A Shower of Stardust: Prospects for the August Perseid Meteor Shower
August 2020 :
After more than 45 years of enjoying the splendor of the heavens, I still look forward to a simple yet rewarding observing experience watching “burning rocks” falling from the sky. I’m referring to a meteor shower. There are about a dozen major meteor showers and hundreds of minor ones. During August we are fortunate to encounter the second most productive (the December Geminids are better) meteor display of the year — the Perseids. These meteors are a stream of particles stripped off Comet 109P/Swift-Tuttle’s surface by the solar wind and left in orbit around the Sun. Annually the Earth passes through this stream and we experience a display of shooting stars.
For 2020 the Perseids peak on the night of August 11-12, with the best time to observe as many meteors as possible between midnight and dawn. This shooting star display is the northern hemisphere’s most widely observed meteor shower because people spend more time with outdoor activities during late summer. Unfortunately, a last quarter Moon rises around midnight not far from the radiant point in the constellation Perseus from where the meteors appear to emanate. The Moon’s brightness will somewhat reduce the number of meteors to be seen. While the Perseid shower can produce between 60 and 90 meteors per hour, around southern New England we can usually expect to see no more than 60 shooting stars per hour. Moonlight will further reduce that number this year.
The Perseids, no larger than a thumbnail, blaze across the heavens at 134,222 miles per hour and completely disintegrate as they plunge through our atmosphere. In fact, J. Kelly Beatty, senior editor of Sky & Telescope Magazine, makes this analogy. “The little nuggets in Grape-Nuts cereal (see accompanying photo) are a close match to the size of particles that typically create meteors in our atmosphere.” The Perseids are usually green, red or orange in color. And some members of this shower are bright and often produce exploding fireballs. Also, fireballs may be more prevalent as we approach morning twilight. Why? At that time, we are hitting the meteor stream head-on! Maximize your viewing opportunity by finding a dark sky location well away any from light pollution.
The best way to observe any meteor shower is to get comfortable on a chaise lounge or blanket. During the Perseids you must protect yourself from the hungry mosquitoes. (Last summer the EEE virus prevented many of us from observing the Perseids. I prefer the cold December Geminids any day!) Perseus is well up in the northeast sky after midnight. Use the accompanying sky map to locate this star pattern above the northeast horizon. If you can identify the constellation of Cassiopeia, which looks like an “M” or “W” tipped sideways, then you’re close enough. As Perseus rises higher the number of meteors will increase. Don’t simply concentrate your gaze in that direction. The meteors can appear anywhere in the sky, so constantly scan as much of the heavens as possible without straining your neck. If the weather cooperates and you have the time, continue your observing session until dawn’s early light overwhelms the stars.
If the weather does not cooperate or you are unable to observe on peak night, try your luck on the nights before and after. You won’t see 60 meteors per hour, but you may catch a couple of dozen or so. And if you happen to see a stationary meteor (think about it—it’s headed directly at you), don’t forget to duck!
And finally, while you are out there under the stars please take notice of Jupiter and Saturn. They will be located to the east (left) of the teapot asterism that is the constellation Sagittarius. Next month I will provide a brief observer’s guide to these beautiful distant worlds.
Keep your eyes to the skies.
Dave Huestis is Skyscrapers Historian and has been contributing monthly columns to local newspapers for nearly 40 years. See more at http://theskyscrapers.org/dave-huestis