From: parish@cactus.org (Tom Parish)
Subject: Skywatch - Nov 15-21 - Meteors Spark up the Night
Keywords: McDonald Observatory, Star Date, Skywatch column
Organization: Capital Area Central Texas UNIX Society, Austin, Tx
Date: Wed, 18 Nov 1992 03:40:39 GMT

If there is interest I will post the weekly Skywatch written by 
Jeff Kanipe who is editor of Star Date Magazine.  We have been 
making these columns avaiable via FidoNet on a couple of the 
echoes (ie. Astronomy, Space) for the last 18 months.  
 
Various FidoNet users who also read sci.space on USENET have asked
me about posting Skywatch here. 
 
So here it is ... you tell me if you "really" want it here.
 
Thanks,
Tom Parish
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Star Date                                                        Turning Point
     
                                 SKYWATCH
                              November 15-21
          
                        Meteors Spark up the Night
                              by Jeff Kanipe
                         Editor of Star Date Magazine
     
 
                                  PLANETS
 
     * Mercury is in inferior conjunction and not visible this month.
     
     * Venus is the bright "evening star" in the west after sunset. It
     sets about two hours after sunset.
     
     * Mars rises mid-evening in the constellation Gemini.
     
     * Jupiter is the "morning star," rising in the east-southeast
     about four hours before the sun.
     
     * Saturn is low in the south at sunset in Capricornus. It sets
     about midnight.
     
                                  EVENTS
 
     Nov. 15: Algol is at minimum brightness.
     
     Nov. 15: Mars is five degrees north of the waning gibbous moon.
     
     Nov. 17: Leonid meteor shower in the early morning hours. Moon
              interferes.
     
     Nov. 17: Last quarter moon.
     
     Nov. 18: Algol is at minimum brightness.
     
     Nov. 19: The moon is at perigee, 369,741 km (229,745 mi).
     
     Nov. 20: Jupiter is seven degrees north of the crescent moon. 
 
     
                         THE LEONID METEOR SHOWER 
                         ------------------------
                
     Most years, the Leonid meteor shower tends to be rather hum-drum.
     At most, one can expect to see maybe 10 to 20 meteors per hour
     zip fleetingly across the sky from a dark location out in the
     country. But every thirty-three years, this shower suddenly
     becomes a storm of "shooting stars." The last major storm
     occurred in 1966 when observers in the central United States saw
     over 5,000 meteors per hour!
     
     Although this is not the year of the storm--that won't happen
     until we get closer to 1998 or 1999--the shower still bears
     watching because the intensity of the shower should increase the
     closer we get to its storm year. Why does a storm happen only
     occasionally? The answer doesn't have as much to do with where
     meteors are in space as much as it has to do with where comets
     are--the sources of the meteors we see in meteor showers.
     
     Comets are like those snow-encrusted cars you often see
     barreling down the freeway in winter, leaving in their wake an
     icy, blustery trail. When a comet comes out of the deep freeze
     of deep space and visits the inner solar system, its surface is
     warmed by the sun. Part of its icy crust suddenly turns to
     vapor, which blows off the comet's surface, leaving a delineated
     path of debris through which Earth passes at a specific time of 
     the year. The "blowback" material contains ice, dust, and small
     gravely material--stuff that later burns up in our atmosphere
     during a shower.
     
     The Leonids in particular are composed of debris from periodic
     Comet Tempel/Tuttle. This comet has a period of 33.176 years. As
     the comet approaches the solar system, it brings with it a
     concentrated trail of debris, which Earth passes through. When
     this happens, we see a greater display of meteors than usual.
     
     Look for the Leonids on the morning of November 17. Although the
     last quarter moon interferes somewhat, the sky should be dark
     enough to see some of the brighter meteors. Leo rises in the
     east around 1:30 a.m., local time, just as Earth is meeting
     these meteors head on. The greatest number, however, will be
     seen when the place in the sky from which the meteors appear to
     radiate (near the Lion's "sickle") is halfway up in the eastern
     sky, and that occurs around 4 a.m.
     
     You can expect to see a half-dozen or more meteors per hour. Then
     again, if we pass through a "knot" of debris, as occasionally
     happens with the Leonids, you may see a brief flurry of meteors.
     Who knows what you may see? I can guarantee, however, that if
     you remain in bed, you won't see anything at all. 
 
     
     --------------------------------------------------------------
          
     Jeff Kanipe is editor of Star Date Magazine, published by
     McDonald Observatory at the University of Texas at Austin. Write
     to Star Date at 2601 University, Room 102, the University of
     Texas at Austin, Austin, TX 78712 for subscription information.  
     It is very reasonable in cost, informative and colorful.
  
     Copyright 1992 The University of Texas McDonald Observatory.
     Material is intended for personal education and should not 
     be rebroadcast in any written or verbal form without 
     prior permission from the University of Texas.
 
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                   Radio Program on the Turning Point.
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