Field Notes

After starting out humid and rainy and finishing dry and not all that hot, the “Dog Days” of summer are finally at an end. This annual astrological event is to be closely followed by an annual celestial event – the Perseids Meteor shower.
The Perseids are always one of the most anticipated and sometimes showy meteor showers of the year and this year has the potential to be exceptional. The new moon will allow for dark skies, if the clouds will just clear out for a couple of days, providing a black background for what could possibly be up to 100 shooting stars per hour. And who doesn’t love a shooting star?
These fiery streaks of light should reach their peak on Wednesday night, August 12 into the early morning hours of Thursday, the 13th. The shower tapers off over the next few days but should still be worth watching.
As always, this showy sky show is brought to you by Swift-Tuttle, a periodic comet that makes a pass through these parts every 133 years. This dirty snowball was on a journey to slingshot around the sun in 1992, then head back out into the outer solar system. As the comet approached the sun, it began to warm up, vaporize and sluff off rock, water, ice and gases. A trail of dust was left in its wake which the earth passes through every year at this time as it rotates around the sun.
When the earth passes through this invisible dust tail, many of the speeding rock pieces are moving at upwards of 50 miles per second. The grain sized particles that penetrate our atmosphere are quickly burned up by the friction of slowing down, but not before leaving a bright, fiery tail in their path.
To best observe this overhead performance, head out to a wide open section of the yard or a field after dark where you have a good view of the sky. Take a blanket or a lawn chair and make yourself comfortable. Although shooting stars may show up anywhere, you should orient yourself toward the north east sky. Somewhere between the constellations Perseus – just east of the North Star, Polaris – and Cassiopeia, (look for the large tilted W) is where many of the meteors will begin.
As a bonus, keep an eye out for the International Space Station as it will be making a brief appearances in the same area. The ISS is bigger and brighter than any other satellite and very impressive. Look for it in the northern sky at these times:
Wednesday, August 12, 10:07 p.m.
Thursday, August 13, 9:15 and 10:50 p.m.
Friday, August 14, 9:57 p.m.
If you really want to check out that night sky, you can print off a great map at
If the clouds stay away, we could be in for some great star gazing.
Dave is a telescope operator at the Green Bank Observatory and can be contacted at

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