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Orionid meteor shower this weekend!

The Orionid meteor shower is expected to peak this weekend, though this year, in 2018, the shower must compete with the glare of the brilliant waxing gibbous moon for much of the night. As is standard for many meteor showers, this shower takes place primarily between midnight and dawn – regardless of your time zone. Typically, the Orionids’ strongest showing comes during the few hours before dawn. offering perhaps 10 to 15 meteors per hour in a dark sky.

The advantage of watching tonight (late Friday to Saturday morning) – rather than the following nights – is that there is less moonlight to obstruct the show. For instance, at mid-northern latitudes in North America, the moon sets roughly 4 hours before sunrise on Saturday, October 20. However, the moon sets about 3 hours before sunrise on Sunday, October 21, and only about 2 hours before sunrise on Monday, October 22.

Want to know when the moon sets in your sky? Or when morning dawn (astronomical twilight) first begins? Click here and remember to check the Moonrise and moonset plus the Astronomical twilight boxes.

Some experts are expecting a possible upswing in Orionid activity in 2018. Who knows? If you’re really lucky, you might see more than the predicted 10 to 15 meteors per hour. These meteors – vaporizing bits of comet debris from Halley’s Comet – look like streaks of light in the night sky. They’re sometimes called shooting stars.

Best of all, you don’t need any special equipment. Find an open sky away from pesky artificial lights, enjoy the comfort of a reclining lawn chair and look upward. That’s all there is to it! Be sure to give your self at least 20 minutes for your eyes to adapt to the darkness, and give yourself at least an hour of viewing time. Meteors often come in spurts followed by lulls.

Because the peak is rather broad, meteor aficionados will be watching these next three nights (October 19-20, October 20-21 and October 21-22). Late Saturday night (October 20) to Sunday morning (October 21) might be the Orionids’ most prolific night, but you never know for sure. Late Sunday night to Monday morning could produce just as many meteors.

What’s more, the predawn/dawn sky offers a great view of Sirius, the sky’s brightest star of nighttime. Watch for it in the south (or overhead if you’re in the Southern Hemisphere) in the predawn/dawn sky.

Halley's Comet at its 1910 visit.  The famous astronomer Edward Emerson Barnard at Yerkes Observatory in Wisconsin took this photo.  Via Wikimedia Commons.

Halley’s Comet at its 1910 visit. The famous astronomer Edward Emerson Barnard at Yerkes Observatory in Wisconsin took this photo. Image via Wikimedia Commons.

The Orionids stem from bits and pieces from the most famous of all comets, Comet Halley, pictured above. The picture shows Comet Halley itself at its 1910 visit. The comet last visited Earth in 1986 and will return next in 2061.

As Comet Halley moves through space, it leaves debris in its wake that strikes Earth’s atmosphere most fully around October 20-22, every year. The comet is nowhere near, but, around this time every year, Earth is intersecting the comet’s orbit.

If the meteors originate from 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.

Orionid meteors radiate from the constellation Orion, which was captured a few days ago - October 16, 2016 - by Zefri Besar in Brunei Darussalam. He wrote:

Orionid meteors radiate from the constellation Orion, shown in this photo from October, 2016 by Zefri Besar in Brunei Darussalam.

Remember … even one meteor can be a thrill. Just be sure you have a dark sky.

Bring along a blanket or lawn chair – after midnight or before dawn – and lie back comfortably while gazing upward. Although a somewhat modest shower, these swift-moving meteors are sometimes bright, occasionally leaving a persistent train – a glowing streak that lingers momentarily after the meteor has gone!

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Photo from Goldpaint Photography of the 2011 Orionid meteor shower near Mount Shasta, California. It’s a composite of every meteor captured during the night. The image was Grand Prize Winner of Outdoor Photographer Magazine’s 3rd Annual Great Outdoors Photography Contest.

Bottom line: Best night for the Orionid meteor shower in 2018 is probably October 20-21, especially between midnight and dawn October 21. You might see as many as 10 to 15 meteors per hour from a dark site. Fortunately, the moon will set in wee hours of the morning, to provide a hour or two of predawn darkness for watching this year’s Orionid meteor shower.

EarthSky’s meteor guide for 2018

Bruce McClure