National Geographic News
An unexpected invasion from outer space has reports streaming in from around the world of intense fireballs illuminating the night sky.
The streaks of light are often brighter than a full moon, causing some viewers to temporarily loose their night vision.
"I thought some wise guy was shining a spotlight at me," backyard astronomer Josh Bowers of New Germany, Pennsylvania, told the Science@NASA news Web site.
According to Reuters, fireball sightings in Germany have put UFO reports on the rise. The wire service notes that some professional astronomers say the phenomenon could be caused by debris from a falling satellite.
But the most likely explanation, according to meteor expert David Asher, is that sky watchers this year are seeing an unusually bright version of the annual Taurid meteor shower. Asher, a scientist at the Armagh Observatory in Northern Ireland, explains on the NASA site that Earth is being bombarded by a river of space dust associated with a passing comet.
Our planet sails through this dust every year in late October and early November. Larger particles in the dust create a meteor shower called the Taurids, so named because the streaks appear to come from the constellation Taurus.
Normally the shower is too weak and slow to draw much attention. But occasionally the Taurids put on a flashier show.
In 1993 Asher and colleague Victor Clube published a paper describing why the shower might be more intense in certain years. The pair also predicted what they dubbed swarm years, when the Taurids would be especially bright2005 was on their list.
The NASA site notes that the Taurid shower normally peaks between November 5 and 12.
Free E-Mail News Updates
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).
SOURCES AND RELATED WEB SITES