METEORS in 2010 - 11
The Geminid Meteor Shower, which peaks in 2010 on Dec. 13th and 14th, is the most intense meteor shower of the year. It lasts for days, is rich in fireballs, and can be seen from almost any point on Earth.
It's also NASA astronomer Bill Cooke's favorite meteor shower—but not for any of the reasons listed above.
"The Geminids are my favorite," he explains, "because they defy explanation."
Most meteor showers come from comets, which spew ample meteoroids for a night of 'shooting stars.' The Geminids are different. The parent is not a comet but a weird rocky object named 3200 Phaethon that sheds very little dusty debris—not nearly enough to explain the Geminids.
"Of all the debris streams Earth passes through every year, the Geminids' is by far the most massive," says Cooke. "When we add up the amount of dust in the Geminid stream, it outweighs other streams by factors of 5 to 500."
This makes the Geminids the 900-lb gorilla of meteor showers. Yet 3200 Phaethon is more of a 98-lb weakling.
3200 Phaethon was discovered in 1983 by NASA's IRAS satellite and promptly classified as an asteroid. What else could it be? It did not have a tail; its orbit intersected the main asteroid belt; and its colors strongly resembled that of other asteroids. Indeed, 3200 Phaethon resembles main belt asteroid Pallas so much, it might be a 5-kilometer chip off that 544 km block.
"If 3200 Phaethon broke apart from asteroid Pallas, as some researchers believe, then Geminid meteoroids might be debris from the breakup," speculates Cooke. "But that doesn't agree with other things we know."
Researchers have looked carefully at the orbits of Geminid meteoroids and concluded that they were ejected from 3200 Phaethon when Phaethon was close to the sun—not when it was out in the asteroid belt breaking up with Pallas. The eccentric orbit of 3200 Phaethon brings it well inside the orbit of Mercury every 1.4 years. The rocky body thus receives a regular blast of solar heating that might boil jets of dust into the Geminid stream.
Could this be the answer?
To test the hypothesis, researchers turned to NASA's twin STEREO spacecraft, which are designed to study solar activity. Coronagraphs onboard STEREO can detect sungrazing asteroids and comets, and in June 2009 they detected 3200 Phaethon only 15 solar diameters from the sun's surface.
What happened next surprised UCLA planetary scientists David Jewitt and Jing Li, who analyzed the data. "3200 Phaethon unexpectedly brightened by a factor of two," they wrote. "The most likely explanation is that Phaethon ejected dust, perhaps in response to a break-down of surface rocks (through thermal fracture and decomposition cracking of hydrated minerals) in the intense heat of the Sun."
Jewett and Li's "rock comet" hypothesis is compelling, but they point out a problem: The amount of dust 3200 Phaethon ejected during its 2009 sun-encounter added a mere 0.01% to the mass of the Geminid debris stream—not nearly enough to keep the stream replenished over time. Perhaps the rock comet was more active in the past …?
"We just don't know," says Cooke. "Every new thing we learn about the Geminids seems to deepen the mystery."
This month Earth will pass through the Geminid debris stream, producing as many as 120 meteors per hour over dark-sky sites. The best time to look is probably between local midnight and sunrise on Tuesday, Dec. 14th, when the Moon is low and the constellation Gemini is high overhead, spitting bright Geminids across a sparkling starry sky.
Bundle up, go outside, and savor the mystery.
Author: Dr. Tony Phillips | Credit: Science@NASA
More Information
ACTIVITY IN GEMINID PARENT (3200) PHAETHON -- The Astronomical Journal, 140:1519–1527, 2010 November
(3200) Phaethon: A Rock Comet by David Jewitt and Jing Li, UCLA
Geminid Sky Map -- by Dr. Tony Phillips
NASA astronomer Bill Cooke is head of the NASA Meteoroid Environment Office
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2011 Meteor Showers
January
Typically, 40 or so bright, blue and fast (25.5 miles per second) meteors will radiate from the constellation Bootes, some blazing more than halfway across the sky. A small percentage of them leave persistent dust trains. This shower usually has a very sharp peak, usually lasting only about an hour.
Parent Comet: 2003 EH1
April
The swift and bright Lyrid meteors disintegrate after hitting our atmosphere at a moderate speed of 29.8 miles per second. They often produce luminous trains of dust that can be observed for several seconds.
Parent Comet: C/Thatcher
May
Parent Comet: 1P/Halley
June
The June Lyrids is a low-rate shower during which you could see up to 10 meteors per hour during its peak.
July
At peak time about 20 bright, yellow meteors can be observed per hour. Because these meteors nearly broadside the Earth, their speed is a moderate 25.5 miles per second.
The Capricornids are characterized by their often yellow coloration and their frequent brightness. They are also slow interplanetary interlopers, hitting our atmosphere at around 15 miles per second. Though you can expect only 15 meteors per hour at best under dark sky conditions, the Capricornids are noted for producing brilliant fireballs.
August
This shower produces about 60 meteors per hour, and its performance is farily consistant from year to year.
Parent Comet: 109P/Swift-Tuttle
October
Expect a peak rate of 10 meteors per hour under clear, moonless conditions.
This shower produces a peak rate of 20 yellow and green meteors per hour, which are fast moving at 41.6 miles per second and are known to produce fireballs.
Parent Comet: 21P/Giacobini-Zinner
Parent Comet: 1P/Halley
November
The Leonids are best known for their 33-year peaks, during which 100s of meteors per hour can be observed. The last of these peaks occured in 2001.
Parent Comet: 55P/Tempel-Tuttle
December
The most reliable meteor shower of the year, the Geminids are characterized by their multi-colored display--65% being white, 26% yellow, and the remaining 9% blue, red and green.
Parent Comet: 3200 Phaethon
Show moon phases for 2012 Meteor Showers
Top image: The Mice/NGC 4676
NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M.Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA
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Skyscrapers, Inc., The Amateur Astronomical Society of Rhode Island is an educational, non-profit organization with the purpose
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Website hosted by Newfangled Web Development.
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Major Meteor Showers in 2010
by Wes Stone
I hope you also check out my Online Observing Log and Astronomy Home Page!
Jump to: Quadrantids, Lyrids, Eta Aquarids, South Delta Aquarids, Perseids, Orionids, Leonids, Geminids or Other Sources of Meteor Activity
2009 was a very nice year for meteor observing. The Quadrantids started out the year with a bang, as a well-observed display peaked at the right time for North America and didn't leave Western Europe out in the cold either. (OK, that's figurative, it's almost always cold when you can see Quadrantids). I personally got to see over 100 Quadrantids/hour. The Lyrids were their normal selves, with a peak of around 15/hour. The Perseids were perhaps the most hyped and two-sided shower of the year, as they were subject to moonlight interference but produced several outbursts over a couple of nights. Some observers were impressed; I had the extra burden of partly cloudy skies and was not. The Orionids performed well, maybe slightly above normal. A Leonid outburst predicted for Asia materialized, but with rates below 100/hour. The Geminids closed the year with a well-observed display, and I even got to see some despite fog.
Why such a long paragraph about 2009? Well, in 2010 the Moon will be a big problem with a lot of showers. The Perseids are the big exception, and promise several nights of moonless meteor observing for those with good August weather. The Geminids don't fare too badly under a first quarter Moon; most of the morning hours will be moon-free. There will be a couple of moon-free hours for the Leonid and Lyrid maxima as well. Other than that, useful observing hours for the major shower peaks are drowned out by bright moonlight.
Don't forget to consider the effect of radiant elevation when planning an observing session. Even if a shower is near its activity peak, you won't see a thing from it if the radiant is below your local horizon. In the case of a strong shower, you may expect a (very) few long "earthgrazing" meteors when the radiant is near the horizon, but even when the radiant has reached an elevation of 30 degrees you will only see half as many meteors as you would if it were at your local zenith. Most shower radiants are highest during local morning hours, often just before twilight begins. That's usually when you want to observe, although occasionally a rising Moon or a sharp activity peak will suggest an earlier time. See "WHEN TO WATCH" below.
I get quite a few questions about "when to watch" and "where to look". "Where to look" is usually fairly easy: center your field of view high in the darkest, least-obstructed part of your sky. If you have tall trees or an overpowering city light dome in one direction, you probably should face another direction. You don't have to look right at the shower's radiant. Indeed, you'll probably see fewer meteors if you do. But it's also nice and productive to keep the radiant somewhere within the field of view. If there's a bright Moon in the sky, keep it out of your field of view or try to block it with something, like a tree or a car or a chair...
WHEN TO WATCH: For each shower, I list the shower's name and a "Predicted Maximum". This is when THE SHOWER should be at its maximum activity, whether or not you are in a position to view it. If this maximum time happens to coincide with a time when it's clear and dark and the radiant is high in your sky, you'll probably be a happy camper. However, life usually involves compromises. So, for each shower I've included a paragraph titled "WHEN TO WATCH". This is my take on the best viewing window for each shower. These times are generally valid for all of North America and are given as local time (i.e., you don't have to worry about converting for your time zone). It may be worth looking up the beginning of astronomical twilight for your location on a given date (in an almanac or planetarium program); this will give you an idea of how late you may observe into the prime morning hours.
Vagaries of meteor activity, your personal ability to perceive meteors, and local sky conditions all have a dramatic effect on the rates you observe. Sky conditions to consider include weather and light pollution. If you can't see the summer Milky Way in Cygnus on a moonless night when this region of the sky is overhead, you probably won't see much from even the strongest annual showers. Clear, dark skies are essential for observing meteors. More shower meteors are visible from a dark site, and sporadic (random) meteor rates are enhanced greatly.
QUADRANTIDS
Predicted Maximum: January 3, ~19:00 UT (= Jan. 3, 11:00am PST; = Jan. 4, 2:00pm EST)
Moon: Waning Gibbous (major interference)
(radiant map from IMO)
WHEN TO WATCH: The Moon (almost 90% illuminated and high in the predawn sky) makes the 2010 Quadrantids an event for die-hard observers only. Watch on the morning of Sunday, January 3, for the last couple of hours before morning twilight. (Asian observers, try the morning of January 4 instead.) If your skies are clear and transparent considering the moonlight, expect something like 10 meteors per hour.
The peak of this shower doesn't last long, and is notoriously variable in strength and timing and duration. Regardless of the timing of the peak, the radiant has to be well above the horizon for you to see much of anything. This generally means the predawn hours. The Quadrantid radiant gets highest for northern latitudes, but the weather in early January is often awful.
Quadrantids are medium-velocity meteors, and some bright ones are often visible around the time of maximum activity. The radiant is in a rather blank area surrounded by the constellation figures of Bootes, Hercules, Draco and Ursa Major (see the radiant map). The nights before and after the sharp maximum show much lower activity, and won't be worth observing this year.
LYRIDS
Predicted Maximum: April 22, ~17:00 UT (= Apr. 22, 10:00am PDT; = Apr, 22, 1:00pm EDT)
Moon: Waxing Gibbous (moderate interference)
(radiant map from IMO)
WHEN TO WATCH: The Moon is just past its first quarter and will set around 2am for mid-northern latitudes. If you're not too far north, this allows a couple of hours between moonset and morning twilight. So, watch these dark hours on the morning of Thursday, April 22 (Friday, April 23 for Asian observers). Expect between 5 and 15 Lyrids per hour from a dark site, plus a few other meteors.
The Lyrids are another shower with a reputation for variable rates and timing. Usually, they produce 10 to 20 meteors per hour at maximum (under dark skies). The predicted peak isn't well-timed for North American observers this year, but given the shower's variability this shouldn't keep you from watching. Lyrids produce fairly fast meteors with a reputation for being faint on average. However, I've seen my share of Lyrid fireballs, and the 2009 display was uncharacteristically bright.
ETA AQUARIDS
Predicted Maximum: May 6 (broad)
Moon: Last Quarter (moderate to major interference)
(radiant map from IMO)
WHEN TO WATCH: The Eta Aquarids have a fairly broad peak. The morning of Thursday, May 6 would be the nominal maximum. The Moon is near the radiant this year, with conditions a little worse on the mornings before the maximum and a little better after the maximum. This is a difficult shower to observe from mid-northern latitudes anyway (see below). If you're going to watch, try May 6th, 7th, and/or 8th.
This shower is better for Southern Hemisphere observers, but is a bit difficult for everyone. The key is to watch during the last hour or so before twilight gets really bright. In terms of local time this depends on your latitude and also on your longitude with respect to the center of your time zone. Check an almanac or planetarium software. At latitude 42.6 degrees North, I've had my best results from about 3:40-4:40am local daylight time.
The Eta Aquarids would produce maximum rates of >50 per hour if we could see them with the radiant high in a dark sky. In the northern temperate latitudes, we don't get close to that. We get just a small taste of them in an intricate dance just before dawn. At 40 degrees North, the radiant is only about 15 degrees up when twilight begins. If I could get those conditions for an hour, I might see 10-15 ETAs. However, everything's changing. Before that time, there are fewer shower members visible because the radiant is lower. After that time, the radiant is higher and rates would keep rising but for the onrush of twilight. You're fortunate indeed if you see 10 ETAs in an hour, along with about 5 sporadic (random) meteors. Moonlight in 2010 might cut those numbers in half.
The low radiant elevation means that the earliest ETAs you see will be "earthgrazers": long, relatively slow and often tracing paths along the horizon. Bright earthgrazers are spectacular. Unfortunately, because of their greater distance from the observer, earthgrazers tend to be faint. As the radiant gets a bit higher, the ETAs take on more of their typical appearance: fast meteors, bright on average and often leaving a glowing train. You'll only catch a few of them, though, because dawn is approaching. This shower seems to fluctuate irregularly, and you could easily hit either a spurt or a lull during the all-too-brief observing windows.
SOUTH DELTA AQUARIDS
Predicted Maximum: July 28 (broad)
Moon: Waning Gibbous (major interference)
(radiant map from IMO--shower is indicated as SDA)
WHEN TO WATCH: Unfortunately, the Moon is just past full this year and so badly placed that there is no way to really observe around the peak of the South Delta Aquarids in 2010. Wait for the Perseids.
The South Delta Aquarids are barely a major shower from 40 degrees N. They are medium-speed meteors, and tend to be faint on average. The moonlight will really kill them this year. Meteors from this stream are easily confused with those of several minor showers with nearby radiants.
PERSEIDS
Predicted Maximum: August 13, ~0:00UT (=August 12, 5:00pm PDT; =August 12, 8:00pm EDT)
Moon: Waxing Crescent (no interference)
(radiant map from IMO)
WHEN TO WATCH: The Perseids will be interesting for a couple of days before and a day after their peak. Best rates should come on Friday morning, August 13. Mid-northern observers can start watching as soon as the sky gets dark in the evening and keep watching until morning twilight.
The Perseids are probably the most-watched annual meteor shower. The shower has a very long duration, from about July 15 through August 25. The shower is most interesting around its peak on August 12 or 13. While the predicted maximum occurs in daylight for North America, the predictions haven't always been accurate. In 2008, the Perseids threw a major curveball and peaked about 14 hours later than anticipated. In 2009, there were a couple of extra peaks in the shower profile that were fairly well predicted. What will 2010 bring? We'll see!
The Perseid radiant is above the horizon the entire night for observers north of latitude 32N, but it is fairly low at the end of evening twilight. Morning rates are generally better. Perseids are fast meteors and tend to be fairly bright on average. An occasional fireball is seen. Peak rates for the Perseids often top 100 per hour. If you miss the peak by a few hours, you might still see rates of 60. If you live in a light-polluted city, you may only see a few. Even for the relatively bright Perseids, dark skies make a big, big difference. The mornings of August 11th, 12th and 14th should also be worthwhile, and meteor-maniacs will probably get satisfaction for the whole week between August 9th and August 15th. The Perseids aren't the only meteors around; expect to see between 10 and 20 other meteors per hour under dark predawn skies.
ORIONIDS
Predicted Maximum: October 21 or 22 (broad and irregular)
Moon: Full (major interference)
(radiant map from IMO)
WHEN TO WATCH: The Full Moon puts a real kink in Orionid observing this year, with the maximum completely wiped out. Die-hards who want to do some useful observing can find one or more moon-free hours on the mornings of Sunday October 17th thru Tuesday, October 19th. Occasionally, interesting activity has been observed this early in the shower's activity period, but expect 5-10 Orionids per hour on the 17th and 10-20 if you can squeeze an hour in before morning twilight on the 19th.
The Orionids are capable of producing interesting activity from October 17-25. Traditionally, the shower produced maximum rates of about 25 per hour, and wasn't very regular. Recently, the shower has been much more exciting. In 2006, rates were much higher than expected for several mornings around the peak. 2007 also saw at least a couple of mornings of enhanced activity. In 2008, it appeared that both October 20 and 21 were slightly enhanced, with rates that would have approached 40 per hour if not for moonlight. In 2009, there was a broad maximum of about 40 per hour.
The Orionids are fast meteors, perhaps a bit faint on average but capable of producing fireballs. The 2006 outburst featured brighter-than-normal Orionids. Note that the radiant is north of Betelgeuse and not right in the middle of Orion. A minor shower called the Epsilon Geminids has a nearby radiant that can cause confusion, but usually produces only 1-2 meteors per hour. Early activity from the Taurids can produce a few nice, slow meteors from radiants farther west. Finally, 5-15 sporadic meteors are usually visible each hour from dark sites
LEONIDS
Predicted Maximum: November 17, ~21:00 UT (=Nov. 17, 1:00pm PST; Nov. 17, 4:00pm EST)
Moon: Waxing Gibbous (minor to moderate interference)
(radiant map from IMO)
WHEN TO WATCH: Try the last couple of hours before morning twilight on the morning of Wednesday, November 17 (Thursday, November 18 for Asian observers). Expect 10-20 Leonids per hour at best.
The Leonids produced several storms recently, and a host of smaller outbursts. Nothing spectacular is predicted in 2010, but part of the interest in meteor observing is seeing the unpredicted. On the other hand, rates could be even lower than expected... Although the predicted maximum occurs during daylight for North America, over the past few years the "normal" maximum has been broad enough to cover the globe. This year's Moon reinforces the mandate to observe during the predawn hours, as it sets at around 3am in most locations. There should still be some decent activity on November 18, but the moon-free window is a lot shorter.
The Leonids are very fast meteors. The shower is active at a low "background" level for about a week from November 14-21. Quite a few sporadic and minor-shower meteors join the cast in the predawn hours.
GEMINIDS
Predicted Maximum: December 14, ~11:00 UT (=Dec. 14, 4:00am PST; =Dec. 14, 7:00am EST)
Moon: Waxing Gibbous (moderate interference)
(radiant map from IMO)
WHEN TO WATCH: Watch from midnight until morning twilight on the morning of Tuesday, December 14. Monday morning, December 13, should be worth watching as well.
The Geminids are accessible from the entire Northern Hemisphere and from many Southern Hemisphere locations as well. The radiant is highest in the sky at around 2am. Normally, late evening hours are good for viewing, but this year the Moon (just past first quarter) will cause problems until around midnight. The peak is usually broad, and in 2009 occurred somewhat earlier than expected. The Geminids can produce observed rates of over 100/hour at maximum, and are reliable (for a meteor shower) as well as spectacular.
Geminids are medium-speed meteors. Most of them don't leave glowing trains, but the brighter ones are often colored (yellow, green and blue are most common). The Geminids seem to produce quite a few fireballs. Often, more bright meteors are seen during and after the maximum than before the maximum. A good number of sporadic and minor-shower meteors add to the show.
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Other Sources of Meteor Activity
The major showers listed here are fairly reliable and occur every year. However, meteor activity is visible on any clear night. Random sporadic meteors, minor showers, and major showers near the beginning or end of their activity period all contribute to this "background". For the Northern Hemisphere, there is a general pattern of lower rates during the first half of the year and higher rates during the second half, but rates vary greatly from hour to hour, day to day, and observer to observer. Occasionally, unexpected high activity occurs. It is up to the observer to objectively describe what was seen. In many cases, high activity may be ascribed to randomness. At other times, many of the meteors seen may be attributed to a common radiant.
There are some periodic, irregular, and hypothetical showers that could produce surprises during 2010. The meteorobs mailing list is a good way to keep track of predictions and developments "beyond the majors".
Other Meteor Shower Info.
The Finer Points of Meteor Shower Observing
Outside Links
The North American Meteor Network
General shower attributes, radiant maps and predicted times of maximum are adapted from the International Meteor Organization's 2010 Meteor Shower Calendar as well as personal data. Recent activity profiles were characterized from http://www.imo.net/zhr. All on-site text and contents are Copyright 2009, 2010 by Wes Stone ---------------- 2009 METEORS BELOW ----
Summary: On Nov. 17, 2009, Earth passed through a cloud of debris from Comet 55P/Tempel-Tuttle, causing an outburst of 100+ meteors per hour over Asia and a lesser display over North America and Europe. [full story] [sky map] [meteor counts]
Photographer, Location
Angsung, ChungNam, South Korea
Nov. 18, 2009
Martin McKenna,
Maghera, Co. Derry, N. Ireland
Nov. 17, 2009
Guffey, Colorado
Nov. 17, 2009
Jurg Wagener's Sterland Boerdery Sutherland, South Africa
Nov. 15, 2009
Comments
Photo details: (#1) Canon 5D Mark2, Sygma 8mm Lens, f/4, ASA6400, 20sec x 26 composition; (#2) Canon 5D Mark2, Nikon 16mm Lens, f/2.8, ASA6400, F:2.8, 20sec x 2 composition
Between 02.00-06.30 UT I observed 89 meteors of which 64 were Leonids. At 05.57 UT I seen the most incredible Leonid fireball of my life which shot into the sky to my E of N. It was brighter than the full Moon with a giant dazzling green 'head' and streaming up from it was a LONG silver tail completely vertical to the horizon and as straight as a ruler filling the entire naked eye field of view. It left behind an incredible smoke train with a silver bulging head and remarable blue and purple vertical glowing trail at least 40 degrees long which hung in the air for 10 min's, it reminded me of a great comet!. The train faded and twisted due to high altitude winds and transformed into an orange coloured coil. I was frozen with astonishment and only managed to get these images as it faded. This was a sight I shall never forget! Fujifilm S6500fd 6.3MP ISO800 30 secs.
This is a composite of 48 Leonid meteors collected with an allsky video camera on the morning of November 17. Non-Leonid meteors have been removed from the image. Several impressive fireballs were recorded as well.
Sunday november 15th, while observing from Jurg Wagener's Sterland Boerdery (www.sutherlandinfo.co.za) in Sutherland, South Africa, at 23:34 (UTC+2) a brief flash bathed the observing site in white light. It was as if someone fired a camera's flash. Looking up we could see a bright trail which quickly faded, close the Magellanic Clouds. My camera which I had set up to take fixed tripod exposures throughout the night captured this suspected Leonid. I will continue to attempt more imaging in the coming nights. As I have limited access to the internet I will not be able to upload pictures to my website until next week.
Photo details: Canon EOS 450D EF 24mm f/1.4L II USM @ f1.4, ISO1600, 25 seconds, tripod mounted
More Images: from James Champagne of Tucson, Arizona; from Tom King of Watauga, Texas; from Yaron Eini of Gatineau, Quebec; from Olivier Staiger in the Swiss Alps; from Runar Sandnes of Reed, Norway
Bright non-Leonid meteors observed during the Leonid meteor shower: from Malcolm Park of Grafton Ontario, Canada; from Yaron Eini of Gatineau, Quebec; from Marsha Adams of Sedona, Arizona; from Andreas Gada of Oak Heights, Ontario
NOW CLICK Go to Page 2
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Details (from Spaceweather.com):
Sunday November 15th, while observing from Jurg Wagener's Sterland Boerdery (www.sutherlandinfo.co.za) in Sutherland, South Africa, at 23:34 (UTC+2) a brief flash bathed the observing site in white light. It was as if someone fired a camera's flash. Looking up we could see a bright trail which quickly faded, close to the Magellanic Clouds. My camera which I had set up to take fixed tripod exposures throughout the night captured this suspected Leonid. I will continue to attempt more imaging in the coming nights. As I have limited access to the internet I will not be able to upload pictures to my website until next week. Canon EOS450D EF 24mm f/1.4L II USM @ f1.4, ISO1600, 25 seconds, tripod mounted
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Found: 62 Meteor Showers New to Science
02:35 23 September 2009 by Jeff Hecht of www.newscientist.com
For similar stories, visit the Solar System and Comets and Asteroids Topic Guides
Every now and again, biologists turn up a bonanza of new species deep in the ocean or in remote corners of the Earth. But astronomers usually have to make do with a trickle of new discoveries, spotting a rare supernova here or a couple of backwards planets there.
Now, researchers in Canada report finding an incredible 62 new meteor showers, displays of 'shooting stars' that recur every year when Earth passes through the trail of debris left behind by a comet or asteroid.
"I was surprised to find so many new ones," says team leader Peter Brown of the University of Western Ontario.
He credits the wealth of discoveries to the nature of his survey, which detects incoming debris about 10 times as small as can generally be seen by eye, catching objects about 0.1 millimeters across. The survey, based near London, Ontario, uses radar to detect the trail of ionized gases produced as the debris particles slam into the atmosphere at blistering speeds.
The survey measures the paths of the debris particles, allowing researchers to trace their orbits around the sun – and potentially track down their parent bodies. "The central reason for looking at these streams is to trace them back to their origins," Brown told New Scientist.
'Archaeological record'
Over seven years of observations, the project has identified 117 annual meteor showers, of which 62 have never been reported before.
Interestingly, the team found that about half of the 117 observed streams follow orbits similar to those from other meteor showers. That bolsters previous research suggesting that the parent objects – mostly comets – likely broke up into smaller bodies that also shed debris trails – a break-up process that can occur over and over.
"In some cases, we can still trace [the trails] back to some parent objects; in others, we can't see an obvious parent," says Brown. For example, his team found half a dozen streams linked to Comet Encke, the parent body of the well-known Taurid meteor shower.
The 62 newly proposed showers join nearly 300 others that are awaiting confirmation by the International Astronomical Union (IAU), which to date has officially recognised 64 meteor showers.
Peter Jenniskens of the SETI Institute in California, who heads up the IAU group tasked with naming meteor showers, says the new finds will be a boon to science: "Each shower is an archaeological record of some comet's past activity."
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QUADRANTID SIGHTS AND SOUNDS: The Quadrantid meteor shower peaked on Jan. 3rd and it was a doozy. According to the International Meteor Organization, the shower produced as many as 145 meteors per hour, mainly over North America. "I aimed my Canon 30D at the western sky and caught a good number of them," says Pierre Martin of Ottawa, Ontario. "This image is a composite of the best frames."
"The most active hour shortly before dawn had 107 Quadrantids," says Martin. "It was a great show!"
In New Mexico, amateur radio astronomer Thomas Ashcraft recorded the reflections of TV signals off the many Quadrantids that passed over his facility. There were so many meteors, all of the reflections ran together and overlapped to produce an eerie-sounding mix. A complete collection of Ashcraft's sono-Quadrantids may be found here.
Quadrantid Meteor Gallery from Spaceweather.com
What are Meteor Showers?
An increase in the number of meteors at a particular time of year is called a Meteor Shower.
Comets shed the debris that becomes most meteor showers. As comets orbit the Sun, they shed an icy, dusty debris stream along the comet's orbit. If Earth travels through this stream, we will see a meteor shower. Depending on where Earth and the stream meet, meteors appear to fall from a particular place in the sky, maybe within the neighborhood of a constellation.
Meteor showers are named by the constellation from which meteors appear to fall, a spot in the sky astronomers call the radiant. For instance, the radiant for the Leonid meteor shower is located in the constellation Leo. The Perseid meteor shower is so named because meteors appear to fall from a point in the constellation Perseus.
What are Shooting Stars?
"Shooting stars" and "falling stars" are both names that people have used for many hundreds of years to describe meteors -- intense streaks of light across the night sky caused by small bits of interplanetary rock and debris called meteoroids crashing and burning high in Earth's upper atmosphere. Traveling at thousands of miles an hour, meteoroids quickly ignite in searing friction of the atmosphere, 30 to 80 miles above the ground. Almost all are destroyed in this process; the rare few that survive and hit the ground are known as meteorites.
When a meteor appears, it seems to "shoot" quickly across the sky, and its small size and intense brightness might make you think it is a star. If you're lucky enough to spot a meteorite (a meteor that makes it all the way to the ground), and see where it hits, it's easy to think you just saw a star "fall."
How can I best view a meteor shower?
If you live near a brightly lit city, drive away from the glow of city lights and toward the constellation from which the meteors will appear to radiate.
For example, drive north to view the Leonids. Driving south may lead you to darker skies, but the glow will dominate the northern horizon, where Leo rises. Perseid meteors will appear to "rain" into the atmosphere from the constellation Perseus, which rises in the northeast around 11 p.m. in mid-August.
After you've escaped the city glow, find a dark, secluded spot where oncoming car headlights will not periodically ruin your sensitive night vision. Look for state or city parks or other safe, dark sites.
Once you have settled at your observing spot, lay back or position yourself so the horizon appears at the edge of your peripheral vision, with the stars and sky filling your field of view. Meteors will instantly grab your attention as they streak by.
How do I know the sky is dark enough to see meteors?
If you can see each star of the Little Dipper, your eyes have "dark adapted," and your chosen site is probably dark enough. Under these conditions, you will see plenty of meteors.
What should I pack for meteor watching?
Treat meteor watching like you would the 4th of July fireworks. Pack comfortable chairs, bug spray, food and drinks, blankets, plus a red-filtered flashlight for reading maps and charts without ruining your night vision. Binoculars are not necessary. Your eyes will do just fine.
FROM THE MacDONALD OBSERVATORY's (in TEXAS) STARDATE ONLINE at:
http://stardate.org/nightsky/meteors/
TERMS: Meteoroids - The Disconnected Cometary Particles from Comets in Space which Swarm in Orbits
that will Intersect the Earth's Orbit to become Part of a Meteor Shower
Meteors - The Visible Meteoroid Particles Streaking Through and Burning Up in our Atmosphere
Meteorites - The Larger Meteoroid Particles which Survived the Trip through the Atmosphere and Landed on the Ground
Meteoritics - The Study of Meteors
FIreballs - Exceptionally Bright Meteors Often Brighter than Venus
Bolides - Exploding Meteors and Fireballs which Sometimes can even be Heard
ZHR - ZENITH HOURLY RATE - Meteor Counts Assume a Complete Sky as Dark as it is
Straight up (the Zenith) which Yields a Maximum Value Rather than the Actual One
Since the Sky Usually Brightens towards the Horizon - The Brighter the Sky, the
Fewer Meteors Will be Seen
Radiant - The Point in the Sky in which the Meteors Seem to be Coming or Radiating from -
The Names of Many of the Major Meteor Showers are Derived from the Constellation
that the Radiant is located in with an "ids" ending such as the Perseids in which the
Radiant is located in the Constellation Perseus
CONTENTS:
compiled by Alastair McBeath. Based on information in IMO Monograph No. 2: Handbook for Visual Meteor Observers, edited by Jürgen Rendtel, Rainer Arlt and Alastair McBeath, IMO, 1995, as amended by the commentaries in WGN 34:3 (June 2006), pp. 71-84, with subsequent corrections, plus additional material extracted from reliable data analyses produced since. Particular thanks are due to Rainer Arlt, David Asher, Jeff Brower, David Entwistle, Esko Lyytinen and Jérémie Vaubaillon for valuable discussions in respect of several events in 2009.
Introduction
Welcome to the 2009 International Meteor Organization (IMO) Meteor Shower Calendar. Of the more active annual showers, the Quadrantids, Lyrids, η- and Southern δ-Aquariids, Orionids, Leonids and Geminids are best placed with regards the Moon, along with the occasionally stronger Ursids in December. Of greatest potential interest for what they may produce are the η-Aquariids and Orionids (which should be near their theoretical 12-year ZHR peaks in 2009, the Orionids having already produced unexpectedly strong activity in both 2006 and 2007, albeit apparently not from this cause), the moonlit Perseids, which may show an additional maximum again this year, and the Leonids, which could yield ZHRs in the 100+ category, maybe (if we are very fortunate) bordering on near-storm levels again! For radio observers, and hopeful daylight fireball enthusiasts, there is the chance of another Taurid 'swarm' return in June-July. There are minor showers to be monitored as well, and ideally, meteor observing should be carried out throughout the year to check on all the established sources, and for any new ones. We appreciate this is impractical for most people, so the Shower Calendar has been helping to highlight times when a particular effort might most usefully be employed since 1991.
The heart of the Calendar is the Working List of Visual Meteor Showers, Table 5, which had its most recent overhaul by IMO analysts in 2006, to help it remain the single most accurate listing available anywhere today for naked-eye meteor observing. Of course, for all its accuracy, it is a Working List, so is continually subject to further checks and corrections, based on the best data we have, so it is always as well to check the information here fully, before going out to observe (and please notify us if you find any anomalies!).
Apart from the visually-observable showers, there are many others weakly active throughout the year which only still-imaging, video, radar or telescopic observations can separate from the omnipresent background sporadics, as well as showers with radiants too near the Sun to be observed by the various optical methods, which can be detected only by forward-scatter radio or radar observations. Some of these showers are given in Table 7, the Working List of Daytime Radio Meteor Showers. The IMO's aims are to encourage, collect, analyze, and publish combined meteor data obtained from sites all over the globe, to help better our understanding of the meteor activity detectable from the Earth's surface. Thus, we encourage these more specialist forms of observing too, so all meteor workers, wherever you are and whatever methods you use to record meteors, should follow the standard IMO observing guidelines when compiling your information, and submit those data promptly to the appropriate Commission for analysis (contact details are at the end of the Calendar). Thanks to the efforts of the many IMO observers worldwide since 1988 that have done this, we have been able to achieve as much as we have to date, including keeping the shower listings vibrant. This is not a matter for complacency however, since it is solely by the continued support of many people across the planet that our steps towards constructing a better and more complete picture of the near-Earth meteoroid flux can proceed.
Although timing predictions are included below on all the more active night-time and daytime shower maxima, as reliably as possible, it is essential to understand that in many cases, such maxima are not known more precisely than to the nearest 1° of solar longitude (even less accurately for the daytime radio showers, which have received little regular attention until quite recently). In addition, variations in individual showers from year to year mean past returns are only a guide as to when even major shower peaks can be expected. The information given here may be updated after the Calendar is published, so be sure to watch for alerts on the Internet (including on IMO-News) and in WGN, the IMO's bimonthly journal. Some showers are known to show particle mass-sorting within their meteoroid streams, so the radar, radio, still-imaging, telescopic, video and visual meteor maxima may occur at different times from one another, and not necessarily just in those showers. The majority of data available are for visual shower maxima, so this must be borne in mind when employing other observing techniques.
However and whenever you are able to observe, we wish you all a most successful year's work and very much look forward to receiving your data. Clear skies!
Antihelion Source
The Antihelion Source (ANT) is a large, roughly oval area with a size of 30° in right ascension and 15° in declination, centred about 12° east of the solar opposition point on the ecliptic, hence its name. It is not a true shower at all, but is rather a region of sky in which a number of variably, if weakly, active minor showers have their radiants. Until 2006, attempts were made to define specific showers within this complex, but this often proved very difficult for visual observers to achieve. IMO video results from the last decade have shown why, because even instrumentally, it was impossible to usefully define distinct radiants for many of the showers here! Consequently, we currently believe it is best for observers to simply identify meteors from these showers as coming from the ANT alone. At present, we think the July-August α-Capricornids (CAP), and particularly the Southern δ-Aquariids (SDA; because their stream parameters are rather different from the average ANT orbits), should remain discretely observable visually from the ANT, so they have been retained in the Working List, but time and plenty of observations will tell, as ever. Later in the year, the strength of the twin Taurid showers (STA and NTA) means the ANT should be considered inactive while the Taurids are underway, from late September to late November. To assist observers, a set of charts showing the location for the ANT and any other nearby shower radiants is included here, to compliment the numerical positions of Table 6, while comments on the ANT's location and likely activity are given in the quarterly summary notes.
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