MESSENGER Spies a Meteor Shower… on Mercury

Leonid meteor storms. Taurid meteor swarms. Earth is no stranger to meteor showers, that’s for sure. Now, it turns out that the planet Mercury may experience periodic meteor showers as well.

The news of extraterrestrial meteor showers on Mercury came out of the annual Meeting of the Division of Planetary Sciences of the American Astronomical Society currently underway this week in National Harbor, Maryland. The study was carried out by Rosemary Killen of NASA’s Goddard Spaceflight Center, working with Matthew Burger of Morgan State University in Baltimore, Maryland and Apostolos Christou from the Armagh Observatory in Northern Ireland.  The study looked at data from the MErcury Surface Space Environment Geochemistry and Ranging (MESSENGER) spacecraft, which orbited Mercury until late April of this year. Astronomers published the results in the September 28th issue of Geophysical Research Letters.

Micrometeoroid debris litters the ecliptic plane, the result of millions of years of passages of comets through the inner solar system. You can see evidence of this in the band of the zodiacal light visible at dawn or dusk from a dark sky site, and the elusive counter-glow of the gegenschein.

The orbit of comet 2P Encke. Image credit: NASA/JPL
The orbit of comet 2P Encke. Image credit: NASA/JPL

Researchers have tagged meteoroid impacts as a previous source of the tenuous exosphere tails exhibited by otherwise airless worlds such as Mercury. The impacts kick up a detectable wind of calcium particles as Mercury plows through the zodiacal cloud of debris.

“We already knew that impacts were important in producing exospheres,” says Killen in a recent NASA Goddard press release. “What we did not know was the relative importance of comet streams over zodiacal dust.”

This calcium peak, however, posed a mystery to researchers. Namely, the peak was occurring just after perihelion—Mercury orbits the Sun once every 88 Earth days, and travels from 0.31 AU from the Sun at perihelion to 0.47 AU at aphelion—versus an expected calcium peak predicted by researchers just before perihelion.

Image credit:
STEREO A catches sight of comet 2P Encke. Image credit: NASA/STEREO

A key suspect in the calcium meteor spike dilemma came in the way of periodic Comet 2P Encke. Orbiting the Sun every 3.3 years—the shortest orbit of any known periodic comet—2P Encke has made many passages through the inner solar system, more than enough to lay down a dense and stable meteoroid debris stream over the millennia.

With an orbit ranging from a perihelion at 0.3 AU interior to Mercury’s to 4 AU, debris from Encke visits Earth as well in the form of the November Taurid Fireballs currently gracing the night skies of the Earth.

The Encke connection still presented a problem: the cometary stream is closest to the orbit of Mercury about a week later than the observed calcium peak. It was as if the stream had drifted over time…

Image credit:
Comet 2P Encke, captured by NASA’s MESSENGER spacecraft. Image credit: NASA/Johns Hopkins/APL/SW Research Institute

Enter the Poynting-Robertson effect. This is a drag created by solar radiation pressure over time. The push on cometary dust grains thanks to the Poynting-Robertson effect is tiny, but it does add up over time, modifying and moving meteor streams. We see this happening in our own local meteor stream environment, as once great showers such as the late 19th century Andromedids fade into obscurity. The gravitational influence of the planets also plays a role in the evolution of meteor shower streams as well.

Researchers in the study re-ran the model, using MESSENGER data and accounting for the Poynting-Robertson effect. They found the peak of the calcium emissions seen today are consistent with millimeter-sized grains ejected from Comet Encke about 10,000 to 20,000 years ago. That grain size and distribution is important, as bigger, more massive grains result in a smaller drag force.

Image credit: Kevin Palmer
A 2015 Taurid meteor. Image credit: Kevin Palmer

This finding shows the role and mechanism that cometary debris plays in exosphere production on worlds like Mercury.

“Finding that we can move the location of stream to match MESSENGER’s observations is gratifying, but the fact that the shift agrees with what we know about Encke and its stream from independent source makes us confident that the cause-and-effect relationship is real, says Christou in this week’s NASA Goddard press release.

Launched in 2004, MESSENGER arrived at Mercury in March 2011 and orbited the world for over four years, the first spacecraft to do so. MESSENGER mapped the entire surface of Mercury for the first time, and became the first human-made artifact to impact Mercury on April 30th, 2015.

The joint JAXA/ESA mission BepiColombo is the next Mercury mission in the pipeline, set to leave Earth on 2017 for insertion into orbit around Mercury on 2024.

An interesting find on the innermost world, and a fascinating connection between Earth and Mercury via comet 2P Encke and the Taurid Fireballs.

From a Roar to a Purr: Prospects for the 2015 November Leonid Meteors

A November rain hails from the Sickle of the Lion.

Hot on the heels of the October Orionids and the Halloween fireballs of the Taurid meteors comes the Leonid meteor shower. On most years, the Leonids are a moderate shower, with hourly local rates reaching around 20. Once every 33 years, however, the Leonids are responsible for putting on one of the greatest astronomical shows ever witnessed, producing a grand storm with a zenithal hourly rate topping thousands per hour.

Image credit: Stellarium
The orientation of the Earth and the relative positions of the Sun, Moon and the Leonid meteor radiant on November 17th at 4:00 UT. Image credit: Stellarium

Prospects for 2015

First, the bad news. 2015 isn’t forecast to be a ‘storm year’ for the Leonids, though that shouldn’t stop a vigilant observer from watching.  The good news is, we’re just about midway betwixt the storm years of 1998-99 and 2031-32. The Leonids intensify once every 33 years, and if the increased activity seen in the late 1990s was any indication, we’d bet we’ll start seeing a pickup in rates from the Leonids in the late 2020’s or so. The good news for 2015, however, is that the peak for the Leonids occur on November 18th at around 4:00 Universal Time (UT)/ (11:00 PM EST on November 17th). This places the waxing crescent Moon out of the picture, just a day before reaching First Quarter phase. New Moon for November 2015 occurs on November 11th at 17:47 UT/12:47 PM EST.

Image credit:
A composite of the 2014 Leonids. Image credit: Alan Dyer/Amazing Sky Photography

Fun fact: the August Perseids, November Leonids and the December Geminid meteor showers are spaced out on the calendar in such a way that, when the Moon phase is favorable for one shower on a particular year, it is nearly always favorable across all of them.

The Leonids are mildly active from November 6th through November 30th, and though the above prediction for activity in 2015 favors European longitudes at dawn, some predictions have the peak arriving up to seven hours early this year.

Image credit: Stellarium
A simulated ‘Leonid storm.’ Note the true position of the radiant in the center of the backwards ‘?’ asterism is slightly offset.  Image credit: Stellarium

The Leonids are the dusty remnants laid down by periodic comet 55P Tempel-Tuttle on its 33-year path through the inner solar system. The Leonids are fast-movers, hitting the Earth nearly head-on in the dawn. You can see this in the relative position of the radiant, which rises in mid-November around 11PM local, and reaches the zenith around 6AM local time.

A late season Leonid meteor from 2014. Image credit: The UK Monitoring network (UKMON)
A late season Leonid meteor from 2014. Image credit: The UK Monitoring network (UKMON)

Often bluish in color, the Leonids hit the Earth’s atmosphere at over 70 km/sec… almost the fastest theoretical speed possible. For best results, watch for Leonids to spike in activity close to local dawn.

A 1799 woodcut depicting the Leonids at sea. Image credit: Public Domain
A 1799 woodcut depicting the Leonids at sea. Image credit: Public Domain

The Leonids have a storied history, going back 902 AD report from Arabic annals of the ‘Year of Stars.’ The Great Meteor Storm of 1833 dazzled (and terrified) residents of the eastern seaboard of the United States, and the spectacle not only inspired astronomer Denison Olmsted to pioneer studies into the fledgling field of meteor shower science, but has been attributed to adding fervor to many of the religious revivalist movements that sprang up in the 1830s in the United States as well.

The last outburst from the Leonids that reached such an apocalyptic scale was in 1966, when observers across the southwestern United States reported hourly rates approaching an amazing ZHR=144,000. Witnesses that remember this spectacle say it produced an illusion reminiscent of the Star Trek ‘warp speed’ effect, as Earth rammed headlong into the dense Leonid meteor stream.

Our own personal encounter with a Leonid meteor storm in 1998 from the dark desert skies of Kuwait wasn’t quite that intense, but thrilling to see nonetheless. Rates neared one every few seconds towards sunrise, with several fireballs punctuating the action, lighting up the desert floor. Here, as US coalition forces were on the verge of unleashing what would become Operation: Desert Fox over Iraq, the Universe was putting on a fireworks show of its own.

The Leonid meteor storms are the stuff of astronomical legend, a once in a lifetime event. Ever since we witnessed just what the Leonids are capable of, we never miss this annual shower, as we remember one night back in 1998, and look forward to the storms of 2032.

Here’s what the Leonids have been doing on previous recent years:

ZHR=15 +/-4 (2014)

Mostly washed out by the near-Full Moon (2013)

ZHR=47 +/-11 (2012)

ZHR=22 +/-3 (2011)

ZHR=32+/-4 (2010)

  • Report those Leonid sightings to the International Meteor Organization, and also be sure to Tweet em to #Meteorwatch
  • Got an image of a Leonid meteor? Send ‘em in to Universe Today at our Flickr Forum… we just might feature it in an after-action round up!

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!

Gallery: 2015 Perseids Are Putting on a Show

Have you been looking up the past few nights, trying to see the Perseid Meteor Shower? Many of our readers have been turning their eyes — and cameras — to the skies, with spectacular results. This year’s Perseids were predicted to be one of the best ever, since there has been little to no moonlight to upstage the shower. As you can see from the images here, many astrophotographers were able to capture fast and bright meteors, and even some that left persistent trains.

Remember, tonight (Wednesday, August 12, 2015) is projected to be the peak, so if you’ve got clear skies, take advantage of this opportunity to see a great meteor shower. You can find out how and when to see them in our previous detailed articles by our in-house observing experts David Dickinson and Bob King.

And enjoy the view from our readers in this gallery of 2015 Perseids:

A Perseid Meteor, the Milky Way and the photographer on August 11, 2015 near Bamburgh, Northumberland, England. Credit and copyright:  Peter Greig.
A Perseid Meteor, the Milky Way and the photographer on August 11, 2015 near Bamburgh, Northumberland, England. Credit and copyright:
Peter Greig.
An 'exploding' Perseid meteor as seen on August 11, 2015. Credit and copyright: Chris Lyons.
An ‘exploding’ Perseid meteor as seen on August 11, 2015. Credit and copyright: Chris Lyons.
Bright Perseid and Perseus. Credit and copyright: Chris Lyons.
Bright Perseid and Perseus. Credit and copyright: Chris Lyons.
A green Perseid meteor, along with 2 satellites show up in this image taken on August 11, 2015. Credit and copyright: eos-001 on Flickr.
A green Perseid meteor, along with 2 satellites show up in this image taken on August 11, 2015. Credit and copyright: eos-001 on Flickr.
Perseid meteor from early morning, August 12, 2015 in Weatherly, Pennsylvania. Taken with a Canon 6D and Samyang 14mm lens, 40 second exposure at ISO 3200, unguided. Credit and copyright: Tom Wildoner.
Perseid meteor from early morning, August 12, 2015 in Weatherly, Pennsylvania. Taken with a Canon 6D and Samyang 14mm lens, 40 second exposure at ISO 3200, unguided. Credit and copyright: Tom Wildoner.
Perseid Meteor near Cassiopeia along with the Andromeda Galaxy, as seen from France on August 10, 2015. Credit and copyright: VegaStar Carpentier/ VegaStar Carpentier Photography.
Perseid Meteor near Cassiopeia along with the Andromeda Galaxy, as seen from France on August 10, 2015. Credit and copyright: VegaStar Carpentier/ VegaStar Carpentier Photography.
A Perseid Meteor as seen on August 8, 2015, taken from Oxfordshire with a Canon 1100D + 18-55mm lens, ISO-1600 for 30 seconds. Credit and copyright: Mary Spicer.
A Perseid Meteor as seen on August 8, 2015, taken from Oxfordshire with a Canon 1100D + 18-55mm lens, ISO-1600 for 30 seconds. Credit and copyright: Mary Spicer.

Prolific night sky photographer John Chumack near Dayton, Ohio put together this video of 81 Perseid meteors he captured on August 12, 2015 with his Automated low light -Meteor Video Camera Network:

If you are clouded out, you can still enjoy the shower. NASA TV will be tracking the Perseids live on Wednesday, August 12 starting at 10PM EDT/02:00 UT:

The 2015 Perseids: Weather Prospects, Prognostications and More

The venerable ‘old faithful of meteor showers’ is on tap for this week, as the August Perseids gear up for their yearly performance. Observers are already reporting enhanced rates from this past weekend, and the next few mornings are crucial for catching this sure-fire meteor shower.

First, here’s a quick rundown on prospects for 2015. The peak of the shower as per theoretical modeling conducted by Jérémie Vaubaillon projects a broad early maximum starting around Wednesday, August 12th at 18:39 UT/2:39 PM EDT. This favors northeastern Asia in the early morning hours, as the 1862 dust trail laid down by Comet 109P Swift-Tuttle — the source of the Perseids — passes 80,000 km (20% of the Earth-Moon distance, or about twice the distance to geostationary orbit) from the Earth. This is worth noting, as the last time we encountered this same stream was 2004, when the Perseids treated observers to enhanced rates up towards 200 per hour. Typically, the Perseids exhibit a Zenithal Hourly Rate (ZHR) of 80-100 per hour on most years.

Image credit
The terrestrial situation at the projected peak of the 2015 Perseids. Image credit: NOAA/Dave Dickinson

This translates into a local peak for observers worldwide on the mornings of August 12th and 13th. Comet 109P Swift-Tuttle orbits the Sun once every 120 years, and last reached perihelion in 1992, enhancing the rates of the Perseids throughout the 1990s.

Don’t live in northeast Asia? Don’t despair, as meteor showers such as the Perseids can exhibit broad multiple peaks which may arrive early or late. Mornings pre-dawn are the best time to spy meteors, as the Earth has turned forward into the meteor stream past local midnight, and rushes headlong into the oncoming stream of meteor debris. It’s a metaphor that us Floridians know all too well: the front windshield of the car gets all the bugs!

Perseid radiant
The flight of the Perseid radiant through August. Image credit: Dave Dickinson/Stellarium

Weather prospects — particularly cloud cover, or hopefully, the lack of it — is a factor on every observer’s mind leading up to a successful meteor hunting expedition. Fortunately here in the United States southeast, August mornings are typically clear, until daytime heating gives way to afternoon thunder storms. About 48 hours out, we’re seeing favorable cloud cover prospects for everyone in the CONUS except perhaps the U.S. northeast.

Weather and cloud cover prospects for the mornings of August 12th and August 13th. Image credit: NOAA
Weather and cloud cover prospects for the mornings of August 12th and August 13th. Image credit: NOAA

The Moon is also under 48 hours from New on Wednesday, allowing for dark skies. This is the closest New Moon to the peak of the Perseids we’ve had since 2007, and it won’t be this close again until 2018.

Fun fact: the August Perseids, October Orionids, November Leonids AND the December Geminids are roughly spaced on the calendar in such a way that if the Moon phase is favorable for one shower on a particular year, it’ll nearly always be favorable (and vice versa) on the others as well.

Sky watchers have observed the annual Perseid meteors since antiquity, and the shower is often referred to as ‘The Tears of Saint Lawrence.’ The Romans martyred Saint Lawrence on a hot grid iron on August 10th, 258 AD. The radiant crosses from the constellation Perseus in early August, and sits right on the border of Cassiopeia and Camelopardalis on August 12th at right ascension 3 hours 10’ and declination +50N 50.’ Technically, the shower should have the tongue-twisting moniker of the ‘Camelopardalids’ or perhaps the ‘Cassiopeiaids!’

The last few years have seen respectable activity from the Perseids:

2014- ZHR = 68 (Full Moon year)

2013- ZHR = 110

2012- ZHR = 120

2011- ZHR = 60 (Full Moon year)

2010- ZHR = 90

You can see the light-polluting impact of the nearly Full Moon on the previous years listed above. Light pollution has a drastic effect on the number of Perseids you’ll see. Keep in mind, a ZHR is an ideal rate, assuming the radiant is directly overhead and skies are perfectly dark. Most observers will see significantly less. We like to watch at an angle about 45 degrees from the radiant, to catch meteors in sidelong profile.

Imaging the Perseids is as simple as setting up a DSLR on a tripod as taking long exposures of the sky with a wide angle lens. Be sure to take several test shots to get the combination of f-stop/ISO/and exposure just right for current sky conditions. This year, we’ll be testing a new intervalometer to take automated exposures while we count meteors.

Clouded out? NASA TV will be tracking the Perseids live on Wednesday, August 12th starting at 10PM EDT/02:00 UT:

Remember, you don’t need sophisticated gear to watch the Perseids… just a working set of ‘Mark-1 eyeballs.’ You can even ‘hear’ meteor pings on an FM radio on occasion similar to lightning static if you simply tune to an unused spot on the dial. Sometimes, you’ll even hear a distant radio station come into focus as it’s reflected off of an ionized meteor trail:

And if you’re counting meteors, don’t forget to report ‘em to the International Meteor Organization and tweet ‘em out under hashtag #Meteorwatch.

Good luck and good meteor hunting!

Kick Back, Look Up, We’re In For a GREAT Perseid Meteor Shower

Every year in mid-August, Earth plows headlong into the debris left behind by Comet 109P/Swift-Tuttle. Slamming into our atmosphere at 130,000 mph, the crumbles flash to light as the Perseid meteor shower. One of the world’s most beloved cosmic spectacles, this year’s show promises to be a real crowd pleaser.

The author tries his best to enjoys this year's moon-drenched Perseids from the "astro recliner". Credit: Bob King
The author takes in last year’s moon-drenched Perseids from a recliner. Credit: Bob King

Not only will the Moon be absent, but the shower maximum happens around 3 a.m. CDT (8 UT) August 13 — early morning hours across North America when the Perseid radiant is highest. How many meteors will you see? Somewhere in the neighborhood of 50-100 meteors per hour. As always, the darker and less light polluted your observing site, the more zips and zaps you’ll see.

Find a place where there’s as few stray lights as possible, the better to allow your eyes to dark-adapt. Comfort is also key. Meteor showers are best enjoyed in a reclining position with as little neck craning as possible. Lie back on a folding lawn chair with your favorite pillow and bring a blanket to stay warm. August nights can bring chill and dew; a light coat and hat will make your that much more comfortable especially if you’re out for an hour or more.

The Perseids appear to radiate from spot below the W of Cassiopeia in the constellation Perseus, hence the name "Perseids". Source: Stellarium
The Perseids appear to radiate from spot below the W of Cassiopeia in the constellation Perseus, hence the shower’s name. This map shows the sky facing northeast around 12:30 a.m. local time August 13. Source: Stellarium

I’m always asked what’s the best direction to face. Shower meteors will show up in every corner of the sky, but can all be traced backwards to a point in Perseus called the radiant. That’s the direction from which they all appear to stream out of like bats flying out of a cave.

Another way to picture the radiant it is to imagine driving through a snowstorm at night. As you accelerate, you’ll notice that the flakes appear to radiate from a point directly in front of you, while the snow off to the sides streams away in long trails. If you’re driving at a moderate rate of speed, the snow flies past on nearly parallel paths that appear to focus in the distance the same way parallel railroad tracks converge.

At some personal peril, I grabbed a photo of snow in the headlights while driving home in a recent storm. Meteors in a meteor shower appear to radiate from a point in the distance in identical fashion. Photo: Bob King
Meteors in a meteor shower appear to radiate from a point in the distance in identical fashion to driving a car in a snowstorm. The motion of the car (Earth) creates the illusion of  meteors radiating from a point in the sky ahead of the observer. Credit: Bob King

Now replace your car with the moving Earth and comet debris for snow and you’ve got a radiant and a meteor shower. With two caveats. We’re traveling at 18 1/2 miles per second and our “windshield”, the atmosphere, is more porous. Snow bounces off a car windshield, but when a bit of cosmic debris strikes the atmosphere, it vaporizes in a flash. We often think friction causes the glow of meteors, but they’re heated more by ram pressure.

A bright fireball breaking to pieces near Yellow Springs, Ohio. Meteors are really tubes of ionized air energized by the passage of comet bits. Credit: John Chumack
A bright fireball breaking to pieces near Yellow Springs, Ohio. Meteors are really tubes of ionized air energized by the passage of comet bits. Credit: John Chumack

The incoming bit of ice or rock rapidly compresses and heats the air in front of it, which causes the particle to vaporize around 3,000°F (1,650°C). The meteor or bright streak we see is really a hollow “tube” of glowing or ionized air molecules created by the tiny rock as its energy of motion is transferred to the surrounding air molecules. Just as quickly, the molecules return to their rest state and release that energy as a spear of light we call a meteor.

Imagine. All it takes is something the size of a grain of sand to make us look up and yell “Wow!”

Speaking of size, most meteor shower particles range in size from a small pebble to beach sand and generally weigh less than 1-2 grams or about what a paperclip weighs. Larger chunks light up as fireballs that shine as bright as Venus or better. Because of their swiftness, Perseids are generally white and often leave chalk-like trails called trains in their wakes.

Comet 109P/Swift-Tuttle captured during its last pass by Earth on Nov. 1, 1992. A filament of dust deposited by the comet in 1862 may cause a temporary spike in activity on Aug. 12 around 18:39 UT. Credit: Gerald Rhemann
Comet 109P/Swift-Tuttle seen during its last pass by Earth on Nov. 1, 1992. A filament of dust deposited by the comet in 1862 may cause a temporary spike in activity around 18:39 UT on August 12. Credit: Gerald Rhemann

This year’s shower is special in another way. According to Sky and Telescope magazine, meteor stream modeler Jeremie Vaubaillon predicts a bump in the number of Perseids around 1:39 p.m. (18:39 UT) as Earth encounters a debris trail shed by the Comet Swift-Tuttle back in 1862. The time favors observers in Asia where the sky will be dark. It should be interesting to see if the prediction holds.

How To Watch

Already the shower’s active. Go out any night through about the 15th and you’ll see at least at least a handful of Perseids an hour. At nightfall on the peak night of August 12-13, you may see only 20-30 meteors an hour because the radiant is still low in the sky. But these early hours give us the opportunity to catch an earthgrazer — a long, very slow-moving meteor that skims the atmosphere at a shallow angle, crossing half the sky or more before finally fading out.

I’ve only seen one good earthgrazer in my earthly tenure, but I’ll never forget the sight. Ambling from low in the northeastern sky all the way past the southern meridian, it remained visible long enough to catch it in my telescope AND set up a camera and capture at least part of its trail!

A Perseid meteor streaks across the northeastern sky two Augusts ago. This year's shower will peak on the night of August 12-13 with up to 100 meteors per hour visible from a dark sky. Credit: Bob King
A Perseid meteor streaks across the northeastern sky two Augusts ago. Give the shower an hour’s worth of your time – you won’t be disappointed. Credit: Bob King

The later you stay up, the higher the radiant rises and the more meteors  you’ll see. Peak activity of 50-100 meteors per hour will occur between about 2-4 a.m. No need to stare at the radiant to see meteors. You can look directly up at the darkest part of the sky or face east or southeast and look halfway up if you like. You’re going to see meteors everywhere. Some will arrive as singles, others in short burst of 2, 3, 4 or more. I like to face southeast with the radiant off to one side. That way I can see a mix of short-trailed meteors from near the radiant and longer, graceful streaks further away just like the snow photo shows.

If there’s a lull in activity, don’t think it’s over. Meteor showers have strange rhythms of their own. Five minutes of nothing can be followed by multiple hits or even a fireball. Get into the feel of the shower as you sense spaceship Earth speeding through the comet’s dusty orbit. Embrace the chill of the August night under the starry vacuum.

The 2015 Lyrid Meteors Peak Tomorrow Night!

April showers bring May flowers, and this month also brings a shower of the celestial variety, as the Lyrid meteors peak this week.

And the good news is, 2015 should be a favorable year for the first major meteor shower of the Spring season for the northern hemisphere.  The peak for the shower in 2015 is predicted to arrive just after midnight Universal Time on Thursday April 23rd, which is 8:00 PM EDT on the evening of Wednesday April 22nd. This favors European longitudes right around the key time, though North America could be in for a decent show as well. Remember, meteor showers don’t read forecasts, and the actual peak can always arrive early or late. We plan to start watching tonight and into Wednesday and Thursday morning as well. April also sees a extremely variable level of cloud cover over the northern hemisphere, another reason to start your meteor vigil early on if skies are clear.

The radiant for the 2015 Lyrids as seen from 40 degrees north latitude at local midnight. Credit: Stellarium.
The radiant for the 2015 Lyrids as seen from 40 degrees north latitude at local midnight. Credit: Stellarium.

Another favorable factor this year is the phase of the Moon, which is only a slender 20% illuminated waxing crescent on Wednesday night. This means that it will have set well before local midnight when the action begins.

The source of the Lyrid meteors is Comet C/1861 G1 Thatcher, which is on a 415 year orbit and is expected to come back around again in 2276 A.D. 1861 actually sported two great comets, the other being C/1861 J1, also known as the Great Comet of 1861.

The orientation of the Sun, Moon, and the Lyrid radiant at the expected peak of the shower at 24UT/20EDT April 22nd. credit: Stellarium
The orientation of the Sun, Moon, and the Lyrid radiant at the expected peak of the shower at 24UT/20EDT April 22nd. credit: Stellarium

The Lyrids typically exhibit an ideal Zenithal Hourly Rate (ZHR) of 15-20 per hour, though this shower has been known to produce moderate outbursts from time to time. In 1803 and 1922, the Lyrids produced a ZHR of 100 per hour, and in recent times, we had an outburst of 250 per hour back in 1982. Researchers have tried over the years to tease out a periodicity for Lyrid outbursts, which seem erratic at best. In recent years, the Lyrids hit a ZHR of 20 (2011), 25 (2012), 22 (2013), and 16 last year in 2014.

Keep in mind, we say that the ZHR is an ideal rate, or what you could expect from the meteor shower with the radiant directly overhead under dark skies: expect the actual number of meteors observed during any shower to be significantly less.

A 2014 Lyrid fireball. Credit: The UK Meteor Network
A 2014 Lyrid fireball. Credit: The UK Meteor Network

The radiant for the Lyrids actually sits a few degrees east of the bright star Vega across the Lyra border in the constellation Hercules. They should, in fact, be named the Herculids! In mid-April, the radiant for the April Lyrids has already risen well above the northeastern horizon as seen from latitude 40 degrees north at 10 PM local, and is roughly overhead by 4 AM local. Several other minor showers are also active around late April, including the Pi Puppids (April 24th), the Eta Aquarids (May 6th), and the Eta Lyrids (May 9th). The constellation of the Lyre also lends its name to the June Lyrids peaking around June 6th.

The April Lyrids are intersecting the Earth’s orbit at a high 80 degree angle at a swift velocity of 49 kilometres per second. About a quarter of the Lyrid meteors are fireballs, leaving bright, persistent smoke trains. It’s a good idea to keep a set of binoculars handy to study these lingering smoke trails post-passage.

The Lyrids also have the distinction of having the longest recorded history of any known meteor shower.  Chinese chronicles indicate that “stars dropped down like rain,” on a late Spring night in 687 BC.

Observing a meteor shower requires nothing more than a set of working ‘Mark-1 eyeballs’ and patience. The International Meteor Organization always welcomes reports of meteor counts from observers worldwide to build an accurate picture of evolving meteor debris streams. You can even hear meteor ‘pings’ via FM radio.

Expect the rate to pick up past local midnight, as the Earth plows headlong into the oncoming meteor stream. Remember, the front of the car gets the love bugs, an apt analogy for any Florida resident in mid-April.

A composite view of the 2012 Lyrids plus sporadic meteors. Credit: NASA/MSFC/Danielle Moser
A composite view of the 2012 Lyrids plus sporadic meteors. Credit: NASA/MSFC/Danielle Moser

Catching a photograph of a Lyrid or any meteor is as simple as plopping a DSLR down on a tripod and doing a series of 30 second to several minute long time exposures. Use the widest field of view possible, and aim the camera off at about a 45 degree angle from the radiant to catch the meteors sidelong in profile. Be sure to take a series of test shots to get the ISO/f-stop combination set for the local sky conditions.

Don’t miss the 2015 Lyrids, possibly the first good meteor shower of the year!

Work Those Quads: Our Guide to the 2015 Quadrantid Meteors

Quick… what’s the only major meteor shower named after a defunct constellation?  If you said the January Quadrantids, you’d be correct, as this often elusive but abrupt meteor shower is set to peak this coming weekend early in 2015.

And we do mean early, as in the night of January 3rd going into the morning of January 4th. This is a bonus, as early January means long dark nights for northern hemisphere observers. But the 2015 Quadrantids also has two strikes going against them however: first, the Moon reaches Full just a day later on January 5th, and second, January also means higher than average prospects for cloud cover (and of course, frigid temps!) for North American observers.

Jan 4th 3AM local. Starry Night Education Software.
The rising radiant of the Quads on the morning of January 4th at 3AM local. Note that the Moon and Jupiter are on the scene as well. Created using Starry Night Education software.

Don’t despair, however. In meteor shower observing as in hockey, you miss 100% of the shots that you don’t take.

Sorry for the sports analogy. The radiant for the Quadrantids is located in the modern day constellation of Draco near the Hercules-Boötes border at a right ascension 15 hours, 18 minutes and declination +49.5 degrees north. This puts it very near the +3.3 magnitude star Iota Draconis (Edasich).

Quads 2UT. Credit: Orbitron
The orientation of the Earth’s shadow at the predicted peak of the Quads on January 4th,  2:00 UT. Credit: Orbitron.

In 2015, bets are on for the Quadrantids to peak centered on 2:00 UT January 4th (9:00 PM EST on the 3rd), favoring northern Europe pre-dawn. The duration for the Quadrantids is short lived, with an elevated rate approaching 100 per hour lasting only six hours in duration. Keep in mind, of course, that it’ll be worth starting your vigil on Saturday morning January 3rd in the event that the “Quads” kick off early! I definitely wouldn’t pass up on an early clear morning on the 3rd, just in case skies are overcast on the morning of the 4th

Due to their high northern radiant, the Quadrantids are best from high northern latitudes and virtually invisible down south of the equator.  Keep in mind that several other meteor showers are active in early January, and you may just spy a lingering late season Geminid or Ursid ‘photobomber’ as well among the background sporadics.

Photo by author
Avast: ye ole Mural Quadrant spied at the Columbia River Maritime Museum in Astoria, Oregon. Photo by author.

Moonset on the morning of the 4th occurs around 6 AM local, giving observers a slim one hour moonless window as dawn approaches. Blocking the Moon out behind a building or hill when selecting your observing site will aid you in your Quadrantid quest.

Stellarium
The approximate realm of the “Mural Quadrant” overlaid on modern day constellations. Credit Stellarium.

Antonio Brucalassi made the first historical reference to the Quadrantids, noting that “the atmosphere was traversed by… falling stars” on the morning of January 2nd, 1825. It’s interesting to note that the modern day peak for the Quads has now drifted a few days to the fourth, due mostly to the leap year-induced vagaries of our Gregorian calendar. The early January meteor shower was noted throughout the 19th century, and managed to grab its name from the trendy 19th century constellation of Quadrans Muralis, or the Mural Quadrant. Hey, we’re lucky that other also-rans, such as Lumbricus the ‘Earthworm’ and Officina Typograhica the ‘Printing Office’ fell to the wayside when the International Astronomical Union formalized the modern 88 constellations in 1922. Today, we know that the Quadrantids come from 2003 EH1, which is thought to be an extinct comet now trapped in the inner solar system on a high inclination, 5.5 year orbit. Could 2003 EH1 be related to the Great Comet of 1490, as some suggest? The enigmatic object reached perihelion in March of 2014, another plus in the positive column for the 2015 Quads.

What the heck is a Mural Quadrant?
What the heck is a Mural Quadrant? Like everything he did, Tycho Brahe super-sized his quadrant, depicted here. Credit: Wikimedia Commons.

Previous years for the Quadrantids have yielded the following Zenithal Hourly Rate (ZHR) maximums as per the International Meteor Organization:

2011= 90

2012= 83

2013= 137

2014= +200

The Quadrantid meteor stream has certainly undergone alterations over the years as a result of encounters with the planet Jupiter, and researchers have suggested that the shower may go the way of the 19th century Andromedids and become extinct entirely in the centuries to come.

Don’t let cold weather deter you, though be sure to bundle up, pour a hot toddy (or tea or coffee, as alcohol impacts the night vision) and keep a spare set of batteries in a warm pocket for that DSLR camera, as cold temps can kill battery packs quicker than you can say Custos Messium, the Harvest Keeper.

And though it may be teeth-chatteringly cold where you live this weekend, we actually reach our closest point to the Sun this Sunday, as Earth reaches perihelion on January 4th at around 8:00 UT, just 5 hours after the Quads are expected to peak. We’re just over 147 million kilometres from the Sun at perihelion, a 5 million kilometre difference from aphelion in July. Be thankful we live on a planet with a relatively circular orbit. Only Venus and Neptune beat us out in the true roundness department!

…and no, you CAN’T defy gravity around perihelion, despite the current ill conceived rumor going ‘round ye ole net…

And as a consolation prize to southern hemisphere observers, the International Space Station reaches a period of full illumination and makes multiple visible passes starting December 30th until January 3rd. This happens near every solstice, with the December season favoring the southern hemisphere, and June favoring the northern.

2003 Credit and Copyright: Frankie Lucena.
A 2003 south bound Quad nabbed from Cabo Rojo, Puerto Rico (Yes, that’s the Southern Cross!) Credit and Copyright: Frankie Lucena.

So don’t let the relatively bad prospects for the 2015 Quadrantids deter you: be vigilant, report those meteor counts to the IMO, send those meteor pics in to Universe Today and tweet those Quads to #Meteorwatch. Let’s “party like it’s 1899,” and get the namesake of an archaic and antiquated constellation trending!

The Top 101 Astronomical Events to Watch for in 2015

Phew! It’s here.

Now in its seventh year of compilation and the second year running on Universe Today, we’re proud to feature our list of astronomical happenings for the coming year. Print it, bookmark it, hang it on your fridge or observatory wall. Not only is this the yearly article that we jokingly refer to as the “blog post it takes us six months to write,” but we like to think of it as unique, a mix of the mandatory, the predictable and the bizarre. It’s not a 10 ten listicle, and not a full-fledged almanac, but something in between.     

A rundown of astronomy for 2015: There’s lots of astronomical action to look forward to in the coming year. 2015 features the minimum number of eclipses that can occur, two lunars and two solars. The Moon also reaches its minimum standstill this coming year, as its orbit runs shallow relative to the celestial equator. The Moon will also occult all naked eye planets except Saturn in 2015, and will occult the bright star Aldebaran 13 times — once during every lunation in 2015. And speaking of Saturn, the rings of the distant planet are tilted an average of 24 degrees and opening to our line of sight in 2015 as they head towards their widest in 2018.

Finally, solar activity is trending downwards in 2015 after passing the sputtering 2014 maximum for solar cycle #24 as we now head towards a solar minimum around 2020.

Our best bets: Don’t miss these fine celestial spectacles coming to a sky near YOU next year:

– The two final total lunar eclipses in the ongoing tetrad, one on April 4th and September 28th.

– The only total solar eclipse of 2015 on March 20th, crossing the high Arctic.

– A fine dusk pairing of the bright planets Jupiter and Venus on July 1st.

– Possible wildcard outbursts from the Alpha Monocerotid and Taurid meteors, and a favorable New Moon near the peak of the August Perseids.

– Possible naked eye appearances by comet Q2 Lovejoy opening 2015 and comet US10 Catalina later in the year.

– The occultation of a naked eye star for Miami by an asteroid on September 3rd.

– A series of fine occultations by the Moon of bright star Aldebaran worldwide.

The rules: The comprehensive list that follows has been lovingly distilled down to the top 101 astronomical events for 2015 worldwide. Some, such as lunar eclipses, are visible to a wide swath of humanity, while others, such as many of the asteroid occultations or the sole total solar eclipse of 2015 happen over remote locales. We whittled the list down to a “Top 101” using the following criterion:

Meteor showers: Must have a predicted ZHR  greater than 10.

Conjunctions: Must be closer than one degree.

Asteroid occultations: Must have a probability ranking better than 90 and occult a star brighter than magnitude +8.

Comets: Must reach a predicted brightness greater than magnitude +10. But remember: comets don’t always read prognostications such as this, and may over or under perform at whim… and the next big one could come by at any time!

Times quoted are geocentric unless otherwise noted, and are quoted in Universal Time in a 24- hour clock format.

These events are meant to merely whet the appetite. Expect ‘em to be expounded on fully by Universe Today as they approach. We linked to the events listed where possible, and provided a handy list of resources that we routinely consult at the end of the article.

Got it? Good… then without further fanfare, here’s the top 101 astronomical events for 2015 in chronological order:

The path of Comet Q2 Lovejoy From January 1st to January 31st.
The path of Comet Q2 Lovejoy from January 1st to January 31st. Created using Starry Night Education software.

January

01- Comet C/2012 Q2 Lovejoy may reach naked eye visibility.

04- The Quadrantid meteors peak at 02:00 UT, favoring northern Europe with an expected ZHR of 120.

04- The Earth reaches perihelion at ~8:00 UT.

14- Mercury reaches greatest evening elongation 18.9 degrees east of the Sun at ~16:00 UT.

17- The moons Io and Europa cast a double shadow on Jupiter from 3:53 to 4:58 UT.

20- Mars passes 0.2 degrees from Neptune at ~20:00 UT.

24- A triple shadow transit of Jupiter’s moons occurs from 6:26 to 6:54 UT.

29- The Moon occults Aldebaran at ~17:31 UT for the Arctic, marking the first of 13 occultations of the star by the Moon in 2015.

The view at 6:40 UT.
The view at 6:40 UT on January 24th, as 3 of Jupiter’s moons cast shadows on to the Jovian cloud tops simultaneously. Created using Starry Night Education software.

February

01- Venus passes 0.8 degrees south of Neptune at ~17:00 UT.

05- Earth crosses through Jupiter’s equatorial plane, marking the middle of occultation and eclipse season for the Galilean moons.

06- Jupiter reaches opposition at ~18:00 UT.

18- A “Black Moon” occurs, in the sense of the third New Moon in a season with four.

22- Venus passes 0.4 degrees south of Mars at 5:00 UT.

24- Mercury reaches greatest morning elongation at 26.7 degrees west of the Sun at 19:00 UT.

25- The Moon occults Aldebaran for northern Europe at 23:26 UT.

Credit: Eclipse-Maps
The path of the only total solar eclipse of 2015, occurring on March 20th. Credit: Michael Zeiler/Eclipse-Maps.

March

01- Geostationary satellite & Solar Dynamics Observatory eclipse season begins on the weeks leading up to the March Equinox.

04- Venus passes 0.1 degrees north of Uranus at ~18:00 UT. This is the closest planet-planet conjunction of 2015.

05- A Minimoon occurs, marking the most distant Full Moon of 2015 at 18:07 UT, just 10 hours from apogee.

11- Mars passes 0.3 degrees north of Uranus at ~16:00 UT.

20- A total solar eclipse occurs over the Arctic centered on 9:47 UT.

20- The March northward equinox occurs at 22:45 UT.

21- The Moon occults Mars for South America at ~22:14 UT.

25- The Moon occults Aldebaran for northwestern North America at ~7:17 UT.

Stellarium
Neith lives… the close passage of Uranus near Venus on March 4th. Credit: Stellarium.

April

04- A total lunar eclipse occurs, centered on 12:01 UT and visible from eastern Asia, the Pacific and the Americas.

08- Mercury passes 0.5 degrees from Uranus at ~11:00 UT.

21- The Moon occults Aldebaran for northern Asia at ~16:57 UT.

22- The Lyrid meteors peak at 24:00 UT, favoring northern Europe with a ZHR of 18.

May

05- The Eta Aquarid meteors peak (time variable), with an estimated ZHR of 55.

07- Mercury reaches greatest evening elongation at 21.2 degrees east of the Sun at 4:00 UT.

19- The Moon occults Aldebaran for northern North America at ~2:53 UT .

20- Comet C/2014 Q1 PanSTARRS may reach binocular visibility.

21- Io and Ganymede both cast shadows on Jupiter from 00:04 to 00:33 UT.

21- Callisto and Europa both cast shadows on Jupiter from 13:26 to 13:59 UT.

23- Saturn reaches opposition at ~1:00 UT.

24- Asteroid 1669 Dagmar occults the +1st magnitude star Regulus at ~16:47 UT for the Arabian peninsula,

the brightest star occulted by an asteroid for 2015. 

28- Ganymede and Io both cast shadows on Jupiter from 02:01 to 04:18 UT.

30- Comet 19P/Borrelly may reach binocular visibility.

June

01- The International Space Station reaches full illumination as the June solstice nears, resulting in multiple nightly passes favoring  northern hemisphere observers.

04- Io and Ganymede both cast shadows on Jupiter from 4:54 to 6:13 UT.

05- Venus reaches greatest eastern (dusk) elongation for 2015, 45 degrees from the Sun at 16:00 UT.

10- Asteroid 424 Gratia occults a +6.1 magnitude star at ~15:10 UT for northwestern Australia.

15- The Moon occults Mercury for the South Indian Ocean at ~2:26 UT.

15- Moon occults Aldebaran in the daytime for the high Arctic at ~11:33 UT.

16- Comet C/2014 Q1 PanSTARRS may reach naked eye visibility.

21- The June northward solstice occurs at 16:38 UT.

24- Mercury reaches greatest (morning) elongation at 22.5 degrees west of the Sun at 17:00 UT.

Stellarium
Venus and Jupiter pair together low in the west on July 1st. Credit: Stellarium.

July

01- Venus passes 0.4 degrees from Jupiter at 9:00 UT, marking the closest conjunction of two naked eye planets for 2015.

02- Comet C/2013 US10 Catalina may reach binocular visibility.

06- Earth reaches aphelion at 13:00 UT.

06- Pluto reaches opposition at 15:00 UT, just a week prior to New Horizons’ historic flyby of the distant world.

12- The Moon occults Aldebaran for northeastern Asia ~18:17 UT.

19- The Moon occults Venus for the South Pacific at ~1:07 UT.

25- Asteroid 49 Pales occults a +6.6 magnitude star at 10:55 UT for Mexico.

28- The Delta Aquarids peak (time variable) with a predicted ZHR of 16.

31- A “Blue Moon” occurs, in the sense of the second Full Moon in a given month.

Credit:
The light curve of comet C/2013 US10 Catalina through its peak in 2015. Credit: Seiichi Yoshida’s Weekly Information About Bright Comets.

August

07- Mercury, Jupiter and Regulus pass within a degree of each other over the next few evenings.

08- The Moon occults Aldebaran for central Asia at ~23:45 UT.

13- The Perseid meteors peak from 06:30 to 09:00 UT, with a maximum predicted ZHR of 100 favoring North America.

19- Mars crosses the Beehive Cluster M44.

28- Asteroid 16 Psyche occults a +6.4 magnitude star at ~9:49 UT for Bolivia and Peru.

29- Supermoon 1 of 3 for 2015: The Moon reaches Full at 18:38 UT, 20 hours from perigee.

Lunar eclipse
The path of the Moon through the Earth’s shadow on September 28th. Credit: Fred Espenak/NASA/GSFC

September

01- Neptune reaches opposition at ~3:00 UT.

03- Asteroid 112 Iphigenia occults a +3rd magnitude star for Mexico and Miami at ~9:20 UT. This is the brightest star occulted by an asteroid in 2015 for North America.

02- Geostationary satellite and SDO eclipse season begins as we approach the September equinox.

04- Mercury reaches its greatest elongation for 2015, at 27 degrees east of the Sun at 8:00 UT in the dusk skies.

05- The Moon occults Aldebaran for northeastern North America at ~5:38 UT.

13- “Shallow point” (also known as the minor lunar standstill) occurs over the next lunation, as the Moon’s orbit reaches a shallow minimum of 18.1 degrees inclination with respect to the celestial equator… the path of the Moon now begins to widen towards 2025.

13- A partial solar eclipse occurs, centered on 6:55 UT crossing Africa and the Indian Ocean.

23- The September southward equinox occurs at 8:20 UT.

25- Mars passes 0.8 degrees from Regulus at ~4:00 UT.

28- A total lunar eclipse occurs centered on 2:48 UT, visible from the Pacific, the Americas and eastern Europe.

28- Supermoon 2 of 3 for 2015: The Moon reaches Full at 2:52 UT, approximately an hour from perigee. This marks the closest Full Moon of the year.

Credit
The path of the September 3rd occultation of a +3rd magnitude star by an asteroid over central Mexico and the Florida Keys. Credit: IOTA/Steve Preston.

October

01- Comet C/2013 US10 Catalina may reach naked eye visibility.

02- The Moon occults Aldebaran for the northern Pacific at 13:14 UT.

02- Io and Callisto both cast shadows on Jupiter from 12:26 to 13:35 UT.

08- The Moon occults Venus for Australia at ~20:32 UT.

11- The Moon occults Mercury for Chile at ~12:00 UT.

12- Uranus reaches opposition at ~3:00 UT.

16- Mercury reaches greatest elongation (morning) 18.1 degrees west of the Sun at 10:00 UT.

17- Mars passes 0.4 degrees from Jupiter at 22:00 UT.

18- Io and Ganymede both cast shadows on Jupiter from 10:45 to 12:10 UT.

21- The Orionid meteors peak (time variable) with a projected ZHR of 15.

25- Venus passes 1 degree from Jupiter ~19:00 UT.

25- Io and Ganymede both cast shadows on Jupiter from 12:37 to 14:51 UT.

27- Supermoon 3 of 3 for 2015: The Moon reaches Full at 12:06 UT, 23 hours from perigee.

29- The Moon occults Aldebaran for Europe at ~23:07 UT.

Credit
The Moon occults Aldebaran: the visibility footprint for North America. The dashed line denotes the area in which the event occurs during the daytime. Credit: Occult 4.1.0.11.

November

01- Io and Ganymede both cast shadows on Jupiter from 17:36 to 17:47 UT.

02- Venus passes 0.7 degrees south of Mars at 00:30 UT.

12- Will the 7 year “Taurid fireball meteor shower” produce?

18- The Leonid meteor shower peaks at 04:00 UT, with an estimated ZHR of 15 favoring Europe.

22- Are we in for a once per decade Alpha Monocerotids outburst? The 2015 peak arrives at 4:25 UT, favoring Europe… with a max ZHR = 400+ possible.

26- The Moon occults Aldebaran for North America at ~9:56 UT.

29- Comet C/2013 X1 PanSTARRS may reach binocular visibility.

Occultation
The daytime occultation of Venus by the Moon over North America on December 7th. Credit: Occult 4.1.0.11.

December

01- The International Space Station reaches full illumination as the December solstice nears, resulting in multiple nightly passes favoring the  southern hemisphere.

04- Mercury occults the +3.3 magnitude star Theta Ophiuchi for South Africa at 16:16 UT prior to dusk.

06- The Moon occults Mars for central Africa at ~2:42 UT.

07- The Moon occults Venus in the daytime for North America at ~16:55 UT.

14- The Geminid meteor shower peaks at 18:00 UT, with a ZHR=120 favoring NE Asia.

22- The December southward solstice occurs at 4:48 UT.

23- The Ursid meteor shower peaks at 2:30 UT with a ZHR variable from 10-50 favoring Europe and the Middle East.

23- The Moon occults Aldebaran for Europe and central Asia at ~19:32 UT.

29- Mercury reaches greatest evening elongation at 19.7 degrees east of the Sun at 00:01 UT.

 

Didn’t see your favorite event on the list? Let us know, and be sure to send in any images of these fine events to Universe Today’s Flickr forum.

Enjoy another exciting year of space and astronomy… we’ll be expounding on these events and more as 2015 unfolds.

Sources:

Occult 4.0

-Kevin McGill’s outstanding astronomical simulations.

-Greatest Elongations of Mercury and Venus.

Stellarium

Starry Night Pro

Orbitron

-Steve Preston’s asteroid occultation predictions for 2015.

-The USNO forecast of phenomena for 2015.

-Seiichi Yoshida’s Weekly Information About Bright Comets.

-Fred Espenak’s NASA Eclipse web page.

-The American Meteor Society’s 2015 predictions.

-The International Meteor Organization’s 2015 page.

-Fourmilab’s lunar perigee and apogee calculator.

 

Astrophotos: Views of the Geminid Meteor Shower from Around the World

It’s nice to know that not everyone around the world was plagued by clouds, dense fog, driving rain and snowstorms like we had in Minnesota during this year’s Geminid Meteor Shower (and all that weather was within one 24-hour period!) In fact, some astrophotographers were able to capture some stunning views of the Geminids, like this absolutely gorgeous shot of a meteor over Mt. Fuji in Japan.

“I’ve captured Fuji with meteors many times in the past,” said photographer Yuga Kurita. “So I went ambitious this time. I tried to capture Fuji and a meteor reflected in Lake Saiko with a standard focal length lens. When I saw this meteor, I was absolutely stunned.”

See more Geminids from around the world, below:

Geminid meteors over Beijing, China. A stacked image of  more than 20 meteors, taken in just 140 minutes. Credit and copyright: Steed Yu.
Geminid meteors over Beijing, China. A stacked image of more than 20 meteors, taken in just 140 minutes. Credit and copyright: Steed Yu.
Geminid Meteor on 12-15-2014 .Captured cutting through the winter Milkyway in the constellation of Auriga, you can see the very colorful trail of the meteor in this image, the trail stretched more than 15 degrees of sky. Taken near Warrenton, Virginia. Credit and copyright: John Chumack.
Geminid Meteor on 12-15-2014 .Captured cutting through the winter Milkyway in the constellation of Auriga, you can see the very colorful trail of the meteor in this image, the trail stretched more than 15 degrees of sky. Taken near Warrenton, Virginia. Credit and copyright: John Chumack.
Four different Geminid meteors as seen from Oxfordshire, England with a Canon 1100D with standard lens.  The time of the meteor is marked on the photo. Credit and copyright: Mary Spicer.
Four different Geminid meteors as seen from Oxfordshire, England with a Canon 1100D with standard lens. The time of the meteor is marked on the photo. Credit and copyright: Mary Spicer.

Astrophotographer Mary Spicer shared these four meteor shots, and added, “Over about 90 minutes we saw a total of 61 meteors, 57 of which were Geminids and 6 were fireballs.”

In a 3.5 hour period on Dec. 13/14, 2014, the photographer  managed to capture 38 Geminid meteors. This composite contains just 11 of those meteors. Credit and copyright: Paul Andrew.
In a 3.5 hour period on Dec. 13/14, 2014, the photographer managed to capture 38 Geminid meteors. This composite contains just 11 of those meteors. Credit and copyright: Paul Andrew.

A timelapse movie taken by Michael Mauldin of the clouds and stars over Liberty Hill, Texas on Saturday, December 13, 2014. Two Geminid meteors are captured (each frame is frozen for a few seconds so you can see them):

Geminid meteors caught over Connaught Dome, at the Norman Lockyer Observatory in  Devon, England.  Credit and copyright: David Strange.
Geminid meteors caught over Connaught Dome, at the Norman Lockyer Observatory in Devon, England. Credit and copyright: David Strange.
Two Geminid meteors — one especially bright — streak through the sky on Sunday, December 14, 2014. This photo is a composite of two separate frames, taken a few minutes apart, to capture both meteors. Credit and copyright: David Murr.
Two Geminid meteors — one especially bright — streak through the sky on Sunday, December 14, 2014. This photo is a composite of two separate frames, taken a few minutes apart, to capture both meteors. Credit and copyright: David Murr.
A Geminid fireball captured on Dec. 13, 2014 near Cabo Rojo, Puerto Rico. Credit and copyright:  Frankie Lucena.
A Geminid fireball captured on Dec. 13, 2014 near Cabo Rojo, Puerto Rico. Credit and copyright: Frankie Lucena.
A faint green Geminid meteor joined in the sky scene with On display are : M44, Jupiter , the Moon, and Procyon in Canis Minor. Credit and copyright:  Carsten Pauer.
A faint green Geminid meteor joined in the sky scene with On display are : M44, Jupiter , the Moon, and Procyon in Canis Minor. Credit and copyright: Carsten Pauer.
A unique view of the 2014 Geminid Meteor Shower, taken on Dec. 14. 5 images stacked. Credit and copyright:  Jason Asplin.
A unique view of the 2014 Geminid Meteor Shower, taken on Dec. 14. 5 images stacked. Credit and copyright: Jason Asplin.
A Geminid Meteor  taken on Dec. 14, 2014 from a garden in the middle of Worthing, West Sussex England. Credit and copyright: BiteYourBum.com Photography.
A Geminid Meteor
taken on Dec. 14, 2014 from a garden in the middle of Worthing, West Sussex England. Credit and copyright: BiteYourBum.com Photography.
A bright Geminid meteor on Dec. 14, 2014. Credit and copyright:  Slave Stojanoski.
A bright Geminid meteor on Dec. 14, 2014. Credit and copyright: Slave Stojanoski.
Waiting for Geminids: a self portrait of the photographer waiting for the meteor shower to peak. Credit and copyright: Sergio Garcia Rill.
Waiting for Geminids: a self portrait of the photographer waiting for the meteor shower to peak. Credit and copyright: Sergio Garcia Rill.

While the above photo doesn’t have any meteors, it still garners a place in this post because astrophotographer Sergio Garcia Rill was waiting and hoping to capture some. Alas, writes Rill on Flickr, “While I had good enough luck to get some relatively clear skies for the Geminids meteor shower I think I wasn’t fortunate enough to catch any meteors on camera. I saw about a dozen meteors with my eyes, and a couple in the direction my cameras were pointing, but they probably weren’t strong enough to get captured with the settings I had.”