Orionid meteors, debris from Comet Halley, before dawn October 22

The object in the picture isn’t a meteor. It’s the most famous of all comets, Comet Halley, the parent of the Orionid meteor shower. Although moonlight will interfere, you might see some Orionid meteors tonight or especially before dawn tomorrow morning (October 22). The meteors look like streaks of light in the night sky. They’re sometimes called shooting stars.

Comet Halley – the Orionid’s parent object, pictured at the top of this post – last visited Earth in 1986. As the comet moves through space, it leaves debris in its wake that strikes Earth’s atmosphere most fully around October 20-22. Around this time every year, Earth is more or less intersecting the comet’s orbit.

The cometary debris left behind by Comet Halley — bits of ice, dust and rubble — create the Orionid meteor shower.

The annual Orionid meteor shower is expected to produce the greatest number of meteors before dawn on Friday morning, October 21, or on Saturday, October 22, 2011. As usual, the best time to watch this shower will be between the hours of midnight and dawn. Oftentimes, 10 to 15 meteors per hour can be seen on a dark, moonless night. However, the waning crescent moon will probably subdue the meteor count for the Orionids this year.

Moon, Regulus, Mars and the constellation Leo the Lion

This isn’t the year’s richest meteor shower, or even the second-richest, but try watching this shower from midnight to dawn, when the most meteors will be flying. If you’re hankering to see some meteors, the moonlight makes 2011 a less than ideal year for the Orionids. But with the waning crescent moon showing you the planet Mars and the star Regulus in the glorious predawn sky, not all is lost. Moreover, the dazzling planet Jupiter will be blazing away in the west, plus the glorious constellation Orion will be beaming high in the southern sky. With all this thrown in the mix, the predawn hours are prime for watching the lore-laden skies and the Orionid meteors.

See Sirius, nighttime’s brightest star before dawn

Orion meteor shower radiant in the constellation Orion

If the meteors originate in Comet Halley, why are they called the Orionids? The answer is that meteors in annual showers are named for the point in our sky from which they appear to radiate. The radiant point for the Orionids is in the direction of the constellation Orion the Hunter. Hence the name Orionids.

For me, even one meteor can be a thrill. But you might want to observe the 2011 Orionid meteor shower for an hour or more, and in that case the trick is to find a place to observe in the country. Bring along a blanket or lawn chair — after midnight or before dawn — and lie back comfortably while gazing upward. Watch debris from Halley’s Comet streak the predawn sky on October 22!

EarthSky’s meteor guide for 2011

How high up are meteors?

How do astronomers predict meteor showers?

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