Explody Eta Aquarid Meteor Caught in the Act

An Eta Aquarid meteor captured on video by astrophotographer Justin Ng shows an amazing explodingred meteor and what is known as a persistent train — what remains of a meteor fireball in the upper atmosphere as winds twist and swirl the expanding debris.

The meteor pierced through the clouds and the vaporized “remains” of the fireball persisted for over 10 minutes, Justin said. It lasts just a few seconds in the time-lapse.

Here’s the video:

Justin took this footage during an astrophotography tour to Mount Bromo in Indonesia, where he saw several Eta Aquarid meteors. The red, explody meteor occurred at around 4:16 am,local time. The Small Magellanic Cloud is also visible just above the horizon on the left.

Persistent trains occur when a meteoroid blasts through the air, ionizes gases in our atmosphere. Until recently, these have been difficult to study because they are rather elusive. But lately, with the widespread availability of ultra-fast lenses and highly sensitive cameras, capturing these trains is becoming more common, much to the delight of astrophotography fans!

Mount Bromo, 2,329 meters (7600 ft.) high is an active volcano in East Java, Indonesia.

Check out more of Justin’s work at his website, on Twitter, Facebook or G+.

6 May 2017 – Eta Aquarid Captured at Mount Bromo (4K Timelapse) from Justin Ng Photo on Vimeo.

Comet Halley Plays Bit Part In Weekend Eta Aquarid Meteor Shower

Watch for the Eta Aquarid shower this week, so called because meteors will appear to radiate from near the star Eta Aquarii.  The meteors originate from fragments of Halley’s Comet strewn about its orbit. Every May, Earth crosses the stream and we get a meteor shower. At maximum on Saturday morning May 6, 25-30 meteors per hour might be seen from the right location under dark skies. Map: Bob King, Source: Stellarium

Halley’s Comet may be at the far end of its orbit 3.2 billion miles (5.1 billion km) from Earth, but this week fragments of it will burn up as meteors in the pre-dawn sky as the Eta Aquarid meteor shower. The comet last passed our way in 1986, pivoted about the Sun and began the long return journey to the chilly depths of deep space.

Comet Halley’s still hanging around in the evening sky a few degrees to the west of the head of Hydra the Water Snake not far from Procyon in Canis Minor. It’s currently 3.2 billion miles from Earth. Created with Stellarium

Today, Halley’s a magnitude +25 speck in the constellation Hydra. Although utterly invisible in most telescopes, you can imagine it below tonight’s half-moon near the outermost point in its orbit four Earth-sun distances beyond Neptune. Literally cooling its jets, the comet mulls its next Earth flyby slated for summer 2061.

Halley’s Comet follows an elongated orbit that takes 76 years to complete. Solar heating boils off debris that peppers the comet’s path coming and going.  Earth intersects the stream twice: first in May on the outbound portion of Halley’s orbit, and again in October, on the inbound leg. Each time, the planet plows into the debris at high speed and it burns up in our atmosphere. Credit: Bob King

Some meteor showers have sharp peaks, others like the Eta Aquarids, a broad, plateau-like maximum. The shower’s been active since mid-April and will continue right up till the end of this month with the peak predicted Saturday morning May 6. Observers in tropical latitudes, where the constellation Aquarius rises higher than it does from my home in northern Minnesota, will spy 25-30 meteors an hour from a dark sky in the hour or two before dawn.

Skywatchers further north will see fewer meteors because the radiant will be lower in the sky; meteors that flash well below the radiant get cut off by the horizon, reducing the rate by about half ( about 10-15 meteors an hour). That’s still a decent show. I got up with the first robins a couple years back to see the shower and was pleasantly surprised with a handful of flaming Halley particles in under a half hour.

A long-trailed, earthgrazing Eta Aquarid meteor crosses a display of northern lights on May 6, 2013. Credit: Bob King

While a low radiant means fewer meteors, there’s an up side. You have a fair chance of seeing an earthgrazer, a meteor that skims tangent to the upper atmosphere, flaring for many seconds before either burning up or skipping back off into space.

The Eta Aquarids will be active all week. With the peak occurring Saturday morning, you should be able to see at least a few prior to dawn each morning. The quarter-to-waxing gibbous moon will set in plenty of time through Friday morning, leaving dark skies, but cuts it close Saturday when it sets about the same time the radiant rises in the east.

The annual Eta Aquarids meteor shower captured from Otago Harbour at Aramoana in New Zealand. Eta Aquarids are fast, striking the atmosphere at more than 147,000 mph (66  km/ sec).  The photographer stacked multiple unguided 30-second exposures over 50 minutes taken with an 8mm fisheye lens @ f/3.5, Nikon D90, ISO 3200. Credit: Starman_nz

For best viewing, find as dark a place as possible with an open view to the east and south. I like to tote out a reclining lawn chair, face east and get comfy under a warm sleeping bag or wool blanket. Since twilight starts about an hour and three-quarters before your local sunrise, plan to be out watching an hour before that or around 3:30 a.m. I know, I know. That sounds harsh, but I’ve discovered that once you make the commitment, the act of watching a meteor shower becomes a relaxed pleasure punctuated by the occasional thrill of seeing a bright meteor.

You’ll be in magnificent company, too. The Milky Way rides high across the southeastern sky at that hour, and Saturn gleams due south in Sagittarius at the start of dawn.  If you’d like to contribute observations of the shower to help meteor scientists better understand its behavior and evolution, check out the International Meteor Organization’s Eta Aquariids 2017 campaign for more information.

Start the Year With Spark: See the Quadrantid Meteor Shower

The Quadrantid meteor shower, named for the obsolete constellation Quadran Muralis, will appear to stream from a point in the sky called the radiant (yellow star), located below the end of the Big Dipper’s handle and across from the bright, orange-red star Arcturus. The map shows the sky around 4 a.m. local time Tuesday, Jan. 3. The shower will be best between 4 a.m. and 6 a.m., the start of dawn. Map: Bob King, Source: Stellarium

If one of your New Year’s resolutions is to spend more time under the stars in 2017, you’ll have motivation to do so as soon as Tuesday. That morning, the Quadrantid (kwah-DRAN-tid) meteor shower will peak between 4 to about 6 a.m. local time just before the start of dawn. This annual shower can be a rich one with up to 120 meteors flying by an hour — under perfect conditions.

Those include no moon, a light-pollution free sky and most importantly, for the time of maximum meteor activity to coincide with the time the radiant is highest in the pre-dawn sky. Timing is everything with the “Quads” because the shower is so brief. Meteor showers occur when Earth passes through either a stream of dusty debris left by a comet or asteroid. With the Quads, asteroid 2003 EH1 provides the raw material — bits of crumbled rock flaked off the 2-mile-wide (~3-4 km) object during its 5.5 year orbit around the sun.

A Quadrantid fireball flares to the left of the Hyades star cluster and Jupiter in 2013. As Earth travels across the debris stream, bits and pieces of asteroid 2003 EH1 strike the atmosphere at nearly 100,000 mph (43 km/second) and vaporize while creating a glowing dash of light called a meteor. Credit: Jimmy Westlake via NASA

Only thing is, the debris path is narrow and Earth tears through it perpendicularly, so we’re in and out in a hurry. Just a few hours, tops. This year’s peak happens around 14 hours UT or 8 a.m. Central time (9 a.m. Eastern, 7 a.m. Mountain and 6 a.m. Pacific), not bad for the U.S. and Canada. The timing is rather good for West Coast skywatchers and ideal if you live in Alaska. Alaska gets an additional boost because the radiant, located in the northeastern sky, is considerably higher up and better placed than it is from the southern U.S. states.

Another Quadrantid fireball. Credit: NASA

The Quads will appear to radiate from a point in the sky below the Big Dipper’s handle, which stands high in the northeastern sky at the time. This area was once home to the now defunct constellation Quadrans Muralis (mural quadrant), the origin of the shower’s name. As with all meteor showers, you’ll see meteors all over the sky, but all will appear to point back to the radiant. Meteors that point back to other directions don’t belong to the Quads are called sporadic or random meteors.

The long-obsolete constellation Quadrans Muralis represents the wall quadrant, a instrument once used to measure star positions. It was created by French astronomer Jerome Lalande in 1795. Credit: Johann Bode atlas

Off-peak observers can expect at least a decent shower with up to 25 meteors an hour visible from a reasonably dark sky. Peak observers could see at least 60 per hour. Tropical latitude skywatchers will miss most of the the show because the radiant is located at or below the horizon, but they should be on the lookout for Earthgrazers, meteors that climb up from below the horizon and make long trails as they skirt through the upper atmosphere.

Set your clock for 4 or 5 a.m. Tuesday, put on a few layers of clothing, tuck hand warmers in your boots and gloves, face east and have at it!  The Quads are known for their fireballs, brilliant meteors famous for taking one’s breath away. Each time you see one chalk its way across the sky, you’re witnessing the fiery end of an asteroid shard. As the crumble burns out, you might be fulfilling another resolution: burning away those calories while huddling outside to see the show.

 

 

101 Astronomical Events for 2017: A Teaser

It’s that time of year again… time to look ahead at the top 101 astronomical events for the coming year.

And this year ’round, we finally took the plunge. After years of considering it, we took the next logical step in 2017 and expanded our yearly 101 Astronomical Events for the coming year into a full-fledged guide book, soon to be offered here for free download on Universe Today in the coming weeks. Hard to believe, we’ve been doing this look ahead in one form or another now since 2009.

This “blog post that takes six months to write” will be expanded into a full-fledged book. But the core idea is the same: the year in astronomy, distilled down into the very 101 best events worldwide. You will find the best occultations, bright comets, eclipses and much more. Each event will be interspersed with not only the ‘whens’ and ‘wheres,’ but fun facts, astronomical history, and heck, even a dash of astronomical poetry here and there.

It was our goal to take this beyond the realm of a simple almanac or Top 10 listicle, to something unique and special. Think of it as a cross between two classics we loved as a kid, Burnham’s Celestial Handbook and Guy Ottewell’s Astronomical Calendar, done up in as guide to the coming year in chronological format. Both references still reside on our desk, even in this age of digitization.

And we’ve incorporated reader feedback from over the years to make this forthcoming guide something special. Events will be laid out in chronological order, along with a quick-list for reference at the end. Each event is listed as a one- or two-page standalone entry, ready to be individually printed off as needed. We will also include 10 feature stories and true tales of astronomy. Some of these were  culled from the Universe Today archives, while others are new astronomical tales written just for the guide.

Great American Eclipse
Don’t miss 2017’s only total solar eclipse, crossing the United States! Image credit: Michael Zeiler/The Great American Eclipse.

The Best of the Best

Here’s a preview of some of the highlights for 2017:

-Solar cycle #24 begins to ebb in 2017. Are we heading towards yet another profound solar minimum?

-Brilliant Venus reaches greatest elongation in January and rules the dusk sky.

-45P/Honda-Mrkos-Pajdusakova passes 0.08 AU from Earth on February 11th, its closest passage for the remainder of the century.

-An annular solar eclipse spanning Africa and South America occurs on February 26th.

A sample occultation map from the book. Image credit: Occult 4.1.2.
A sample occultation map from the book. Image credit: Occult 4.1.2.

-A fine occultation of Aldebaran by the Moon on March 5th for North America… plus more occultations of the star worldwide during each lunation.

-A total solar eclipse spanning the contiguous United States on August 21st.

-A complex grouping of Mercury, Venus, Mars and the Moon in mid-September.

-Saturn’s rings at their widest for the decade.

Getting wider... the changing the of Saturn's rings. Image credit and copyright: Andrew Symes (@FailedProtostar).
Getting wider… the changing face of Saturn’s rings. Image credit and copyright: Andrew Symes (@FailedProtostar).

-A fine occultation of Regulus for North America on October 15th, with  occultations of the star by the Moon during every lunation for 2017.

-Asteroid 335 Roberta occults a +3rd magnitude star for northern Australia…

And that’s just for starters. Entries also cover greatest elongations for the inner planets and oppositions for the outer worlds, the very best asteroid occultations of bright stars, along with a brief look ahead at 2018.

Get ready for another great year of skywatching!

And as another teaser, here’s a link to a Google Calendar download of said events, complied by Chris Becke (@BeckePhysics). Thanks Chris!

Our Guide to the 2016 Geminid Meteors: Watching a Good Shower on a Bad Year

2015 Geminids

One of the best yearly meteor showers contends with the nearly Full Moon this year, but don’t despair; you may yet catch the Geminids.

The Geminid meteor shower peaks next week on the evening of Tuesday night into Wednesday morning, December 13th/14th. The Geminids are always worth keeping an eye on in early through mid-December. As an added bonus, the radiant also clears the northeastern horizon in the late evening as seen from mid-northern latitudes. The Geminids are therefore also exceptional among meteor showers for displaying early evening activity.

Stellarium
The Geminid radiant, looking east around 11 PM local on the evening of December 13th. Note the nearby Moon in the same constellation. Image credit: Stellarium.

First, though, here is the low down of the specifics for the 2016 Geminids: the Geminid meteors are expected to peak on December 13th/14th at midnight Universal Time (UT), favoring Western Europe. The shower is active for a two week period from December 4th to December 17th and can vary with a Zenithal Hourly Rate (ZHR) of 50 to 80 meteors per hour, to short outbursts briefly topping 200 per hour. In 2016, the Geminids are expected to produce a maximum ideal ZHR of 120 meteors per hour. The radiant of the Geminids is located at right ascension 7 hours 48 minutes, declination 32 degrees north at the time of the peak, in the constellation of Gemini.

The Moon is a 98% illuminated waning gibbous just 20 degrees from the radiant at the peak of the Geminids, making 2016 an unfavorable year for this shower. In previous years, the Geminids produced short outbursts topping 200 per hour, as last occurred in 2014.

The Geminid meteors strike the Earth at a relatively slow velocity of 35 kilometers per second, and produce many fireballs with an r vaule of 2.6. The source of the Geminid meteors is actually an asteroid: 3200 Phaethon

Orbitron
The orientation of the radiant versus the Sun, Moon and Earth’s shadow just past midnight Universal Time on the evening of December 13th/14th. (Created using Orbitron).

A moderate shower in the late 20th century, the Geminids have increased in intensity during the opening decade and a half of the 21st century, surpassing the Perseids for the title of the top annual meteor shower.

Image credit: NASA JPL.
The orbit of 3200 Phaethon. Image credit: NASA JPL.

The Geminid shower seems to have breached the background sporadic rate around the mid-19th century. Astronomers A.C. Twining and R.P. Greg observing from either side of the pond in the United States and the United Kingdom both first independently noted the shower in 1862.

Orbiting the Sun once every 524 days, 3200 Phaethon wasn’t identified as the source of the Geminids until 1983. The asteroid is still a bit of a mystery; reaching perihelion just 0.14 astronomical units (AU) from the Sun, (interior to Mercury’s orbit) 3200 Phaethon is routinely baked by the Sun. Is it an inactive comet nucleus? Or a ‘rock comet’ in a transitional state?

Observing meteors is as simple as setting out in a lawn chair, laying back and watching with nothing more technical than a good ole’ Mk-1 pair of human eyeballs. Our advice for 2016 is to start watching early, like say this weekend, before the Moon reaches Full on Wednesday, December 14th. This will enable you to watch for the Geminids after morning moonset under dark skies pre-peak, and before moonrise on evenings post-peak.

Two other minor showers are also active next week: the Coma Bernicids peaking on December 15th, and the Leo Minorids peaking on December 19th. If you can trace a suspect meteor back to the vicinity of the Gemini ‘twin’ stars of Castor and Pollux, then you’ve most likely spied a Geminid and not an impostor.

And speaking of the Moon, next week’s Full Moon is not only known as the Full Cold Moon (For obvious reasons) from Algonquin native American lore, but is also the closest Full Moon to the December 21st, northward solstice. This means that next week’s Full Moon rides highest in the sky for 2016, passing straight overhead for locales sited along latitude 17 degrees north, including Guatemala City and Mumbai, India.

A 2015 Geminid over Sariska Palace in Rajastan, Pakistan (ck). Image credit and copyright: Abhinav Singhai.
A 2015 Geminid over Sariska Palace in Rajastan, India. Image credit and copyright: Abhinav Singhai.

Photographing the Geminids is also as simple as setting a camera on a tripod and taking wide-field exposures of the sky. We like to use an intervalometer to take automated sequences about 30 seconds to 3 minutes in length. Said Full Moon will most likely necessitate shorter exposures in 2016. Keep a fresh set of backup batteries handy in a warm pocket, as the cold December night will drain camera batteries in a pinch.

Looking to contribute some meaningful scientific observations? Report those meteor counts to the International Meteor Organization.

Our humble meteor imaging rig. Credit: Dave Dickinson.
Our humble meteor imaging rig. Credit: Dave Dickinson.

And although the Geminids might be a bust in 2016, another moderate shower, the Ursids has much better prospects right around the solstice… more on that next week!

Japanese Company Plans Artificial Meteor Shower

A company named Sky Canvas plans to launch a colorful artificial meteor shower barrage via micro-satellite.

In the ‘strange but true department’ and a plan that would make any super-villain envious, a Japanese start-up plans to shoot meteoroids at the Earth to create the first orchestrated artificial meteor shower. The effort is benign in a bid to study the behavior of meteors and reentry characteristics, while also putting on a good show.

The idea is brainchild of Lena Okajima, who started the ALE Company which is funding the project.

“I’m very excited about this project, not only because it will turn my childhood dream into a reality, but also because it can contribute to fundamental scientific research in a new form without relying on public funds and donations,” Okajima said on her biography on the ALE website.

First, a clarification: despite what several news sites have reported, Sky Canvas/ALE have not made a formal bid to incorporate the proposal as part of the 2020 Olympics in Japan, though they’re certainly open to the idea. An artificial meteor shower during the opening ceremonies for the 2020 Olympics in Japan would definitely be a unique first!

Sky Canvas
A meteor shower-dispensing satellite in low Earth Orbit. Image credit: Sky Canvas.

Early testing and a first satellite launch with an as-yet unannounced carrier may occur in the later half of 2017, with another launch per year, each year following.

Long a dream of astronomer Lena Okajima, an artificial meteor shower may soon grace a sky near you.

Image credit: Sky Canvas.
A ball-bearing sized artificial meteor on reentry. Image credit: Sky Canvas.

Visibility Prospects

The meteoric payload will be carried into low Earth orbit aboard a small 50x 50x 50 centimetre cubical satellite dispenser. Different pellets will burn blue, orange and green. The team won’t reveal the ‘secret formula’ for the colors, but you only have to think back to high school chemistry class and Bunsen Burner flame tests to imagine the elements probably used. (hint: the green isn’t kryptonite). Laboratory tests suggest that the artificial meteors should be visible from about 200 kilometers (120 miles) away. Said satellite dispenser will carry about a 300-500 pellets. At say, a meteor a second, such a display would last from five to just over eight minutes in duration.

Image credit: Sky Canvas.
A rainbow of elemental colors. Image credit: Sky Canvas.

A test carried out in the lab verified that the brightness for the pellets should be right around apparent magnitude -0.86, just a bit fainter than the brightest star in the sky Sirius at magnitude -1.5.

Looking for an artificial meteor shower to light up your next event? Well, such a performance isn’t cheap. With a roughly eight million dollar price tag, an artificial meteor shower breaks down to about $16,000 USD per meteor.

The plan is to place the 50 kilogram satellite (fully loaded) in a sun-synchronous orbit. This is a highly inclined retrograde polar orbit, also favored by Earth-observing and (supervillians take note) spy satellites.

The visibility prospects for Sky Canvas over a major urban area. Image credit: Sky Canvas.
The visibility prospects for Sky Canvas over a major urban area. Image credit: Sky Canvas.

The Sky Canvas system will also have the ability to ‘weather abort’ about 100 minutes prior to the event in case of inclement weather. Once in low Earth orbit, said satellite will orbit the planet once every 90 minutes. Such a dispenser is a one shot affair, and will burn up shortly after use.

Are artificial meteor showers a great idea? On one hand, it might be a great educational resource, and a way to get the general public excited about space and astronomy. Still, for those of us who have endured many an early morning vigil for the occasional surprise flash of a meteor, there’s perhaps something a bit kitschy about meteor showers on demand. It’s also slightly reminiscent of the early Space Age ideas to create nighttime illumination via large mirrors floating in space, or place advertising (!) in low Earth orbit. Streaks of artificial satellites already routinely photobomb deep sky images… do we want to contend with orbiting Pepsi logos as well?

Some may also bemoan the advent of yet more artificial light – however ephemeral — streaking across the already brightening sky. And here’s another possible dilemma: will a -1 magnitude artificial meteor appear all that impressive from the already garish glare of downtown Tokyo, Las Vegas or Dubai? Still, I’d make the trip to see the world’s first artificial meteor shower… and humanity already routinely creates similar unheralded “shows” every time a piece of space junk reenters the Earth’s atmosphere.

I also can’t help but think of the fictional metal band Disaster Area from Douglas Adams’ Hitchhiker’s Guide to the Galaxy, which ended each concert with a sun-diving spaceship.

There are also possible practical applications for the project, including understanding meteor showers, spacecraft reentry, studying the upper atmosphere, etc. And though this may seem far-fetched, NASA already uses luminous chemicals dispersed from sounding rockets to do the same thing.

JAXA has already performed similar artificial meteor experiments here on Earth using an arc-heated wind tunnel laboratory, mimicking and modeling the Chelyabinsk meteor and the asteroid sample return mission Hayabusa-1 and the future return of Hayabusa-2.

Just maybe though, light pollution awareness might prove to be the project’s greatest strength. An artificial meteor shower might just cause city dwellers and urban planners to turn the lights down, and simply gaze up at the night sky for a brief moment.

When Good Showers Turn Bad: The 2016 Leonids

Leonid Meteor

A flash of light recently reminded us of the most stunning sight we ever saw.

We managed to catch an early Leonid meteor this past Saturday morning while waiting for the new Chinese space station Tiangong-2 to pass over southern Spain. The Leonids are active this week, and although the light-polluting just past Super Moon lurks nearby, we’ve learned to never ignore this shower, even on an off year.

First though, here’s a rundown on what’s up with the Leonids in 2016:

The Leonid meteors are expected to peak on the night of Thursday, November 17th into the morning of Friday, November 18th. The shower is active for a 25 day span from November 5th to November 30th and though the Leonids can vary with an Zenithal Hourly Rate (ZHR) of thousands of meteors per hour, and short outbursts briefly topping hundreds of thousands per hour, in 2016, the Leonids are expected to produce a maximum ideal ZHR of only 10 to 15 meteors per hour. The radiant of the Leonids is located at right ascension 10 hours 8 minutes, declination 21.6 degrees north at the time of the peak, in the Sickle or backwards Question Mark asterism of the astronomical constellation of Leo the Lion.

The rising radiant of the Leonids versus the nearby waning gibbous Moon. image credit: Stellarium.
The rising radiant of the Leonids versus the nearby waning gibbous Moon. Image credit: Stellarium.

The source of the Leonids is periodic Comet 55P/Tempel-Tuttle.

Now, for the bad news. The Moon is an 82% illuminated, waning gibbous phase at the peak of the Leonids, making 2016 an unfavorable year for this shower. In fact, the Moon is located just 42 degrees from the shower’s radiant in the nearby constellation of Gemini at the shower’s peak on Friday morning. In previous years, the Leonids produced a ZHR numbering in the 15-20 per hour. The estimated ZHR last topped 100 in 2008.

The Leonid meteors strike the Earth at a moderate/fast velocity of 71 km/s, and produce many fireballs with an r value of 2.5.

The Leonids are notorious for producing storms of epic proportions every 33 years. This last occurred in years surrounding 1999, and isn’t expected to occur again until around 2032. Some older observers still remember the great Leonid meteor storm over the southwestern United States in 1966, and the U.S. East Coast witnessed a massive storm in 1833.

A woodcut engraving depicting the 1833 Leonids over Niagara Falls. Public Domain image.
A woodcut engraving depicting the 1833 Leonids over Niagara Falls. Public Domain image.

We can attest to what the Leonids are capable of. We saw an amazing display from the shower in 1998 from Al Jaber Air Base in Kuwait, with an estimated rate of around 900 per hour towards dawn. When a shower edges towards a zenithal hourly rate of 1,000, you’re seeing meteors every few seconds, with fireballs lighting up the desert night.

And it is possible to defeat the waning gibbous Moon. Though the Moon is near the zenith as seen from the mid-northern latitudes in the early AM hours (the best time to watch the shower,) its almost always possible to view the shower with the Moon blocked behind a house or hill… unless you have the bad luck of viewing from latitude 20 degrees north, where the Moon crosses directly through the zenith on Friday morning.

But take heart, as we’re past the halfway mark in 2014, headed to the Leonid ‘storm years’ of the early 2030s.

Don’t miss the 2016 Leonids… if for no other reason, to catch a flash of storms to come.

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

Orionid

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.

Perseid Meteor Shower Briefly Storms, Still Has Legs

A brilliant Perseid meteor streaks along the Summer Milky Way as seen from Cinder Hills Overlook at Sunset Crater National Monument—12 August 2016 2:40 AM (0940 UT). It left a glowing ion trail that lasted about 30 seconds. The camera caught a twisting smoke trail that drifted southward over the course of several minutes.
A brilliant Perseid meteor streaks along the Summer Milky Way as seen from Cinder Hills Overlook at Sunset Crater National Monumen at 2:40 a.m. (9:40 UT) August 12.  It left a glowing ion trail that lasted about 30 seconds. The camera caught a twisting smoke trail that drifted southward over the course of several minutes. Credit: Jeremy Perez

The Perseid meteor shower must have looked fantastic from 10,000 feet. That’s how high you would have had to go to get past the pervasive fog and overcast skies at my home last night. Tonight looks a little better for weather, so I’ll do what all hopeful amateurs astronomers do. Set the alarm for 2 a.m. and peek out the shade looking for those glimmers of starlight that indicate clear skies.

A composite photo, made from images taken last night August 11-12 from the UK, captures multiple Perseids. Credit: Peter Greig
A composite photo, made from images taken last night August 11-12 from the UK, captures multiple Perseids. Credit: Peter Greig

From observations reported as of mid-afternoon to the International Meteor Observers 2016 Perseids Quick-Look site, it appears the greatest activity or highest meteor counts happened over Europe and points east in two outbursts: a brief but intense display around 23:15 Universal Time (6:15 p.m. CDT in daylight) August 11 when some observers briefly saw up to 15 Perseids a minute (!) with many bright ones, and a second peak starting around 2:00 UT (9 p.m. CDT) and lasting till 5:00 UT (midnight CDT).


90+ Perseid meteors captured on video August 11-12, 2016 by Ohio amateur John Chumack

While Europeans clearly hit the jackpot — some observers calling it the best since the 2002 Leonid storm — U.S. observers varied in their meteor counts. A few thought the shower was a bust, others reported numbers more typical of an “average year” shower. It appears that Earth passed through a dense filament of comet dust while it was night in Europe but late afternoon in the Americas. C’est la vie météore!

We should be past peak by today, but experience shows that tonight should still be a very good time for Perseid watching. Indeed, the next few nights will reward skywatchers with at least a dozen an hour. I’ll be out watching and hopefully not imagining what’s happening 10,000 feet over my head. Good luck to you too!

Get Ready for the 2016 Perseids

perseid meteor

Out camping under the August sky? The coming week gives us a good reason to stay up late, as the Perseid meteor shower graces the summer sky. An ‘old faithful’ of annual meteor showers, the Perseids are always sure to produce.

The 2016 Perseids present a few challenges, though persistent observers should still see a descent show. The Perseids are typically active from July 17th to August 24th, with the peak arriving this year right around 13:00 to 15:30 Universal Time on Friday, August 12th. This will place the radiant for the Perseids high in the sky after local midnight for observers in the northern Pacific, though observers worldwide should be vigilant over the next week. Meteor showers don’t read predictions and prognostications, and an arrival of the peak just a few hours early would place North America in the cross-hairs this coming Friday. The Perseids typically produce an average Zenithal Hourly Rate of 60-200 per hour, and the International Meteor Organization predicts a ZHR of 150 for 2016.

Looking to the northeast from latitude 50 degrees north at 1AM local on the morning of August 12th. Image credit: Stellarium.
Looking to the northeast from latitude 50 degrees north at 1AM local on the morning of August 12th. Image credit: Stellarium.

The nemesis of the 2016 is the Moon, which reaches Full on August 18th, six days after the shower’s peak. The time to start watching this shower is now, before the waxing Moon becomes a factor. The farther north you are, the earlier the Moon sets this week:

Moonset on the evening of August 11/12th:

Latitude versus Moonset ( in local daylight saving time)

20 degrees north – 1:30 AM

30 degrees north – 1:14 AM

40 degrees north – 0:56 AM

50 degrees north – 0:30 AM

Early morning is almost always the best time to watch any meteor shower, as the Earth-bound observer faces in to the meteor stream head on. The December Geminids only recently surpassed the Perseids in annual intensity in the past few years.

The orientation of the Earth's shadow versus, the Sun, Moon and the radiant of the Perseids at the start of the projected peak on August 12th. Image credit: Orbitron.
The orientation of the Earth’s shadow versus the Sun, Moon and the radiant of the Perseids at the start of the projected peak on August 12th. Image credit: Orbitron.

The radiant of the Perseids drifts through the constellations of Cassiopeia, Perseus and Camelopardalis from late July to mid-August. The Perseids could just as easily have received the tongue-twisting moniker of the ‘Cassiopeiaids’ or the ‘August Camelopardalids.’ The source of the Perseids is comet Comet 109P/Swift-Tuttle discovered by Lewis Swift and Horace Tuttle in 1862. Comet Swift-Tuttle reached perihelion on 1992, and visits the inner solar system once again in 2126.

The Perseids are also sometimes referred as the “Tears of Saint Lawrence” who was martyred on a hot grid iron on August 10th, 258 AD.

The Perseids have been especially active in recent decades, following the perihelion passage of Comet Swift-Tuttle.  Meteor showers come and go. For example, the Andromedids were a shower of epic storm proportions until the late 19th century. We have records of the Perseids back to 36AD, but on some (hopefully) far off date, the debris path of Comet Swift-Tuttle will fail to intersect the Earth’s orbit annually, and the Perseids will become a distant memory. During previous years, the Perseids exhibited a peak of ZHR= 95 (2015), 68 (2014), 110 (2013), 121 (2012) and 58 (2011). Keep in mind, the Perseids have also sometimes displayed a twin peak during previous years, as well.

An early snapshot of the activity for the 2016 Perseids. image credit: The International Meteor Organization.
An early snapshot of the activity for the 2016 Perseids. Image credit: The International Meteor Organization.

Observing the Perseids

The best instrument to observe the Perseids with is a pair of old fashioned, ‘Mk-1 eyeballs.’ Simply lay back, warm drink in hand, and watch. Remember, the quoted ZHR is an ideal rate that we all strive for, though there are strategies to maximize your chances of catching a meteor. Watching early in the morning when the radiant rides highest (around sunrise in the case of the Perseids), seeking out dark skies, and enlisting a friend to watch in an opposite direction can raise your hourly meteor count.

perseid meteor
An early Perseid captured by Chris-Lyons. Image credit and copyright: Chris Lyons.

Keep a pair of binoculars handy to examine any persistent glowing trains and lingering smoke trails from bright fireballs. Monitoring the FM band for the pings of accompanying radio meteors can add another dimension to an observation session. The ionized trail of a meteor can very occasionally reflect the signal of a distant radio station, bringing it through clear for a few seconds before fading out.

Also, keep an ear out for an even stranger phenomenon, as bright meteors are sometimes accompanied by a hissing or crackling sound. Long thought to be a psychological phenomenon, a team of Japanese astronomers managed to catch recordings of this strange effect during the 1988 Perseid meteors.

Imaging meteors is also pretty straight forward. Simply tripod mount a DSLR with a wide field lens, take some test exposures of the sky to get the ISO, f-stop and exposure combination just right, and begin taking exposures 30 seconds to five minutes long. An intervalometer can automate the process, freeing you up to kick back and watch the show.

Got science? Be sure to send those meteor counts into the International Meteor Organization (IMO) and watch their live updated graph as the shower progresses.

Also, be sure to tweet those meteor sightings to #Meteorwatch.