SB NEWS @ AMSAT $SPC1009 * SpaceNews 09-Oct-95 * BID: $SPC1009 ========= SpaceNews ========= MONDAY OCTOBER 9, 1995 SpaceNews originates at KD2BD in Wall Township, New Jersey, USA. It is published every week and is made available for unlimited free distribution. * COMET HEADED FOR BRIGHT ENCOUNTER * ===================================== A very unusual comet was discovered on 23-Jul-95, on its way from the outer reaches of the solar system towards the Sun. Although it is still situated beyond the orbit of Jupiter, it is so bright that it can be observed in even small telescopes. It has been named `Hale-Bopp' after the discoverers and is already of great interest to cometary astronomers. The comet is expected to pass about 120 million kilometres from Jupiter in April 1996, and it will approach the Sun to about 140 million kilometres when it passes perihelion in early April 1997. At the time of perihelion, the comet's geocentric distance will be about 200 million kilometres, the angular distance (`elongation') in the sky from the Sun about 45 degrees and it will be located in the northern sky at declination +45 degrees. It will actually by `circumpolar' in Northern Europe and therefore well observable all night from there. One possible cause for the unusual brightness of Comet Hale-Bopp at its present location, more than 200 million kilometres outside the orbit of Jupiter, is that it possesses a very large nucleus, that is the `dirty snowball' of dust and ice at the centre of a comet. The larger the diameter of the nucleus, the more sunlight will be reflected from its surface and the brighter will it appear. A corresponding estimate indicates that the diameter of its nucleus would be nearly 100 kilometres, as compared to about 10 kilometres for Comet Halley. If the orbital period is near 3000 years, the brightness near perihelion in April 1997 could reach magnitude -1.5. This means that Comet Hale-Bopp would become almost as bright as Jupiter which will also be visible in the night sky at that time. What is even more exciting, the comet would stay this bright during several weeks and be visible from the Northern hemisphere during many hours each night. It will even be above the horizon all night for observers located north of geographic latitude 45 degrees. Thus, in addition to providing a wonderful opportunity to astronomers for learning more about comets, Hale-Bopp may become an object of great public interest. This is especially so, because it is now almost 20 years since a comet has been this bright. The last one (Comet 1976 VI - which was discovered at ESO) attained this magnitude during a few days in early March 1976. At the present time, Comet Hale-Bopp is located in the southern constellation of Sagittarius and it is very well placed for observations from southern observatories. Irrespective of its performance later on, the unusual brightness at the present heliocentric distance already makes it a very interesting object for astronomers. Because of its unusual brightness, and in order to follow the future evolution of Comet Hale-Bopp, coordinated observations at La Silla are now being planned for the next several months. Thereafter, the comet will move behind the Sun as seen from the Earth and observations with the large telescopes will only become possible again in March 1996. There is no doubt, however, that from then on, its further development will be followed with great care by the observers. Better predictions for its brightness near perihelion will also become available. [Info via Dick Harris, KW8B] * IMAX IMAGES AVAILABLE * ========================= Several dramatic new images highlighting the historic docking of the Space Shuttle Atlantis and the Mir space station are available via the Internet. The high resolution images show crew activities and views of Atlantis taken from Mir. The images were recorded using the 70-mm IMAX camera system. The IMAX images are part of a larger photo gallery that includes images from the STS-71 docking mission and from STS-63, a mission flown earlier this year in which the Shuttle Discovery performed a rendezvous with the Mir that served as a dress rehearsal for the docking mission. Links to the collection can be found on the "Today at NASA Home Page" at URL: http://www.hq.nasa.gov/office/pao/NewsRoom/today.html [Info via NASA] * INFOESPACE ARCHIVES AVAILABLE * ================================= Archives of the French translation of SpaceNews, InfoEspace, are now available in the C:\INFOESP subdirectory of the Laval-Laurentides ARC BBS, VE2CRL.#MTL.PQ.CAN.NOAM. To request a copy of a back issue of InfoEspace, send a private message to the REQFIL server of VE2CRL. The server will automatically send the requested file to you. Use the following procedure to request a file from the server: SP REQFIL @ VE2CRL Subject: C:\INFOESP\ESPmmdd.yy @ homebbs Body of msg: CTRL-Z or /EX The files are named according to their date of issue, which is always a Monday. In ESPmmdd.yy, mm represents the month (e.g. 05 for May), dd is the date, and yy is the last two digits of the year (e.g. 94 or 95). Don't forget to specify your home BBS! 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Magliacane, KD2BD Department of Engineering and Technology Advanced Technology Center Brookdale Community College Lincroft, New Jersey 07738 U.S.A. <<=- SpaceNews: The first amateur newsletter read in space! -=>> /EX