Meteor Shower Promises Seven Shooting Stars an Hour

John Roach
for National Geographic News

November 7, 2003

Chances for stargazers to witness a blazing fireball streak across the night sky improve as the Taurid meteor shower peaks over the next few weeks.

"They do tend to produce a good fraction of bright fireballs," said Duncan Steel, an Adelaide, Australia-based space researcher and world expert on comets and meteors.

The showers should be visible around the world to the naked eye, particularly on moonless nights and away from city lights.

The Taurid meteor stream formed over the past 20,000 to 30,000 years. Today it consists of the comet Encke, which is thought to be a remnant of a much larger comet, and a conglomeration of asteroids, meteorites, and assorted fragments of celestial matter.

Bill Napier, a research astronomer with Ireland's Armagh Observatory said the Taurid meteors "make up the most massive stream in the inner planetary system." When the stream's orbit passes close to Earth, stray particles burn in Earth's atmosphere, causing a streak of light across the night sky commonly referred to as a shooting star.

"There are lots of very large pieces within the stream which produces occasionally very notable fireballs," said Gary Kronk, a St. Louis, Missouri-based science writer who maintains the Comets & Meteor Showers Web site.

Over time, the Taurids have split into a northern branch and a southern branch due to the gravitational pull of planets like Jupiter disrupting various bits in the stream at slightly different rates. As a result, the branches interact with Earth's atmosphere at different times.

During the next two weeks, both the northern and southern branches of the Taurids will produce about seven shooting stars per hour.

"Because the meteor stream is rather spread out in space, the Earth takes a week or two to pass through it, unlike, say, the Leonids, which are tightly bunched and through which Earth passes in a few hours, sometimes to great effect," said Napier.

There are several other meteor showers linked to the Taurid meteor stream, including daytime showers, which are observable with radar. Steel and Napier suggest the daytime Beta Taurids are the source of the Tunguska object which flattened thousands of square miles of Siberian forest on June 30, 1908.

Slow Burn

Relative to other, more well-known meteor showers such as the Leonids, which will streak across the sky later this month at speeds over 37 miles (60 kilometers) per second, the Taurids appear slow. They move across the sky at about 17 miles (27 kilometers) per second.

This relatively stately pace and the Taurid's brightness make them of particular interest to astro-photographers, according to the American Meteor Society.

Their name derives from the fact that the Taurids appear to radiate from the constellation Taurus the Bull. (To find Taurus, follow the three well-known stars that form the belt of Orion up to a bright, orange-red star known as Aldebaran.)

Every 2,500 to 3,000 years or so, the core of the Taurid stream passes near Earth and produces much more intense meteor showers for a few centuries, said Steel. A gap of a few centuries separates the era of intensity between Northern Taurids and Southern Taurids.

"It is about 1,000 years before the next such epoch is due," he said. "I have suggested that megalith building, for example Stonehenge, was prompted by such events in the past, when the sky started going wild, repeatedly, every year."

Astronomers believe the source of the Taurid meteor stream was a giant comet that has since dissipated. A remnant of this giant is believed to be comet Encke, which can currently be viewed through binoculars as it heads west across the evening sky.