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.

A Halloween Season ‘Taurid Meteor Swarm’ on Tap for 2015?

Asteroid 2015 TB145 isn’t the only cosmic visitor paying our planet a trick-or-treat visit over the coming week. With any luck, the Northern Taurid meteor shower may put on a fine once a decade show heading into early November.

About once a decade, the Northern Taurid meteor stream puts on a good showing. Along with its related shower the Southern Taurids, both are active though late October into early November.

The motion of the radiant of the Northern Taurid meteors from mid-October through mid-November. Image credit: Stellarium
The motion of the radiant of the Northern Taurid meteors from mid-October through mid-November. The shower typically peaks around November 12th annually. Image credit: Stellarium

Specifics for 2015

This year sees the Moon reaching Full on Tuesday October 27th, just a few days before Halloween. The Taurid fireballs, however, have a few things going for them that most other showers don’t. First is implied in the name: the Northern Taurids, though typically exhibiting a low zenithal hourly rate of around 5 to 10, are, well, fireballs, and thus the light-polluting Moon won’t pose much of a problem. Secondly, the Taurid meteor stream is approaching the Earth almost directly from behind, meaning that unlike a majority of meteor showers, the Taurids are just as strong in the early evening as the post midnight early morning hours.  As a matter of fact, we saw a brilliant Taurid just last night from light-polluted West Palm Beach in Florida, just opposite to the Full Moon and a partially cloudy sky.

A 2014 Taurid. Image credit and copyright: Brian who is called Brian
A 2014 Taurid. Image credit and copyright: Brian who is called Brian

In stark contrast to the swift-moving Orionids from earlier this month, expect the Taurid fireballs to trace a brilliant and leisurely slow path across the night sky, moving at a stately 28 kilometre per second (we say stately, as the October Orionids smash into our atmosphere at over twice that speed!)

Ever since the 2005 event, the Northern Taurids seemed to have earned the name as “The Halloween Fireballs” in the meme factory that is the internet. It’s certainly fitting that Halloween should have its very own pseudo-apocalyptic shower. The last good return for the Northern Taurids was 2005-2008, and 2015 may see an upswing in activity as well.

Obviously, something interesting has to be occurring on Comet 2P Encke—the source of the two Taurid meteor streams—to shed the pea-sized versus dust-sized material seen in the Southern and Northern Taurids. With the shortest orbital period 3.3 years of all periodic comets known, the Taurid meteor stream—like Encke itself—follows a shallow path nearly parallel to the ecliptic plane.

Discovered in 1822 by astronomer Johann Encke, Comet 2P Encke has been observed through many perihelion passages over the last few centuries, and passes close to Earth once 33 years, as it last did in 2013.

What constitutes a ‘meteor swarm?’ As with many terms in meteoritics, no hard-and-fast definition of a true ‘meteor swarm’ exists. A meteor storm is generally quoted as having a zenithal hourly rate greater than 1000. Expect activity to be broad over the next few weeks, and the Taurid fireballs always have the capacity to produce the kind of brilliant events captured by security cams and dashboard video cameras that go viral across ye ole Internet.

Watching for fireballs is a thrilling pursuit. These may often leave persistent glowing meteor trails in their wake.  We caught the 1998 Leonids from the dark sky deserts of Kuwait, and can attest to the persistence of glowing fireball trails from this intense storm, sometimes for minutes. Again, the 2015 Taurids aren’t expected to reach that level of intensity, though the ratio of fireballs to faint meteors will be enhanced.

The path of the stream isn’t fully understood, and that is where volunteer observations can come in handy. The International Meteor Organization is always looking for reports from skilled observers, as is the American Meteor Society (AMS).

Image Credit:
The light curve of the suspected Taurid that hit the Moon on Nov 7th. Image Credit: NASA

There’s even been evidence for a recorded meteorite strike related to the northern Taurid fireballs back in 2015 on the dark limb of the Moon as well, a rare event indeed.

After a slow summer, Fall meteor shower activity is definitely heating up. And though 2015 is an off year for the November Leonids, we’re now almost midway between the 1998-99 outbursts, and the possibility of another grand meteor storm in the early 2030s. And another obscure wildcard shower known as the Alpha Monocerotids may put on a surprise showing in November 2015 as well…

Bright Meteor 4th November 2013 from Richard Fleet on Vimeo.

More to come on that. Keep watching the skies, and don’t forget to tweet those Northern Taurid fireball sightings and images to #Meteorwatch!

-Got an image of a Northern Taurid fireball? Send ‘em in to Universe Today for our Flickr forum… we may just feature your pic in an after action round up!

The Draconid Meteor Shower – A Storm is Coming!

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The Draconids are coming! Will this meteor shower produce a storm of observable meteors, or just a minor squall? The Draconid Meteor Show should begin on October 8, 2011 starting at dusk (roughly 19:00 BST) and continue through the evening. Peak activity of this normally minor and quiet shower is estimated to be at 21:00 BST (20:00 UT). There seems to be a wide range of predictions for this year’s shower, but some astronomers believe there could be up to 1,000 meteors per hour, making this a meteor storm!

The Draconids or Giacobinids as they are also known, radiate from a point in the constellation of Draco the Dragon in the Northern hemisphere. In the past, notably in 1933 and 1946, the Draconids turned into a meteor storm with meteor rates of more than one every second!

So, will this year bring us a storm? Astronomers believe so as the predicted path of the Earth through the debris streams of comet 21P/Giacobini-Ziner is favorable for a major storm, similar to what has been seen in previous years. Some reports say NASA is even considering the potential risk of damage to the International Space Station and other satellites due to meteroid impacts.

Some astronomers, on the other hand, are saying this shower could be a dud, with only 5 or so meteors per hour.

Credit: Alex Tudorica

Observers in the UK and Northern Europe are ideally placed to see the peak of the Draconids. Unfortunately the peak occurs in the day time for North America. There will also be a bright Moon which may drown out many but the brightest meteors, but if predictions are correct, you will still see many. You may see Draconid meteors on the 7th an the 9th also, so it is worth going out and checking the skies.

The Constellation Draco in the northern sky in the northern hemisphere.

Draco is a circumpolar constellation visible all night from northern latitudes.

There is no skill or even astronomical knowledge needed to enjoy meteor showers. All you need is to be comfortable, away from bright lights and your eyes. Sit back on a recliner or garden chair and fill your gaze with sky as meteors can appear anywhere as they radiate from the constellation of Draco. For more info on how to enjoy meteor showers visit meteorwatch.org

So what will you see? Draconid meteors are usually slow and bright streaks of light, but if you look away, you can still miss them so keep your gaze on the sky.

There are no guarantees of a meteor storm or even a good meteor shower as these phenomena can be very unpredictable, but the only way to find out is to go outside and look up.

If predictions are correct, you could be in for a spectacular treat and something truly memorable, so don’t miss it. Even if it is cloudy, you can listen to the meteor shower or you can watch as they enter Earths atmosphere

For more information on the Draconids, see the International Meteor Organization’s post on this year’s shower.

Good Luck!

Fireball Meteor
Credit: Pierre Martin of Arnprior, Ontario, Canada.