Posted on by VirtualAstro

The Perseids: Why is There a Meteor Shower?

Bright Fireball Credit: Adrian West

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Every year from late July to mid-August, the Earth encounters a trail of debris left behind from the tail of a comet named Swift-Tuttle. This isn’t the only trail of debris the Earth encounters throughout the year, but it might be one of the most notorious as it is responsible for the annual Perseid meteor shower, one of the best and well-known yearly meteor showers.

Comet Swift-Tuttle is a very long way away from us right now, but when it last visited this part of the Solar system, it left behind a stream of debris made up of particles of dust and rock from the comet’s tail.

Earth encounters this debris field for a few weeks, reaching the densest part on the 11th to 13th August.

The tiny specs of dust and rock collide with the Earth’s atmosphere, entering at speeds ranging from 11 km/sec (25,000 mph), to 72 km/sec (160,000 mph). They are instantly vaporised, emitting bright streaks of light. These tiny particles are referred to as meteors or for the more romantic, shooting stars.

Perseid meteor shower
Perseid meteor shower

The reason the meteor shower is called the Perseid, is because the point of the sky or radiant where the meteors appear to originate from is in the constellation of Perseus, hence Perseid.

When the Perseid meteor shower reaches its peak, up to 100 meteors an hour can be seen under ideal dark sky conditions, but in 2011 this will be greatly reduced due to a full Moon at this time. Many of the fainter meteors (shooting stars) will be lost to the glare of the Moon, but do not despair as some Perseids are bright fireballs made from larger pieces of debris, that can be golf ball size or larger.

These amazingly bright meteors can last for a few seconds and can be the brightest thing in the sky. They are very dramatic and beautiful, and seeing one can be the highlight of your Perseid observing experience.

So while expectations may be low for the Perseids this year, keep an eye out for the bright ones and the fireballs. You will not be disappointed, even if you only see one!

Join in on twitter with a worldwide event with Universe Today and Meteorwatch.org just follow along using the hashtag #meteorwatch ask questions, post images, enjoy and share your Perseid Meteor Shower experience.

Posted on by Tammy Plotner

Meteor Shower Points Towards Undiscovered Earthbound Comet

This February Eta Draconid was filmed by Peter Jenniskens with one of the low-light-level video cameras of the Cameras for Allsky Meteor Surveillance (CAMS) station in Mountain View, California, at 07:59:24 UT on February 4, 2011. CREDIT: All Sky Cameras/Peter Jenniskens

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With the annual Perseid Meteor Shower already underway, we’re looking to the skies and thinking about what causes these celestial fireworks. We know for the most part that meteor showers are the by-product of comets, but what happens when seemingly random meteors become not so random? The answer is a long term comet which could be pointed right at Earth.

Comets don’t just wander through the Solar System. They take very specific paths around the Sun and when its orbit passes close to ours, we get visual clues in the form of a meteor shower. Long term comets are in no hurry. Their elliptical sojourns can take anywhere from 200 to 10,000 years to complete – with a dense dust trail leading the way. We compute when and where the comet comes from by its orbital period, but what happens if that orbital period leads to a new discovery? And what happens if that comet’s orbit seems destined to encounter us? We just might get some advance warning from monitoring an unexpected meteor shower.

“Such meteor showers are extremely rare. They happen only about once or twice every sixty years, when the thin meteoroid stream is exactly in Earth’s path at the time when Earth arrives at that spot.” says Peter Jenniskens (SETI Institute) and Peter S. Gural (SAIC). “Because they are so rare, many of these showers remain to be discovered. Here, we report that one such shower, previously unknown, just showed up on February 4, 2011.”

Thanks to the use of the new NASA-sponsored network of low-light video cameras called the Cameras for Allsky Meteor Surveillance (CAMS) project, more than three hundred “new” meteor showers documented by the IAU Working List of Meteor Showers are under investigation. The February 4 occurrence centered around Eta Draconis came as a surprise, but the observing team of three separate stations went to work confirming the meteoroid orbital elements. The event lasted around seven hours and was confirmed through astrometric tracks for all moving objects in all cameras that recorded that night and with radio reflections during that day taken in Finland.

“The similarity of the orbits implies that the February eta Draconids are a dynamically young stream. The orbital period suggests a long-period comet, perhaps a Halley-type comet. If this indeed is a long-period comet dust trail, then the dust was ejected in the previous return to the Sun.” says Jenniskens and Gural. “Such dust trails get perturbed enough on the way in that the orbital periods change dramatically and dust trail sections catch up on each other, spreading out into a more diffuse stream already after one orbit.”

Oddly enough, no meteoritic activity from this new stream was recorded either before or after its February 4th apparition… nor was it active between 2007 through 2009. The conclusion is that it’s caused by the dust trail of a long period comet and it has formally been named the February Eta Draconids. What long term comet does the stream belong to? Well, the answer to that question is still up in the air and a good point to ponder while viewing this year’s Perseids.

“This is an important discovery, because it points to the presence of a potentially hazardous comet. If the dust trail can hit the Earth, so can the comet: the planetary perturbations do not depend on the mass of the object.” says the team. “Of course, an impact will occur only if the comet orbit is perturbed into Earth’s path right at the time when Earth passes by the comet orbit on February 4. It is in principle possible to guard against such impacts by looking along the comet orbit to those spots where the comet would be in such a dangerous position. In that way, perhaps a few years of warning could be provided.”

Original New Story: Space.Com.

Posted on by Tammy Plotner

The Early Morning Show – Eta Aquarid Meteor Showers While The Planets Align

Comet Halley Courtesy of Halley Multicolor Camera Team, Giotto Project, ESA

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Are you ready for the Eta Aquarid Meteor Shower? While the peak activity will be on the night of May 5/6, the offspring of Comet Halley are already beginning to make their appearance known. No matter where you live or what time zone you observe from, the best time to look for “shooting stars” is over the next week or so during the hours just before dawn.

Somewhere in the outer reaches of our solar system beyond the orbit of Jupiter, Comet Halley continues on its track – far away from its 1986 debris trail. However, now isn’t the only time we encounter this famous comet’s leftovers. Three times a year the Earth cruises through the dusty trail causing the Eta Aquarids, the Beta Aquarids (both in May) and the Orionids (during October). When a piece of this debris enters our atmosphere, it is traveling about 66 kilometers per second and can shine as brightly as the stars (3rd magnitude) in the constellation from which it appears to originate. Encountering a dense paticle stream may spark activity of up to 70 meteors per hour for lucky observers in the southern hemisphere, but don’t count yourself out if you live in the north! Because the constellation of Aquarius is relatively low for northern observers, this means we have at least a better chance of spotting those breathtaking Earth grazers!

Eta Aquarid Radiant Courtesy of NASA
Staring aound 4:00 a.m. (local time) the constellation of Aquarius is beginning to rise low to the southeast for the northern hemisphere and fall rates could be as marked as an average of one meteor every three or four minutes. Although meteors can appear from any point in the sky, your best northern skies bet will be to face generally southeast, gaze roughly halfway up the sky and get as comfortable as possible. A reclining lawn chair makes a wonderful meteor watching companion! Getting as far away as possible from city lights will also increase the amount of meteors you see – typically about 30 per hour for the northern hemisphere.

Don’t be discouraged if you’re clouded out or unable to view at the peak time. The most wonderful part about the Eta Aquarids is the fact the stream is very broad and activity is extended from April 21 until May 12. And there’s an added treat – the ongoing planetary alignment…

May 1 Visualization by Dave Reneke

Don’t let anyone discourage you from watching the Eta Aquarids if you have an opportunity. While it isn’t one of the most prolific showers of the year for the north, it is very well established and having dark skies will help tremendously. There is nothing finer than cradling a cup of hot coffee, sneaking a donut and waiting on the dawn while watching Kepler’s Laws of planetary motion in action. I am sure that you’ll come away feeling very happy indeed that you took the time to look for Comet Halley’s children racing by!

Posted on by Tammy Plotner

Lingering Lyrids…

Meteor FireBall Break-up Courtesy of John Chumack

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Although we couldn’t remind you just before the date of the Lyrid meteor shower peak, there’s no reason to believe the show is over just yet! If you’re an early riser, this just might be your chance to catch a lingering Lyrid…

Every year the Earth encounters the dusty remnants of the tail of Comet Thatcher (C/1861 G1). It doesn’t occur on a very specific date, but we do know it happens in late April. While the peak time is dawn on April 23, it’s not uncommon to see between 5-20 meteors per hour through the 26th.

Why such a widely varied date and diversified fall rate? The answer is… thanks to Jupiter’s massive gravity, we never know exactly when we might encounter a “clump” of comet debris. The majority of the time, the spawn of Comet Thatcher is no bigger than a grain of sand, traveling through our atmosphere at 49 km/s (110,000 mph). Incredibly enough, these fast moving particles can light up as brightly as 2nd magnitude – easily seen from moderately light polluted skies. Some have even been known to appear as fireballs and leave smoke-like trails that linger in the sky for several minutes!

For the past 2600 years, mankind has been observing the Lyrids – and you can, too. Since their radiant is near the bright star, Vega, your best time to observe is in the hours just before dawn. For many observers, the constellation of Lyra will be high to the east around 4:30 a.m. local time and nearly overhead just before dawn. Even southern hemisphere observers with an unobstructed northern horizon can enjoy the show, too. While there will be some Moon to contend with, placing it behind an obstruction like the corner of a building or a tree will help reduce the glare.

Clouded out or decided to sleep until it was light? Don’t forget your lessons on how to “listen” with your radio! According to NASA, “This year many amateur radio operators tuned into the Lyrids using a technique called radio forward scattering. When fast-moving meteoroids strike Earth’s atmosphere they heat and ionize the air in their path. The luminous ionized trails are not only visually striking — they also reflect radio waves. During a major meteor shower, radio signals from TV stations, RADAR facilities, and AM/FM transmitters are constantly bouncing off short lived meteor trails. For those who know how to listen, it’s easy to hear the echoes.” Don’t remember how to listen? Then take the radio meteor listening tutorial courtesy of the North American Meteor Network.

Will you catch a lingering Lyrid? You never know until you try…

Many thanks to John Chumack of Galactic Images and to NASA for the illustrations.

Posted on by VirtualAstro

April’s Shooting Stars

Lyrids Radiant Credit: Adrian West

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April showers? Yes! The 16th to the 26th this month brings us the April Lyrid Meteor Shower, with the peak occurring on April 22nd.

The meteors in this shower tend to be bright and leave persistent trains as they enter the Earth’s atmosphere. In recent years the shower has averaged 10 to 20 meteors per hour.

You may think that this sounds like a fairly mediocre shower and not worth bothering with, but it has been known for the Lyrids to surge and rates rise rapidly to over 100 per hour! This is what makes this shower so interesting and difficult to predict. Will it be a biggy this year or not?

Lyrid meteors radiate from a point (radiant) in the constellation of Lyra and this is where this shower gets its name. The best time to look for Lyrid meteors will late in the evening on April 22nd after 10 pm as the constellation of Lyra rises up from the northeast horizon.

This will give you 2 or 3 hours of meteor watching before the waning gibbous moon rises and starts to wash out the sky. But still, it’s well worth staying up to see as many bright meteors as possible.

Posted on by Tammy Plotner

Delta Leonid Meteors May Show On February 26

If you like keeping track of somewhat obscure meteor showers, tonight will be one of your best opportunities to spot the Delta Leonids. What’s the history of these meteors and when and where do you look? Let’s go outside and find out…

The Delta Leonids aren’t ancient and first came to attention during the early 20th century when W. F. Denning first made record of them in 1911. They were described as slow, with trains – but 16 independent observers report one of them as being at least six times as bright as the planet Venus. At the time, the fall rate was an average of 7 per hour.

Studies continued in 1924 and 1930 as scientists endeavored to pinpoint a radiant and an orbital stream. The results were rather inconclusive and the validity of the stream left to speculation. Are they Delta Leonids? Or the precursors of the Beta stream? From 1961 to 1965 a radio echo survey was employed and the results showed Earth passing through the stream between February 9th to March 12th. After several years of observation, the Western Australia Meteor Section has provided the most positive conculsions to date. While the stream cannot be attributed to any particular comet orbit, it does exist and peaks on (or about) February 26th.

If you’re out and about tonight, keep watch around the constellation of Leo… it will be relatively high in the sky around 10-11:00 pm local time. You’ll find its signature “backwards question mark” asterism along the ecliptic plane – the imaginary path the Sun and Moon take across the sky. With a typical magnitude of 2.8, these slow moving travellers will stand out against a fainter backdrop of stars. However, don’t expect to see a huge amount of activity, because the fall rate only averages about 5 per hour.

So why bother? It won’t hurt to keep an eye on the sky if you’re out walking your dog, or perhaps enjoying social activities which take you out to your car. The Delta Leonids are a temporary meteor stream and won’t be around forever. Catch ’em while you can!

Meteor Photo Credit: Yukihiro Kida/NASA Science

Posted on by Tammy Plotner

2011 Quadrantid Meteor Shower… Tonight’s the Night!

"Fireball Breakup" by John Chumack

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In just a few hours the peak of the first meteor shower of 2011 will begin – the Quadrantids. Where did these mysterious meteors begin their life and how can you observe one yourself? Then step inside…

Beginning each New Year and lasting for nearly a week, the Quadrantid Meteor Shower sparkles across the night sky for nearly all viewers around the world. Its radiant belongs to an extinct constellation once known as Quadran Muralis, but any meteors will seem to come from the general direction of bright Arcturus and Bootes. This is a very narrow stream, which may have once belonged to a portion of the Aquarids, but recent scientific data points to a what may have been a cosmic collision. According the most recent data, the Quandrantid meteors may have been formed about five centuries ago when a near-Earth asteroid named 2003 EH1 and a comet smashed into one another. Historic records from ancient China put comet C/1490 Y1 in the path of probability.

As Jupiter‘s gravity continues to perturb the stream, another 400 years may mean this shower will become as extinct as the constellation for which it was once known, but we aren’t out of the running just yet. “Peaking in the wee morning hours of Tuesday, Jan. 4, the Quads have a maximum rate of about 100 per hour (varies between 60 and 200),” says Bill Cooke of NASA’s Meteoroid Environment Office. “What makes this year so special is that the Moon is New on the night of the peak, so there will be no interference from moonlight.”

As exciting as it may seem, there are a few problems associated with observing the Quadrantid meteor shower. The first is the weather, because this northern hemisphere show occurs during a notoriously cold season making observations uncomfortable at best. The second is the brevity of the activity itself. Because Earth intersects the debris orbit of 2003 EH1 at a perpendicular angle, we zip right through the trail. That’s why the shower activity is so fast and slightly unpredictable. A third consideration is the high probability of cloud cover – but take heart… NASA has you covered!

“Got clouds? No problem.” says SpaceWeather. “You can stay inside and listen to the Quadrantids. Tune into SpaceWeather Radio for a live audio stream from the Air Force Space Surveillance Radar. When a Quadrantid passes over the facility, you will hear a “ping” caused by the radar’s powerful transmitter echoing from the meteor’s ion trail. During the shower’s peak, the soundtrack is guaranteed to entertain.

So where and when to look? “You can start watching after 2:30am in the North to North East look between the handle of the Big Dipper -Ursa Major and the Constellation of Bootes or the Kite shaped constellation, this is the radiant location as the Meteors will appear to radiate from this general area.” says professional astrophotographer, John Chumack. “Or after 2:30am simply look between the North Star and bright star Arcturus in the East. The Quadrantid Meteors will appear to be coming from this general area of the sky. There is no moon present during this year’s shower, so you can watch all night if you like without moonlight interfering, but the best time will be after 2:30am. As the night goes on the Big Dipper, Bootes and Arcturus climb higher into the sky, so keep watching because the number of meteors usually picks up after 2:30am and gets better through 6:00am. as Earth rotates into the stream. Meteors can appear anywhere in the sky, so look in all directions of the sky as the Quadrantid radiant reaches straight over head. The Quadrantid Meteors are rather fast movers. They enter the atmosphere at about 90,000 to 120,000mph, and can have some impressive long trails.”

Will the Quadrantid Meteor Shower live up to its expectations? No one knows for sure… But we’ll be watching!

Many thanks to John Chumack of Galactic Images for his inspiring photo and to NASA for the locator chart. We thank you so much!

Posted on by Nancy Atkinson

Get Ready for the Geminids — In the Sky and Online!

Geminids by Bob Yen / APOD.

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One of the best night sky events of the year is on tap: The Geminid Meteor shower. According to the Royal Astronomical Society, the evening of December 13 and the morning of December 14, skywatchers across the northern hemisphere could see up to 100 “shooting stars” or meteors each hour. This number is what will be seen at the peak of activity, but if conditions are clear you can definitely take the time to observe any time between Sunday night, Dec. 12 to Wednesday morning, Dec. 15.

You can also participate and share in the event on Twitter, with the #Meteorwatch crew.

Of course, meteors are the result of small particles entering the Earth’s atmosphere at high speed, burning up and super-heating the air around them, which shines as a characteristic short-lived streak of light. In this case the debris is associated with the asteroidal object 3200 Phaethon, which many astronomers believe to be an extinct comet.

The meteors appear to originate from a ‘radiant’ in the constellation of Gemini, and so the name Geminid.

For US skywatchers, Sky & Telescope predicts that under a clear, dark sky, one or two shooting stars per
minute will likely be seen from about 11 p.m. local time Monday until dawn Tuesday morning. If you live under the artificial skyglow of light pollution the numbers will be less, but the brightest meteors will still shine through.

For European, and particularly British observers, the RAS says by 0200 GMT on December 14, the radiant will be almost overhead in the UK, making it the best time to see the Geminids. By that time the first quarter Moon will have set so the prospects for a good view of the shower are excellent.

Meteors in the Geminid shower are less well known, probably because the weather in December is less reliable. But those who brave the cold can be rewarded with a fine view. In comparison with other showers, Geminid meteors travel fairly slowly, at around 35 km (22 miles) per second, are bright and have a yellowish hue, making them distinct and easy to spot.

To watch for meteors, all you need are your eyes. Find a dark spot with an open view of the sky and no glary lights nearby. Bundle up as warmly. “Go out late in the evening, lie back, and gaze up into the stars,” says Sky & Telescope senior editor Alan MacRobert. “Relax, be patient, and let your eyes
adapt to the dark. The best direction to watch is wherever your sky is darkest, probably straight up.”

As with most astronomical events, the best place to see meteors is at dark sites away from the light pollution of towns and cities. You can also check with astronomy clubs or science museums if they are hosting any viewing events.

The Geminids will also feature in a Twitter event, called Meteorwatch, where observers can post their text, images and videos to share them with other observers (and also for those having less favorable locations. Anyone with Internet access can join in by following @virtualastro and the #meteorwatch hashtag on Twitter.

Sources: RAS, Sky & Telescope,

Posted on by Tammy Plotner

The Lion Tamer – Leonid Meteor Shower 2010

Are you ready to walk into the lion’s cage? Then break out your favorite skywatching gear because the 2010 Leonid meteor shower is underway…

In the pre-dawn hours on the mornings of November 17 and November 18, the offspring of Comet Temple/Tuttle will be flashing through our atmosphere and just taunting you to test your meteor watching skills against bright skies. Although the phat Moon will greatly interfere with fainter meteor trails, don’t let that stop you from enjoying your monring coffee with the sparkling “cubs” that will be shooting out from the constellation of Leo.

Where? For all observers the constellation of Leo is along the ecliptic plane and will be near its peak height during best viewing times. When? Because of the Moon, just a couple of hours before local dawn is the best time to watch. Why? Read on!

Although it has been a couple of years since Temple/Tuttle was at perihelion, don’t forget that meteor showers are wonderfully unpredictable and the Leonids are sure to please with fall rate of around 20 (average) per hour. Who knows what surprises it may bring! Each time the comet swings around our Sun it loses some of its material in the debris trail. Of course, we all know that is the source of a meteor shower, but what we don’t know is just how much debris was shed and where it may lay.

As our Earth passes through the dusty matter, it may encounter a place where the comet let loose with a large amount of its payload – or it may pass through an area where the “comet stuff” is thin. We might even pass through an area which produces an exciting “meteor storm” like the Leonids produced in 1883! For those in the know, the Leonid meteor shower also made a rather incredible appearance in 1866 and 1867 – dumping up to 1000 (not a typo, folks) shooting stars recorded even with a Moon present! It erupted again in 1966 and in 1998 and produced 3000 (yep. 3000!) video recorded meteors during the years of 2001 and 2002. But remember, human eyes may only be able to detect just a few…

And I ain’t lion!

Photo Courtesy of Stardate.org, Texas University

Posted on by Jon Voisey

Hartley 2 Spawns Meteor Shower

Universe Image Gallery

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The comet of the year for 2010 seems to be Hartley 2. Although this comet is receding from Earth now (its closest approach was in the latter half of October) and growing fainter, it seems to have left us with one last hurrah: The spawning a brief meteor shower.


Although other comets, such as 2009 R1 (McNaught) and 2P/Encke have passed earlier this year, none has presented an especially tempting target for amateur astronomers (both McNaught and Encke were too close to the Sun during perihelion to be easily observed). Additionally, Hartley is the target of a flyby of the Deep Impact probe bringing it further attention.

Meanwhile, observationally, the comet has been somewhat difficult to observe. I went out on October 17th to hunt for it with a 4″ telescope, but despite my best efforts, couldn’t find it. Although the comet was predicted to reach 5th magnitude, the growing nucleus has apparently become so diffuse, reaching over 1° in the sky, that it’s hard to spot. Undeterred, I attempted again this past weekend with my 8″ SCT. Again, my attempts were frustrated. Even a 15 second exposure with my camera barely brought out more than a smudge.

Yet that night we observed several bright meteors radiating from near Cassiopeia which is where Hartley had been a few weeks prior. We checked to ensure there weren’t any other annual meteor showers from that region. Sure enough, there weren’t, and we wondered if there might be a connection between Hartley’s passing and the meteors we witnessed.

Sure enough, just such a shower was a predicted possibility. Whether or not the shower would occur would depend on just how much dust Hartley had given off in the past and how diffuse the cloud had grown (on this pass and others) since its closest approach to Earth was still 12 million km. Although the meteors my friends and I witnessed were notable (around 2nd to 3rd magnitude) they came from the wrong direction. Meteors spawning from Hartley should have a radiant in Cygnus, the swan. But while ours may not have caught these “Hartley-ids”, others have been witnessing a far grander show in the past few nights that seem to come from the right direction.

In Seascape California, Helga Cabral caught a bright fireball. “I saw a bright white ball and tail, arcing towards the ocean. It was quite beautiful and it looked like it was headed out to sea and so picture perfect it could have been a movie!” A similar fireball was reported the same night near Boston, Massachusetts by Teresa Witham. The predicted peak of this shower occurs tonight so if you have a chance and clear skies, go out and look. As with most showers, there may be some stragglers just before and after so you may be able to catch some for the next few nights if conditions tonight aren’t favorable.

Meteors from Hartley 2 will have a relatively low velocity upon entering our atmosphere since the comet is traveling roughly in the same direction. As such, the expected velocity as it hits our planet is a mere 7 miles a second. The result of this is that they will likely travel slowly across the sky, taking perhaps as much as a few seconds. In contrast, the Leonid showers coming later this month have a relative velocity of 45 miles per second, which causes the meteors to streak across the entire sky in less than a second. The lower velocity for the Hartley-ids will also mean they won’t undergo as much frictional heating and will likely glow fainter shades of reds and yellows.