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Look for Orionid meteors this month

Details on the annual Orionid meteor shower. How and when to watch. In 2017, the peak morning is probably October 21.

John Ashely captured this photo from Montana during the 2015 Orionid shower.

John Ashely captured this photo from Montana during the 2015 Orionid shower.

In 201, you have a chance to glimpse an Orionid meteor between about October 2 to November 7. That’s when Earth is passing through the stream of debris left behind by Comet Halley, the parent comet of the Orionid shower. Like all meteors in annual showers, the Orionids have an expected peak; in 2017, the Orionids are expected to rain down the greatest number of meteors before dawn on October 21, with no moonlight to ruin the show. How many meteors might you see that night, or in the nights leading up to the shower? Tips on when to watch below.

What are the prospects for the 2017 Orionid shower?

Where do I look in the sky to see the Orionids?

How many Orionid meteors will I see?

What are meteors, anyway?

Joe Randall created this composite shot of the Orionid meteor shower from images taken on October 21, 2014.  Thanks, Joe!

Joe Randall created this composite shot of the 2014 Orionid meteor shower.

What are the prospects for this year’s Orionid shower? On a dark, moonless night, at this shower’s peak, 10 to 20 meteors per hour can be seen. In 2017, no moonlight obtrudes on the show during the shower’s peak. As is usual for most (but not all) meteor showers, the best time to watch the Orionids is in the dark hours before dawn.

So start watching now. You might catch an Orionid meteor or two before the shower’s peak, before dawn, over the coming days. How will you know it’s an Orionid? You’ll know because it’ll come from the shower’s radiant point. More about that below.

The Orionids radiate from a point near the upraised Club of the constellation Orion the Hunter.  The bright star near the radiant point is Betelgeuse.

The Orionids radiate from a point near the upraised Club of the constellation Orion the Hunter. The bright star near the radiant point is Betelgeuse.

Where do I look in the sky to see the Orionids? 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 famous constellation Orion the Hunter, which you’ll find ascending in the east in the hours after midnight. Hence the name Orionids.

You don’t need to know or be staring toward Orion to see the meteors. The meteors often don’t become visible until they are 30 degrees or so from their radiant point – and remember, they are streaking out from the radiant in all directions. They will appear in all parts of the sky.

However, if you do see a meteor – and trace its path backward – you might see that it comes from the Club of Orion. And, if so, that meteor will be an Orionid. This year, in 2017, there is no moonlight to ruin the show! You might know Orion’s bright, ruddy star Betelgeuse. The radiant is north of Betelgeuse.

So our advice in 2017 is to jump the gun on the peak nights of the shower, and find yourself outside before dawn sometime in the coming week. You won’t see a shower of meteors. But you might see a meteor or two from the annual Orionid shower.

Which direction do you look? No particular direction. It’s best to find a wide-open viewing area. Sometimes friends like to watch together, facing different directions. When somebody sees one, they can call out “Meteor!”

Brian Brace wrote,

Brian Brace caught the 2014 Orionid shower, too. He wrote, “A few hours into our adventure, we’d witnessed only a few meteors flying by. But right before I took the camera down this huge fireball streamed across the northeastern sky. That one meteor made the whole night worth it.”

How many Orionid meteors will I see? The word shower might give you the idea of a rain shower. But few meteor showers resemble showers of rain. The Orionids are a relatively modest shower, offering about 10 to 20 meteors per hour on a dark, moonless night. In the coming weeks, when we’re nowhere near the peak of the shower, you can count on somewhere from none to a handful after several hours of observing.

Even at their peak, meteor showers are more subtle than rain showers, and the Orionid shower isn’t as rich a meteor shower as, for example, the Perseids in August or the Geminids in December.

But Orionids can be very beautiful meteors. They’re known to be fast and on the faint side, but can sometimes surprise you with an exceptionally bright meteor – one that would be visible, even on a moonlit night – that might break up into fragments.

For me … even one meteor can be a thrill. But you might want to observe 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 and lie back comfortably while gazing upward.

Halley's Comet, the parent of the May Eta Aquarid and October Orionid meteor showers. Image Credit: NASAblueshift

Halley’s Comet, perhaps the most famous of all comets, is parent of both the Eta Aquarid meteor shower in May and October’s Orionid meteor shower. Image via NASA.

What are meteors, anyway? Meteors are fancifully called shooting stars. Of course, they aren’t really stars. They’re space debris burning up in the Earth’s atmosphere.

The Orionid meteors are debris left behind by Comet Halley. The object in the photo above isn’t a meteor. It’s that most famous of all comets – Comet Halley – which last visited Earth in 1986. This comet leaves debris in its wake that strikes Earth’s atmosphere most fully around October 20-22, while Earth intersects the comet’s orbit, as it does every year at this time.

Particles shed by the comet slam into our upper atmosphere, where they vaporize at some 100 kilometers – 60 miles – above the Earth’s surface.

The Orionids are extremely fast meteors, plummeting into the Earth’s atmosphere at about 66 kilometers – 41 miles – per second. Maybe half of the Orionid meteors leave persistent trains – ionized gas trails that last for a few seconds after the meteor itself has gone.

Bottom line: In 2016, the Orionid meteor shower is expected to rain down its greatest number of meteors on the morning of October 21, though under the light of a bright waning gibbous moon. Our advice is to start watching in early October, and settle for a meteor or two glimpsed in a moon-free sky. Who knows? You might see a bright one!

EarthSky’s meteor shower guide for 2017

Deborah Byrd