Jimmy Westlake's Celestial News column appears Tuesdays in the Steamboat Today.
Find more columns by Westlake here.
Steamboat Springs If you enjoy watching the sky for shooting stars, mark the night of Oct. 8 on your observing calendar. You just might get treated to a flurry of meteors courtesy of the comet Giacobini-Zinner. Here’s the scoop:
A meteor shower can occur when the Earth crosses paths with an old comet. After many passes around the sun, a comet’s orbit fills with dusty debris, like a dust river flowing around the sun. Each year, the Earth plows through dozens of these dusty rivers, giving rise to our annual meteor showers. Some are nearly always spectacular, like the August Perseids and December Geminids, which produce scores of meteors per hour. Others are unremarkable, like the Alpha Puppids and Gamma Normids, which produce only a couple of meteors each hour. A few of our annual meteor showers have a dual personality, usually being unremarkable but occasionally flaring up and putting on a spectacular show. The November Leonids and October Draconids fall into this category.
The Draconid meteors are produced by dust particles shed by the short-period comet Giacobini-Zinner. This little comet first was discovered by astronomer Michel Giacobini in 1900 and then rediscovered by Ernst Zinner in 1913. It moves in a 6.6-year orbit around the sun and on each pass leaves a dense ribbon of dust particles in its wake. When Earth crosses this comet’s orbit every Oct. 8, the number of meteors we see depends on how close we come to one of these dense ribbons of dust.
Astronomers predict that this year Earth will clip the dense ribbon of dust created by the comet on its pass in 1900, briefly producing a burst of 600 meteors per hour on Oct. 8. But as with many things in life, timing is everything, and for the U.S., the timing is not good. If astronomers’ calculations are correct, the burst of meteor activity should occur over Europe, during daylight in North America. However, their predictions could be off by plus or minus seven hours. That could put us right in the thick of it, but even if it does, the nearly full moon will no doubt wash out most of the meteors. Still, the prospect of seeing dozens of the brighter meteors shoot across the sky makes it worth the effort.
So head outside right after darkness falls on the evening of Oct. 8 and look up. The constellation Draco will be high in the northwestern sky, near the bright star Vega, and the meteors will seem to stream from that region. With a little luck, we might get to see something spectacular — a Draconid meteor storm.
Jimmy Westlake teaches astronomy and physics at Colorado Mountain College’s Alpine Campus. He is an avid astronomer whose photographs and articles have been published all around the world. Check out Jimmy’s astrophotography website at www.jwestlake.com.