The Orionids are the legacy of the famous Halley's Comet.
Comets are leftover pieces that date back to the formation of the solar system. The "dirty snowballs" are the odd bits and pieces of simple gases — methane, ammonia, carbon dioxide and water vapor — that went unused when the sun and its attendant planets came into their present form.
Meteoroids released into space out of cometary debris are the remnants of a comet's nucleus. All comets eventually disintegrate into meteor swarms and Halley's is well into that process at this time.
Tiny particles — mostly ranging in size from dust to sand grains — remain along the original comet's orbit, creating a "river of rubble" in space. (See Photos of Halley's Comet Through History)
In the case of Halley's comet (which has likely circled the sun many hundreds, if not thousands of times), its dirty trail of debris has been distributed more or less uniformly all along its entire orbit. When these tiny bits of comet collide with Earth, friction with our atmosphere raises them to white heat and produces the effect popularly referred to as "shooting stars."
The orbit of Halley's Comet closely approaches the Earth's orbit at two places. Therefore, the debris creates two meteor showers: the Orionids in October and the Eta Aquarids in May.
Step outside before sunrise this weekend or early next week, and if you catch sight of a meteor, there's about a 75 percent chance that it likely originated from the nucleus of Halley's Comet.
Editor's note: If you snap an amazing picture of the Orionid meteor shower or any other night sky view that you'd like to share for a possible story or image gallery, send photos, comments and your name and location to managing editor Tariq Malik at firstname.lastname@example.org.
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