Astro Bob

This false-color, composite shows the Orionid meteor shower over Huntsville, Alabama in Oct. 2009. They peak again on the morning of Oct. 21.  NASA The Orionid meteor shower may be no match for the August Perseids, but it's special for different reasons: the material responsible for the annual shower comes directly from Halley's Comet, and the meteors it produces zing across the sky in the blink of an eye. Every October the Earth crosses the trail of dust and pebbles called meteoroids lost by the Comet during its repeated trips to the inner solar system. Heated by the sun, some of Halley's dirty ice (the principal ingredient of comets) boils away and releases the trapped debris. That material settles and spreads across the comet's orbit in a great band that travels like a conveyor belt around the sun. Twice each year, first in May and then October, Earth's orbital path intersects that of Halley's Comet. Our first encounter produces the Eta Aquarid meteor showe