This weekend of December 13th and 14th will mark the peaks days of the annual Geminid Meteor Shower, one of the better meteor showers of the year. The shower rivals the famous Perseid and Leonid shows, and this year may out class both. Even though the event will occur during the Last Quarter Moon rising near midnight on both nights, there will be ample time to watch for the meteors during the evening hours for a change. Most showers are best observed after midnight until dawn.
This year the radiant, in the constellation Gemini, will be fairly high in the southeast by midnight. The two twin stars Castor and Pollux mark the location near the radiant. This the point where the meteors will appear to originate, but they can be seen in every portion of the night sky. Even after the moon has risen higher in the sky after midnight until dawn, the shower traditionally produces very bright meteors which will not be washed out by the moon’s glare. A watcher can expect to log up to 50-80 meteors per hour. A superior show can produce upwards to 120 meteors per hour.
Another novelty about this shower is the meteors often appear in colors, principally in white, reds and greens. Although most meteor showers are due to the Earth passing through remnant comet debris, the parent object of the Geminid shower is believed to be the small asteroid Phaethon crossing the Earth’s path. The elongated orbit of Phaethon brings it very close to the Sun, prompting some astronomers to believe the object may well be a burn out comet. This is supported by the asteroid supporting a short tail in recent years. This may be due to the Sun scorching it’s surface to the point that small portions of the asteroid crumbles apart into dust, resembling a cometary trail of debris. The asteroid is small, only 3.2 miles in diameter.
To view the shower start watching about mid-evening until dawn as your schedule permits. Most watchers usually view the sky at comfortable intervals of an hour or so. Since the weather in December is usually quite chilly, taking an indoor break periodically is recommended. When outside, dress warmly and be sure you allow time for getting your “Night Eyes”, or letting your eyes adjust to dark seeing. Should you have enough time and patience, you may want to also try some time-lapse photography using a wide-field, tripod mounted digital camera. It will take a good bit of luck and lots of camera memory, but success will put you in a much sought after club of sky photographers (see top frame) .
Although the peak of the shower is this weekend, plenty of bright meteors may be spotted several days before and after. Some Geminid meteors have been spotted as early as December 1st this year.