As the days tick down to the December solstice, stargazers can engage in a little meteor watching as the Geminids meteor shower peaks during the nights of December 13-14, 2015. One of the best meteor showers of the year, the Geminids shows up to 100-150 meteors per hour in dark sky. This will be an excellent year because the waxing crescent Moon will set before the shower peaks.
The Geminids sometimes rivals August’s Perseid meteor shower for total numbers of meteors. They occur when Earth passes through a debris stream from the strange body 3200 Phaeton, which is either a rocky and defunct comet or an asteroid. This may explain why the Geminids are so bright: they’re little pieces of mostly rocky material which take longer to burn up as they fall into the atmosphere, whereas most meteor showers are caused by softer, icier debris from comets. The Geminids show up as mostly white and yellow, with perhaps 10% of Geminid meteors showing red, blue, or yellow. Geminids trace their path back to a point in the constellation Gemini near the bright star Castor. In good conditions, you might see one or two Geminids a minute near the peak.
You can see the Geminids anywhere in the sky, but they trace their path back to a point near the star Castor in the constellation Gemini. In the evening hours and near midnight in December, you will find Gemini rising in the northeastern sky above the distinctive shape of the constellation Orion.
Unlike the Perseids, which peak well after midnight, the Geminids are best seen about 11 p.m. when the radiant is high above the horizon. The period of peak activity is long lived, nearly 24 hours, so you can usually see the most meteors on the nights of December 13-14 and 14-15. Since Gemini is one of the northernmost zodiacal constellations, the radiant is much higher in the northern hemisphere and more meteors are visible. But many Geminids are visible from the southern hemisphere too.
Many northern observers, however, have to contend with the cold. As you sit back on a chair or lie back on a blanket, relatively motionless, you will find yourself growing cold quite quickly. Make sure you wear several layers of clothing, a good hat and pair of gloves, and bring an extra blanket or sleeping bag. A sip of good bourbon helps some stargazers feel warmer, but it does not really help your internal temperature. And it’s not good for the eyesight…