The Leonids, an annual meteor shower, return this week, slamming into the Earth's atmosphere at 158,000 mph and burning up. If astronomers' predictions are right, the shooting stars could light up the heavens at the rate of 20 a minute.
The Leonids arrive on the night of Nov. 17-18 every year. They are the dust of comet Tempel-Tuttle, which swings around the sun every 33 years, showering dust and ice in the path of the orbiting Earth.Every 33 years, astronomers expect not a shower but a storm. In 1966, Leonids flashed across the sky at a peak rate of 40 a second. In 1833, with 100,000 shooting stars in an hour, the storm was so spectacular that the young Abraham Lincoln remembered being woken up by his landlord to be told that the day of judgment was at hand.
With a clear, dark sky early on Nov. 18, an observer might see 20 shooting stars a minute coming from the direction of the constellation Leo.
But the observer might also be disappointed. "It is sometimes said that comets are like cats," says Mark Bailey of the Armagh Observatory, in Northern Ireland. "They have tails, and they are unpredictable. If that's the case, predicting a meteor storm has to be about as easy as herding cats."