Meteor(ocre) Prospects for the Geminid Meteor Shower
Last month I reported on the mini-storm for the Draconid meteor shower on October 8 over Europe. We saw little or no activity here. I still had hopes for the Orionids on the night of October 21-22. Unfortunately as the time approached the midnight hour the clouds rolled in. They hung around until sunrise. Outside of our local area some folks were more fortunate. See the following web site for a few images of meteors streaking across a cloud free sky: http://www.space.com/13363-photos-orionid-meteor-shower-2011-skywatchers.html.
I am writing this column before the meteor showers of November, so I’ve got my fingers crossed that despite interfering moonlight with both of them we have some chance of observing a few shooting stars.
We amateur astronomers have had quite a poor year of enjoying our hobby. The weather has been absolutely horrible. If the precipitation keeps up its year-long trend I fear we may be snowbound this winter. The Winter Solstice begins at 12:30 a.m. on December 22. Note how low the Sun travels in its arc across the southern sky.
The last major meteor shower of 2011 peaks on the night of December 13-14. This annual shower, known as the Geminids, is the most consistent meteor shower of the year, producing 60+ meteors per hour at peak under the best dark sky conditions we have here in southern New England. We can always hope that the weather will cooperate, but unfortunately the waning gibbous Moon (Full on the 10th) will somewhat reduce the number of meteors one can observe. What makes conditions even worse is that the Moon will rise around 8:28 p.m. locally and will be in the sky the rest of the night.
Unlike some of the other major meteor showers, the Geminids can be observed early in the evening. Why? Gemini, the constellation from where the shooting stars appear to radiate, is about 30 degrees above the eastern horizon by 9:00 p.m. (The actual radiant point is very near Gemini’s bright stars Castor and Pollux.) Unfortunately that bright Moon will be sitting in the adjacent constellation of Cancer. Therefore you will want to look in any direction away from the direction of Gemini and the Moon.
You’ll know you’ve seen a Geminid if you can trace the origin of the meteor’s trail back to the radiant point near Castor and Pollux. Seldom do meteors begin exactly at that point in the sky. An observer needs to scan as much of the sky as possible, constantly shifting your gaze high and low, right and left.
While the above stated conditions seem somewhat dire, the Geminids do deserve your attention, even if it is for only a couple of hours. An observer shielded from unwanted light pollution may still see 30 or so meteors per hour. The Geminids are fairly bright and moderate in speed, hitting our atmosphere at 21.75 miles per second. They are characterized by their multicolored display (65% being white, 26% yellow, and the remaining 9% blue, red and green). Geminids also have a reputation for producing exploding meteors called fireballs.
Remember that while you’re out there watching for “burning rocks” to fall from the sky, dress warmly and get comfortable. Just don’t fall asleep! I want you to survive to observe another night.
We can only hope that the last shooting star display of 2011 will shower us with a few cosmic gifts from the sky.
Just a quick FYI: on December 10 a total lunar eclipse will occur. It will not be visible to us in the eastern United States. However, if one travels to the west coast you will be able to see a portion of totality as the Moon sets. Further west to Asia the eclipse will be seen in its entirety. Let me know if you are fortunate to view this event.
Don’t forget to visit the local observatories to enjoy the wonders of the heavens. Throughout the winter months Jupiter will be the center of attention, as well as the beautiful Orion Nebula. Seagrave Memorial Observatory in North Scituate is open to the public every clear Saturday night, though it will be closed on December 3. Also, Ladd Observatory in Providence is open every clear Tuesday night. Frosty Drew Observatory in Charlestown is open every clear Friday night year-round. Be sure to check all the websites for the public night schedules and opening times before visiting these wonderful facilities. Wintry conditions can force unexpected closures.
Clear skies to all and happy holidays.
David A. Huestis