For the next few nights, Draco the Dragon will be spitting out meteors, also known as shooting stars. The Draconid shower is predicted to produce the greatest number of meteors on the night of October 7, 2013. Watch for them first thing at nightfall. Fortunately, the thin waxing gibbous moon won’t obtrude on this year’s Draconid meteor display. In fact, the moon and planets set in the southwestern sky around nightfall, serving as a wonderful prelude to tonight’s Draconid meteor show.
If you live at middle and far northern latitudes anywhere around the globe, this shower is well worth a try. Unlike many major showers, the radiant for the Draconids is highest up at nightfall, so it’s best to watch for these meteors as soon as darkness falls, not in the wee hours before dawn. Spend an hour or more under a dark and open sky, lying down and with your feet pointing northward. Oftentimes, this hard-to-predict shower doesn’t offer much more than a handful of languid meteors per hour. But watch out if the Dragon awakes! Once again, watch at nightfall and early evening because that’s when the radiant point for the Draconid shower is highest in the nighttime sky.
This shower produced awesome meteor displays in 1933 and 1946 – with thousands of meteors per hour seen in those years. Even two years ago – in October 2011 – people around the globe saw an elevated number of Draconid meteors, even though the moon was bright that night. European observers saw over 600 meteors per hour in 2011.
As far as we know, nobody is calling for the Draconid meteor shower to burst into storm in 2013. But you never know for sure with the Draconids, so it’s worth watching out for on the moonless evenings of October 7 and 8. Just keep in mind that meteor showers are notorious for defying predictions, either surpassing or falling shy of expectation, so you never know for sure.
Most meteor showers are named for the constellation from which the meteors radiate on the sky’s dome. The Draconids, however, are sometimes also called the Giacobinids, to honor the man who first sighted the comet that spawned this meteor shower.
Michel Giacobini discovered this comet on December 20, 1900. Another sighting in 1913 added Zinner to the name of the comet, 21P Giacobini-Zinner. It is a periodic comet, which returns every 6 years and 4 months. Tracking this comet, and noting this October meteor shower, helped astronomers figure out how to predict meteor showers in 1915. The great Draconid/Giacobinid meteor storms occurred in 1933 and 1946. The comet returned in 1998 as well, and the Draconids picked up that year, but only to a rate of about 100 per hour. Then last year, 2011, observers in Europe saw over 600 Draconid meteors per hour.
Why was the meteor shower so good in 2011? And why is it good in some years but not in others? Comet Giacobini-Zinner was at perihelion – closest to the sun – in 2011. Meteors are debris from comets, so when a parent comet is nearby, a good meteor shower is possible.
In 2013 – approximately two years after the comet’s 2011 perihelion (closest point to the sun) – there might be another meteor storm around the time of this shower’s peak. Or there might not be.
Perhaps the rates could go up this year. Or we might see only a handful of meteors per hour. Under normal conditions, when astronomers speak of a meteor shower peaking, it is similar to a weather forecaster saying, “The heaviest rain/snow is predicted for such-and-such hour.” In other words, the prediction might not be precise, since nature is always unpredictable to a degree. But the rate of the meteors is higher during the peak of a meteor shower than on any other night.
For tips on viewing meteor showers read this EarthSky article.
For a taste of history related to this shower, go to the Astronomy Abstract Service from the Smithsonian and NASA and find a 1934 article called “The Meteors from Giacobini’s Comet” by C.C. Wylie. It is an account of the famed meteor storm of 1933.
If you want to try your luck, lie down on a reclining chair and look upward, starting at nightfall. Find as much open sky as possible. How many Draconid meteors can you count in the moon-free skies these next few evenings?