The NASA All Sky Fireball Network detected this beauty on May 16, 2013 at 03:11:50 UTC. Observed by 6 meteor cameras, this fireball penetrated deep into the atmosphere, making it down to an altitude of 36 km (22 miles).
A view of the fireball from Cartersville, Georgia. (NASA/MEO)
The 350 gram meteoroid responsible for this brilliant display entered the atmosphere at around 22 km/s (49,000 mph) — slow for a meteoroid! — and decelerated to about 10 km/s (22,000 mph) before disintegrating over northwest Georgia.
Map showing the location of 6 cameras in the NASA All Sky Fireball Network. Color-coded circles indicate the approximate field of view of each camera. The meteor’s path is shown in white. (NASA/MEO/D. Moser)
Calculations indicate a radiant in the constellation Libra.
Same meteor — same location — two different meteor cameras! The video shows the same meteor (an Eta Aquarid!) from one of our all-sky cameras and from our wide-field camera (~20×15 degree FOV) both located at Marshall Space Flight Center in Huntsville.
A composite image of 13 Eta Aquarid meteors from the NASA All Sky Fireball Network station in Mayhill, New Mexico the morning of May 6, 2013. Clouds seriously hampered our view of the ETAs this year. Observations reported to the International Meteor Organization indicate an outburst in the early hours of May 6th UTC.
A Lyrid meteor streaks though the dawn sky over North Georgia College and State University. Moving at 105,800 mph, this inch-diameter piece of Comet Thatcher lasted less than one and a half seconds, burning up 46 miles above Earth’s surface. The second image shows the same meteor seen from the Tellus Science Museum located in Cartersville, GA, some 50 miles distant. By measuring the change in the meteor’s position (triangulation), we can determine its trajectory and speed.
Lyrids are pieces of debris from the periodic Comet C/1861 G1 Thatcher and have been observed for more than 2,600 years. In mid-April of each year, Earth runs into the stream of debris from the comet, which causes the Lyrid meteor shower. You can tell if a meteor belongs to a particular shower by tracing back its path to see if it originates near a specific point in the sky, called the radiant. The constellation in which the radiant is located gives the shower its name, and in this case, Lyrids appear to come from a point in the constellation Lyra.
This is the question that keeps cropping up, and it deserves an answer. Images are being posted showing the fragments and they look like ordinary chondrites of asteroidal origin. This material is dark, and not very reflective, which makes it difficult to spot out in outer space, especially if the object is bus or house size.
Astronomers measure brightnesses in magnitudes — the larger, more positive the number, the fainter the object is. The Sun is magnitude -27, the planet Venus -4, the star Vega 0, and the faintest star you can see is about +6. The best asteroid survey telescopes have a magnitude limit of about +24, which is about 16 million times fainter than what you can see with the unaided eye.
We can now use the latest orbit determined by Dave Clark (and yes, the meteor came roughly from the East, not from the North as stated in the initial NASA reports) and combine it with the estimated size and reflectivity to figure out when we should have seen the meteoroid in the asteroid survey telescopes. The calculations can be displayed in a graph like this one. Note that, even with very large telescopes, the meteoroid would not have been visible until a mere 2 hours (135,000 km from Earth) before impact — very little time to sound a warning.
Even if we had been looking at the right spot and the right time, there is another problem — the meteoroid would be in the daylit sky, and telescopes cannot see faint objects in the daytime.
Simply put, the meteoroid was too small for the survey telescopes and came at us out of the Sun.
There are numerous reports of a bright fireball over northwest Alabama on Sunday, Nov. 18 at approximately 7:30 p.m. EST (6:30 p.m. CST). Southeastern cameras managed by NASA’s Meteoroid Environment Office recorded the fireball, which was brighter than the moon.
The image above is from the Marshall Space Flight Center camera. The moon is the bright object at the bottom right, and the fireball is the REALLY bright object. Even though this was a very bright fireball, the meteor fragmented too high in the atmosphere to produce meteorites on the ground — very spectacular, but nothing of substance survived.
Details for the fireball meteor:
Time: Sunday, Nov. 18, 7:29:25 p.m. EST (6:29:25 p.m. CST) Speed: 28,400 mph Direction: Roughly north to south
The fireball appeared 49 miles above the Alabama/Tennessee state line just north of Athens, Ala. It disintegrated 28 miles above Ole Carriage Dr., just east of Athens. A map of the meteor trajectory appears below.
This may very well be the brightest fireball we have seen with the Marshall Center camera!
This year’s Leonids meteor shower peaks on Nov. 17 at 4:30 AM Eastern Time. If forecasters are correct, the shower should produce a mild but pretty sprinkling during the night of the 16th/morning of the 17th. The moon will be a waxing crescent setting before midnight, clearing the way for some unobstructed Leonid viewing. “We’re predicting a normal year of 15 to 20 meteors per hour” says Bill Cooke of the Meteoroid Environment Office at NASA’s Marshall Space Flight Center.
Leonids are bits of debris from Comet Tempel-Tuttle. Every 33 years the comet visits the inner solar system and leaves a stream of dusty debris in its wake. Many of these streams have drifted across the November portion of Earth’s orbit. Whenever our planet hits one, meteors appear to be flying out of the constellation Leo.
For best meteor viewing Cooke suggests going to a location away from city lights, dressing warmly, and lie flat on your back and look straight up. No special viewing equipment needed — just your eyes.
The Leonids occur each year in mid-November.
Leonid meteor storm of 1999 (NASA)
Leonids meteor shower as seen from Joshua Tree National Park in 2001 (Wally Pacholka/AstroPics.com)
“Halloween fireballs” or Taurid meteors are frequently seen in the night sky from mid-October until mid-November. The Marshall all-sky camera network captured an image of an early Halloween fireball Tuesday morning. The fireball appeared low on the horizon from Huntsville at 6:10 a.m. Tuesday morning and was visible just above trees from the Tullahoma station.
“The bolide or fireball appeared some 44 miles above a point midway between the towns of Stanton and Mason, Tennessee and moved slightly north of east at a speed 3 times faster than that of the International Space Station.” said Dr. Bill Cooke, lead of Marshall Space Flight Center’s Meteoroid Environment Office in Huntsville, Ala. “The fireball finally terminated above the town of Pinson, which is southeast of Jackson, TN.,” Cooke continued, “with an altitude at last visibility of 18.1 miles, which is fairly low for a meteor.”
Widely referred to as shooting stars, meteors are generated when debris enters and burns up in Earth’s atmosphere. Taurids are thought to be debris left behind by Encke’s comet.