Oct 292011  Each year Earth passes through the dusty path that
comet Halley takes through our solar system.  In fact, Halley’s
orbit and the Earth’s orbit intersect twice; once in early
summer and once in the fall.  As we pass through the dust trail,
the small bits the comet leaves behind impact the atmosphere. 
The sand sized grains hit at roughly 148,000 miles an hour. 
Friction heats them to the point that they glow, and we see them
as meteors.  The rendezvous in early summer produces the meteor
shower known as the Eta Aquarids.  That stream usually peaks
about the 6th of May.  The spot in the sky that they appear to
come from is in the constellation Aquarius, is fairly low on the
horizon and is only visible right before dawn.  The event more
conveniently positioned for northern hemisphere viewers is the
fall one.  Since the meteors associated with Halley appear to
come from near the constellation Orion, they are known as the
Orionids.  Like most meteor showers, the Orionids last a couple
of weeks.  The nu