It’s coming on Aug. 11, 2013: the Perseid meteor shower

Last year, during the annual Perseid meteor shower, the moon in the cloudless skies was at the start of a bright crescent phase and outshone the meteor shower every night. Now it’s time again for the Perseids to dazzle us and this year the shower comes a few days prior to the moon’s first quarter. In addition, the moon will be setting early in the evening, allowing a dark, moonless night stage for the meteors to dance upon.

You can observe the shower with no equipment, not even a telescope or binoculars. Find an area that is dark, away from streetlights and stores. Best would be away from any buildings or mountains. Find a dark open sky. The meteors may streak through the sky from any direction, at any angle. They are pretty much unpredictable. But once you see one, you see more. Maybe many more. The shower should spray 20 to 30 meteors every hour starting around 4 am on the mornings of August 11th through the 13th.

Why is there a shower of meteors this time each year? In the days from mid-July to this time in August, the earth, on its orbit around the sun, intersects the longer, more elliptical path of the Swift-Tuttle comet. The comet, like all comets, is not a stable ball like a planet, moon, or even an asteroid. Comets hurtle through the solar system, spewing gases and scattering debris from rocks coming loose from them. Not having any significant gravity, as they are so relatively small, comets lose their debris. These pieces of the comet entering our thick atmosphere at more than 100,000 miles per hour and burning up, are what we call the Perseid meteor shower.

Here’s a video of last year’s shower: http://www.youtube.com/watch?v=_zLVdE6ElHE

The intensity and beauty of any particular year’s shower is just a matter of how thick the matter coming loose from the comet is at the point, lasting three weeks or so, that our world crosses the path of the comet.

This meteor shower was named “Perseids” because,  at the time of year the shower occurs, the constellation Perseus is directly above it. Perseus was a hero in Greek mythology. He was the son of Zeus and a mortal woman, Danae. The blaze of the meteor shower commemorates Zeus “visiting” Danae in a shower of golden light.

Of course, the location of the shower in front of any constellation is arbitrary. The Perseus constellation is composed of stars light-years distant  from the meteor shower.