Tuesday, December 27, 2011
Jimmy Westlake's Celestial News column appears Tuesdays in the Steamboat Today.
Find more columns by Westlake here.
On any given night of the year, a single observer can expect to see about five or six shooting stars, or meteors, every hour of the night. These sporadic meteors can dart randomly from any direction in the sky. But there are certain nights of the year when a single observer can see 10 times that many meteors or more, all coming from the same direction in the sky. These are the nights of our annual meteor showers, each caused when the Earth plows through the dusty wake of an old comet tail.
The most reliable annual meteor showers are the Perseids seen every Aug. 11-12, the Geminids every Dec. 13-14 and the Quadrantids every Jan. 3-4.
The source of the tiny particles that make our Quadrantid meteor shower is uncertain, but it might be a burned-out comet called 2003 EH1. Early risers on the morning of Jan. 4 might see as many as 40 to 60 meteors per hour before sunrise.
The Quadrantid meteors seem to fan out from a point in the sky just below the handle of the Big Dipper, which hangs high in the northeastern sky in the pre-dawn hours of Jan. 4. The shower is named for a defunct constellation called Quadrans Muralis, or the Wall Quadrant, which in modern times has been absorbed into our constellation of Bootes, the Herdsman.
The Quadrantid meteor shower is less well known than the August Perseids or the December Geminids for a number of reasons. First and foremost is the cold winter air on January mornings in the northern hemisphere. Brrr! It takes a dedicated meteor watcher to crawl out of a nice, warm bed at 3 a.m. and stumble out into the sub-freezing or even sub-zero temperatures. Complicating things further is the fact that the peak of the Quadrantid meteor shower is very brief, lasting only a few hours at most. Timing is everything, and the timing this year favors folks living in North America. This year’s peak is predicted for just after midnight on the morning of Jan. 4. The moon will be a fat waning gibbous phase that morning and won’t set until 3:21 a.m., but that still will allow a couple of dark hours before dawn breaks to watch these very fast meteors zip across the sky.
Jimmy Westlake teaches astronomy and physics at Colorado Mountain College’s Alpine Campus. Check out “Jimmy’s 2012 Cosmic Calendar” of sky events at www.jwestlake.com. It features 12 of his best astrophotographs and a day-by day listing of cool celestial events that you and your family can have fun watching in 2012. Proceeds from the sale of Cosmic Calendars support the CMC SKY Club.