Fort Lauderdale, Fla. -- Astronomers tonight hope to find a key clue in the mysterious case of the missing comet. And you can look along with them.
The comet, named Swift-Tuttle, was last seen during the Civil War. It was supposed to return in 1981 but did not.
Yet every year around Aug. 12, like clockwork, the comet's debris is visible as the Perseids meteor shower, one of the brightest shooting star shows of the year.
The Perseids should peak about 11 p.m. and again about sunrise, with about 100 shooting stars an hour zipping across the sky at up to 60 miles per second, said Dave Menke, director of the Buehler Planetarium in Davie.
You do not need a telescope, and you should look all around the sky.
Last year, the Perseids display was abnormally bright, so bright in Japan that it was called a "storm of meteors," said Brian Marsden, a comet expert at the Harvard-Smithsonian Center for Astrophysics.
If storms of fireballs reappear tonight, astronomers may be able to find some clue to the fate of the parent comet, maybe even a hint that Swift-Tuttle will return to the solar system this fall, Mr. Marsden said yesterday.
"It sort of makes it interesting," Mr. Marsden said. "Nobody would be more surprised than I for this comet to come."
The full moon will complicate the astronomers' detective work. It is harder to see streaks of shooting stars with the moon shining so brightly.
"There are many twists to this whole thing," Mr. Marsden said.
Jack Horkheimer, director of the Miami Space Transit Planetarium, said: "Moonlight will wipe out 80 percent of the meteors. But if it is a storm, you might see some bright ones, some big ones, some fireballs. Nobody can tell for sure; it might be a complete bust."
Mr. Menke is optimistic. He said that last week, he saw "a beautiful bright fireball. That kind of is a foreboding to me that it is going to be a good shower, even though the moon is out."
Gary Bogner, planetarium director of the South Florida Science Museum in West Palm Beach, said he will set his alarm clock so he can see the showers in the early morning hours.
Comet Swift-Tuttle last moved through the solar system in 1862 and should have returned sometime between 1979 and 1983, Mr. Marsden said, but it was not observed. It was either too dim when it returned, died in the depths of space or had its orbit affected by some other heavenly body, he said.
If its orbit was modified, "then the comet should be returning late in 1992, nominally in November," Marsden said.