Jimmy Westlake's Celestial News column appears Tuesdays in the Steamboat Today.
Find more columns by Westlake here.
Steamboat Springs The annual Perseid meteor shower is in progress and is scheduled to reach its peak tonight. Although some meteor showers can disappoint because of less-than-expected activity, the Perseid meteor shower is the "Old Faithful" of meteor showers, regularly producing 40 to 60 meteors per hour at its peak. Even a bad year for the Perseid makes for exciting meteor watching.
The Perseid meteor shower has been observed in mid-August every year since at least 258 A.D., when the Romans martyred a Christian deacon named Laurentius on a hot gridiron. That night, as Laurnetius' family and friends carried away his body, they noticed a number of bright streaks falling through the sky, and they marveled at the miracle, believing that the streaks were the fiery tears of Laurentius falling from heaven. For centuries after that August night, people across the world have continued to marvel at the sight of "St. Lawrence's tears" each summer.
We now know that the streaks of light are produced when tiny bits of space dust, shed by Comet Swift-Tuttle, enter the Earth's atmosphere at 130,000 mph and burn up as meteors about 60 miles high. These dust particles are so tiny that you easily could hold 1,000 of them in the palm of your hand.
The August meteors seem to fan out from a point in the northeastern sky within our constellation Perseus, so the meteor shower is named the Perseid meteor shower. The night of peak activity is Aug. 11 to 12, but some Perseid meteors can be seen for about a week on either side of that date. You always will see the most meteors between midnight and dawn because that's when Earth has you facing the direction from which the meteors are coming.
This year, the bright waning gibbous moon will wash out many of the fainter meteors after it rises at about 10:30 p.m., but there still should be plenty of medium to bright "shooting stars" to keep you awake. Try facing a part of the sky with the moon at your back, or stand with the bright lunar orb behind the edge of a building to block it from view. This will help keep your eyes adapted to see the most meteors.
Last week, veteran meteor forecasters Jeremie Vaubaillon and Mikhail Maslov predicted a brief but dramatic spike in Perseid activity between 2 and 3 a.m. MDT on the morning of Aug. 12. During that hour, meteor counts could jump as high as 200 or so as the Earth plows through a dense thread of dusty debris shed by Comet Swift-Tuttle in the year 1610. If you go outside to watch meteors for only a single hour, this is the hour you should choose.
So, grab that comfy recliner and sleeping bag, some insect repellant, and a Thermos of your favorite hot beverage, and watch the sky for St. Lawrence's tears. You never know when the next big one will flash into view.
Professor 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 Westlake's astrophotography Web site at www.jwestlake.com.