Alisha Klingenmeyer of Anchorage recalled spotting an orange-red fireball streaking across the sky as she drove north at about 8 p.m. Thursday. Paul Vos was watching a movie with his wife and son at their home in Hope at about 8:30 p.m. the same night when all three saw an arc of light over the mountains in the southern sky.

"It had a real long tail, kind of a silvery white, and from a real perspective it was about the size of a large softball or basketball or soccer ball," Vos said.

A spectacular sky show is playing over Alaska this month as Earth passes through the fiery remnants of a comet.

Fireballs and bright streaks of light seen in the sky around Anchorage Thursday were part of the Taurid meteor shower (search), the annual spray of comet dust over the Earth's upper atmosphere, according to a University of Alaska Fairbanks scientist.

Residents of Fairbanks also saw the meteors, said Neal Brown (search), director of the Alaska Space Grant Program (search), an educational organization.

Meteor showers, mistakenly known as shooting stars, occur when Earth's atmosphere collides with space debris, according to the National Aeronautics and Space Administration.

Often, it's debris that has come loose from a comet's body after some of the comet's ice has evaporated during its passage around the sun, said John Chappelow, a post-doctoral researcher at the University of Alaska Fairbanks' Geophysical Institute (search).

The dust particles are usually tiny, sometimes microscopic, although they can be the size of large rocks. No matter the particle size, the chemical reaction produces a blaze of light and sometimes vivid colors.

Regular meteor showers, such as the Taurids, Leonids and Perseids, are named for the constellations from which they appear to emerge.

The Taurids arrive in late October and early November off the comet Encke, discovered in 1786.

This year's Taurids, whose weeklong peak of meteor activity NASA said would start today, were expected to be brighter and more frequent than usual, Chappelow said.

"We're running through the [comet's] orbit, which is like a flow, an orbiting ellipse of debris, and we're passing through an especially dense knot of this stuff," he said.

The better viewing is generally after midnight, and the best time is in the vicinity of 3 a.m., said Don Martins (search), chair of the UAA Department of Physics and Astronomy.