DRACONID METEOR SHOWER: The notoroiusly unpredictable Draconid meteor shower peaks this year on the night of Oct. 7-8. In most years, the Draconids come and go with a barely noticable peak of 10 or so meteors per hour. Occasionally, however, Earth passes through a dense clump of debris from parent comet 21P/Giacobini-Zinner and a meteor storm erupts. Just last year, Europeans witnessed a faint but furious outburst of 600 per hour. There is no reason to believe that 2012 is a “storm year.” Nevertheless, northern hemisphere sky watchers are encouraged to be alert for slow-moving Draconids on Sunday night
THE PERSEID METEOR SHOWER IS UNDERWAY: Earth is entering a stream of debris from Comet Swift-Tuttle, source of the annual Perseid meteor shower. Worldwide observers are now reporting more than 30 Perseids per hour, a number that could triple during the weekend when Earth reaches the heart of the debris zone. Forecasters recommend looking during the dark hours before dawn, especially Sunday morning, August 12th, when activity is expected to be highest.
Got clouds? Tune into SpaceWeather Radio for live echoes from Perseid meteors flying over the US Space Surveillance Radar in Texas.
The multi-station Canadian Meteor Orbit Radar, sponsored by NASA’s Meteoroid Environment Office, is also monitoring the Perseids. Live data are available here. Bright spots in this sample radar sky map show the radiants of currently active showers:
Clearly, the Perseids are not the only meteors in the sky this weekend. The Northern and Southern Delta Aquarids (NDA and SDA) are also active. These showers, which are minor compared to the Perseids, spring from 96P/Machholz, a comet that some researchers suspect is a visitor from another star system.
This is a great weekend for watching meteors–but that’s not all. Venus, Jupiter and the crescent Moon are lining up in the pre-dawn sky right in the middle of the Perseid display. The conjunction of planets guarantees that you will see something beautiful even in the unlikely event that the shower fizzles.
EARLY PERSEID METEORS: Earth is entering a broad stream of debris from Comet Swift-Tuttle, source of the annual Perseid meteor shower. Meteoroids in the outskirts of the stream are now hitting Earth’s atmosphere, producing as many as 10-15 meteors per hour according to worldwide counts from the International Meteor Organization. NASA’s network of all-sky meteor cameras captured 17 Perseid fireballs on the nights of July 28th through 30th. Here are their orbits:
The position of Earth is denoted by the red starburst; all of the meteoroid orbits intersect at that point. The purple line traces the orbit of the parent Comet Swift-Tuttle. Fortunately, the comet itself does not intersect Earth.
In the days ahead, Earth will plunge deeper into the meteoroid stream, and meteor rates will increase accordingly. Forecasters expect the shower to peak on August 12-13 with as many as 100+ meteors per hour visible from dark-sky sites.
METEORS FROM HALLEY’S COMET: Earth is entering a stream of debris from Halley’s Comet, source of the annual eta Aquarid meteor shower. The shower peaks this weekend; the best time to look is during the hours before sunrise on Sunday, May 6th. Because the shower’s radiant is located below the celestial equator, southern hemisphere observers are favored, but even northerners should be able to see a few flecks of Halley-dust disintegrating in the atmosphere. Super-bright moonlight will cap the meteor rate at about 30 per hour.
In recent nights, NASA’s all-sky meteor network has picked up a number of early eta Aquarid fireballs. This one was bright enough to shine through the glow of sunrise and clouds over Tullahoma, Tennessee, on April 29th:
According to analysts at NASA’s Meteoroid Environment Office, this particular speck of comet dust hit the atmosphere traveling 62 km/s (139,000 mph) and disintegrated about 84 km (52 mi) above Earth’s surface.
The full Moon of May 5-6, 2012, with interfere with the visibility of the eta Aquarid peak.
Massive Fireball Witnessed Over The UK By Countless Observers
by ADRIAN WEST on MARCH 4, 2012
A large meteor seen in the sky over the UK, near a rainbow light display. Credit: Mike Ridley. mikeridleyphotography.com
On the evening of March 3rd 2012 at approximately 21:40 GMT, an incredibly bright fireball/bollide was seen over the United kingdom.
Many people were outside enjoying a clear evening under the stars, or going about their ordinary business when they spotted the amazingly bright object shooting across the sky. Nearly all of the observations from the public from across much of the country described the object as a very bright fireball traveling from north to south and disappearing low in the sky.
The image above is from Mike Ridley, who said, “I was out tonight photographing the global rainbow display at Whitly Bay and saw this bright light hurtling across the sky. I quickly turned the camera to capture it as it flew overhead. With the naked eye I could see it white hot with an orange tail & really low in the sky. I thought it was a massive firework rocket.”
See two videos of the fireball, below.
Most accounts give a duration of around 10 to 15 seconds and the fireball showed a bright orange nucleus with a bright green tail. There was some fragmentation as the fireball ploughed through the atmosphere.
At present, it is unknown whether any pieces of the object survived and hit Earth’s surface, but there is a high possibility that if it did, it landed in the ocean.
Feb. 22, 2012: In the middle of the night on February 13th, something disturbed the animal population of rural Portal, Georgia. Cows started mooing anxiously and local dogs howled at the sky. The cause of the commotion was a rock from space.
“At 1:43 AM Eastern, I witnessed an amazing fireball,” reports Portal resident Henry Strickland. “It was very large and lit up half the sky as it fragmented. The event set dogs barking and upset cattle, which began to make excited sounds. I regret I didn’t have a camera; it lasted nearly 6 seconds.”
Strickland witnessed one of the unusual “Fireballs of February.”
A fireball over north Georgia recorded on Feb. 13th by a NASA all-sky camera in Walker Co., GA. [video]
“This month, some big space rocks have been hitting Earth’s atmosphere,” says Bill Cooke of NASA’s Meteoroid Environment Office. “There have been five or six notable fireballs that might have dropped meteorites around the United States.”
It’s not the number of fireballs that has researchers puzzled. So far, fireball counts in February 2012 are about normal. Instead, it’s the appearance and trajectory of the fireballs that sets them apart.
“These fireballs are particularly slow and penetrating,” explains meteor expert Peter Brown, a physics professor at the University of Western Ontario. “They hit the top of the atmosphere moving slower than 15 km/s, decelerate rapidly, and make it to within 50 km of Earth’s surface.”
The action began on the evening of February 1st when a fireball over central Texas wowed thousands of onlookers in the Dallas-Fort Worth area.
“It was brighter and long-lasting than anything I’ve seen before,” reports eye-witness Daryn Morran. “The fireball took about 8 seconds to cross the sky. I could see the fireball start to slow down; then it exploded like a firecracker artillery shell into several pieces, flickered a few more times and then slowly burned out.” Another observer in Coppell, Texas, reported a loud double boom as “the object broke into two major chunks with many smaller pieces.”
The fireball was bright enough to be seen on NASA cameras located in New Mexico more than 500 miles away. “It was about as bright as the full Moon,” says Cooke. Based on the NASA imagery and other observations, Cooke estimates that the object was 1 to 2 meters in diameter.
So far in February, NASA’s All-Sky Fireball Network has photographed about a half a dozen bright meteors that belong to this oddball category. They range in size from basketballs to buses, and all share the same slow entry speed and deep atmospheric penetration. Cooke has analyzed their orbits and come to a surprising conclusion:
This camera is part of NASA’s All-Sky Fireball Network. [more]
“They all hail from the asteroid belt—but not from a single location in the asteroid belt,” he says. “There is no common source for these fireballs, which is puzzling.”
This isn’t the first time sky watchers have noticed odd fireballs in February. In fact, the “Fireballs of February” are a bit of a legend in meteor circles.
Brown explains: “Back in the 1960s and 70s, amateur astronomers noticed an increase in the number of bright, sound-producing deep-penetrating fireballs during the month of February. The numbers seemed significant, especially when you consider that there are few people outside at night in winter. Follow-up studies in the late 1980s suggested no big increase in the rate of February fireballs. Nevertheless, we’ve always wondered if something was going on.”
Indeed, a 1990 study by astronomer Ian Holliday suggests that the ‘February Fireballs’ are real. He analyzed photographic records of about a thousand fireballs from the 1970s and 80s and found evidence for a fireball stream intersecting Earth’s orbit in February. He also found signs of fireball streams in late summer and fall. The results are controversial, however. Even Halliday recognized some big statistical uncertainties in his results.
NASA’s growing All-Sky Fireball Network could end up solving the mystery. Cooke and colleagues are adding cameras all the time, spreading the network’s coverage across North America for a dense, uninterrupted sampling of the night sky.
“The beauty of our smart multi-camera system,” notes Cooke, “is that it measures orbits almost instantly. We know right away when a fireball flurry is underway—and we can tell where the meteoroids came from.” This kind of instant data is almost unprecedented in meteor science, and promises new insights into the origin of February’s fireballs.
Meanwhile, the month isn’t over yet. “If the cows and dogs start raising a ruckus tonight,” advises Cooke, “go out and take a look.”
During this period the moon reaches its full phase on Saturday December 10th. At this time the moon will lie above the horizon the entire night and will severely impact meteor observing by obscuring all but the brightest meteors. As this week progresses the moons phase will wane and it will rise approximately forty-five minutes later each night. Toward the end of the week there will be a window of opportunity to view evening activity under dark skies between the end of dusk and moon rise. The estimated total hourly rates for evening observers this week is near two as seen from the northern hemisphere and one as seen from the southern hemisphere. For morning observers the estimated total hourly rates should be near eight as seen from mid-northern latitudes and five from mid-southern latitudes. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. All rates are reduced due to intense moonlight.
The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning December 10/11 These positions do not change greatly day to day so the listed coordinates may be used during this entire period. Most star atlases (available at science stores and planetariums) will provide maps with grid lines of the celestial coordinates so that you may find out exactly where these positions are located in the sky. A planisphere or computer planetarium program is also useful in showing the sky at any time of night on any date of the year. Activity from each radiant is best seen when it is positioned highest in the sky, either due north or south along the meridian, depending on your latitude. It must be remembered that meteor activity is rarely seen at the radiant position. Rather they shoot outwards from the radiant so it is best to center your field of view so that the radiant lies at the edge and not the center. Viewing there will allow you to easily trace the path of each meteor back to the radiant (if it is a shower member) or in another direction if it is a sporadic. Meteor activity is not seen from radiants that are located below the horizon. The positions below are listed in a west to east manner in order of right ascension (celestial longitude). The positions listed first are located further west therefore are accessible earlier in the night while those listed further down the list rise later in the night.
The list below presents a condensed version of the expected activity this week. Rates and positions are exact for Saturday night/Sunday morning. Detailed descriptions of each shower will continue next week when the moonlight is less of a problem.
SHOWER
DATE OF MAXIMUM ACTIVITY
CELESTIAL POSITION
ENTRY VELOCITY
CULMINATION
HOURLY RATE
CLASS*
RA (RA in Deg.) DEC
Km/Sec
Local Standard Time
North-South
Antihelions (ANT)
–
06:04 (091) +23
30
0000
1 – 1
II
Monocerotids (MON
Dec 08
06:45 (101) +08
41
0100
<1 – <1
II
Geminids (GEM)
Dec 14
07:22 (110) +33
35
0200
3 – 2
I
Puppid-Velids (PUP)
Dec 07
08:22 (125) -45
40
0300
<1 – 1
II
Sigma Hydrids (HYD)
Dec 06
08:32 (128) +02
61
0300
<1 – <1
II
December Leonis Minorids (DLM)
Dec 20
10:15 (154) +34
64
0500
<1 – <1
II
Psi Ursa Majorids (PSU)
Dec 05
11:49 (177) +41
61
0700
<1 – <1
IV
December Alpha Draconids (DAD)
Dec 05
13:54 (208) +58
44
0900
<1 – <1
IV
Submitted by Robert Lunsford on Fri, 2011-12-09 21:47.
LEONID METEOR SHOWER: Earth is passing through the debris field of Comet Tempel-Tuttle, parent of the annual Leonid meteor shower. Barring a direct hit by a filament of dust, which forecasters consider unlikely, this year’s shower should be mild. Peak rates of 10 to 20 meteors per hour are expected on Nov. 17th and 18th.
A METEOR SHOWER IN BROAD DAYLIGHT: The annual Arietid meteor shower peaks this week on June 7th and 8th. The Arietids are unusual because they are daytime meteors; the shower is most intense after sunrise. People who wake up early might notice a small number of Arietids during the dark hours before dawn. The real action, however, occurs in broad daylight.
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