Every year at this time, the Earth passes through the orbit of a comet called Swift-Tuttle, and the result is a meteor shower -- shooting stars, perhaps 50 or 60, and occasionally as many as 100 per hour -- streaking across the night sky as debris from the comet enters the earth's atmosphere and burns up.
If you're reading this story on Friday or later, you've missed the peak, but there are still likely to be a good number of meteors tonight. Diligent stargazers have spotted Perseid meteors -- so-called because they appear to come from the constellation Perseus in the northern sky -- two or three weeks before or after the best night.
This year happens to be a particularly good one if you'd like to wish upon a star. There was a new moon Monday night, which meant the sky would be nice and dark after midnight. In general, there are more shooting stars in the morning hours -- since that's the side of the Earth that faces forward as we orbit the Sun, so it's less shielded from orbiting junk.
Even though the comet itself is far beyond the Sun's planets now, in an elliptical orbit that only brings it close to the sun once every 133 years, rock and ice from it have spread out in a ring all along its path. The comet itself will probably be pretty good to see if you can hang on until July 2126, but in the meantime, like clockwork, it gives us a meteor shower in mid-August.
"Expect to see dozens of meteors between midnight and dawn," said Rebecca Johnson, editor of StarDate magazine, published by the McDonald Observatory of the University of Texas. "Some will be faint, some bright. If you get really lucky, you might see a fireball -- a really large meteor streaking from one side of the sky to the other, and leaving a burning tail in its wake. That's pretty rare."
Be alert; most meteors streak by in a second or less, sometimes in clusters. Most of the shooting stars are created by small cometary fragments, some as small as grains of sand, completely vaporized as they plunge into our protective blanket of air.
The best way to see them is to find a nice, dark place with no street lights and as few trees as possible, and look up. You may want to bring a lawn chair or a blanket. The streaks may be anywhere in the sky, though if they're Perseids they'll all appear to come from the north.
Perseid Meteor Shower: Best Seen Friday Before Dawn
One does need to be patient. Yes, the Perseids usually peak at one or two shooting stars a minute -- but only if you're far from cities, have clear skies, and happen to be looking in the right direction. (Go to our weather page for conditions near you.) Astronomers will tell you that meteor showers are best if you regard them as something to be savored, rather than awed by.
"That's a good way of putting it," said Alan MacRobert of Sky & Telescope magazine in an e-mail to ABC News. "Late at night, with dark-adapted eyes, under a sky with only a little light pollution, you'll probably see about one a minute on average. Greater amounts of light pollution in the sky will cut down on the numbers -- but the bright ones will still shine through."
Several of our users reported they saw a good show this morning. And, perhaps, they had the satisfaction of knowing that Chicken Little was half-right: The sky is indeed falling...harmlessly.