (1998-04-23) От: Alexander Bondugin Тема: Possible Two-Star Solar System Observed Привет всем! Вот, свалилось из Internet... UF ASTRONOMERS PART OF TEAM TO SPOT POSSIBLE TWO-STAR SOLAR SYSTEM April 20, 1998 Writer: Steve Orlando, sfo@ufl.edu Source: Charles Telesco, (352) 392-4455 GAINESVILLE --- In a discovery they say could shed new light on the genesis of our solar system, astronomers with the University of Florida and Harvard University have found a star surrounded by a disk of dust that may be forming planets. "It's very exciting. We don't see planets directly in this system, but there is indirect evidence of a planet," said Charles Telesco, the astronomy professor leading the four-member UF team. He said a wake-like void that appears in the disk is typical of what would be left by a moving celestial body. NASA is scheduled to announce the discovery at 11 a.m. Tuesday (4/21) at its headquarters in Washington, D.C. The find, made in mid-March, marks the first time such a disk has been confirmed to exist around a binary, or two-star, system, Telesco said. A similar dust disk was discovered about 14 years ago surrounding a single star, Beta Pictoris. "This may be the primordial dust that planets form from. These are the conditions that would have to be met for planets to form," said Scott Fisher, a UF graduate student who was part of the UF astronomy team. The UF/Harvard team made its find at Cerro Tololo, Chile, using a telescope at an observatory belonging to the National Optical Astronomy Observatories. At almost the same time, another team comprising astronomers from Cal Tech/Jet Propulsion Laboratory and Franklin & Marshall College spotted it using an observatory on Mauna Kea, Hawaii. Known as HR 4796A, the star is about 220 light years from Earth and about 47 billion miles from its companion star, HR 4796B. It is in the constellation Centaurus, visible primarily from the Southern hemisphere. Astronomers estimate HR 4796A could represent what Earth's solar system looked like in its infancy, Telesco said. The sun is about 5 billion years old, and the earth is about 4.5 billion years old. The HR 4976 pair, by comparison, is estimated to be about 10 million years old, which Telesco said puts the dust disk precisely in the proper planet-building time frame. "What we may be looking at is a solar system like our solar system but at a much earlier stage," Telesco said. If the entire dust disk has formed planets or is forming them, the solar system would be considerably larger than our own. Measuring from Pluto, the planet farthest from the sun, our system is about 80 astronomical units across. The HR 4976 disk is more than three times that size -- some 250 astronomical units. An astronomical unit is the distance from the earth to the sun -- about 93 million miles. However, Telesco said, planets may be forming only near the inside edge of the disk, an area roughly the size of our solar system. The teams have submitted documentation of their discovery to "Astrophysical Journal Letters," an astronomical professional journal. Funding for the project came from NASA, UF and the National Science Foundation. The UF-built, mid-infrared array camera that made the images of the disk-star is known as OSCIR, which stands for Observatory Spectrometer Camera for the Infrared. "The new generation of mid-infrared detectors is what made this discovery possible," said Telesco, whose team built the camera. "These sensitive cameras, when used on the world's best telescopes, will lead to an explosion of new results as exciting as the HR 4976 disk." He predicts the discovery will be of major significance, both in the astronomy world as well as elsewhere. "This will become a very famous object, I guarantee you," he said. "Beta Pictoris is kind of a touchstone; HR 4976 doesn't have as poetic a name, but it's very pretty to me." Hа сегодня все, пока! =SANA=

Дата: 23 апреля 1998 (1998-04-23) От: Alexander Bondugin Тема: US DOD Fireball Release Привет всем! Вот, свалилось из Internet... Forwarded from Peter Brown (PETER@danlon.physics.uwo.ca) Subject: US DOD FIREBALL RELEASE Fireball Detection On 9 December 1997, sensors aboard DOD satellites detected the impact of a meteoroid at 08:15:55 UTC roughly midway between Nuuk and Qaqortoq, Greenland. The object broke into at least 4 pieces. One piece detonated at an altitude of about 46 km at 62.9 degrees North Latitude, 50.9 degrees West Longitude. The remaining 3 pieces detonated in close proximity to one another at altitudes between 28 km, at 62.9 degrees North Latitude, 50.1 degrees West Longitude and 25 km at 62.9 degrees North Latitude, 50.0 degrees West Longitude. Fireball Detection On 11 January 1998, sensors aboard DOD satellites detected the impact of a meteoroid at 07:11:13 UTC roughly midway between Denver and Grand Junction, Colorado. The object was detected at 39.4 degrees North Latitude, 106.4 degrees West Longitude. ************************************************************************ PLEASE NOTE THAT THIS SATELLITE BOLIDE RELEASE AND ALL PREVIOUS SUCH RELEASES CAN BE FOUND ON THE WWW AT http://phobos.astro.uwo.ca/~pbrown/usaf.html Hа сегодня все, пока! =SANA=

Дата: 23 апреля 1998 (1998-04-23) От: Alexander Bondugin Тема: New Device Detects Plant Stress Earlier Привет всем! Вот, свалилось из Internet... David E. Steitz Headquarters, Washington, DC April 22, 1998 (Phone: 202/358-1730) Lanee Cooksey Stennis Space Center, MS (Phone: 228/688-3341) RELEASE: 98-67 NEW DEVICE DETECTS PLANT STRESS EARLIER Thanks to a new imaging tool developed at NASA's Stennis Space Center in South Mississippi, farmers and foresters may now be better able to detect unhealthy crops and trees before the damage becomes visible to the naked eye -- information that may be used to increase crop production. Developed by NASA's Bruce Spiering, an electrical engineer at Stennis, the Portable Multi-spectral Imaging System -- an evolution of the basic color television camera -- gives the viewer a picture of which plants are under stress. "Until now, there was no fast and relatively easy way to acquire multi-spectral, matched images," Spiering said. "This system allows the images to be processed and immediately displayed as they are acquired." The system provides researchers with a new tool for gathering this information. Multi-spectral imaging is the use of several individual parts of the light spectrum -- specific wavelengths of light -- to look at objects in different ways and to obtain many different types of information about the objects. The new imager has two benefits over earlier imaging systems. First, each component of the system can be adjusted so that separate images can be processed and combined automatically by application-specific signal processors attached to the system. This provides an instant multi-spectral view of the target while reducing the need for processing the image in a lab. Traditional collecting of multi-spectral information involved use of cameras that recorded information about a specific part of the light spectrum. Images in different wavelengths of light were then combined and processed at a later time. This was a time and labor-intensive process. Second, the use of off-the-shelf parts makes the imager easily adaptable to any application. One application of the imaging system being researched is the detection of plant stress in crops and forests. The new system currently is designed for use on the ground, but will soon be adapted for use in light aircraft. Plant stress is the adverse reaction of plants to environmental conditions that are unfavorable to growth, such as lack of sufficient nutrients, inadequate watering, disease or insect infestation. The reaction with which most people are familiar is a change in leaf color, but research has found that in many cases, pre-visible signs of stress can be detected using the proper instruments and techniques. Plant stress can be monitored, in part, by observing variations of the plant's reflectance in two specific wavebands of light. Relative levels of chlorophyll, the pigment that enables photosynthesis and gives plants their green color, can be determined by measuring the plant's reflectance of light in those parts of the spectrum. If the plant is under stress, its chlorophyll production typically decreases, which results in more light being reflected from the plant to the imager. "When used in this application, the multi-spectral imaging system along with the real-time processor immediately provides the user with an indication of the amount of chlorophyll in the plant's leaves," Spiering explains. "Previously, the process required the recording of multiple images of the same scene. The images were then matched and aligned with each other, processed and then made available for display only on a computer." Another possible application of the device would be to identify ice on the Space Shuttle external tank prior to launch. The system would record a near-infrared band image that could identify the location of ice, frost or condensing water, and would then record a second, thermal infrared image to determine the temperature at those locations. The system would combine those two separate images instantly to identify patches of ice on the tank. This application is based on a technique that uses thermal imaging to locate the colder areas on the tank where ice could form. This would be an extension of the work already being done at NASA's Kennedy Space Center, FL. The imager also can be modified for use as an instrument to detect hydrogen fires at such facilities as rocket test stands and other industries that use hydrogen. Hydrogen burns so cleanly that hydrogen fires are practically invisible to the human eye. Several imaging systems already exist for this application, but the Portable Multi-spectral Imaging System can be easily reconfigured to test different cameras and light filters to fine- tune the system for a variety of applications. -end- Hа сегодня все, пока! =SANA=

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