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165Oversky for November 2003: EXCELLENT ECLIPSE

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  • Erich Landstrom
    Oct 19, 2003
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      Oversky for November 2003: EXCELLENT ECLIPSE, MEDIOCRE
      METEORS
      Posted by Erich Landstrom, NASA JPL Solar System
      Educator

      The Moon is like a diva; if she�s not the star of the
      show, then she upstages everyone else. This month it�s
      especially true. There�s a total lunar eclipse at 8 PM
      on November 8th, when the Moon changes colors before
      our eyes. But then there�s the Leonid Meteor Shower on
      November 18th, when there is so much moonlight, the
      Moon will outshine all but the brightest meteors.

      On Saturday, November 8th, North Americans experience
      a TOTAL LUNAR ECLIPSE. Lunar eclipses occur whenever
      the full Moon passes through the Earth�s shadow. The
      shadow blocks most of the Sun�s light from reaching
      it, but a little light, passing over the edges of the
      Earth where sunrise and sunset is occurring gets bent
      by Earth�s atmosphere in toward the shadow, making our
      diva�s face flush. Luna�s Saturday evening performance
      begins around 6:30 PM and ends around 10 PM. The Moon
      begins entering the umbra (the darkest part of Earth�s
      shadow cone) at 6:32 PM. The first blush starts on the
      northeast corner, near the crater Pythagoras (I say
      �corner� and �Pythagoras,� but despite popular
      misconception, the ancient Greeks knew the Earth was
      round and not flat thanks to eclipses. The shape of
      curved shadow told them the Earth must be a sphere).
      The Moon will be totally eclipsed at 8:06 PM, at
      deepest eclipse at 8:19 PM, and will begin to exit the
      umbra at 8:31 PM. By 10:05 PM, it will have completely
      exited the umbra and be back to its usual frosty self.
      To review: eclipse starts at 6:32 PM, totality between
      8:06 and 8:31 PM, show over at 10:05 PM.

      Each eclipse is unique in how the Moon reflects the
      reds and oranges that tint the twilight sky during a
      totality. Anything in the air � hurricane clouds,
      volcanic dust, and forest fire ash � can affect the
      eclipse�s coppery coloration, changing the Moon�s
      muted grays in a range from dark brown to a freshly
      minted penny. Astronomers use a five-point scale of
      brightness (L = 0 being darkness and L = 4 being the
      brightest) known as the Danjon scale to measure how
      dark the shadow makes the Moon appear. The November
      issue of SKY AND TELESCOPE magazine has more pertinent
      information, or you can visit the website of the
      essential magazine of astronomy at
      www.SkyandTelescope.com/. This should be an excellent
      eclipse.

      But during November�s other great sky event, the Moon
      spoils the show in the predawn morning of Tuesday the
      18th. On November 18-19, the Earth transits though the
      tail of Comet Temple-Tuttle. Plowing into the bits and
      pieces of the comet's cloud of dust causes a
      spectacular light show known as the LEONID METEOR
      SHOWER, when the grit and gravel incinerate in the
      Earth's atmosphere due to friction. Meteors are the
      flashes of light caused by cometary debris hitting our
      upper atmosphere and vaporizing (and phenomena related
      to the ablation such as ionization). A combination of
      the dusty debris crashing down at 71 km/sec, and the
      relative velocities of the Earth, at a tangent heading
      toward the constellation Leo, make the meteor shower
      appear to radiate from the "sickle" of Leo the Lion.

      The celestial fireworks show should be returning to
      normal this year, producing 10-20 meteors per hour
      after having storm-level displays of 1,000 per hour in
      the last five years. But the Moon manages to upstage
      the meteor shower, by being in the wrong place at the
      wrong time. She positions her spotlight right in the
      midst of Leo on the 17th and 18th, a fat waning
      crescent phase that outshines the meteors and nearby
      Jupiter. At best, this will be a mediocre meteor
      shower.

      LUNAR ALMANAC NOVEMBER 2003 (All times are Eastern
      Time)
      November 2 & 3: Moon by Mars
      November 8: Full Moon (8:13 PM); total lunar eclipse
      November 10: Moon at apogee (406,301 km); lower high
      tides, higher low tides.
      November 13 & 14: Moon by Saturn
      November 16: Last Quarter (11:15 PM)
      November 18 & 19: Moon by Jupiter
      November 23: New Moon (5:59 PM); solar eclipse visible
      over Antarctica and Australia
      November 23: Moon at perigee (356,812 km); higher high
      tides, lower low tides.
      November 25: Moon by Venus
      November 30: First Quarter (12:16 PM)
      Tip: The full moon's diameter measures about 1/2 of
      one degree in the night sky.

      SOLAR ALMANAC NOVEMBER 2003 (All times are Eastern at
      the 80 deg. N. longitude of West Palm Beach. Add 20
      minutes to each time for each 5� west.)
      November 1: Sun Rise: 6:29 AM EST, Sun Set: 5:37 PM
      November 15: Sun Rise: 6:39 AM EDT, Sun Set: 5:29 PM
      November: Sun Rise: 6:50 AM EDT, Sun Set: 5:26 PM
      --------------------------------------------------------------------------------

      PLANET PLACEMENT
      VENUS (mag. -3.9) is caught in claws of Scorpius the
      Scorpion, low in the west at sunset.
      MERCURY (mag. -0.5) keeps close to Venus in Libra low
      in the west after sunset.
      MARS drops another magnitude (from mag. -1.2 to -0.4)
      as it moves through Aquarius. Its ginger glow is
      easily visible after sunset in the south, under the
      �circlet� of Pisces.
      SATURN shines (mag. -0.2) between the kneecaps of
      Castor and Pollux, the Gemini Twins, visible high in
      southwest at dawn.
      JUPITER beams brightly (mag. -2.0) at the hind feet of
      Leo in the southeast before dawn.
      EARTH eclipses the Moon the night of the 8th, and
      eclipses the Sun on the 23rd.

      Join the "science giant" Erich Landstrom on SCIFI
      OVERDRIVE radio program for science fiction, and
      science fact stranger sounding than fiction. It�s like
      Paul Harvey, with pointy ears. Listen to a broadcast
      Monday mornings on the Business Talk radio network and
      at www.scifioverdrive.com over the Internet!


      =====
      Erich Landstrom, NASA JPL Solar System Educator
      Solar System Educators Program http://www.ssep.org
      [Hands-on teacher training workshops sharing NASA's
      missions of research, discovery and exploration!]

      Science fiction & science fact stranger than fiction.
      Listen Monday mornings on http://www.SCIFIOVERDRIVE.com

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