Geminid Meteor Shower

Geminid Meteor Shower:  During December, Arizonans are treated to our best meteor shower, the Geminids.  Each year the Earth passes through the debris trail of a long-dead comet, and small particles of the former comet’s nucleus become visible in the sky as flashing meteors as they burn up in Earth’s atmosphere.  These December meteors appear to come from a spot in the zodiac constellation of Gemini, and so are known as the “Geminids.”

Under the best conditions (a dark sky and with Gemini high in the sky) observers may see as many as 60 meteors per hour shooting in all directions from a point near the bright stars Castor and Pollux in eastern Gemini.  Pairs or teams of observers will see more meteors than will a single observer, as they can watch more of the sky simultaneously.

Meteors have spread out along the old comet’s orbit, but the best displays should appear on evenings between the 10th and the 14th, with the very best displays on the evenings of the 12th 13th and the 13th – 14th.

In mid-December the constellation of Gemini rises just after sunset and it is visible all night, so the Geminid meteors should also be visible all night. However, one can see more meteors when Gemini is high in the sky, so try to observe at or after midnight. Also, when the Moon is high in the sky and bright, the sky will be brighter and this interferes with seeing fainter meteors.
In 2005 the Full Moon severely interfered with meteor watchers, but in 2006 the Moon rises much later, giving evening Arizona observers prospects of excellent meteor watching.
Moonrise times for 2006 are:

11:06p.m. the evening of December 10th;
12:02a.m. the morning of the 12th;
12:57a.m. the morning of the 13th, and
1:52a.m. the morning of the 14th.

Note that meteor watching is strictly a naked-eye observing event!! Binoculars or a telescope severely narrow one’s field of view, and since meteors may appear anywhere in the sky, a clear view of the sky is all one needs to glimpse bright Geminid meteors.

Those with a tripod-mounted film or digital camera set to take longer (“time”) exposures may be lucky enough to photograph a bright meteor. Set the camera on a tripod and point near Gemini. Use exposure times of 1 minute to 5 minutes (or longer if in a location with dark skies!). Feel free to experiment!