Like its mythological cohorts, the constellation Draco sometimes breathes fire. Most of the time, the dragon's effort is puny -- a few little sparks in the night sky. But every once in a while, it really puts on a show -- a spectacular shower of Draconid meteors.
The best one ever recorded took place 75 years ago today. Observers in western Europe saw thousands of "shooting stars" in just a few hours. One wrote that the meteors were as thick as snowflakes.
The meteors are bits of dust from Comet Giacobini/Zinner. As it orbits the Sun, some of the comet's outer layers of ice vaporize. That releases small particles of solid material. They spread out along the comet's orbital path. When Earth flies through this path, some of the particles ram into the atmosphere and vaporize, forming streaks of light across the sky. If you trace their paths, they all appear to come from the dragon.
But the timing is tricky, because the stream of comet dust is clumpy. To see a great shower, we have to fly through one of the clumps at just the right time.
Most years, we miss them. We see perhaps a dozen or so Draconid meteors over an entire night. But every once in a while -- especially when the comet is passing close to the Sun -- the show can be spectacular.
The best took place in 1933. But there was another great one in 1946, visible from the Americas. Some observers saw thousands of meteors -- a major "fire-breathing" effort for the celestial dragon.
Script by Damond Benningfield, Copyright 2008
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