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Comet Thatcher is pretty ordinary. It’s a ball of ice and rock that takes about 415 years to orbit the Sun. It follows a long, skinny orbit that takes it deep into the outer solar system — more than five billion miles from the Sun.
The comet reminds us of its presence every year, though, with a meteor shower. And the shower should be at its best tomorrow night. It’s called the Lyrid shower because its meteors all appear to “rain” into the atmosphere from the constellation Lyra.
Comet Thatcher was discovered 160 years ago this month. Amateur astronomer A.E. Thatcher was scanning the skies above his home in New York with a telescope when he saw a small, fuzzy blob. The comet soon became bright enough to see with the naked eye. A few years later, astronomers figured out that the comet was the source of the Lyrid meteors.
As the comet moves close to the Sun, heat vaporizes some of the ice at its surface. That releases bits of rock and dirt into space. They spread out along the comet’s orbit. Earth passes through that path every April. So some of the bits of debris plunge into our atmosphere at speeds of 30 miles per second. At that rate, they quickly vaporize — forming the streaks of light known as meteors.
This year’s Lyrids should be at their best late tomorrow night. Unfortunately, the gibbous Moon will be in the way during the peak hours. So only a few Lyrids are likely to shine through — the offspring of a comet.
Script by Damond Benningfield