Our annual sky show from Halley's comet, the Orionid meteor shower, will peak overnight Saturday, with as many as 20 shooting stars an hour expected to be visible from dark locations away from city lights.
(See Perseid pictures: "Meteor Shower Dazzles Every August.")
"The peak of the shower starts at about 11:30 p.m. local time on October 20th, just as the moon is setting, and should be strongest just before dawn," said Anthony Cook, astronomer at Griffith Observatory in Los Angeles, California.
Sky-watchers should also be on the lookout for fireballs—baseball- to basketball-size space rocks that create especially brilliant meteors as they burn up in Earth's atmosphere.
"These can be bright enough to cast shadows and create luminous trails that remain visible for many seconds after the meteor has disappeared," Cook said. "Even if you must make do with less-than-ideal sky conditions, the view of a swift Orionid or a bright fireball will make the watch worthwhile."
(Read about 2011's Orionid meteor shower.)
Orionids Are Reminders of Distant Comet
Just like all other meteor showers, the Orionids gets its name from the constellation from which its shooting stars appear to radiate—what astronomers call the shower's radiant.
In this case observers can trace back the streaks of light to the area in the sky occupied by the mythical hunter Orion—all radiating out from a spot just above its bright orange star Betelgeuse.
The Orionid shower is caused when Earth slams into a debris field left behind by Halley's comet, which won't return to our neck of the woods for another five decades. (Find out why Halley's comet has been hailed as an omen of doom.)
"Seeing Orionids is a little like getting a postcard from the comet, which only makes a local appearance every 76 years," Cook said.
"While the Orionids are mostly caused by sand-grain-size pebbles shed by the famous comet in past centuries, it's amazing to think that Halley's itself will not be seen by eye until July of 2061, just less than 49 years from now."