Bay AreaIn Brief

You're going to have to get up pretty early this weekend if you want to catch one of the most spectacular celestial displays in the last 35 years.

Scientists at NASA's Ames Research Center say the annual Leonid meteor shower should probably be visible in the predawn hours Sunday.

"It's time to set your alarm clocks and get yourself out under a dark sky,'' says Donald Yeomans, head of NASA's Near Earth Object program office. "This could be the last opportunity for watching an impressive meteor storm in a dark sky for decades to come.''

Meteors, also called shooting stars, are really streaks of light that flash across the sky as bits of dust and rock in space collide with the Earth's upper atmosphere and vaporize. Leonid showers appear every year around Nov. 17 and 18 as the Earth intersects the orbit of comet Tempel-Tuttle and runs into streams of dust shed by the comet.

Because the stream of comet dust hits the Earth almost head-on, the Leonids are among the fastest meteors around, zipping across the sky at 44 miles per second.

Every once in a while, the Earth will pass through an especially dense clump of comet dust, creating a more spectacular meteor shower. The last big one occurred in 1966 and produced 150,000 meteors per hour. A similar showing is expected this year.

The name Leonid comes from the direction in the sky from which the meteors appear to originate