Posted on by David Dickinson

Tears of the Hunter: Our Guide to the 2016 Orionid Meteor Shower

Orionid
A 2014 Orionid meteor. Image credit and copright: Sharin Ahmad (@Shahgazer).

The month of October is upon us this coming weekend, and with it, one of the better annual meteor showers is once again active: the Orionids.

In 2016, the Orionid meteors are expected to peak on October 22nd at 2:00 UT (10:00 PM U.S. Eastern Time on October 21st) , favoring Europe and Africa in the early morning hours. The shower is active for a one month period from October 2nd to November 2nd, and can vary with a Zenithal Hourly Rate (ZHR) of 10-70 meteors per hour. This year, the Orionids are expected to produce a maximum ideal ZHR of 15-25 meteors per hour. The radiant of the Orionids is located near right ascension 6 hours 24 minutes, declination 15 degrees north at the time of the peak. The radiant is in the constellation of Orion very near its juncture with Gemini and Taurus.

A gallery of Fall meteor shower radiants, including the October Orionids. Image credit: Stellarium
A gallery of Fall meteor shower radiants, including the October Orionids. Image credit: Stellarium

The Moon is at a 55% illuminated, waning gibbous phase at the peak of the Orionids, making 2016 an unfavorable year for this shower, though that shouldn’t stop you from trying. It’s true that the Moon is only 19 degrees east of the radiant in the adjacent constellation Gemini at its peak on the key morning of October 22, though it’ll move farther on through the last week of October.

In previous recent years, the Orionids produced a Zenithal Hourly Rate (ZHR) of 20 (2014) and a ZHR of 30 (2013).

The Orionid meteors strike the Earth at a moderately fast velocity of 66 km/s, and the shower tends to produce a relatively high ratio of fireballs with an r value of = 2.5. The source of the Orionids is none other than renowned comet 1/P Halley. Halley last paid the inner solar system a visit in early 1986, and will once again reach perihelion on July 28, 2061. Let’s see, by then I’ll be…

The orientation of the Earth's shadow vs, the zenith positions of the Sun, Moon and the radiant of the Orionid meteors at the expected peak of the shower on October 22nd. Image adapted from Orbitron
The orientation of the Earth’s shadow vs the zenith positions of the Sun, Moon and the radiant of the Orionid meteors at the expected during the peak of the shower on October 22nd. Image adapted from Orbitron.

Unlike most meteor showers, the Orionids display a very unpredictable maximum – many sources decline to put a precise date on the shower’s expected maximum at all. On some years, the Orionids barely top 10 per hour at their maximum, while on others they display a broad but defined peak. One 1982 study out of Czechoslovakia suggested a twin peak for this shower after looking at activity from 1944 to 1950. All good reasons to be vigilant for Orionids throughout the coming month of October.

And check out this brilliant meteor that lit up the skies over the southern UK this past weekend:

‘Tis the season for cometary dust particles to light up the night sky. Trace the path of a suspect meteor to the club of Orion, and you’ve likely sighted an Orionid meteor. But other showers showers are active in October, including:

The Draconids: Peaking around October 8th, these are debris shed by Comet 21P Giacobini-Zinner. The Draconids are prone to great outbursts, such as the 2011 and 2012 meteor storm, but are expected to yield a paltry ZHR of 10 in 2016.

The Taurids: Late October into early November is Taurid fireball season, peaking with a ZHR of 5 around October 10th (the Southern Taurids) and November 12th (the Northern Taurids).
The Camelopardalids: Another wildcard shower prone to periodic outbursts. 2016 is expected to be an off year for this shower, with a ZHR of 10 topping out on October 5.

And farther afield, we’ve got the Leonids (November 17th) the Geminids (December 14th) and the Ursids (December 22nd) to close out 2016.

A 2015 Orionid captured by a NASA All-Sky camera atop Mt. Lemmon, Arizona. Image credit: NASA.
A 2015 Orionid captured by a NASA All-Sky camera atop Mt. Lemmon, Arizona. Image credit: NASA.

Observing a meteor shower like the Orionids is as simple as finding a dark site with a clear horizon, laying back and watching via good old Mark-1 eyeball. Blocking that gibbous Moon behind a building or hill will also increase your chances of catching an Orionid. Expect rates to pick up toward dawn, as the Earth turns forward and plows headlong into the meteor stream.

You can make a count of what you see and report it to the International Meteor Organization which keeps regular tabs of meteor activity.
Photographing Orionids this year might be problematic, owing to the proximity of the bright Moon, though not impossible. Again, aiming at a wide quadrant of the sky opposite to the Moon might just nab a bright Orionid meteor in profile. We like to just set our camera’s intervalometer to take a sequence of 30” exposures of the sky, and let it do the work while we’re observing visually. Nearly every meteor we’ve caught photographically turned up in later review, a testament to the limits of visual observing.

Clear skies, good luck, and send those Orionid images in the Universe Today’s Flickr forum.

Posted on by Tammy Plotner

Observing Alert – Draconid Meteor Shower Could Unleash A Burst Of Activity On October 8!

Meteor Burst - Credit: NASA

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If you live in the Europe, North Africa, and the Middle East area, then keep watching the clock for 17-18:00 UTC when you may be in the right place at the right time for a burst of activity from the annual Draconid Meteor Shower. There’s a possibility you might see up to 1,000 meteors an hour!

As always, meteor showers are unpredictable events – but that doesn’t mean you can’t be prepared or forewarned. While the gibbous Moon will put a damper on fainter meteor streaks, observers in Europe, North Africa, and the Middle East. are well situated to catch a strong pocket of activity.

“Meteor showers are as difficult to predict as rain showers. The Draconids have surprised us before, and they may do so again.” says Canadian astronomer Paul Wiegert. “I’d encourage anyone outside on the night of October the 8 to look to the northern skies, just in case.”

This isn’t the first time the Draconid meteor shower has produced a brief storm. In 1933 and 1946 the activity reached an average hourly rate of 10,000. While that’s pretty incredible, the same cometary debris trail left quite a show in the years 1952, 1985, and 1998 when it produced hundreds per hour. These remnants of Comet Giacobini-Zinner aren’t the most dramatic of all showings – but knowing where the meteoroid stream is located makes such predictions valid.

When and where? In this case, start your observations just as soon as the sky gets dark. Since Draco is a northern constellation, those at high latitudes are move favored (sorry, southern hemisphere), so face toward the north and get comfortable. While the storm prediction will happen during daylight hours for North American observers, don’t give up hope! It looks like clear skies for many of us and chances are above average for catching a shooting star.

When opportunity knocks, ya’ gotta’ be there to open the door…

And don’t despair if you don’t live in Europe, North Africa, and the Middle East, or if you get clouded out. You can still watch and listen to meteors enter the atmosphere on Spaceweather radio. Meteors reflect radio signals as they burn up and you can hear this as eerie whistles and pings.

A similar system, still employing the radio reflection method displays meteors coming in on your computer with a cool graph – The Meteorwatch Live View

And follow Universe Today’s Adrian West on his Twitter feed, VirtualAstro and on his website MeteorWatch as he’ll be providing updates on observed meteor rates in various parts of the world.

For Further Reading: Wiegert’s original announcement via Physorg.com.