BID: $SPC0809 ========= SpaceNews ========= MONDAY AUGUST 9, 1993 SpaceNews originates at KD2BD in Wall Township, New Jersey, USA. It is published every week and is made available for unlimited distribution. * STS-51 NEWS * =============== Workers continue to prepare Space Shuttle Discovery for the upcoming STS-51 mission. The ACTS-TOS deployment and the deployment and retrieval of the ORFEUS-SPAS science satellite will highlight this mission. A spacewalk is scheduled as well. The crew will have the opportunity to evaluate several tools that may be used during the servicing of the Hubble Space Telescope during the STS-61 mission later this year. Launch is scheduled for August 12 at 9:10 AM EDT. Mission duration is 8 days with the possibility of a one-day extension. The STS-51 mission will conclude with a landing at the Kennedy Space Center. [Info via NASA] * METEOR STORM ALERT * ====================== Astronomers predict the possibility of exceptionally high meteor activity on the night of August 11-12, 1993. If the prediction proves to be true both astronomers and the general public might be treated to a spectacular rain of shooting stars of an intensity that is seen only a few times in a century. If it actually occurs, the event can be easily observed with the naked eye. The possibility that sky-watchers will be treated to a spectacular celestial pyrotechnics show in the night of August 11-12 during the annual Perseid meteor shower has greatly increased since the re-discovery last September of the parent comet of the meteor stream, named Swift-Tuttle. The meteoroids in the Perseid stream are derived from the dust emitted by Comet Swift-Tuttle as it moves in its orbit about the Sun. This dust is dispersed along the entire orbit of the comet, but the concentration is the greatest in the vicinity of the comet itself, where recently ejected material is still present. Since Comet Swift-Tuttle only "just" passed through the inner Solar System (late in 1992) the Earth will actually encounter the main dust-belt located behind the comet on August 11-12, 1993, as a consequence of which we may see a very strong meteor shower. The first indications that the Perseid stream might produce something unusual this year were found by the International Meteor Organization when an analysis of world-wide observations in 1988 and 1989 revealed slightly increased Perseid activity. In 1991, the shower produced a rate of many hundreds of meteors per hour for about an hour for Japanese stargazers, while an even more spectacular display was observed in Asia and Eastern Europe in 1992. This year, the passage of the Earth through the comet's orbit only a few months after the comet passed the same location leaves open the chance that we might encounter a very dense collection of dust and even be witness to an outburst stronger than in 1991 or 1992. This geometry might even lead to a "storm" of shooting stars. Meteor storms are characterized by meteors occurring at the rate of one every few seconds and sometimes as high as several per second. Real meteor storms are very rare events. In the last two centuries, strong meteor storms have taken place on only a handful of nights: November 13, 1833 (America), November 14, 1866 (Europe, America), November 27, 1872 (Europe), October 9, 1933 (Europe), October 9, 1946 (America), and November 17, 1966 (America). Contrary to most other rare astronomical events, such as eclipses, a meteor storm may be seen only once in a lifetime. It can be observed only on the night side of Earth. Also, unlike eclipses, meteor storms cannot be predicted in advance with certainty as it is impossible to know precisely the dust distribution around the parent comet's orbit. However, the conditions that MAY lead to a meteor storm can be calculated beforehand. The encounter geometry in 1993 is similar to that of another meteor shower, the Leonids, in 1833 when a most spectacular meteor storm occurred. Some witnesses compared the 1833 event to a snow storm. During the meteor storm of 1966, meteor activity reached 40 meteors per second. Some observers were left with the impression that the Earth was traveling through a tunnel of shooting stars at an incredible speed. The present calculations suggest that meteor activity will be at its climax near 0100 Universal Time on August 12, 1993. This timing favors Europe and may include Eastern North America, as observers there might witness the event during the night of August 11 - 12. The exact time is also somewhat uncertain; storm activity could occur as much as 6 hours on either side of this time. Even if storm activity does not occur, a spectacular outburst as in 1991 and 1992 remains very likely. Hence it is more than worth-while to watch the Perseids during the night of August 11-12. Higher than normal activity might furthermore extend to the nights of August 9, 10, 12, and 13 as well. The best period to watch the shower on these other nights is from midnight until dawn local time, though, because the position of the point in the sky where the meteors appear to radiate from is higher at those times. Whatever the 1993 display produces it will go down in history as one of the most waited for showers ever. [Info via the International Meteor Organization] * THANKS! * =========== Thanks to all those who sent messages of appreciation regarding SpaceNews, especially: KC1CO XE1RK DL3SET * FEEDBACK/INPUT WELCOMED * =========================== Mail to SpaceNews should be directed to the editor (John, KD2BD) via any of the following paths: FAX : 1-908-747-7107 UUCP : ...catfish.ocpt.ccur.com!ka2qhd!kd2bd PACKET : KD2BD @ NN2Z.NJ.USA.NA INTERNET : kd2bd@ka2qhd.ocpt.ccur.com -or- kd2bd@amsat.org MAIL : John A. 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