UK UFO Sightings
Mon, 01 Jun 2009 15:40 UTC
Posted: June 1, 2009
Date of Sighting: 31st. May '09
Time: 00:30 a.m. approx.
Witness Statement: Huge ball of bright orange light traveling at speed from North to West. There was no sound. Same height as plane would be, but faster than plane. I thought it must be an aircraft on fire, perhaps being hijacked and I was waiting to hear a crash as it landed, but heard nothing. I thought then it must be a meteor or something.
Can't see it being chinese lanterns. Too high up, too fast and powerful, too big.
Date of Sighting: 30th May 2009
Time: 10:50pm
Witness Statement: I saw the anomaly, much like a flaming orange ball traveling North to South initially, at an estimated 5-10,000 ft. It was traveling about 2 or 3 times faster than a plane with no noise, I thought it was an asteroid initially. However, it seemed to slow down and then travel in a West direction rapidly increasing in speed and altitude, traveling roughly 5 times the speed of a plane. The whole experience lasted about 1m 30 secs. Both my partner and I witnessed it and have never seen anything like it before.
Date of Sighting: 31st. May '09
Time: 00:30 a.m. approx.
Witness Statement: Huge ball of bright orange light traveling at speed from North to West. There was no sound. Same height as plane would be, but faster than plane. I thought it must be an aircraft on fire, perhaps being hijacked and I was waiting to hear a crash as it landed, but heard nothing. I thought then it must be a meteor or something.
Can't see it being chinese lanterns. Too high up, too fast and powerful, too big.
UK UFO Sightings
Mon, 01 Jun 2009 15:48 UTC
Date of Sighting: 30th May 2009
Time: 10:50pm
Witness Statement: I saw the anomaly, much like a flaming orange ball traveling North to South initially, at an estimated 5-10,000 ft. It was traveling about 2 or 3 times faster than a plane with no noise, I thought it was an asteroid initially. However, it seemed to slow down and then travel in a West direction rapidly increasing in speed and altitude, traveling roughly 5 times the speed of a plane. The whole experience lasted about 1m 30 secs. Both my partner and I witnessed it and have never seen anything like it before.
Brian Vike
HBCC UFO Research
Tue, 02 Jun 2009 13:21 UTC
Posted: June 2, 2009
Date: May 28, 2009
Time Approx: 11:30 p.m.
Number of witnesses: 2
Number of Objects: 1
Shape of Objects: Orb-like.
Full Description of Event/Sighting: Driving down highway 12 slowing down for construction, I had seen a medium-sized green fireball-like orb falling towards the ground at a close 45 degree angle approximately 1 mile away. I wasn't sure if it were fireworks or a flare gun initially considering the construction nearby. I also had considered a falling star. A couple of seconds later I realized it couldn't have been either of those and quickly asked my girlfriend sitting next to me what it could be. We both looked at it for 3-4 seconds as it rapidly fell towards the ground. We weren't able to see where it fell due to a blocking view caused by a big-rig truck.
We're not exactly sure if anyone else had seen the green fireball as well since there were so many distractions and nobody stopped in their tracks to look in awe.
Date of Sighting: 31st May 2009
Time: 10-11 PM
Witness Statement: I was having a ciggie out of the bathroom window and saw a large 'fireball' (glowing orange) moving horizontally and quite low in the sky. This thing appeared to be both bigger than a 747, and faster than any plane or helicopter. I watched it, shouted and ran to get my partner, was literally gone 3-4 seconds, and when I returned it had just vanished ! Impossible! I know what I saw, and it wasn't anything man made (that I know of !). Just a big ball of 'fire' flying at a constant speed and height.
It's stayed in my mind all day as it was so bizarre. This definitely wasn't a meteor so what was it ?
Date: May 28, 2009
Time Approx: 11:30 p.m.
Number of witnesses: 2
Number of Objects: 1
Shape of Objects: Orb-like.
Full Description of Event/Sighting: Driving down highway 12 slowing down for construction, I had seen a medium-sized green fireball-like orb falling towards the ground at a close 45 degree angle approximately 1 mile away. I wasn't sure if it were fireworks or a flare gun initially considering the construction nearby. I also had considered a falling star. A couple of seconds later I realized it couldn't have been either of those and quickly asked my girlfriend sitting next to me what it could be. We both looked at it for 3-4 seconds as it rapidly fell towards the ground. We weren't able to see where it fell due to a blocking view caused by a big-rig truck.
We're not exactly sure if anyone else had seen the green fireball as well since there were so many distractions and nobody stopped in their tracks to look in awe.
UK UFO Sightings
Thu, 04 Jun 2009 14:41 UTC
Date of Sighting: 31st May 2009
Time: 10-11 PM
Witness Statement: I was having a ciggie out of the bathroom window and saw a large 'fireball' (glowing orange) moving horizontally and quite low in the sky. This thing appeared to be both bigger than a 747, and faster than any plane or helicopter. I watched it, shouted and ran to get my partner, was literally gone 3-4 seconds, and when I returned it had just vanished ! Impossible! I know what I saw, and it wasn't anything man made (that I know of !). Just a big ball of 'fire' flying at a constant speed and height.
It's stayed in my mind all day as it was so bizarre. This definitely wasn't a meteor so what was it ?
Abhinav Malhotra
The Times of India
Wed, 03 Jun 2009 18:15 UTC
"Meteorite is a rocky material which enters into earth's atmosphere
from outside the earth (for eg, Mars) whereas numerous small and big
rocks circulating in between the planets Mars and Jupiter are known as
asteroids," said Prof Harish Chandra Verma of department of Physics of
IIT-K while talking to TOI, specifying the difference between a
meteorite and an asteroid.
Prof Verma ruled out the possibility of the stone being an asteroid as reported in some newspapers and emphatically remarked that the initial study of the piece of the rock done on Wednesday confirms that it's a meteorite. Usually such pieces of rock (debris) come from asteroid belt only but sometimes they may very well be a part of other celestial bodies also.
Prof Verma was referring to the incident of May 28, when a 1 kg stone resembling a meteorite fell down from the sky about 12 noon and left the people of the Karimatti hamlet in Hamirpur district amazed and puzzled. The stone which is ten inches in length and five inches in width was put in water to bring down its high temperature. Eyewitness to the entire incident, Mannu Lal, a villager was the first to observe this heavenly body. In no time, the news of the incident had spread like a wild fire in the entire village. The matter was then referred to the administration, which took the stone in its possession.
Prof Verma, travelled 200 km and brought the stone to IIT-K on Tuesday last for detailed study. Visibly excited with the discovery of the magnetic stone, Prof Verma shared his experience and said, "It's confirmed now that it is a meteorite due to its properties. As it was getting attracted towards a magnet and also the whole of the stone was covered with a black layer it gave us an idea of it being a meteorite.''
"Genuine scientific tests done on this meteorite will help us to know more about the secrets of the solar system like what was the composition of the solar system when it was formed, what was the early solar system like etc," he further said.
Prof Verma went on to say that the researchers from Physical Research Lab, Ahmedabad, University of Jodhpur, Bhaba Atomic Research Centre (BARC) and IIT-K will carry out tests in collaboration.
Swiss
astronomer Jose De Queiroz on Wednesday announced the discovery of two
new asteroids between the orbits of Mars and Jupiter.
According to the Mirasteilas Observatory, De Queiroz has located two new asteroids with a diameter of between 1 kilometer and 2 kilometers.
According to the Associated Press, the discovery of 2009FM1 and 2009FA1 was confirmed by the Minor Planet Center of the International Astronomical Union in Cambridge, Massachusetts in March.
"They're perfectly ordinary objects and intrinsically very faint," said Bryan Marsden, of the Minor Planet Center.
Marsden added that De Queiroz would have to continue to observe the two new asteroids for the next four years in order to confirm their existence.
"They've only been observed this year," he said.
The newly discovered asteroids are just two out of hundreds of thousands currently falling between the two planets. Marsden said many of the asteroids around the main belt have been documented, but amateur astronomers like De Queiroz continue to find new ones.
De Queiroz hopes to name the asteroids 'Falera,' after the site of his observatory, and 'Marcia,' after his daughter.
"If the observations are just over the course of a month or two, that's not enough for us to accept the names that he's proposing," said Marsden.
The annual Arietid meteor shower peaks this
weekend on Sunday, June 7th. The Arietids are unusual because they are
daytime meteors; the shower is most intense after sunrise. Early risers
could spot a small number of earthgrazing Arietids during the dark
hours before dawn on Sunday morning.
Every year in early June, hundreds of meteors streak across the sky. Most are invisible, though, because the sun is above the horizon while the shower is most intense. These daylight meteors are called the Arietids. They stream from a radiant point in the constellation Aries, which lies just 30 degrees from the Sun in June.
Arietid meteoroids hit Earth's atmosphere with a velocity of 39 km/s (87,000 mph). No one is sure where these meteoroids come from. Possibilities include sungrazing asteroid 1566 Icarus, Comet 96P/Machholz, and the Kreutz family of sungrazing comets. The debris stream is quite broad: Earth is inside it from late May until early July. In most years, the shower peaks on June 7th or 8th.
If you want to see a few Arietids, try looking just before sunrise. The Arietid radiant rises in the east about 45 minutes before the sun. (This is true for observers in both of Earth's hemispheres, north and south.) Pre-dawn Arietids tend to be "Earthgrazers"--meteors that skim horizontally through the upper atmosphere from radiants near the horizon. Spectacular Earthgrazers are usually slow and bright, streaking far across the sky--worth waking up for!
Southern Hemisphere
After daybreak, you can listen to the shower by tuning into our online meteor radar.
Prof Verma ruled out the possibility of the stone being an asteroid as reported in some newspapers and emphatically remarked that the initial study of the piece of the rock done on Wednesday confirms that it's a meteorite. Usually such pieces of rock (debris) come from asteroid belt only but sometimes they may very well be a part of other celestial bodies also.
Prof Verma was referring to the incident of May 28, when a 1 kg stone resembling a meteorite fell down from the sky about 12 noon and left the people of the Karimatti hamlet in Hamirpur district amazed and puzzled. The stone which is ten inches in length and five inches in width was put in water to bring down its high temperature. Eyewitness to the entire incident, Mannu Lal, a villager was the first to observe this heavenly body. In no time, the news of the incident had spread like a wild fire in the entire village. The matter was then referred to the administration, which took the stone in its possession.
Prof Verma, travelled 200 km and brought the stone to IIT-K on Tuesday last for detailed study. Visibly excited with the discovery of the magnetic stone, Prof Verma shared his experience and said, "It's confirmed now that it is a meteorite due to its properties. As it was getting attracted towards a magnet and also the whole of the stone was covered with a black layer it gave us an idea of it being a meteorite.''
"Genuine scientific tests done on this meteorite will help us to know more about the secrets of the solar system like what was the composition of the solar system when it was formed, what was the early solar system like etc," he further said.
Prof Verma went on to say that the researchers from Physical Research Lab, Ahmedabad, University of Jodhpur, Bhaba Atomic Research Centre (BARC) and IIT-K will carry out tests in collaboration.
redOrbit Staff & Wire Reports
Wed, 03 Jun 2009 06:50 UTC
© NASA
The asteroid 951 Gaspra, the first ever imaged by a spacecraft, taken by Galileo as it passed by it in 1991; the colors are exaggerated.
The asteroid 951 Gaspra, the first ever imaged by a spacecraft, taken by Galileo as it passed by it in 1991; the colors are exaggerated.
According to the Mirasteilas Observatory, De Queiroz has located two new asteroids with a diameter of between 1 kilometer and 2 kilometers.
According to the Associated Press, the discovery of 2009FM1 and 2009FA1 was confirmed by the Minor Planet Center of the International Astronomical Union in Cambridge, Massachusetts in March.
"They're perfectly ordinary objects and intrinsically very faint," said Bryan Marsden, of the Minor Planet Center.
Marsden added that De Queiroz would have to continue to observe the two new asteroids for the next four years in order to confirm their existence.
"They've only been observed this year," he said.
The newly discovered asteroids are just two out of hundreds of thousands currently falling between the two planets. Marsden said many of the asteroids around the main belt have been documented, but amateur astronomers like De Queiroz continue to find new ones.
De Queiroz hopes to name the asteroids 'Falera,' after the site of his observatory, and 'Marcia,' after his daughter.
"If the observations are just over the course of a month or two, that's not enough for us to accept the names that he's proposing," said Marsden.
Space Weather
Sat, 06 Jun 2009 14:09 UTC
© Unknown
This image shows the area of sky around the Arietid radiant (indicated by a red dot) as seen from mid-northern latitudes at 4 a.m. on June 7th or 8th.
This image shows the area of sky around the Arietid radiant (indicated by a red dot) as seen from mid-northern latitudes at 4 a.m. on June 7th or 8th.
Every year in early June, hundreds of meteors streak across the sky. Most are invisible, though, because the sun is above the horizon while the shower is most intense. These daylight meteors are called the Arietids. They stream from a radiant point in the constellation Aries, which lies just 30 degrees from the Sun in June.
Arietid meteoroids hit Earth's atmosphere with a velocity of 39 km/s (87,000 mph). No one is sure where these meteoroids come from. Possibilities include sungrazing asteroid 1566 Icarus, Comet 96P/Machholz, and the Kreutz family of sungrazing comets. The debris stream is quite broad: Earth is inside it from late May until early July. In most years, the shower peaks on June 7th or 8th.
If you want to see a few Arietids, try looking just before sunrise. The Arietid radiant rises in the east about 45 minutes before the sun. (This is true for observers in both of Earth's hemispheres, north and south.) Pre-dawn Arietids tend to be "Earthgrazers"--meteors that skim horizontally through the upper atmosphere from radiants near the horizon. Spectacular Earthgrazers are usually slow and bright, streaking far across the sky--worth waking up for!
Southern Hemisphere
Statesman News Service
Wed, 10 Jun 2009 02:15 UTC
Dhenkanal, India: Mr Anil Hota of Ichchbatipur, under Baruna gram
panchayat, in Kamakshanagar subdivision, was carrying a palm leaf sheet
over his head, while moving around in the village today.
Scorching heat, is not the only reason for such protective measures adopted by Mr Anil and other villagers, as all of them resort to leaf sheets or umbrellas, at the dead of the night, these days too. Much to the disbelief of the outsiders, the villagers of Ichchbatipur claim that, for last few days they have been witnessing bizarre and mysterious incidents like dropping of stone pieces and splinters from above and other directions.
Hence, it was no surprise that at the Pandua outpost and Kamakshanagar police station police officers, were taken aback yesterday when the villagers came in large numbers and narrated the "disturbance" in the village, which is taking place from Saturday night, while requesting them to take "necessary action". The police, however, were helpless too and could do nothing except visiting the village and starting an inquiry.
Saturday night was as like any other night for Mr Hemant Mohapatra. But at about 12, his slumber was disturbed by a strange sound. He woke up and realized that stone pieces were falling on his roof. Though, he immediately could not figure out what exactly had happened or who was doing it, he saw similar "attack" on the verandah and roof of many neighbours. They too could not understand what was happening and with utter disbelief, fear and confusion, all started searching for any clue, but in vain.
Mr Srikant Hota, a fellow villager informed the curious and confused neighbours that one big stone had fallen from above injuring him. He showed the injuries marks on his body.
As the news spread in the morning, thousands of people from nearby areas rushed to the village. Though the whole incident is still wrapped in mystery, the villagers preferred to remain indoors.
"We searched extensively for the origin of the stones, but found no answer for the mystery," said Mr Hemant Mohapatra, who has sustained injuries.
Many villagers feel that it is a supernatural phenomenon, while some maintain that this was the handwork of a sorcerer. Kamakshanagar MLA, Mr Prafulla Mallick, visited the village and discussed with the residents yesterday.
Meanwhile, the villagers are getting ready to offer mass prayer before Lord Hanuman, seeking divine intervention to ward off the evil power.
When
asteroids fall through Earth's atmosphere, a variety of things can
happen. Large iron-heavy space rocks are almost sure to slam into the
planet. Their stony cousins, however, can't take the pressure and are
more likely to explode above the surface.
Either outcome can be dismal. But the consequences vary.
So scientists who study the potential threat of asteroids would like to know more about which types and sizes of asteroids break apart and which hold together. A new computer model helps to quantify whether an asteroid composed mostly of stone will survive to create a crater or not.
A stony space rock must be about the size of two football fields, or 720 feet (220 meters) in diameter, to endure the thickening atmosphere and slam into the planet, according to the study, led by Philip Bland of the Department of Earth Science and Engineering at Imperial College London.
"Stones of that size are just at the border where they're going to reach the surface -- a bit lower density and strength and it'll be a low-level air burst, a bit higher and it'll hit as a load of fragments and you'll get a crater," said Bland, who is also a Royal Society Research Fellow.
The distinction would mean little to a person on the ground.
Two ways to destroy a city
"An airburst would be a blast somewhere in the region of 500-600 megatons," Bland said in an e-mail interview. "As a comparison, the biggest-ever nuclear test was about 50 megatons."
A presumed airburst in 1908, over a remote region of Siberia called Tunguska, flattened some 800 square miles (2,000 square kilometers) of forest. The object is estimated to have been just 260 feet wide (80 meters). Bland said the event was probably equal to about 10 megatons.
"If most of it made it to the ground you might actually be a bit better off, because the damage would be a little more localized," he said. "A lot of energy would still get dumped in the atmosphere, but you'd probably also have a ragged crater, or crater field, extending over several kilometers, with the surrounding region flattened by the blast."
Smaller stony asteroids, say those the size of the car, enter the atmosphere more frequently but typically disintegrate higher up and cause no damage. In fact, as many as two or three dozen objects ranging from the size of a television to a studio apartment explode in the atmosphere every year, according to data from U.S. military satellites.
Separate research in recent years has shown that stony asteroids are often mere rubble piles, somewhat loose agglomerations of material that may have been shattered in previous collisions but remain gravitationally bound.
Pieces and parts
The new computer model is detailed in the July 17 issue of the journal Nature. It was created with the help of Natalia Artemieva at the Russian Academy of Sciences.
Previous models treated the cascade of fragments from a disintegrating asteroid as a continuous liquid "pancake." The new model tracks individual forces acting on each fragment as the bunch descends.
The researchers can plug in asteroid size, density, strength, speed and entry angle at the top of the atmosphere. With "reasonable confidence" a computer program then details how that rock should behave in the air and what will happen at the surface.
The model has implication not just for land-based impacts, but also splashdowns in the ocean that can trigger devastating tsunamis. An airburst is not likely to generate much of a tsunami, possibly lowering that risk compared to what scientists had figured.
The results suggest rocks about 720 feet across (220 meters) are likely to actually hit the surface every 170,000 years or so. Some previous research has suggested a frequency of every 4,000 years or less.
Looking back
The model can also "hindcast" what sort of rock might have generated a certain known crater.
"You see a crater field on Mars, we can tell you what sort of object caused it," Bland said.
In fact, he and Artemieva have done just that. In their most recent tests, which are not discussed in the Nature paper, they plugged in the atmospheric details of Mars, as well as Venus, and hurled some hypothetical space rocks at those planets.
"The simulated crater fields that the model produces look almost exactly like the real thing," Bland said.
For now, the model does not handle very large asteroids, those that could cause widespread regional or even global damage, though Bland said the flaw may be fixable. He is careful to point out that computer models do not provide solid proof for what might happen.
"There are still a lot of unknowns in this," he said.
Flashback: When Meteors Explode: Full Account of a Wild Chicago Night
Scorching heat, is not the only reason for such protective measures adopted by Mr Anil and other villagers, as all of them resort to leaf sheets or umbrellas, at the dead of the night, these days too. Much to the disbelief of the outsiders, the villagers of Ichchbatipur claim that, for last few days they have been witnessing bizarre and mysterious incidents like dropping of stone pieces and splinters from above and other directions.
Hence, it was no surprise that at the Pandua outpost and Kamakshanagar police station police officers, were taken aback yesterday when the villagers came in large numbers and narrated the "disturbance" in the village, which is taking place from Saturday night, while requesting them to take "necessary action". The police, however, were helpless too and could do nothing except visiting the village and starting an inquiry.
Saturday night was as like any other night for Mr Hemant Mohapatra. But at about 12, his slumber was disturbed by a strange sound. He woke up and realized that stone pieces were falling on his roof. Though, he immediately could not figure out what exactly had happened or who was doing it, he saw similar "attack" on the verandah and roof of many neighbours. They too could not understand what was happening and with utter disbelief, fear and confusion, all started searching for any clue, but in vain.
Mr Srikant Hota, a fellow villager informed the curious and confused neighbours that one big stone had fallen from above injuring him. He showed the injuries marks on his body.
As the news spread in the morning, thousands of people from nearby areas rushed to the village. Though the whole incident is still wrapped in mystery, the villagers preferred to remain indoors.
"We searched extensively for the origin of the stones, but found no answer for the mystery," said Mr Hemant Mohapatra, who has sustained injuries.
Many villagers feel that it is a supernatural phenomenon, while some maintain that this was the handwork of a sorcerer. Kamakshanagar MLA, Mr Prafulla Mallick, visited the village and discussed with the residents yesterday.
Meanwhile, the villagers are getting ready to offer mass prayer before Lord Hanuman, seeking divine intervention to ward off the evil power.
Robert Roy Britt
Space
Wed, 16 Jul 2003 18:39 UTC
© ISAS
Either outcome can be dismal. But the consequences vary.
So scientists who study the potential threat of asteroids would like to know more about which types and sizes of asteroids break apart and which hold together. A new computer model helps to quantify whether an asteroid composed mostly of stone will survive to create a crater or not.
A stony space rock must be about the size of two football fields, or 720 feet (220 meters) in diameter, to endure the thickening atmosphere and slam into the planet, according to the study, led by Philip Bland of the Department of Earth Science and Engineering at Imperial College London.
"Stones of that size are just at the border where they're going to reach the surface -- a bit lower density and strength and it'll be a low-level air burst, a bit higher and it'll hit as a load of fragments and you'll get a crater," said Bland, who is also a Royal Society Research Fellow.
The distinction would mean little to a person on the ground.
Two ways to destroy a city
"An airburst would be a blast somewhere in the region of 500-600 megatons," Bland said in an e-mail interview. "As a comparison, the biggest-ever nuclear test was about 50 megatons."
A presumed airburst in 1908, over a remote region of Siberia called Tunguska, flattened some 800 square miles (2,000 square kilometers) of forest. The object is estimated to have been just 260 feet wide (80 meters). Bland said the event was probably equal to about 10 megatons.
"If most of it made it to the ground you might actually be a bit better off, because the damage would be a little more localized," he said. "A lot of energy would still get dumped in the atmosphere, but you'd probably also have a ragged crater, or crater field, extending over several kilometers, with the surrounding region flattened by the blast."
Smaller stony asteroids, say those the size of the car, enter the atmosphere more frequently but typically disintegrate higher up and cause no damage. In fact, as many as two or three dozen objects ranging from the size of a television to a studio apartment explode in the atmosphere every year, according to data from U.S. military satellites.
Separate research in recent years has shown that stony asteroids are often mere rubble piles, somewhat loose agglomerations of material that may have been shattered in previous collisions but remain gravitationally bound.
Pieces and parts
The new computer model is detailed in the July 17 issue of the journal Nature. It was created with the help of Natalia Artemieva at the Russian Academy of Sciences.
Previous models treated the cascade of fragments from a disintegrating asteroid as a continuous liquid "pancake." The new model tracks individual forces acting on each fragment as the bunch descends.
The researchers can plug in asteroid size, density, strength, speed and entry angle at the top of the atmosphere. With "reasonable confidence" a computer program then details how that rock should behave in the air and what will happen at the surface.
The model has implication not just for land-based impacts, but also splashdowns in the ocean that can trigger devastating tsunamis. An airburst is not likely to generate much of a tsunami, possibly lowering that risk compared to what scientists had figured.
The results suggest rocks about 720 feet across (220 meters) are likely to actually hit the surface every 170,000 years or so. Some previous research has suggested a frequency of every 4,000 years or less.
Looking back
The model can also "hindcast" what sort of rock might have generated a certain known crater.
"You see a crater field on Mars, we can tell you what sort of object caused it," Bland said.
In fact, he and Artemieva have done just that. In their most recent tests, which are not discussed in the Nature paper, they plugged in the atmospheric details of Mars, as well as Venus, and hurled some hypothetical space rocks at those planets.
"The simulated crater fields that the model produces look almost exactly like the real thing," Bland said.
For now, the model does not handle very large asteroids, those that could cause widespread regional or even global damage, though Bland said the flaw may be fixable. He is careful to point out that computer models do not provide solid proof for what might happen.
"There are still a lot of unknowns in this," he said.
Flashback: When Meteors Explode: Full Account of a Wild Chicago Night
Space
Mon, 19 Apr 2004 18:07 UTC
You might think meteor expert Steven Simon knew exactly what was
happening one evening when the skies over his home were lit up by an
exploding, 2,000-pound space rock bigger than a refrigerator. But it
was only the next day, when nearby residents brought him chunks of the
extraterrestrial visitor that had landed in the street and punched
through their roofs, that Simon began to understand the true nature of the frightening event.
Now after a year of study, the University of Chicago researcher has helped produce a full account of the giant rock that tore through the atmosphere at 54 times the speed of sound.
Simon was in his Park Forest home about 30 miles south of Chicago with the drapes drawn near midnight on March 26, 2003.
"I saw the flash, and although it lasted longer than a lightning flash, that's what I thought it was," he told SPACE.com last week. "I knew it had rained that night, and thought maybe it was multiple flashes, perhaps diffused by the clouds."
Lawrence Grossman, a geophysicist who oversees Simon's research, got a different impression of the incoming object from his home in nearby Flossmoor.
"I heard a detonation," Grossman said the morning after the event. "It was sharp enough to wake me up."
The fireball in the sky was witnessed across a wide area, from Illinois, Indiana, Michigan and Missouri. Simon and Grossman teamed up with other researchers to gather rocks and eyewitness accounts and then calculate the space rock's original size, composition and origin, and to trace its fragmented path from space to Earth. Their findings are detailed in the April issue of the journal Meteoritics and Planetary Science.
Daily barrage
Several tons of space stuff rain down on the planet every day. Much of it is dust. Objects no larger than sand grains generate typical "shooting stars" when they vaporize.
Playing marble-sized objects can create dramatic fireballs that prompt phone calls to local law enforcement. Asteroids bigger than about 100 feet (30 meters) can mostly survive the plunge, possibly hitting the surface or exploding devastatingly close to the ground. The latter events are very rare.
Scientists call all these things meteors once they enter the atmosphere. When in space, the same objects might be referred to as asteroids if they are large, or meteoroids if they are small. If they hit the ground, they're called meteorites.
Whether the things vaporize, break apart or reach the surface intact depends in part on whether they are made mostly of fragile stone or of more durable iron.
The Chicago rock was stony and about 6 feet in diameter, the researchers conclude.
About 10 objects of this size enter the atmosphere every year, according Doug ReVelle of the Los Alamos National Laboratory, which uses satellites and other means to monitor the resulting explosions and separate them from possible rogue-nation nuclear detonations. Most of these in-air explosions are not noticed by eyewitnesses because so much of the world, including the two-thirds that is water, is unpopulated.
Chicago fireball
Here's what happened over Chicago:
"It hit the atmosphere at about 40,000 mph," Simon said. "At this great speed, air pressure builds up in front of the object and is much greater than the pressure behind it. This will pull apart many meteors, especially if they already had some cracks. This object probably went though four fragmentation events as it passed through the atmosphere."
Tremendous heat created by the pressure lit much of the object in a fiery display.
Park Forest resident Noe Garza was asleep when a fragment burst through his ceiling, sliced some window blinds, then bounced across the room and broke a mirror. "I thought somebody was breaking in," Garza told a new agency the next day. "It was a big bang. I can't really describe it."
Another resident whose home was hit said the room lit up and it sounded like a plane had crashed.
Simon's team examined hundreds of fragments -- 65 pounds worth that were picked up and delivered to the scientists -- to estimate the original rock's size and weight.
The measurements are difficult to pin down, he explained, because a lot of fragments probably hit wooded areas and were not found. And some of the original meteor was probably broken into particles too small to notice. The scientists also analyzed the fragments for a certain radioactive form of cobalt, which can reveal the rock's minimum size. "If the object is too small [while in space for eons] the cosmic rays will just pass through and not make 60 cobalt," Simon said.
He said the original rock weighed at least 1,980 pounds as it entered the atmosphere. Long ago, the analysis shows, it was probably heated for a long period of time inside a larger parent asteroid. That asteroid then broke apart, again a long time ago, perhaps in a collision with another asteroid.
The researchers found in the fragments a mineral called shocked feldspar, which suggests the ancient collision between two asteroids.
There are no records of a meteorite ever killing anyone. But there have been injuries. A dog was killed by a space rock in Egypt in 1911.
The Park Forest meteorite event is not totally unlike others that have been reported in recent years. A similar meteorite shower rattled a village in India last September, apparently injuring three people. Other reports of fireballs in the sky are fairly common, and the occasional small rock slices through a home.
But Simon and his colleagues write in their report of an important distinction with the Chicago event: "This is the most densely populated region to be hit by a meteorite shower in modern times."
Flashback: Exploding Asteroids; Satellites Monitor Threat to Earth
Comment: This article was written in 2002, obviously things have changed celestially since those days.....and changed legally too: Military Hush-Up: Incoming Space Rocks Now Classified
Now after a year of study, the University of Chicago researcher has helped produce a full account of the giant rock that tore through the atmosphere at 54 times the speed of sound.
Simon was in his Park Forest home about 30 miles south of Chicago with the drapes drawn near midnight on March 26, 2003.
"I saw the flash, and although it lasted longer than a lightning flash, that's what I thought it was," he told SPACE.com last week. "I knew it had rained that night, and thought maybe it was multiple flashes, perhaps diffused by the clouds."
Lawrence Grossman, a geophysicist who oversees Simon's research, got a different impression of the incoming object from his home in nearby Flossmoor.
"I heard a detonation," Grossman said the morning after the event. "It was sharp enough to wake me up."
The fireball in the sky was witnessed across a wide area, from Illinois, Indiana, Michigan and Missouri. Simon and Grossman teamed up with other researchers to gather rocks and eyewitness accounts and then calculate the space rock's original size, composition and origin, and to trace its fragmented path from space to Earth. Their findings are detailed in the April issue of the journal Meteoritics and Planetary Science.
Daily barrage
Several tons of space stuff rain down on the planet every day. Much of it is dust. Objects no larger than sand grains generate typical "shooting stars" when they vaporize.
Playing marble-sized objects can create dramatic fireballs that prompt phone calls to local law enforcement. Asteroids bigger than about 100 feet (30 meters) can mostly survive the plunge, possibly hitting the surface or exploding devastatingly close to the ground. The latter events are very rare.
Scientists call all these things meteors once they enter the atmosphere. When in space, the same objects might be referred to as asteroids if they are large, or meteoroids if they are small. If they hit the ground, they're called meteorites.
Whether the things vaporize, break apart or reach the surface intact depends in part on whether they are made mostly of fragile stone or of more durable iron.
The Chicago rock was stony and about 6 feet in diameter, the researchers conclude.
About 10 objects of this size enter the atmosphere every year, according Doug ReVelle of the Los Alamos National Laboratory, which uses satellites and other means to monitor the resulting explosions and separate them from possible rogue-nation nuclear detonations. Most of these in-air explosions are not noticed by eyewitnesses because so much of the world, including the two-thirds that is water, is unpopulated.
Chicago fireball
Here's what happened over Chicago:
"It hit the atmosphere at about 40,000 mph," Simon said. "At this great speed, air pressure builds up in front of the object and is much greater than the pressure behind it. This will pull apart many meteors, especially if they already had some cracks. This object probably went though four fragmentation events as it passed through the atmosphere."
Tremendous heat created by the pressure lit much of the object in a fiery display.
Park Forest resident Noe Garza was asleep when a fragment burst through his ceiling, sliced some window blinds, then bounced across the room and broke a mirror. "I thought somebody was breaking in," Garza told a new agency the next day. "It was a big bang. I can't really describe it."
Another resident whose home was hit said the room lit up and it sounded like a plane had crashed.
Simon's team examined hundreds of fragments -- 65 pounds worth that were picked up and delivered to the scientists -- to estimate the original rock's size and weight.
The measurements are difficult to pin down, he explained, because a lot of fragments probably hit wooded areas and were not found. And some of the original meteor was probably broken into particles too small to notice. The scientists also analyzed the fragments for a certain radioactive form of cobalt, which can reveal the rock's minimum size. "If the object is too small [while in space for eons] the cosmic rays will just pass through and not make 60 cobalt," Simon said.
He said the original rock weighed at least 1,980 pounds as it entered the atmosphere. Long ago, the analysis shows, it was probably heated for a long period of time inside a larger parent asteroid. That asteroid then broke apart, again a long time ago, perhaps in a collision with another asteroid.
The researchers found in the fragments a mineral called shocked feldspar, which suggests the ancient collision between two asteroids.
There are no records of a meteorite ever killing anyone. But there have been injuries. A dog was killed by a space rock in Egypt in 1911.
The Park Forest meteorite event is not totally unlike others that have been reported in recent years. A similar meteorite shower rattled a village in India last September, apparently injuring three people. Other reports of fireballs in the sky are fairly common, and the occasional small rock slices through a home.
But Simon and his colleagues write in their report of an important distinction with the Chicago event: "This is the most densely populated region to be hit by a meteorite shower in modern times."
Flashback: Exploding Asteroids; Satellites Monitor Threat to Earth
Robert Roy Britt
SPACE.com
Wed, 20 Nov 2002 18:19 UTC
Researchers have determined, with the assistance of US military
satellites, that the risk of Earth being struck by a killer asteroid is
less likely than previously believed.
If you've ever gazed up and spotted a shooting star, you engaged in a form of astronomy in which Earths atmosphere serves as a giant detector: Space debris screams through the air, which heats the stuff up and makes it visible.
By noting observations night after night, you could develop a record of how frequently certain sized objects most no larger than a pea meet their demise by running into our planet.
But if you want to know how often larger hunks of cosmic rubble arrive, your job is far more difficult. It could take hundreds or even thousands of years of continuous observations to arrive at a reliable estimate.
The prospect was not an option for Peter Brown of the University of Western Ontario. So he and some colleagues turned to a higher-tech version of the same method, and then applied some fancy extrapolations. The researchers studied observations by U.S. government satellite sentinels that watch for potential nuclear detonations around the globe, 24/7.
More than eight years of data reveal 300 in-air explosions of space rocks ranging in size from large televisions to studio apartments.
Objects in this size range rarely reach the ground. They disintegrate catastrophically but high up. While some of their shards can hit the planet the burned remains of space debris add tons of heft to Earth every day, astronomers say the damage potential is limited.
"There will often be a shower of small stony objects," Brown explained. "But theres essentially no significant amount of energy thats imparted to the ground."
Because most of these events occur over remote regions or oceans (Earth is about two-thirds water) the majority of them go unnoticed except by satellites operated by the Department of Defense and the Department of Energy. Brown and his colleagues used the power output of the explosions to estimate how big each rock was.
The researchers were interested in larger objects, however, those roughly as big as a football field that strike even less often but can get real nasty down here on the ground. These large boulders typically explode, too, but they do so closer to the surface. A shock wave could kill millions of people if one exploded over a populated area.
The last known event like this was in 1908, over the remote Tunguska region of Siberia. Mostly uninhabited forest was flattened for hundreds of miles in every direction.
Until recently, experts thought events like this might occur once per century. A perception had developed in some minds that Earth was due for another mini-cataclysm.
When Brown extrapolated his data on relatively small rocks upward to estimate Tunguska event frequency, he found they probably occur every 1,000 years or so. The results will be reported in tomorrows issue of the journal Nature.
He notes, however, that because his team had less than a decade of data to work with, its possible the actual rate of events is higher than observed. Other researchers have speculated that swarms or streams of asteroids might generate flurries of impacts now and then.
No such events have been recorded in modern times. However, ancient tales and drawings hint at the possibility.
The new analysis dovetails with another recent study that approached the question from the opposite direction. Alan Harris of the Space Science Institute in Boulder, CO used actual tallies of Tunguska-sized rocks discovered out in space to estimate the quantity of smaller rocks that probably exist. He, too, found that Tunguska events ought to occur only about once every 1,000 years.
"We can all worry a little less about the risk of the next hazardous impact," said Robert Jedicke, a University of Arizona researcher who was not involved in the new study but wrote an analysis of it for Nature.
However, unlike the recent Leonid meteor shower, which was well predicted, scientists dont yet have enough data on the populations of large meteoroids and asteroids to say when the next one is coming. They caution that statistics and odds cannot be converted to precise timetables. A giant asteroid might explode disastrously above San Francisco tomorrow, or none might arrive on the entire planet for millennia.
Nature does not deliver doom on any scientists schedule.
If you've ever gazed up and spotted a shooting star, you engaged in a form of astronomy in which Earths atmosphere serves as a giant detector: Space debris screams through the air, which heats the stuff up and makes it visible.
By noting observations night after night, you could develop a record of how frequently certain sized objects most no larger than a pea meet their demise by running into our planet.
But if you want to know how often larger hunks of cosmic rubble arrive, your job is far more difficult. It could take hundreds or even thousands of years of continuous observations to arrive at a reliable estimate.
The prospect was not an option for Peter Brown of the University of Western Ontario. So he and some colleagues turned to a higher-tech version of the same method, and then applied some fancy extrapolations. The researchers studied observations by U.S. government satellite sentinels that watch for potential nuclear detonations around the globe, 24/7.
More than eight years of data reveal 300 in-air explosions of space rocks ranging in size from large televisions to studio apartments.
Objects in this size range rarely reach the ground. They disintegrate catastrophically but high up. While some of their shards can hit the planet the burned remains of space debris add tons of heft to Earth every day, astronomers say the damage potential is limited.
"There will often be a shower of small stony objects," Brown explained. "But theres essentially no significant amount of energy thats imparted to the ground."
Because most of these events occur over remote regions or oceans (Earth is about two-thirds water) the majority of them go unnoticed except by satellites operated by the Department of Defense and the Department of Energy. Brown and his colleagues used the power output of the explosions to estimate how big each rock was.
The researchers were interested in larger objects, however, those roughly as big as a football field that strike even less often but can get real nasty down here on the ground. These large boulders typically explode, too, but they do so closer to the surface. A shock wave could kill millions of people if one exploded over a populated area.
The last known event like this was in 1908, over the remote Tunguska region of Siberia. Mostly uninhabited forest was flattened for hundreds of miles in every direction.
Until recently, experts thought events like this might occur once per century. A perception had developed in some minds that Earth was due for another mini-cataclysm.
When Brown extrapolated his data on relatively small rocks upward to estimate Tunguska event frequency, he found they probably occur every 1,000 years or so. The results will be reported in tomorrows issue of the journal Nature.
He notes, however, that because his team had less than a decade of data to work with, its possible the actual rate of events is higher than observed. Other researchers have speculated that swarms or streams of asteroids might generate flurries of impacts now and then.
No such events have been recorded in modern times. However, ancient tales and drawings hint at the possibility.
The new analysis dovetails with another recent study that approached the question from the opposite direction. Alan Harris of the Space Science Institute in Boulder, CO used actual tallies of Tunguska-sized rocks discovered out in space to estimate the quantity of smaller rocks that probably exist. He, too, found that Tunguska events ought to occur only about once every 1,000 years.
"We can all worry a little less about the risk of the next hazardous impact," said Robert Jedicke, a University of Arizona researcher who was not involved in the new study but wrote an analysis of it for Nature.
However, unlike the recent Leonid meteor shower, which was well predicted, scientists dont yet have enough data on the populations of large meteoroids and asteroids to say when the next one is coming. They caution that statistics and odds cannot be converted to precise timetables. A giant asteroid might explode disastrously above San Francisco tomorrow, or none might arrive on the entire planet for millennia.
Nature does not deliver doom on any scientists schedule.
Comment: This article was written in 2002, obviously things have changed celestially since those days.....and changed legally too: Military Hush-Up: Incoming Space Rocks Now Classified
Andrea Thompson
SPACE.com
Wed, 25 Mar 2009 18:45 UTC
Meteorite fragments of the first asteroid ever spotted in space before
it slammed into Earth's atmosphere last year were recovered by
scientists from the deserts of Sudan.
These precious pieces of space rock, described in a study detailed in the March 26 issue of the journal Nature, could be an important key to classifying meteorites and asteroids and determining exactly how they formed.
The asteroid was detected by the automated Catalina Sky Survey telescope at Mount Lemmon , Ariz., on Oct. 6, 2008. Just 19 hours after it was spotted, it collided with Earth's atmosphere and exploded 23 miles (37 kilometers) above the Nubian Desert of northern Sudan.
Because it exploded so high over Earth's surface, no chunks of it were expected to have made it to the ground. Witnesses in Sudan described seeing a fireball, which ended abruptly.
But Peter Jenniskens, a meteor astronomer with the SETI Institute's Carl Sagan Center, thought it would be possible to find some fragments of the bolide. Along with Muawia Shaddad of the University of Khartoum and students and staff, Jenniskens followed the asteroid's approach trajectory and found 47 meteorites strewn across an 18-mile (29-km) stretch of the Nubian Desert.
"This was an extraordinary opportunity, for the first time, to bring into the lab actual pieces of an asteroid we had seen in space," Jenniskens said.
Classification
Astronomers were able to detect the sunlight reflected off the car-sized asteroid (much smaller than the one thought to have wiped out the dinosaurs) while it was still hurtling through space. Looking at the signature of light, or spectra of space rocks is the only way scientists have had of dividing asteroids into broad categories based on the limited information the technique gives on composition.
However, layers of dust stuck to the surfaces of the asteroids can scatter light in unpredictable ways and may not show what type of rock lies underneath. This can also make it difficult to match up asteroids with meteorites found on Earth - that's why this new discovery comes in so handy.
Both the asteroid, dubbed 2008 TC3, and its meteoric fragments indicate that it could belong to the so-called F-class asteroids.
"F-class asteroids were long a mystery," said SETI planetary spectroscopist Janice Bishop. "Astronomers have measured their unique spectral properties with telescopes, but prior to 2008 TC3 there was no corresponding meteorite class, no rocks we could look at in the lab."
Cooked carbon
The chemical makeup of the meteorite fragments, collectively known as "Almahata Sitta," shows that they belong to a rare class of meteorites called ureilites, which may all have come from the same original parent body. Though what that parent body was, scientists do not know.
"The recovered meteorites were unlike anything in our meteorite collections up to that point," Jenniskens said.
The meteorites are made of very dark, porous material that is highly fragile (which explains why the bolide exploded so high up in the atmosphere).
The carbon content of the meteorites shows that at some point in the past, they were subjected to very high temperatures.
"Without a doubt, of all the meteorites that we've ever studied, the carbon in this one has been cooked to the greatest extent," said study team member Andrew Steele of the Carnegie Institution in Washington, D.C. "Very cooked, graphite-like carbon is the main constituent of the carbon in this meteorite."
Steele also found nanodiamonds in the meteorite, which could provide clues as to whether heating was caused by impacts to the parent asteroid or by some other process.
Rosetta Stone
Having spectral and laboratory information on the meteorites and their parent asteroid will help scientists better identify ureilite asteroids still circling in space.
"2008 TC3 could serve as a Rosetta Stone, providing us with essential clues to the processes that built Earth and its planetary siblings," said study team member Rocco Mancinelli, also of SETI.
One known asteroid with a similar spectrum, the 2.6-km wide 1998 KU2, has already been identified as a possible source for the smaller asteroid 2008 TC3 that impacted Earth.
With efforts such as the Pan-STARRS project sweeping the skies in search of other near-Earth asteroids, Jenniskens expects that more events like 2008 TC3 will happen.
"I look forward to getting the next call from the next person to spot one of these," he said. "I would love to travel to the impact area in time to see the fireball in the sky, study its breakup and recover the pieces. If it's big enough, we may well find other fragile materials not yet in our meteorite collections."
The root of both: debris from a disintegrating comet.
Biblical stories, apocalyptic visions, ancient art and scientific data all seem to intersect at around 2350 B.C., when one or more catastrophic events wiped out several advanced societies in Europe, Asia and Africa.
Increasingly, some scientists suspect comets and their associated meteor storms were the cause. History and culture provide clues: Icons and myths surrounding the alleged cataclysms persist in cults and religions today and even fuel terrorism.
And a newly found 2-mile-wide crater in Iraq, spotted serendipitously in a perusal of satellite images, could provide a smoking gun. The crater's discovery, which was announced in a recent issue of the journal Meteoritics & Planetary Science, is a preliminary finding. Scientists stress that a ground expedition is needed to determine if the landform was actually carved out by an impact.
Yet the crater has already added another chapter to an intriguing overall story that is, at best, loosely bound. Many of the pages are washed away or buried. But several plot lines converge in conspicuous ways.
Too many coincidences
Archeological findings show that in the space of a few centuries, many of the first sophisticated civilizations disappeared. The Old Kingdom in Egypt fell into ruin. The Akkadian culture of Iraq, thought to be the world's first empire, collapsed. The settlements of ancient Israel, gone. Mesopotamia, Earth's original breadbasket, dust.
Around the same time -- a period called the Early Bronze Age -- apocalyptic writings appeared, fueling religious beliefs that persist today.
The Epic of Gilgamesh describes the fire, brimstone and flood of possibly mythical events. Omens predicting the Akkadian collapse preserve a record that "many stars were falling from the sky." The "Curse of Akkad," dated to about 2200 B.C., speaks of "flaming potsherds raining from the sky."
Roughly 2000 years later, the Jewish astronomer Rabbi bar Nachmani created what could be considered the first impact theory: That Noah's Flood was triggered by two "stars" that fell from the sky. "When God decided to bring about the Flood, He took two stars from Khima, threw them on Earth, and brought about the Flood."
Another thread was woven into the tale when, in 1650, the Irish Archbishop James Ussher mapped out the chronology of the Bible -- a feat that included stringing together all the "begats" to count generations -- and put Noah's great flood at 2349 B.C.
All coincidence?
A number of scientists don't think so.
Mounting hard evidence collected from tree rings, soil layers and even dust that long ago settled to the ocean floor indicates there were widespread environmental nightmares in the Near East during the Early Bronze Age: Abrupt cooling of the climate, sudden floods and surges from the seas, huge earthquakes.
Comet as a culprit
In recent years, the fall of ancient civilizations has come to be viewed not as a failure of social engineering or political might but rather the product of climate change and, possibly, heavenly happenstance. As this new thinking dawned, volcanoes and earthquakes were blamed at first. More recently, a 300-year drought has been the likely suspect.
But now more than ever, it appears a comet could be the culprit. One or more devastating impacts could have rocked the planet, chilled the air, and created unthinkable tsunamis -- ocean waves hundreds of feet high. Showers of debris wafting through space -- concentrated versions of the dust trails that create the Leonids -- would have blocked the Sun and delivered horrific rains of fire to Earth for years.
So far, the comet theory lacks firm evidence. Like a crater.
Now, though, there is this depression in Iraq. It was found accidentally by Sharad Master, a geologist at the University of Witwatersrand in South Africa, while studying satellite images. Master says the crater bears the signature shape and look of an impact caused by a space rock.
The finding has not been developed into a full-fledged scientific paper, however, nor has it undergone peer review. Scientist in several fields were excited by the possibility, but they expressed caution about interpreting the preliminary analysis and said a full scientific expedition to the site needs to be mounted to determine if the landforms do in fact represent an impact crater.
Researchers would look for shards of melted sand and telltale quartz that had been shocked into existence. If it were a comet, the impact would have occurred on what was once a shallow sea, triggering massive flooding following the fire generated by the object's partial vaporization as it screamed through the atmosphere. The comet would have plunged through the water and dug into the earth below.
If it proves to be an impact crater, there is a good chance it was dug from the planet less than 6,000 years ago, Master said, because shifting sediment in the region would have buried anything older.
Arriving at an exact date will be difficult, researchers said.
"It's an exciting crater if it really is of impact origin," said Bill Napier, an astronomer at the Armagh Observatory.
Cultural impact
Napier said an impact that could carve a hole this large would have packed the energy of several dozen nuclear bombs. The local effect: utter devastation.
"But the cultural effect would be far greater," Napier said in an e-mail interview. "The event would surely be incorporated into the world view of people in the Near East at that time and be handed down through the generations in the form of celestial myths."
Napier and others have also suggested that the swastika, a symbol with roots in Asia stretching back to at least 1400 B.C., could be an artist's rendering of a comet, with jets spewing material outward as the head of the comet points earthward.
But could a single impact of this size take down civilizations on three continents? No way, most experts say.
Napier thinks multiple impacts, and possibly a rain of other smaller meteors and dust, would have been required. He and his colleagues have been arguing since 1982 that such events are possible. And, he says, it might have happened right around the time the first urban civilizations were crumbling.
Napier thinks a comet called Encke, discovered in 1786, is the remnant of a larger comet that broke apart 5,000 years ago. Large chunks and vast clouds of smaller debris were cast into space. Napier said it's possible that Earth ran through that material during the Early Bronze Age.
The night sky would have been lit up for years by a fireworks-like display of comet fragments and dust vaporizing upon impact with Earth's atmosphere. The Sun would have struggled to shine through the debris. Napier has tied the possible event to a cooling of the climate, measured in tree rings, that ran from 2354-2345 B.C.
Supporting evidence
Though no other craters have been found in the region and precisely dated to this time, there is other evidence to suggest the scenario is plausible. Two large impact craters in Argentina are believed to have been created sometime in the past 5,000 years.
Benny Peiser, a social anthropologist at Liverpool John Moores University in England, said roughly a dozen craters are known to have been carved out during the past 10,000 years. Dating them precisely is nearly impossible with current technology. And, Peiser said, whether any of the impact craters thought to have been made in the past 10,000 years can be tied back to a single comet is still unknown.
But he did not discount Napier's scenario.
"There is no scientific reason to doubt that the break-up of a giant comet might result in a shower of cosmic debris," Peiser said. He also points out that because Earth is covered mostly by deep seas, each visible crater represents more ominous statistical possibilities.
"For every crater discovered on land, we should expect two oceanic impacts with even worse consequences," he said.
Tsunamis generated in deep water can rise even taller when they reach a shore.
Reverberating today
Peiser studies known craters for clues to the past. But he also examines religions and cults, old and new, for signs of what might have happened way back then.
"I would not be surprised if the notorious rituals of human sacrifice were a direct consequence of attempts to overcome this trauma," he says of the South American impact craters. "Interestingly, the same deadly cults were also established in the Near East during the Bronze Age."
The impact of comets on myth and religion has reverberated through the ages, in Peiser's view.
"One has to take into consideration apocalyptic religions [of today] to understand the far-reaching consequences of historical impacts," he says. "After all, the apocalyptic fear of the end of the world is still very prevalent today and can often lead to fanaticism and extremism."
An obsession with the end of the world provides the legs on which modern-day terrorism stands, Peiser argues. Leaders of fundamentalist terror groups drum into the minds of their followers looming cataclysms inspired by ancient writings. Phrases run along these lines: a rolling up of the sun, darkening of the stars, movement of the mountains, splitting of the sky.
No smoking gun yet
Despite the excitement of the newfound hole in the ground in Iraq, it is still far from clear why so many civilizations collapsed in such a relatively short historical time frame. Few scientists, even those who find evidence to support the idea, are ready to categorically blame a comet.
French soil scientist Marie-Agnes Courty, who in 1997 found material that could only have come from a meteorite and dated it to the Early Bronze Age, urged caution on drawing any conclusions until a smoking gun has been positively identified.
"Certain scientists and the popular press do prefer the idea of linking natural catastrophes and societal collapse," Courty said.
Multiple cosmic impacts are an attractive culprit though, because of the many effects they can have, including some found in real climate and geologic data. The initial impact, if it is on land, vaporizes life for miles around. Earthquakes devastate an even wider area. A cloud of debris can block out the Sun and alter the climate. The extent and duration of the climate effects is not known for sure, because scientists have never witnessed such an event.
It might not have taken much. Ancient civilizations, which depended on farming and reliable rainfall, were precarious.
Mike Baillie, a professor of palaeoecology at Queens University in Belfast, figures it would have taken just a few bad years to destroy such a society.
Even a single comet impact large enough to have created the Iraqi crater, "would have caused a mini nuclear winter with failed harvests and famine, bringing down any agriculture based populations which can survive only as long as their stored food reserves," Baillie said. "So any environmental downturn lasting longer than about three years tends to bring down civilizations."
Other scientists doubt that a single impact would have altered the climate for so long.
Lessons for tomorrow
Either way, there is a giant scar on the planet, near the cradle of civilization, that could soon begin to provide some solid answers, assuming geologists can get permission to enter Iraq and conduct a study.
"If the crater dated from the 3rd Millennium B.C., it would be almost impossible not to connect it directly with the demise of the Early Bronze Age civilizations in the Near East," said Peiser.
Perhaps before long all the cometary traditions, myths and scientific fact will be seen to converge at the Iraqi hole in the ground for good purpose. Understanding what happened, and how frequent and deadly such impacts might be, is an important tool for researchers like Peiser who aim to estimate future risk and help modern society avoid the fate of the ancients.
"Paradoxically, the Hebrew Bible and other Near Eastern documents have kept alive the memory of ancient catastrophes whose scientific analysis and understanding might now be vital for the protection of our own civilizations from future impacts," Peiser said.
The
infamous Tunguska explosion, which mysteriously leveled an area of
Siberian forest nearly the size of Tokyo a century ago, might have been
caused by an impacting asteroid far smaller than previously thought.
The fact that a relatively small asteroid could still cause such a massive explosion suggests "we should be making more efforts at detecting the smaller ones than we have till now," said researcher Mark Boslough, a physicist at Sandia National Laboratory in Albuquerque, N.M.
The explosion near the Podkamennaya Tunguska River on June 30, 1908, flattened some 500,000 acres (2,000 square kilometers) of Siberian forest. Scientists calculated the Tunguska explosion could have been roughly as strong as 10 to 20 megatons of TNT - 1,000 times more powerful than the atom bomb dropped on Hiroshima.
Wild theories have been bandied about for a century regarding what caused the Tunguska explosion, including a UFO crash, antimatter, a black hole and famed inventor Nikola Tesla's "death ray." In the last decade, researchers have conjectured the event was triggered by an asteroid exploding in Earth's atmosphere that was roughly 100 feet wide (30 meters) and 560,000 metric tons in mass - more than 10 times that of the Titanic.
The space rock is thought to have blown up above the surface, only fragments possibly striking the ground.
Now new supercomputer simulations suggest "the asteroid that caused the extensive damage was much smaller than we had thought," Boslough said. Specifically, he and his colleagues say it would have been a factor of three or four smaller in mass and perhaps 65 feet (20 meters) in diameter.
The simulations run on Sandia's Red Storm supercomputer - the third fastest in the world - detail how an asteroid that explodes as it runs into Earth's atmosphere will generate a supersonic jet of expanding superheated gas. This fireball would have caused blast waves that were stronger at the surface than previously thought.
At the same time, previous estimates seem to have overstated the devastation the event caused. The forest back then was not healthy, according to foresters, "and it doesn't take as much energy to blow down a diseased tree than a healthy tree," Boslough said. In addition, the winds from the explosion would naturally get amplified above ridgelines, making the explosion seem more powerful than it actually was. What scientists had thought to be an explosion between 10 and 20 megatons was more likely only three to five megatons, he explained.
All in all, the researchers suggest that smaller asteroids may pose a greater danger than previously believed. Moreover, "there are a lot more objects that size," Boslough told SPACE.com.
NASA Ames Research Center planetary scientist and astrobiologist David Morrison, who did not participate in this study, said, "If he's right, we can expect more Tunguska-sized explosions - perhaps every couple of centuries instead of every millennia or two." He added, "It raises the bar in the long term - ultimately, we'd like to have a survey system that can detect things this small."
Boslough and his colleagues detailed their findings at the American Geophysical Union meeting in San Francisco on Dec. 11. A paper on the phenomenon has been accepted for publication in the International Journal of Impact Engineering.
Comment: Actually it appears that small asteroids or comets hit the earth far more often than thought or reported. Read the latest SOTT focus: New Light on the Black Death: The Cosmic Connection to get the idea...
These precious pieces of space rock, described in a study detailed in the March 26 issue of the journal Nature, could be an important key to classifying meteorites and asteroids and determining exactly how they formed.
The asteroid was detected by the automated Catalina Sky Survey telescope at Mount Lemmon , Ariz., on Oct. 6, 2008. Just 19 hours after it was spotted, it collided with Earth's atmosphere and exploded 23 miles (37 kilometers) above the Nubian Desert of northern Sudan.
Because it exploded so high over Earth's surface, no chunks of it were expected to have made it to the ground. Witnesses in Sudan described seeing a fireball, which ended abruptly.
But Peter Jenniskens, a meteor astronomer with the SETI Institute's Carl Sagan Center, thought it would be possible to find some fragments of the bolide. Along with Muawia Shaddad of the University of Khartoum and students and staff, Jenniskens followed the asteroid's approach trajectory and found 47 meteorites strewn across an 18-mile (29-km) stretch of the Nubian Desert.
"This was an extraordinary opportunity, for the first time, to bring into the lab actual pieces of an asteroid we had seen in space," Jenniskens said.
Classification
Astronomers were able to detect the sunlight reflected off the car-sized asteroid (much smaller than the one thought to have wiped out the dinosaurs) while it was still hurtling through space. Looking at the signature of light, or spectra of space rocks is the only way scientists have had of dividing asteroids into broad categories based on the limited information the technique gives on composition.
However, layers of dust stuck to the surfaces of the asteroids can scatter light in unpredictable ways and may not show what type of rock lies underneath. This can also make it difficult to match up asteroids with meteorites found on Earth - that's why this new discovery comes in so handy.
Both the asteroid, dubbed 2008 TC3, and its meteoric fragments indicate that it could belong to the so-called F-class asteroids.
"F-class asteroids were long a mystery," said SETI planetary spectroscopist Janice Bishop. "Astronomers have measured their unique spectral properties with telescopes, but prior to 2008 TC3 there was no corresponding meteorite class, no rocks we could look at in the lab."
Cooked carbon
The chemical makeup of the meteorite fragments, collectively known as "Almahata Sitta," shows that they belong to a rare class of meteorites called ureilites, which may all have come from the same original parent body. Though what that parent body was, scientists do not know.
"The recovered meteorites were unlike anything in our meteorite collections up to that point," Jenniskens said.
The meteorites are made of very dark, porous material that is highly fragile (which explains why the bolide exploded so high up in the atmosphere).
The carbon content of the meteorites shows that at some point in the past, they were subjected to very high temperatures.
"Without a doubt, of all the meteorites that we've ever studied, the carbon in this one has been cooked to the greatest extent," said study team member Andrew Steele of the Carnegie Institution in Washington, D.C. "Very cooked, graphite-like carbon is the main constituent of the carbon in this meteorite."
Steele also found nanodiamonds in the meteorite, which could provide clues as to whether heating was caused by impacts to the parent asteroid or by some other process.
Rosetta Stone
Having spectral and laboratory information on the meteorites and their parent asteroid will help scientists better identify ureilite asteroids still circling in space.
"2008 TC3 could serve as a Rosetta Stone, providing us with essential clues to the processes that built Earth and its planetary siblings," said study team member Rocco Mancinelli, also of SETI.
One known asteroid with a similar spectrum, the 2.6-km wide 1998 KU2, has already been identified as a possible source for the smaller asteroid 2008 TC3 that impacted Earth.
With efforts such as the Pan-STARRS project sweeping the skies in search of other near-Earth asteroids, Jenniskens expects that more events like 2008 TC3 will happen.
"I look forward to getting the next call from the next person to spot one of these," he said. "I would love to travel to the impact area in time to see the fireball in the sky, study its breakup and recover the pieces. If it's big enough, we may well find other fragile materials not yet in our meteorite collections."
Space
Tue, 13 Nov 2001 18:25 UTC
"...and the seven judges of hell ... raised their torches, lighting the land with their livid flame. A stupor of despair went up to heaven when the god of the storm turned daylight into darkness, when he smashed the land like a cup."If you are fortunate enough to see the storm of shooting stars predicted for the Nov. 18 peak of the Leonid meteor shower, you'll be watching a similar but considerably less powerful version of events which some scientists say brought down the world's first civilizations.
-- An account of the Deluge from the Epic of Gilgamesh, circa 2200 B.C.
The root of both: debris from a disintegrating comet.
Biblical stories, apocalyptic visions, ancient art and scientific data all seem to intersect at around 2350 B.C., when one or more catastrophic events wiped out several advanced societies in Europe, Asia and Africa.
Increasingly, some scientists suspect comets and their associated meteor storms were the cause. History and culture provide clues: Icons and myths surrounding the alleged cataclysms persist in cults and religions today and even fuel terrorism.
And a newly found 2-mile-wide crater in Iraq, spotted serendipitously in a perusal of satellite images, could provide a smoking gun. The crater's discovery, which was announced in a recent issue of the journal Meteoritics & Planetary Science, is a preliminary finding. Scientists stress that a ground expedition is needed to determine if the landform was actually carved out by an impact.
Yet the crater has already added another chapter to an intriguing overall story that is, at best, loosely bound. Many of the pages are washed away or buried. But several plot lines converge in conspicuous ways.
Too many coincidences
Archeological findings show that in the space of a few centuries, many of the first sophisticated civilizations disappeared. The Old Kingdom in Egypt fell into ruin. The Akkadian culture of Iraq, thought to be the world's first empire, collapsed. The settlements of ancient Israel, gone. Mesopotamia, Earth's original breadbasket, dust.
Around the same time -- a period called the Early Bronze Age -- apocalyptic writings appeared, fueling religious beliefs that persist today.
The Epic of Gilgamesh describes the fire, brimstone and flood of possibly mythical events. Omens predicting the Akkadian collapse preserve a record that "many stars were falling from the sky." The "Curse of Akkad," dated to about 2200 B.C., speaks of "flaming potsherds raining from the sky."
Roughly 2000 years later, the Jewish astronomer Rabbi bar Nachmani created what could be considered the first impact theory: That Noah's Flood was triggered by two "stars" that fell from the sky. "When God decided to bring about the Flood, He took two stars from Khima, threw them on Earth, and brought about the Flood."
Another thread was woven into the tale when, in 1650, the Irish Archbishop James Ussher mapped out the chronology of the Bible -- a feat that included stringing together all the "begats" to count generations -- and put Noah's great flood at 2349 B.C.
All coincidence?
A number of scientists don't think so.
Mounting hard evidence collected from tree rings, soil layers and even dust that long ago settled to the ocean floor indicates there were widespread environmental nightmares in the Near East during the Early Bronze Age: Abrupt cooling of the climate, sudden floods and surges from the seas, huge earthquakes.
Comet as a culprit
In recent years, the fall of ancient civilizations has come to be viewed not as a failure of social engineering or political might but rather the product of climate change and, possibly, heavenly happenstance. As this new thinking dawned, volcanoes and earthquakes were blamed at first. More recently, a 300-year drought has been the likely suspect.
But now more than ever, it appears a comet could be the culprit. One or more devastating impacts could have rocked the planet, chilled the air, and created unthinkable tsunamis -- ocean waves hundreds of feet high. Showers of debris wafting through space -- concentrated versions of the dust trails that create the Leonids -- would have blocked the Sun and delivered horrific rains of fire to Earth for years.
So far, the comet theory lacks firm evidence. Like a crater.
Now, though, there is this depression in Iraq. It was found accidentally by Sharad Master, a geologist at the University of Witwatersrand in South Africa, while studying satellite images. Master says the crater bears the signature shape and look of an impact caused by a space rock.
The finding has not been developed into a full-fledged scientific paper, however, nor has it undergone peer review. Scientist in several fields were excited by the possibility, but they expressed caution about interpreting the preliminary analysis and said a full scientific expedition to the site needs to be mounted to determine if the landforms do in fact represent an impact crater.
Researchers would look for shards of melted sand and telltale quartz that had been shocked into existence. If it were a comet, the impact would have occurred on what was once a shallow sea, triggering massive flooding following the fire generated by the object's partial vaporization as it screamed through the atmosphere. The comet would have plunged through the water and dug into the earth below.
If it proves to be an impact crater, there is a good chance it was dug from the planet less than 6,000 years ago, Master said, because shifting sediment in the region would have buried anything older.
Arriving at an exact date will be difficult, researchers said.
"It's an exciting crater if it really is of impact origin," said Bill Napier, an astronomer at the Armagh Observatory.
Cultural impact
Napier said an impact that could carve a hole this large would have packed the energy of several dozen nuclear bombs. The local effect: utter devastation.
"But the cultural effect would be far greater," Napier said in an e-mail interview. "The event would surely be incorporated into the world view of people in the Near East at that time and be handed down through the generations in the form of celestial myths."
Napier and others have also suggested that the swastika, a symbol with roots in Asia stretching back to at least 1400 B.C., could be an artist's rendering of a comet, with jets spewing material outward as the head of the comet points earthward.
But could a single impact of this size take down civilizations on three continents? No way, most experts say.
Napier thinks multiple impacts, and possibly a rain of other smaller meteors and dust, would have been required. He and his colleagues have been arguing since 1982 that such events are possible. And, he says, it might have happened right around the time the first urban civilizations were crumbling.
Napier thinks a comet called Encke, discovered in 1786, is the remnant of a larger comet that broke apart 5,000 years ago. Large chunks and vast clouds of smaller debris were cast into space. Napier said it's possible that Earth ran through that material during the Early Bronze Age.
The night sky would have been lit up for years by a fireworks-like display of comet fragments and dust vaporizing upon impact with Earth's atmosphere. The Sun would have struggled to shine through the debris. Napier has tied the possible event to a cooling of the climate, measured in tree rings, that ran from 2354-2345 B.C.
Supporting evidence
Though no other craters have been found in the region and precisely dated to this time, there is other evidence to suggest the scenario is plausible. Two large impact craters in Argentina are believed to have been created sometime in the past 5,000 years.
Benny Peiser, a social anthropologist at Liverpool John Moores University in England, said roughly a dozen craters are known to have been carved out during the past 10,000 years. Dating them precisely is nearly impossible with current technology. And, Peiser said, whether any of the impact craters thought to have been made in the past 10,000 years can be tied back to a single comet is still unknown.
But he did not discount Napier's scenario.
"There is no scientific reason to doubt that the break-up of a giant comet might result in a shower of cosmic debris," Peiser said. He also points out that because Earth is covered mostly by deep seas, each visible crater represents more ominous statistical possibilities.
"For every crater discovered on land, we should expect two oceanic impacts with even worse consequences," he said.
Tsunamis generated in deep water can rise even taller when they reach a shore.
Reverberating today
Peiser studies known craters for clues to the past. But he also examines religions and cults, old and new, for signs of what might have happened way back then.
"I would not be surprised if the notorious rituals of human sacrifice were a direct consequence of attempts to overcome this trauma," he says of the South American impact craters. "Interestingly, the same deadly cults were also established in the Near East during the Bronze Age."
The impact of comets on myth and religion has reverberated through the ages, in Peiser's view.
"One has to take into consideration apocalyptic religions [of today] to understand the far-reaching consequences of historical impacts," he says. "After all, the apocalyptic fear of the end of the world is still very prevalent today and can often lead to fanaticism and extremism."
An obsession with the end of the world provides the legs on which modern-day terrorism stands, Peiser argues. Leaders of fundamentalist terror groups drum into the minds of their followers looming cataclysms inspired by ancient writings. Phrases run along these lines: a rolling up of the sun, darkening of the stars, movement of the mountains, splitting of the sky.
No smoking gun yet
Despite the excitement of the newfound hole in the ground in Iraq, it is still far from clear why so many civilizations collapsed in such a relatively short historical time frame. Few scientists, even those who find evidence to support the idea, are ready to categorically blame a comet.
French soil scientist Marie-Agnes Courty, who in 1997 found material that could only have come from a meteorite and dated it to the Early Bronze Age, urged caution on drawing any conclusions until a smoking gun has been positively identified.
"Certain scientists and the popular press do prefer the idea of linking natural catastrophes and societal collapse," Courty said.
Multiple cosmic impacts are an attractive culprit though, because of the many effects they can have, including some found in real climate and geologic data. The initial impact, if it is on land, vaporizes life for miles around. Earthquakes devastate an even wider area. A cloud of debris can block out the Sun and alter the climate. The extent and duration of the climate effects is not known for sure, because scientists have never witnessed such an event.
It might not have taken much. Ancient civilizations, which depended on farming and reliable rainfall, were precarious.
Mike Baillie, a professor of palaeoecology at Queens University in Belfast, figures it would have taken just a few bad years to destroy such a society.
Even a single comet impact large enough to have created the Iraqi crater, "would have caused a mini nuclear winter with failed harvests and famine, bringing down any agriculture based populations which can survive only as long as their stored food reserves," Baillie said. "So any environmental downturn lasting longer than about three years tends to bring down civilizations."
Other scientists doubt that a single impact would have altered the climate for so long.
Lessons for tomorrow
Either way, there is a giant scar on the planet, near the cradle of civilization, that could soon begin to provide some solid answers, assuming geologists can get permission to enter Iraq and conduct a study.
"If the crater dated from the 3rd Millennium B.C., it would be almost impossible not to connect it directly with the demise of the Early Bronze Age civilizations in the Near East," said Peiser.
Perhaps before long all the cometary traditions, myths and scientific fact will be seen to converge at the Iraqi hole in the ground for good purpose. Understanding what happened, and how frequent and deadly such impacts might be, is an important tool for researchers like Peiser who aim to estimate future risk and help modern society avoid the fate of the ancients.
"Paradoxically, the Hebrew Bible and other Near Eastern documents have kept alive the memory of ancient catastrophes whose scientific analysis and understanding might now be vital for the protection of our own civilizations from future impacts," Peiser said.
Flashback:
Small Asteroids Pose Big New Threat
Charles Q. Choi
Space.com/Yahoo!News
Wed, 19 Dec 2007 07:39 UTC
© Unknown
The fact that a relatively small asteroid could still cause such a massive explosion suggests "we should be making more efforts at detecting the smaller ones than we have till now," said researcher Mark Boslough, a physicist at Sandia National Laboratory in Albuquerque, N.M.
The explosion near the Podkamennaya Tunguska River on June 30, 1908, flattened some 500,000 acres (2,000 square kilometers) of Siberian forest. Scientists calculated the Tunguska explosion could have been roughly as strong as 10 to 20 megatons of TNT - 1,000 times more powerful than the atom bomb dropped on Hiroshima.
Wild theories have been bandied about for a century regarding what caused the Tunguska explosion, including a UFO crash, antimatter, a black hole and famed inventor Nikola Tesla's "death ray." In the last decade, researchers have conjectured the event was triggered by an asteroid exploding in Earth's atmosphere that was roughly 100 feet wide (30 meters) and 560,000 metric tons in mass - more than 10 times that of the Titanic.
The space rock is thought to have blown up above the surface, only fragments possibly striking the ground.
Now new supercomputer simulations suggest "the asteroid that caused the extensive damage was much smaller than we had thought," Boslough said. Specifically, he and his colleagues say it would have been a factor of three or four smaller in mass and perhaps 65 feet (20 meters) in diameter.
The simulations run on Sandia's Red Storm supercomputer - the third fastest in the world - detail how an asteroid that explodes as it runs into Earth's atmosphere will generate a supersonic jet of expanding superheated gas. This fireball would have caused blast waves that were stronger at the surface than previously thought.
At the same time, previous estimates seem to have overstated the devastation the event caused. The forest back then was not healthy, according to foresters, "and it doesn't take as much energy to blow down a diseased tree than a healthy tree," Boslough said. In addition, the winds from the explosion would naturally get amplified above ridgelines, making the explosion seem more powerful than it actually was. What scientists had thought to be an explosion between 10 and 20 megatons was more likely only three to five megatons, he explained.
All in all, the researchers suggest that smaller asteroids may pose a greater danger than previously believed. Moreover, "there are a lot more objects that size," Boslough told SPACE.com.
NASA Ames Research Center planetary scientist and astrobiologist David Morrison, who did not participate in this study, said, "If he's right, we can expect more Tunguska-sized explosions - perhaps every couple of centuries instead of every millennia or two." He added, "It raises the bar in the long term - ultimately, we'd like to have a survey system that can detect things this small."
Boslough and his colleagues detailed their findings at the American Geophysical Union meeting in San Francisco on Dec. 11. A paper on the phenomenon has been accepted for publication in the International Journal of Impact Engineering.
Comment: Actually it appears that small asteroids or comets hit the earth far more often than thought or reported. Read the latest SOTT focus: New Light on the Black Death: The Cosmic Connection to get the idea...
The Local
Thu, 11 Jun 2009 16:26 UTC
A
pebble-sized meteorite crashed and burned into Earth, grazing
14-year-old Gerritt Blank while on his way to catch the school bus.
"At first, I only saw a big, white ball of light. Then, my hand hurt, and then it slammed into the street," he told daily Westdeutsche Allgemeine Zeitung. "After I saw the white light, I felt something on my hand."
The result was a 10-centimetre burn on the back of his left hand, but Blank knew something special had happened to him.
"I thought the meteor struck me, but it could also be a result from the heat as it went by me," he said.
After the intial shock, Blank looked at the glowing rock that left a sizable crater in Brakeler Wald Street. He then took the iced tea from his school lunch and doused his glowing pebble and took it to school with him.
"At school, I told the story. My classmates believed me," he said. His parents didn't get to hear the story until the end of the school day.
Once home, Blank, who plans to focus his studies in science, tested the round, black object and already found some confirmation the pebble is from outer space: like many meteorites, the rock is magnetic.
Approximately 3,000 meteorites hit the Earth's surface daily.
A
1,124-pound (510-kilogram) space probe will "collide" with our home
planet in June 2010 to simulate an approaching asteroid, Japanese
scientists have announced.
The Hayabusa spacecraft is currently on its way back to Earth after a successful mission that landed on and hopefully collected samples from the asteroid Itokawa.
Potential samples will be aboard a heat-resistant capsule that will separate from Hayabusa shortly before re-entry into Earth's atmosphere so they can be recovered. But experts say the main body of the craft will most likely disintegrate during the trip through Earth's atmosphere.
Although the plan was not part of Hayabusa's original mission, scientists at the Japan Aerospace Exploration Agency (JAXA) recently decided to make the most of the doomed probe's return.
"Even though Hayabusa is not actually an asteroid, it will be on a path that will cause it to collide with the Earth in the same way as an asteroid," said JAXA spokesperson Akinori Hashimoto. "We will monitor its movements, and the data will enable us to accurately predict the future paths of asteroids that are on course to come close to the Earth."
A Better Lookout
While other space agencies have programs for tracking asteroids that might hit Earth, JAXA doesn't yet have the ability to monitor these so-called near-Earth asteroids. So a team of researchers headed by Makoto Yoshikawa has developed a prototype system to calculate the trajectory, time, speed, and likelihood of an asteroid impact.
In October 2008, the team had a chance to test its system by tracking asteroid 2008 TC3, an incoming space rock about 13 feet (4 meters) wide that astronomers at the Catalina Sky Survey in Arizona had spotted a few hours before it became a fireball in the skies over Sudan.
A schoolboy has survived a direct hit by a meteorite after it fell to earth at 30,000mph.
Gerrit Blank, 14, was on his way to school when he saw "ball of light" heading straight towards him from the sky.
A red hot, pea-sized piece of rock then hit his hand before bouncing off and causing a foot wide crater in the ground.
The teenager survived the strike, the chances of which are just 1 in a million - but with a nasty three-inch long scar on his hand.
He said: "At first I just saw a large ball of light, and then I suddenly felt a pain in my hand.
"Then a split second after that there was an enormous bang like a crash of thunder."
"The noise that came after the flash of light was so loud that my ears were ringing for hours afterwards.
"When it hit me it knocked me flying and then was still going fast enough to bury itself into the road," he explained.
Scientists are now studying the pea-sized meteorite which crashed to Earth in Essen, Germany.
"I am really keen on science and my teachers discovered that the fragment is really magnetic," said Gerrit.
Chemical tests on the rock have proved it had fallen from space.
Ansgar Kortem, director of Germany's Walter Hohmann Observatory, said: "It's a real meteorite, therefore it is very valuable to collectors and scientists.
"Most don't actually make it to ground level because they evaporate in the atmosphere. Of those that do get through, about six out of every seven of them land in water," he added.
The only other known example of a human being surviving a meteor strike happened in Alabama, USA, in November 1954 when a grapefruit-sized fragment crashed through the roof of a house, bounced off furniture and landed on a sleeping woman.
Comment: Actually, these incidents are not as rare as we are made to believe. From our Comets and Catastrophe installment, read: Meteorites, Asteroids, and Comets: Damages, Disasters, Injuries, Deaths, and Very Close Calls
Reports of strange lights in the English Channel overnight have been put down to a meteor shower, coastguards said.
Calls were made to stations from Hampshire down to Brixham in Devon and across to Jersey and France at about 9.30pm on Monday, with people saying they were seeing white and green flares in the sky.
A Solent Coastguard spokesman said: "There were reports of flares all down the coast which went on for about half an hour but there was a forecast for a meteor shower."
Meteor showers are caused by debris from a comet burning up in the Earth's atmosphere.
This can produce shooting stars across the night sky, particularly visible on clear nights, which was the case over southern England on Monday night.
Solent Coastguard said it could have been one of three showers forecast - the June Lyrids, the Ophruchids or the Zeta Pearseids.
© Westdeutsche Allgemeine Zeitung
The result was a 10-centimetre burn on the back of his left hand, but Blank knew something special had happened to him.
"I thought the meteor struck me, but it could also be a result from the heat as it went by me," he said.
After the intial shock, Blank looked at the glowing rock that left a sizable crater in Brakeler Wald Street. He then took the iced tea from his school lunch and doused his glowing pebble and took it to school with him.
"At school, I told the story. My classmates believed me," he said. His parents didn't get to hear the story until the end of the school day.
Once home, Blank, who plans to focus his studies in science, tested the round, black object and already found some confirmation the pebble is from outer space: like many meteorites, the rock is magnetic.
Approximately 3,000 meteorites hit the Earth's surface daily.
Julian Ryall
National Geographic News
Thu, 11 Jun 2009 02:56 UTC
© A. Ikeshita/MEF/ISAS
Artist's conception of the Hayabusa spacecraft
Artist's conception of the Hayabusa spacecraft
The Hayabusa spacecraft is currently on its way back to Earth after a successful mission that landed on and hopefully collected samples from the asteroid Itokawa.
Potential samples will be aboard a heat-resistant capsule that will separate from Hayabusa shortly before re-entry into Earth's atmosphere so they can be recovered. But experts say the main body of the craft will most likely disintegrate during the trip through Earth's atmosphere.
Although the plan was not part of Hayabusa's original mission, scientists at the Japan Aerospace Exploration Agency (JAXA) recently decided to make the most of the doomed probe's return.
"Even though Hayabusa is not actually an asteroid, it will be on a path that will cause it to collide with the Earth in the same way as an asteroid," said JAXA spokesperson Akinori Hashimoto. "We will monitor its movements, and the data will enable us to accurately predict the future paths of asteroids that are on course to come close to the Earth."
A Better Lookout
While other space agencies have programs for tracking asteroids that might hit Earth, JAXA doesn't yet have the ability to monitor these so-called near-Earth asteroids. So a team of researchers headed by Makoto Yoshikawa has developed a prototype system to calculate the trajectory, time, speed, and likelihood of an asteroid impact.
In October 2008, the team had a chance to test its system by tracking asteroid 2008 TC3, an incoming space rock about 13 feet (4 meters) wide that astronomers at the Catalina Sky Survey in Arizona had spotted a few hours before it became a fireball in the skies over Sudan.
The Telegraph
Fri, 12 Jun 2009 10:04 UTC
© unknown
Gerrit Blank survived a direct hit by a meteorite as it hurtled to Earth at more than 30,000 mph
Gerrit Blank survived a direct hit by a meteorite as it hurtled to Earth at more than 30,000 mph
Gerrit Blank, 14, was on his way to school when he saw "ball of light" heading straight towards him from the sky.
A red hot, pea-sized piece of rock then hit his hand before bouncing off and causing a foot wide crater in the ground.
The teenager survived the strike, the chances of which are just 1 in a million - but with a nasty three-inch long scar on his hand.
He said: "At first I just saw a large ball of light, and then I suddenly felt a pain in my hand.
"Then a split second after that there was an enormous bang like a crash of thunder."
"The noise that came after the flash of light was so loud that my ears were ringing for hours afterwards.
"When it hit me it knocked me flying and then was still going fast enough to bury itself into the road," he explained.
Scientists are now studying the pea-sized meteorite which crashed to Earth in Essen, Germany.
"I am really keen on science and my teachers discovered that the fragment is really magnetic," said Gerrit.
Chemical tests on the rock have proved it had fallen from space.
Ansgar Kortem, director of Germany's Walter Hohmann Observatory, said: "It's a real meteorite, therefore it is very valuable to collectors and scientists.
"Most don't actually make it to ground level because they evaporate in the atmosphere. Of those that do get through, about six out of every seven of them land in water," he added.
The only other known example of a human being surviving a meteor strike happened in Alabama, USA, in November 1954 when a grapefruit-sized fragment crashed through the roof of a house, bounced off furniture and landed on a sleeping woman.
Comment: Actually, these incidents are not as rare as we are made to believe. From our Comets and Catastrophe installment, read: Meteorites, Asteroids, and Comets: Damages, Disasters, Injuries, Deaths, and Very Close Calls
Press Association
Tue, 16 Jun 2009 12:37 UTC
Calls were made to stations from Hampshire down to Brixham in Devon and across to Jersey and France at about 9.30pm on Monday, with people saying they were seeing white and green flares in the sky.
A Solent Coastguard spokesman said: "There were reports of flares all down the coast which went on for about half an hour but there was a forecast for a meteor shower."
Meteor showers are caused by debris from a comet burning up in the Earth's atmosphere.
This can produce shooting stars across the night sky, particularly visible on clear nights, which was the case over southern England on Monday night.
Solent Coastguard said it could have been one of three showers forecast - the June Lyrids, the Ophruchids or the Zeta Pearseids.
John Hayes
UFOINFO
Mon, 15 Jun 2009 15:48 UTC
Posted: June 15, 2009
Date: May 23, 2009
Time: Approx: 6:00 a.m.
Number of witnesses: 2
Number of Objects: 1
Shape of Objects: Round
Full Description of Event/Sighting: Saw what looked like a really large bright star in the sky. We were looking in a easterly direction. My husband left and I continued to look up at the bright light. It suddenly started to fade away like it was something flying away.
We also saw a meteor or something enter the atmosphere around the time of the Lyrid meteor shower. It has a fireball tail. We both saw it. It was around 3:00am in the morning on I think the 22 April 2009. These are most probably both natural phenomenon?
Several
years ago-well, about 65 to 97 million years ago-a gigantic meteorite
struck the earth just east of present-day Kentland in northwestern
Indiana's Benton County.
How big was the meteorite? The best guess is that it or perhaps it was a comet ice mass left a circular crater dome measuring about 4 ½ miles in diameter. The entire "disturbed area" is about eight miles in diameter.
The meteorite hit with such force and velocity that, as it plunged into the earth, it lifted Shakopee dolomite (rock resembling limestone from the Ordovician period) up to the planet's surface from some 2,000 feet below. Much of this rock then stood vertically rather than horizontally. Eventually, over the eons, glaciers and water eroded away much of the crater, but still leaving numerous stone outcroppings.
It became what modern-day meteorologists and geologists call the Kentland Crater, the fourth largest known impact site in the United States. They've been studying the crater for the past 70 years.
Here's the time to explain that, despite the evidence, some believe what happened was not a meteorite strike but rather an earthquake or explosion of gases erupting up through the earth's surface.
In
more modern times, rock from the site was quarried, beginning around
1880. Mostly its major product was crushed stone for road building. It
still is a large working quarry today, operated by Rogers Group, Inc.,
as Newton County Stone.
Interest in the crater remains so strong that Susan Daniel, community relations coordinator for the company, spends considerable time conducting tours and answering questions about the crater.
While school children show up by the bus loads and geologists and meteorologists still beat a path to the crater site, interestingly enough many Hoosiers never have heard of it. As a matter of fact, I've mentioned it to perhaps as many as 50 persons and only one had any idea what I was talking about.
Nor is visiting the crater site the easiest thing to do.
If the area has had recent rain, passage down into the quarry becomes difficult. My friend Howie Snider and I had to cancel three proposed trips because of rain. Certainly you want to call Susan Daniel to make arrangements for your visit.
Finally,
we had a good day. After showing us some rocks from the quarry and
explaining how the operation functions, Susan piled Howie and me into
her truck and away we went. First we traveled down in the quarry to the
raised platform where visitors usually are taken. It provides a
panoramic view.
I'm not sure I can describe the other twists and turns we took as we explored other parts of the quarry. I was especially looking for photo possibilities showing the vertical rock structure still visible in a number of quarry walls.
Hard to believe but two hours had passed by the time when we returned to the quarry office.
Reports
of strange lights in the sky and distress flares being fired in the
English Channel actually turned out to be a meteor shower, coastguards
say.
Calls were made to coastguards across England's south coast, including Cornwall, Devon and Hampshire, reporting white and green flares.
Reports were also made to coastguards in Jersey and France for about 30 minutes from about 2130 BST on Monday.
Solent coastguards said three such showers had been forecast.
Meteor showers are caused by debris from a comet burning up in the Earth's atmosphere.
This can produce shooting stars across the night sky, particularly visible on clear nights, which was the case over southern England on Monday night.
Such showers can be forecast because the earth follows the same path around the Sun every year.
'Real treat'
This means it always crosses a comet trail at the same point in its orbit and meteor showers can be seen at the same time every year.
A Solent Coastguard spokesman said: "There were reports of flares all down the coast which went on for about half an hour but there was a forecast for a meteor shower."
The spokesman said it could have been one of three showers forecast: the June Lyrids, the Ophruchids or the Zeta Perseids.
Round-the-world yachtswoman Dee Caffari and her all-women crew were setting sail off the Isle of Wight at the time of the shower on an attempt to break the round-Britain and Ireland record.
She said the display was "a real treat".
She said: "For a minute there last night I thought we had made such good progress that we were seeing the Northern Lights.
"We later learned that the pyrotechnic display was actually a meteor shower, which was an amazing sight."
Date: May 23, 2009
Time: Approx: 6:00 a.m.
Number of witnesses: 2
Number of Objects: 1
Shape of Objects: Round
Full Description of Event/Sighting: Saw what looked like a really large bright star in the sky. We were looking in a easterly direction. My husband left and I continued to look up at the bright light. It suddenly started to fade away like it was something flying away.
We also saw a meteor or something enter the atmosphere around the time of the Lyrid meteor shower. It has a fireball tail. We both saw it. It was around 3:00am in the morning on I think the 22 April 2009. These are most probably both natural phenomenon?
fwdailynews.com
Sun, 14 Jun 2009 19:14 UTC
© Earl Conn
Geological map in the Benton County Stone office which shows the focal point of where a meteorite struck millions of years ago.
Geological map in the Benton County Stone office which shows the focal point of where a meteorite struck millions of years ago.
How big was the meteorite? The best guess is that it or perhaps it was a comet ice mass left a circular crater dome measuring about 4 ½ miles in diameter. The entire "disturbed area" is about eight miles in diameter.
The meteorite hit with such force and velocity that, as it plunged into the earth, it lifted Shakopee dolomite (rock resembling limestone from the Ordovician period) up to the planet's surface from some 2,000 feet below. Much of this rock then stood vertically rather than horizontally. Eventually, over the eons, glaciers and water eroded away much of the crater, but still leaving numerous stone outcroppings.
It became what modern-day meteorologists and geologists call the Kentland Crater, the fourth largest known impact site in the United States. They've been studying the crater for the past 70 years.
Here's the time to explain that, despite the evidence, some believe what happened was not a meteorite strike but rather an earthquake or explosion of gases erupting up through the earth's surface.
© Earl Conn
Vertical structure in the Benton County Stone quarry is evident in this photo taken down in the quarry
Vertical structure in the Benton County Stone quarry is evident in this photo taken down in the quarry
Interest in the crater remains so strong that Susan Daniel, community relations coordinator for the company, spends considerable time conducting tours and answering questions about the crater.
While school children show up by the bus loads and geologists and meteorologists still beat a path to the crater site, interestingly enough many Hoosiers never have heard of it. As a matter of fact, I've mentioned it to perhaps as many as 50 persons and only one had any idea what I was talking about.
Nor is visiting the crater site the easiest thing to do.
If the area has had recent rain, passage down into the quarry becomes difficult. My friend Howie Snider and I had to cancel three proposed trips because of rain. Certainly you want to call Susan Daniel to make arrangements for your visit.
© Earl Conn
Rock is slanted vertically in another part of the Benton County Stone quarry
Rock is slanted vertically in another part of the Benton County Stone quarry
I'm not sure I can describe the other twists and turns we took as we explored other parts of the quarry. I was especially looking for photo possibilities showing the vertical rock structure still visible in a number of quarry walls.
Hard to believe but two hours had passed by the time when we returned to the quarry office.
BBC News
Wed, 17 Jun 2009 04:02 UTC
© Unknown
Coastguards said three meteor showers had been forecast
Coastguards said three meteor showers had been forecast
Calls were made to coastguards across England's south coast, including Cornwall, Devon and Hampshire, reporting white and green flares.
Reports were also made to coastguards in Jersey and France for about 30 minutes from about 2130 BST on Monday.
Solent coastguards said three such showers had been forecast.
Meteor showers are caused by debris from a comet burning up in the Earth's atmosphere.
This can produce shooting stars across the night sky, particularly visible on clear nights, which was the case over southern England on Monday night.
Such showers can be forecast because the earth follows the same path around the Sun every year.
'Real treat'
This means it always crosses a comet trail at the same point in its orbit and meteor showers can be seen at the same time every year.
A Solent Coastguard spokesman said: "There were reports of flares all down the coast which went on for about half an hour but there was a forecast for a meteor shower."
The spokesman said it could have been one of three showers forecast: the June Lyrids, the Ophruchids or the Zeta Perseids.
Round-the-world yachtswoman Dee Caffari and her all-women crew were setting sail off the Isle of Wight at the time of the shower on an attempt to break the round-Britain and Ireland record.
She said the display was "a real treat".
She said: "For a minute there last night I thought we had made such good progress that we were seeing the Northern Lights.
"We later learned that the pyrotechnic display was actually a meteor shower, which was an amazing sight."
Tudor Vieru
Softpedia
Tue, 16 Jun 2009 22:46 UTC
Captains have reported distress signals in the sky
A number of captains, sailing their ships in the crowded waters of the English Channel on Monday night, signaled to the coastguard services in France and the United Kingdom, saying that they noticed warning flares in the night sky. The lights, they reported, were either white or bright green, and they urged authorities to take steps to save the ships in distress. The cause of the strange phenomenon, which began at around 21:30 BST (2030 GMT), was quickly found to be an expected meteor shower, of which the boat captains in the area had no idea.
Three successive meteor showers were visible yesterday, all coming from the same comet passing near our planet. Astronomers had predicted the shower in advance, and this was made possible by the fact that our planet takes roughly the same course around the Sun every year. Comets and other celestial bodies slamming into our planet's atmosphere are the things that produce what are known as "shooting stars," swarms of meteorites that plummet to the ground at large speeds, which causes them to burn up.
"There were reports of flares all down the coast which went on for about half an hour, but there was a forecast for a meteor shower," a Solent Coastguard spokesman explained to the BBC News. Because most meteor showers are regular occurrences in the evening skies, and are particularly visible when there are no clouds, some of them have names. The spokesman said that the one seen the night before might be either June Lyrids, or the Ophruchids, or maybe the Zeta Perseids.
"For a minute there last night I thought we had made such good progress that we were seeing the Northern Lights. We later learned that the pyrotechnic display was actually a meteor shower, which was an amazing sight," the British news agency quoted Dee Caffari, a yachtswoman, as saying. She was sailing in the English Channel last night as well, along with her all-women crew, in an attempt to break the record at sailing around England and Ireland.
A number of captains, sailing their ships in the crowded waters of the English Channel on Monday night, signaled to the coastguard services in France and the United Kingdom, saying that they noticed warning flares in the night sky. The lights, they reported, were either white or bright green, and they urged authorities to take steps to save the ships in distress. The cause of the strange phenomenon, which began at around 21:30 BST (2030 GMT), was quickly found to be an expected meteor shower, of which the boat captains in the area had no idea.
Three successive meteor showers were visible yesterday, all coming from the same comet passing near our planet. Astronomers had predicted the shower in advance, and this was made possible by the fact that our planet takes roughly the same course around the Sun every year. Comets and other celestial bodies slamming into our planet's atmosphere are the things that produce what are known as "shooting stars," swarms of meteorites that plummet to the ground at large speeds, which causes them to burn up.
"There were reports of flares all down the coast which went on for about half an hour, but there was a forecast for a meteor shower," a Solent Coastguard spokesman explained to the BBC News. Because most meteor showers are regular occurrences in the evening skies, and are particularly visible when there are no clouds, some of them have names. The spokesman said that the one seen the night before might be either June Lyrids, or the Ophruchids, or maybe the Zeta Perseids.
"For a minute there last night I thought we had made such good progress that we were seeing the Northern Lights. We later learned that the pyrotechnic display was actually a meteor shower, which was an amazing sight," the British news agency quoted Dee Caffari, a yachtswoman, as saying. She was sailing in the English Channel last night as well, along with her all-women crew, in an attempt to break the record at sailing around England and Ireland.
New York Times
Tue, 29 May 2001 16:03 UTC
In the early darkness of April 23, as Washington was beginning to relax
after the spy plane crisis in China, alarm bells began to go off on the
military system that monitors the globe for nuclear blasts.
Orbiting satellites that keep watch for nuclear attack had detected a blinding flash of light over the Pacific several hundred miles southwest of Los Angeles. On the ground, shock waves were strong enough to register halfway around the world.
Tension reignited until the Pentagon could reassure official Washington that the flash was not a nuclear blast. It was a speeding meteoroid from outer space that had crashed into the earth's atmosphere, where it exploded in an intense fireball.
"There was a big flurry of activity," recalled Dr. Douglas O. ReVelle, a federal scientist who helps run the military detectors. "Events like this don't happen all the time."
Preliminary estimates, Dr. ReVelle said, are that the cosmic intruder was the third largest since the Pentagon began making global satellite observations a quarter century ago. Its explosion in the atmosphere had nearly the force of the atomic bomb dropped on Hiroshima.
The episode shows how the system that warns of missile attack and clandestine nuclear blasts is fast evolving to detect bomb-size meteors as well. Now, it finds them about once a month, on average. But Dr. ReVelle, a scientist at the Los Alamos National Laboratory in New Mexico, said in an interview that the developing system was likely to find many more of the natural blasts in the years ahead.
"The real number is probably bigger," he said. "There's no doubt about that. But we don't know how much bigger."
Already, the system has shown that the planet is being continually struck by large speeding rocks, and that the rate of bombardment is higher than previously thought. The blasts light the sky with brilliant fireballs but people seldom see the blasts because they usually occur over the sea or uninhabited lands.
The rocky objects are anywhere from a few feet to about 80 feet wide. They vanish in titanic explosions high in the atmosphere, their enormous energy of motion converted almost instantly into vast amounts of heat and light.
The Air Force did not publicly disclose its imaging of the recent blast until late May, more than a month afterward. In a terse release on May 25, its Technical Applications Center, at Patrick Air Force Base in Florida, said the flash was "non- nuclear" and consistent with past observed meteor explosions.
A Defense Department satellite, the Air Force said, detected bright flashes over a period of more than two seconds.
After that disclosure, Los Alamos got the military's permission to reveal its own detection of the April event. Its ground-based sensors are even more sensitive than orbiting satellites to the repercussions of meteor blasts. The ground-based sensors work like sensitive ears to detect very low-frequency sound waves, which radiate outward from an exploding rock over hundreds and thousands of miles.
The sensors record sounds well below the range of human hearing, including those from underground nuclear tests as well as atmospheric blasts.
Dr. ReVelle said four arrays of the lab's sound sensors had picked up the April blast. In addition, he said, sound detectors in Los Angeles, Hawaii, Alaska, Canada and Germany had picked up its shock waves. Two sensors in South America made tentative detections, he added.
"It was a big event," he said. "There are people worrying about impacts on the earth, and these things are giving us a better understanding of the impact rate. That's the real byproduct scientifically."
The speeding boulder was perhaps 12 feet wide, he added.
An even more sensitive global ear is emerging as the world's nations try to monitor the Comprehensive Test Ban Treaty, a tentative accord that seeks to end the exploding of nuclear arms and to police compliance. When finished in the next year or so, the global acoustic system is to consist of 60 arrays that give complete global coverage, increasing the odds that even more large meteor impacts will be detected.
The disclosure of such intruders is seen as bolstering the idea that the earth is periodically subjected to strikes by even larger objects, including doomsday rocks a few miles wide. Objects this size are predicted to hit once every 10 million years or so, causing mayhem and death on a planetary scale.
Orbiting satellites that keep watch for nuclear attack had detected a blinding flash of light over the Pacific several hundred miles southwest of Los Angeles. On the ground, shock waves were strong enough to register halfway around the world.
Tension reignited until the Pentagon could reassure official Washington that the flash was not a nuclear blast. It was a speeding meteoroid from outer space that had crashed into the earth's atmosphere, where it exploded in an intense fireball.
"There was a big flurry of activity," recalled Dr. Douglas O. ReVelle, a federal scientist who helps run the military detectors. "Events like this don't happen all the time."
Preliminary estimates, Dr. ReVelle said, are that the cosmic intruder was the third largest since the Pentagon began making global satellite observations a quarter century ago. Its explosion in the atmosphere had nearly the force of the atomic bomb dropped on Hiroshima.
The episode shows how the system that warns of missile attack and clandestine nuclear blasts is fast evolving to detect bomb-size meteors as well. Now, it finds them about once a month, on average. But Dr. ReVelle, a scientist at the Los Alamos National Laboratory in New Mexico, said in an interview that the developing system was likely to find many more of the natural blasts in the years ahead.
"The real number is probably bigger," he said. "There's no doubt about that. But we don't know how much bigger."
Already, the system has shown that the planet is being continually struck by large speeding rocks, and that the rate of bombardment is higher than previously thought. The blasts light the sky with brilliant fireballs but people seldom see the blasts because they usually occur over the sea or uninhabited lands.
The rocky objects are anywhere from a few feet to about 80 feet wide. They vanish in titanic explosions high in the atmosphere, their enormous energy of motion converted almost instantly into vast amounts of heat and light.
The Air Force did not publicly disclose its imaging of the recent blast until late May, more than a month afterward. In a terse release on May 25, its Technical Applications Center, at Patrick Air Force Base in Florida, said the flash was "non- nuclear" and consistent with past observed meteor explosions.
A Defense Department satellite, the Air Force said, detected bright flashes over a period of more than two seconds.
After that disclosure, Los Alamos got the military's permission to reveal its own detection of the April event. Its ground-based sensors are even more sensitive than orbiting satellites to the repercussions of meteor blasts. The ground-based sensors work like sensitive ears to detect very low-frequency sound waves, which radiate outward from an exploding rock over hundreds and thousands of miles.
The sensors record sounds well below the range of human hearing, including those from underground nuclear tests as well as atmospheric blasts.
Dr. ReVelle said four arrays of the lab's sound sensors had picked up the April blast. In addition, he said, sound detectors in Los Angeles, Hawaii, Alaska, Canada and Germany had picked up its shock waves. Two sensors in South America made tentative detections, he added.
"It was a big event," he said. "There are people worrying about impacts on the earth, and these things are giving us a better understanding of the impact rate. That's the real byproduct scientifically."
The speeding boulder was perhaps 12 feet wide, he added.
An even more sensitive global ear is emerging as the world's nations try to monitor the Comprehensive Test Ban Treaty, a tentative accord that seeks to end the exploding of nuclear arms and to police compliance. When finished in the next year or so, the global acoustic system is to consist of 60 arrays that give complete global coverage, increasing the odds that even more large meteor impacts will be detected.
The disclosure of such intruders is seen as bolstering the idea that the earth is periodically subjected to strikes by even larger objects, including doomsday rocks a few miles wide. Objects this size are predicted to hit once every 10 million years or so, causing mayhem and death on a planetary scale.
Flashback:
The Infrasound Renaissance
GeoTimes
Fri, 18 Jun 2004 17:10 UTC
On April 23, 2001, scientists manning a network designed to detect
covert nuclear tests noticed something unusual - a very "loud" sound
coming from above the Pacific Ocean. This global network, consisting of
sensitive sound-recording instruments, had picked up on a large meteor
slamming into the atmosphere several hundred miles west of Baja
California, and exploding with a force comparable to that of the
nuclear bomb that was dropped on Hiroshima.
On Feb. 1, 2003, these same instruments heard something else - the Space Shuttle Columbia reentering Earth's atmosphere on its tragic final mission. NASA subsequently used those recordings to rule out potential causes of the mission's demise, including a bolide or missile impact.
The sensitive instruments that recorded the meteor's entrance and the end of the Columbia record a range of low-frequency sound that is inaudible to the human ear called infrasound. "It's sort of like infrared light, which is the part of the electromagnetic spectrum that we can't see, in that it's the part of the sound spectrum that we can't hear," says Michael Hedlin, a geophysicist and infrasound specialist at the University of California, San Diego, and Scripps Institution of Oceanography.
The instruments detect atmospheric noise, such as storms, winds, volcanic eruptions, ocean waves and airplane traffic, and they help scientists understand "just what's going on out there," Hedlin says. "Right now, we're just listening to the world," he says, but soon, the researchers will begin to more fully comprehend the interactions between solid earth, the oceans and the atmosphere.
An explosive history
When the Krakatoa volcano erupted in Indonesia in 1883, the eruption was so explosive that it sent low-frequency sound waves around the world several times. Scientists noticed the sound waves through air pressure changes measured by barometers. That was the first recorded instance of infrasound.
Around the turn of the 20th century, scientists recorded a giant meteor exploding above Russia. During World War II, the instruments recorded aircraft movement and munitions explosions. During the Cold War, scientists and the U.S. Department of Defense used the instruments to monitor nuclear bomb tests in the atmosphere.
Then in the late 1960s, the application of infrasound for monitoring nuclear tests around the world became limited by the development of reliable satellite technology, which could see atmospheric nuclear explosions and the subsequent onset of underground testing, which was monitored by seismic data. "So the field sort of went away for 30 years," says Milton Garces, a volcanologist, oceanographer and infrasound specialist at the University of Hawaii. "But luckily, there were a few individuals who kept the knowledge alive," he says. And then, in 1996, the world adopted the Comprehensive Test Ban Treaty, which brought about "a renaissance for infrasound," Garces says.
To enforce compliance with the treaty, the United Nations created the International Monitoring System (IMS), a network of geophysical sensor stations located around the world that monitor seismic signals, atmospheric radioactive material releases, hydroacoustic signals and infrasound, Hedlin says (Geotimes, October 2002). Luckily, he says, so far they haven't heard any nuclear tests - only a plethora of atmospheric sounds.
At work
The IMS infrasound network will eventually contain about 60 stations somewhat evenly distributed around the world, but it is only about one-third complete right now, Garces says. "We hope it'll be all up and running in the next couple of years," he says, "but that might be a little optimistic." Nevertheless, the scientists are already recording more information than they can comprehend, he says.
The infrasound instruments (microbarometers) work similarly to basic barometers that meteorologists use to detect weather patterns through atmospheric pressures. Resembling large thermos bottles, the microbarometers contain sensitive electronic instruments that convert atmospheric pressure to an electric signal. The sensors are connected to white wagon-wheel spokes of PVC piping that filter "unimportant sounds from important sounds," Garces says, and keep animals and debris away.
The instruments constantly measure ambient atmospheric sound waves and transmit them to the International Data Center in Vienna, Austria, which keeps all data related to the test ban treaty. The data then go to a data center in McLean, Va., and also back to the lab that operates the station, where the scientists do their own analysis in-house, Garces says.
"Truthfully, most of the time we don't know what we're listening to," says Henry Bass, a physicist and infrasound specialist at the University of Mississippi. "We receive hundreds of thousands of signals each year and we can only tell what a small fraction of them are," he says. But the more the scientists listen, the better they get at differentiating one sound from another and picking out the important information from the clutter.
"Each station is kind of like your neighborhood," Garces says. "You live there for a year and slowly begin to understand what's going on, all of the idiosyncracies of your neighbors. You have that chatty neighbor - you train yourself to cut out all the chatter and learn to recognize what is important. That's what we do with each station."
After three years of continuous observation, the scientists are now beginning to see patterns and differentiate the sounds emanating from storm fronts, explosions, ocean waves, volcanoes and jet airplanes. For example, Garces says, "the ocean is always singing in this deep bass voice. Now we know what its tune is, so we can pick up on swells and storms."
The researchers have also noticed strong seasonal patterns, Hedlin says, which has been "really exciting." From the station nearest San Diego, for example, the researchers hear a lot more signals from the west in the winter and from the east in the summer, which is related to seasonal wind patterns.
In general, stations will pick up atmospheric sounds from hundreds to thousands of miles away, Hedlin says, but those data are not well understood yet. The scientists monitoring the transmissions can always tell the direction of the recording, but the distance is harder to discern. Furthermore, depending on winds and the strength of a signal, the stations can register waves from around the world.
Ash warnings
Hedlin, Garces and Bass work on a number of applications in concert, although each has their own pet project. Hedlin pays close attention to storms in the Pacific. Garces concentrates on infrasound emitted from the constantly erupting Hawaiian volcanoes as well as sounds of the ocean. Bass focuses on using infrasound to create a 3-D image of the internal structures of the atmosphere (tomography). Together, all three scientists are developing a project that uses infrasound to create a volcanic ash warning system for airplanes.
When volcanoes erupt, they frequently lift large plumes of ash and dust thousands of feet into the atmosphere. To a pilot, the ash and dust can resemble regular clouds; however, if a plane flies into that ash plume, the engines will fail. "Especially in volcanically active remote areas over which planes fly, we'd like to work out a system to warn pilots of eruptions to divert them around the ash clouds," Bass says.
Seismic sensors note any rumbling in volcanoes. But rumbling does not necessarily mean there is an ash release, Garces says. Currently, scientists work with airline companies to divert planes around any rumbling volcano, but diversions can be costly. "And much of the time, those are false alarms," Bass says. If infrasound is in place, the scientists think they can detect the atmospheric disruption from the ash clouds and give the airlines precise rerouting information.
This project is in its infancy, Bass says, but the scientists hope to have sensors in place near some active volcanoes to test their theory by the end of this year. Right now, they are working with the U.S. and Canadian volcanic ash warning centers to get the project off the ground. It is an exciting application, Garces says, in which scientists can contribute to society.
"All of these projects are fascinating," Garces concludes. "We are just at the christening stage of infrasound, where we were with seismic technology 30 years ago. By working with the existing seismic, satellite and other observation networks, this technology has endless possibilities for teaching us about the world."
Belgian scientists have detected ultra-low frequency sound waves - infrasound - from a meteor that exploded over Germany in November 1999.
They were picked up by an observatory more use to searching for the particular infrasound signatures associated with nuclear explosions. It is one of the ways scientists can monitor for compliance with test ban treaties.
This particular meteor would have exploded with a force of 1.5 kilotons of TNT, equivalent to a small nuclear weapon.
The signals were detected by the seismology division of the Royal Netherlands Meteorological Institute.
Too low to hear
The world is full of sounds that humans cannot hear. Infrasound is too low for us but if we could hear it we would be deafened with the noise produced by thunderstorms, ocean waves, creaking continents and meteors.
Belgian scientists operate an infrasound observatory, which consists of an array of micro-barometers that detect very low-frequency (0.002 to 40 hertz) sound waves.
The array is part of a global network of about 60 facilities designed to "listen out" for nuclear weapon tests. The network keeps an "ear" on signatories to the Comprehensive Test Ban Treaty to see if they are meeting their obligations.
Writing in the Geophysical Research Letters, researchers describe an event they detected on 8 November, 1999.
Useful information
An intense burst of infrasound came from the northeast. It was later identified as a meteor explosion in the atmosphere over northern Germany. Several people provided eyewitness accounts of the flash in the sky.
From all the available data, it seems that the meteor exploded with the force of a small nuclear weapon at an altitude of about 15 km (9 miles).
Some astronomers are taking a keen interest in the worldwide infrasound monitoring network.
They hope it could provide valuable sources of data for estimating the number of unseen meteor explosions in our atmosphere.
Think of it as the extreme-sport version of listening for songbirds: Atmospheric scientists Douglas ReVelle, Rodney Whitaker, and Peter Brown are using microphone arrays to eavesdrop on the baritone rumblings of interplanetary rocks slamming into Earth's atmosphere.
Most of the time nobody sees them hit, but hearing them is much easier. A typical meteor arrives traveling 50 to 300 times the speed of sound, fast enough to create a powerful sonic boom and, if the object is large enough, an explosive flash. These disruptions stir up persistent low-frequency infrasound, similar to the waves from a nuclear test, which can travel thousands of miles without losing significant energy. And infrasound monitoring stations, including four arrays at Los Alamos National Laboratory and a network being built to verify the Comprehensive Test Ban Treaty, already exist to detect such waves anywhere in the world.
Combining input from these stations, ReVelle and his colleagues can figure out when and where meteors are striking; the pitch of the waves also indicates the size of the incoming body. The data show that a meteor as powerful as the Hiroshima A-bomb hits Earth once a year, while major fireballs arrive a couple of times a month. Overall, 500 tons of space debris rain down every day. One way or another such information could help avert disaster. "Sooner or later, Earth is going to get hit by a big object; we need to know how many of them are out there," ReVelle says. "And during the Gulf war, there was a big meteor event over the Pacific. Had it occurred over the Gulf, some government could have thought someone was shooting at them."
On Feb. 1, 2003, these same instruments heard something else - the Space Shuttle Columbia reentering Earth's atmosphere on its tragic final mission. NASA subsequently used those recordings to rule out potential causes of the mission's demise, including a bolide or missile impact.
The sensitive instruments that recorded the meteor's entrance and the end of the Columbia record a range of low-frequency sound that is inaudible to the human ear called infrasound. "It's sort of like infrared light, which is the part of the electromagnetic spectrum that we can't see, in that it's the part of the sound spectrum that we can't hear," says Michael Hedlin, a geophysicist and infrasound specialist at the University of California, San Diego, and Scripps Institution of Oceanography.
The instruments detect atmospheric noise, such as storms, winds, volcanic eruptions, ocean waves and airplane traffic, and they help scientists understand "just what's going on out there," Hedlin says. "Right now, we're just listening to the world," he says, but soon, the researchers will begin to more fully comprehend the interactions between solid earth, the oceans and the atmosphere.
An explosive history
When the Krakatoa volcano erupted in Indonesia in 1883, the eruption was so explosive that it sent low-frequency sound waves around the world several times. Scientists noticed the sound waves through air pressure changes measured by barometers. That was the first recorded instance of infrasound.
Around the turn of the 20th century, scientists recorded a giant meteor exploding above Russia. During World War II, the instruments recorded aircraft movement and munitions explosions. During the Cold War, scientists and the U.S. Department of Defense used the instruments to monitor nuclear bomb tests in the atmosphere.
Then in the late 1960s, the application of infrasound for monitoring nuclear tests around the world became limited by the development of reliable satellite technology, which could see atmospheric nuclear explosions and the subsequent onset of underground testing, which was monitored by seismic data. "So the field sort of went away for 30 years," says Milton Garces, a volcanologist, oceanographer and infrasound specialist at the University of Hawaii. "But luckily, there were a few individuals who kept the knowledge alive," he says. And then, in 1996, the world adopted the Comprehensive Test Ban Treaty, which brought about "a renaissance for infrasound," Garces says.
To enforce compliance with the treaty, the United Nations created the International Monitoring System (IMS), a network of geophysical sensor stations located around the world that monitor seismic signals, atmospheric radioactive material releases, hydroacoustic signals and infrasound, Hedlin says (Geotimes, October 2002). Luckily, he says, so far they haven't heard any nuclear tests - only a plethora of atmospheric sounds.
At work
© Fred Greaves, Scripps Institution of Oceanography
Geophysicist Michael Hedlin of the Scripps Institution of Oceanography monitors an international network of infrasound stations, like this one south of Palm Springs, Calif. The sensitive instruments that measure low-frequency sound waves resemble thermoses surrounded by wagon-wheel spokes of PVC piping.
Geophysicist Michael Hedlin of the Scripps Institution of Oceanography monitors an international network of infrasound stations, like this one south of Palm Springs, Calif. The sensitive instruments that measure low-frequency sound waves resemble thermoses surrounded by wagon-wheel spokes of PVC piping.
The IMS infrasound network will eventually contain about 60 stations somewhat evenly distributed around the world, but it is only about one-third complete right now, Garces says. "We hope it'll be all up and running in the next couple of years," he says, "but that might be a little optimistic." Nevertheless, the scientists are already recording more information than they can comprehend, he says.
The infrasound instruments (microbarometers) work similarly to basic barometers that meteorologists use to detect weather patterns through atmospheric pressures. Resembling large thermos bottles, the microbarometers contain sensitive electronic instruments that convert atmospheric pressure to an electric signal. The sensors are connected to white wagon-wheel spokes of PVC piping that filter "unimportant sounds from important sounds," Garces says, and keep animals and debris away.
The instruments constantly measure ambient atmospheric sound waves and transmit them to the International Data Center in Vienna, Austria, which keeps all data related to the test ban treaty. The data then go to a data center in McLean, Va., and also back to the lab that operates the station, where the scientists do their own analysis in-house, Garces says.
"Truthfully, most of the time we don't know what we're listening to," says Henry Bass, a physicist and infrasound specialist at the University of Mississippi. "We receive hundreds of thousands of signals each year and we can only tell what a small fraction of them are," he says. But the more the scientists listen, the better they get at differentiating one sound from another and picking out the important information from the clutter.
"Each station is kind of like your neighborhood," Garces says. "You live there for a year and slowly begin to understand what's going on, all of the idiosyncracies of your neighbors. You have that chatty neighbor - you train yourself to cut out all the chatter and learn to recognize what is important. That's what we do with each station."
After three years of continuous observation, the scientists are now beginning to see patterns and differentiate the sounds emanating from storm fronts, explosions, ocean waves, volcanoes and jet airplanes. For example, Garces says, "the ocean is always singing in this deep bass voice. Now we know what its tune is, so we can pick up on swells and storms."
The researchers have also noticed strong seasonal patterns, Hedlin says, which has been "really exciting." From the station nearest San Diego, for example, the researchers hear a lot more signals from the west in the winter and from the east in the summer, which is related to seasonal wind patterns.
In general, stations will pick up atmospheric sounds from hundreds to thousands of miles away, Hedlin says, but those data are not well understood yet. The scientists monitoring the transmissions can always tell the direction of the recording, but the distance is harder to discern. Furthermore, depending on winds and the strength of a signal, the stations can register waves from around the world.
Ash warnings
© USGS, Cascades Volcano Observatory
To airplane pilots, ash escaping from erupting volcanoes, such as Mount St. Helens (pictured here), can resemble normal clouds. Scientists can use infrasound to divert planes around erupting volcanoes.
To airplane pilots, ash escaping from erupting volcanoes, such as Mount St. Helens (pictured here), can resemble normal clouds. Scientists can use infrasound to divert planes around erupting volcanoes.
Hedlin, Garces and Bass work on a number of applications in concert, although each has their own pet project. Hedlin pays close attention to storms in the Pacific. Garces concentrates on infrasound emitted from the constantly erupting Hawaiian volcanoes as well as sounds of the ocean. Bass focuses on using infrasound to create a 3-D image of the internal structures of the atmosphere (tomography). Together, all three scientists are developing a project that uses infrasound to create a volcanic ash warning system for airplanes.
When volcanoes erupt, they frequently lift large plumes of ash and dust thousands of feet into the atmosphere. To a pilot, the ash and dust can resemble regular clouds; however, if a plane flies into that ash plume, the engines will fail. "Especially in volcanically active remote areas over which planes fly, we'd like to work out a system to warn pilots of eruptions to divert them around the ash clouds," Bass says.
Seismic sensors note any rumbling in volcanoes. But rumbling does not necessarily mean there is an ash release, Garces says. Currently, scientists work with airline companies to divert planes around any rumbling volcano, but diversions can be costly. "And much of the time, those are false alarms," Bass says. If infrasound is in place, the scientists think they can detect the atmospheric disruption from the ash clouds and give the airlines precise rerouting information.
This project is in its infancy, Bass says, but the scientists hope to have sensors in place near some active volcanoes to test their theory by the end of this year. Right now, they are working with the U.S. and Canadian volcanic ash warning centers to get the project off the ground. It is an exciting application, Garces says, in which scientists can contribute to society.
"All of these projects are fascinating," Garces concludes. "We are just at the christening stage of infrasound, where we were with seismic technology 30 years ago. By working with the existing seismic, satellite and other observation networks, this technology has endless possibilities for teaching us about the world."
Flashback:
Noisy end for meteor
Dr David Whitehouse
BBC News
Fri, 19 Jan 2001 16:06 UTC
© unknown
The burst of very-low frequency sound waves from the meteor explosion over Germany in November 1999.
The burst of very-low frequency sound waves from the meteor explosion over Germany in November 1999.
Belgian scientists have detected ultra-low frequency sound waves - infrasound - from a meteor that exploded over Germany in November 1999.
They were picked up by an observatory more use to searching for the particular infrasound signatures associated with nuclear explosions. It is one of the ways scientists can monitor for compliance with test ban treaties.
This particular meteor would have exploded with a force of 1.5 kilotons of TNT, equivalent to a small nuclear weapon.
The signals were detected by the seismology division of the Royal Netherlands Meteorological Institute.
Too low to hear
The world is full of sounds that humans cannot hear. Infrasound is too low for us but if we could hear it we would be deafened with the noise produced by thunderstorms, ocean waves, creaking continents and meteors.
Belgian scientists operate an infrasound observatory, which consists of an array of micro-barometers that detect very low-frequency (0.002 to 40 hertz) sound waves.
The array is part of a global network of about 60 facilities designed to "listen out" for nuclear weapon tests. The network keeps an "ear" on signatories to the Comprehensive Test Ban Treaty to see if they are meeting their obligations.
Writing in the Geophysical Research Letters, researchers describe an event they detected on 8 November, 1999.
Useful information
An intense burst of infrasound came from the northeast. It was later identified as a meteor explosion in the atmosphere over northern Germany. Several people provided eyewitness accounts of the flash in the sky.
From all the available data, it seems that the meteor exploded with the force of a small nuclear weapon at an altitude of about 15 km (9 miles).
Some astronomers are taking a keen interest in the worldwide infrasound monitoring network.
They hope it could provide valuable sources of data for estimating the number of unseen meteor explosions in our atmosphere.
Flashback:
The Sound of One Rock Falling
Fenella Saunders
Discover Magazine
Fri, 01 Feb 2002 17:18 UTC
© Antares Amateur Astronomers Group
A Leonid meteor bursts and sputters over Italy in this false-color computer reconstruction.
A Leonid meteor bursts and sputters over Italy in this false-color computer reconstruction.
Think of it as the extreme-sport version of listening for songbirds: Atmospheric scientists Douglas ReVelle, Rodney Whitaker, and Peter Brown are using microphone arrays to eavesdrop on the baritone rumblings of interplanetary rocks slamming into Earth's atmosphere.
Most of the time nobody sees them hit, but hearing them is much easier. A typical meteor arrives traveling 50 to 300 times the speed of sound, fast enough to create a powerful sonic boom and, if the object is large enough, an explosive flash. These disruptions stir up persistent low-frequency infrasound, similar to the waves from a nuclear test, which can travel thousands of miles without losing significant energy. And infrasound monitoring stations, including four arrays at Los Alamos National Laboratory and a network being built to verify the Comprehensive Test Ban Treaty, already exist to detect such waves anywhere in the world.
Combining input from these stations, ReVelle and his colleagues can figure out when and where meteors are striking; the pitch of the waves also indicates the size of the incoming body. The data show that a meteor as powerful as the Hiroshima A-bomb hits Earth once a year, while major fireballs arrive a couple of times a month. Overall, 500 tons of space debris rain down every day. One way or another such information could help avert disaster. "Sooner or later, Earth is going to get hit by a big object; we need to know how many of them are out there," ReVelle says. "And during the Gulf war, there was a big meteor event over the Pacific. Had it occurred over the Gulf, some government could have thought someone was shooting at them."
Flashback:
Asteroid affirms prediction program
Star Bulletin
Sat, 18 Oct 2008 17:55 UTC
A project on Maui aims to detect potentially hazardous comets and asteroids
Asteroids routinely hit the Earth's atmosphere but the impact by one over northern Africa Monday was the first time astronomers saw one coming and accurately predicted the time and place it would hit, a University of Hawaii astronomer said yesterday.
That successful prediction bodes well for a Maui-based system in development to warn against potentially hazardous space rocks, David Tholen said.
The impact occurred at 4:46 p.m. Hawaii time Monday over northern Sudan. A colleague compared the asteroid, called 2008 TC3, with the size of a Volkswagen, he said.
NASA's Jet Propulsion Laboratory in Pasadena, Calif., sent an e-mail saying the impact occurred yesterday at 2:46 a.m. universal time but provided no details, said Tholen, who hunts for hazardous near-Earth asteroids.
Tholen said more than 500 observations were made of the asteroid approaching Earth by astronomers all over the world, primarily in Europe and western Asia.
"It was the first opportunity to really test the whole impact-prediction software system on a real object," he said, adding that it was 100 percent accurate.
There was one report of a visual sighting by a KLM Airlines pilot, but it was far from the impact location and merely saw "a streak of light," he said.
The only other solid piece of data came from an infrasound station in Kenya that listens for very low-frequency sound waves and can detect the entry of fireballs, he said.
Asteroids create sonic booms, but a lot of the sound energy is lower in pitch than the human ear can hear, he said. The station detected sound waves at about the time the asteroid was predicted and within a few degrees of the impact location, he said.
The Mount Lemon telescope of the NASA-funded Catalina Sky Survey first observed the object early Monday. The Near Earth Object Observation program, called Spaceguard, plots the orbits of these objects to determine if any is a threat to Earth.
Calculations by the University of Pisa in Italy were reported to the International Astronomical Union's Minor Planet Center, located at the Harvard-Smithsonian Center for Astrophysics - the worldwide clearinghouse for asteroid and comet observations.
JPL and the University of Pisa have software for impact calculations, but some amateurs did their own calculations, which were "remarkably consistent" with professional groups, Tholen said.
Tholen said the episode "gives us a lot of confidence in the whole system of predicting when and where an asteroid impact would occur."
And when the Panoramic Survey Telescope and Rapid Response System under construction on Haleakala is up and running, "we should see more events like this," he said. Pan-STARRS' mission will be to detect potentially threatening asteroids and comets.
"These things happen every month or two and most of the time just go unnoticed, except people on the ground who see the fireball," Tholen said. "This time, astronomers saw it first and could predict the fireball. It was unique."
Asteroids routinely hit the Earth's atmosphere but the impact by one over northern Africa Monday was the first time astronomers saw one coming and accurately predicted the time and place it would hit, a University of Hawaii astronomer said yesterday.
That successful prediction bodes well for a Maui-based system in development to warn against potentially hazardous space rocks, David Tholen said.
The impact occurred at 4:46 p.m. Hawaii time Monday over northern Sudan. A colleague compared the asteroid, called 2008 TC3, with the size of a Volkswagen, he said.
NASA's Jet Propulsion Laboratory in Pasadena, Calif., sent an e-mail saying the impact occurred yesterday at 2:46 a.m. universal time but provided no details, said Tholen, who hunts for hazardous near-Earth asteroids.
Tholen said more than 500 observations were made of the asteroid approaching Earth by astronomers all over the world, primarily in Europe and western Asia.
"It was the first opportunity to really test the whole impact-prediction software system on a real object," he said, adding that it was 100 percent accurate.
There was one report of a visual sighting by a KLM Airlines pilot, but it was far from the impact location and merely saw "a streak of light," he said.
The only other solid piece of data came from an infrasound station in Kenya that listens for very low-frequency sound waves and can detect the entry of fireballs, he said.
Asteroids create sonic booms, but a lot of the sound energy is lower in pitch than the human ear can hear, he said. The station detected sound waves at about the time the asteroid was predicted and within a few degrees of the impact location, he said.
The Mount Lemon telescope of the NASA-funded Catalina Sky Survey first observed the object early Monday. The Near Earth Object Observation program, called Spaceguard, plots the orbits of these objects to determine if any is a threat to Earth.
Calculations by the University of Pisa in Italy were reported to the International Astronomical Union's Minor Planet Center, located at the Harvard-Smithsonian Center for Astrophysics - the worldwide clearinghouse for asteroid and comet observations.
JPL and the University of Pisa have software for impact calculations, but some amateurs did their own calculations, which were "remarkably consistent" with professional groups, Tholen said.
Tholen said the episode "gives us a lot of confidence in the whole system of predicting when and where an asteroid impact would occur."
And when the Panoramic Survey Telescope and Rapid Response System under construction on Haleakala is up and running, "we should see more events like this," he said. Pan-STARRS' mission will be to detect potentially threatening asteroids and comets.
"These things happen every month or two and most of the time just go unnoticed, except people on the ground who see the fireball," Tholen said. "This time, astronomers saw it first and could predict the fireball. It was unique."
Flashback:
The Rumble Of Destruction
David Perlman
San Francisco Chronicle
Mon, 24 Feb 2003 17:58 UTC
Denver - In rumbling tones far lower than the sounds that human ears
can hear, a symphony of mysterious noises constantly assails the entire
globe, and scientists are learning to translate and even to exploit the
inaudible signals.
Avalanches rumbling down mountainsides, the seething magma inside volcanoes as eruptions near, the violent twisting air of tornadoes and even the crash of ocean waves -- all send out ultra-long-wave, low-frequency vibrations known as infrasound.
Using sensitive instruments, scientists are studying whether detection of infrasound can provide advance warning of these natural disasters. They also are using infrasound to detect the nuclear weapon tests of enemy nations.
Infrasound is the opposite of the extreme high-frequency whistles that dogs can hear but humans can't, or the high-pitched ultrasound echolocation that bats use home in on their prey or that modern physicians use to create images of a fetus in the womb.
All sound waves are actually pulses of air pressure -- rapid pulses in the case of high-frequency sounds, and very slow-moving pressure waves with extremely long wavelengths in the infrasound ranges.
The frequency of sound waves are measured in hertz, after the 19th century German physicist Heinrch R. Hertz, who first measured them. The human ear can normally discern sounds ranging from a low of 20 Hz to a high of 20,000 Hz. Infrasound signals start below 20 Hz, but can be detected at frequencies as low as a hundredth, or even a thousandth of a hertz.
While ultrasound signals have a relatively short range and last only briefly, the long-lasting pressure waves of infrasound can be picked up by sensitive barometers at extraordinarily long distances.
When the giant Indonesian volcano Krakatoa erupted in 1883, for example, its infrasound waves were detected traveling more than three times around the globe. And two years ago, waves churned up by a tropical storm off Mexico generated infrasound signals that were detected by stations in Boulder, Colo.
At the annual meeting of the American Association for the Advancement of Science last week, Alfred J. Bedard Jr. described how he and his colleagues at the federal Environmental Technology Laboratory in Boulder are trying to use a network of infrasound detectors to warn of oncoming tornadoes.
The funnel-shaped columns twist powerfully and emit strong infrasound signals as they race above the countryside, threatening small towns and farms in the Midwest. Infrasound can signal their approach many minutes before they reach the ground, Bedard said.
Bedard's laboratory is also contracting with commercial firms to apply the technology at ski areas in the Rockies and the Sierra Nevada where inaudible rumblings from early avalanche movements can warn back-country skiers to stay away from the early buildup of downslope snow movements.
Most recently, Bedard and his colleagues reviewed infrasound data to see if they could detect anomalies in the infrasonic boom of the doomed space shuttle Columbia during its re-entry into Earth's atmosphere over California.
The most sensitive infrasound detection network is used to listen for nuclear weapon tests around the world. As the threat of such testing grows, more stations are being built, said Douglas Christie of the United Nation's Comprehensive Nuclear Test Ban Treaty Organization, known as the CTBTO.
Nearly 100 nations have ratified the treaty, and another 59 have signed it. Although the United States signed it during the Clinton administration, the Senate has refused to ratify it.
More than 60 test ban monitoring stations operate on every continent and even on small islands around the world, Christie said. Another half-dozen are under construction. The stations include a variety of instruments, including seismographs that can pick up signals from nuclear weapon blasts underground.
The U.N. nuclear test ban agency has tested the sensitivity of the infrasound detectors by recording the low-frequency rumbles of exploding meteors, known as bolides, as they enter the Earth's atmosphere.
Bolides explode with enormous energy. Douglas O. ReVelle, a meteorologist at Los Alamos National Laboratory, estimates that every year at least one bolide explodes over the Earth's surface with the force of 15 kilotons, or 15, 000 tons of TNT. (The atomic bomb dropped on Hiroshima in World War II was equivalent to about 12,500 tons of TNT).
Infrasound signals from at least five such bolides have been detected and located nearly 5,000 miles away, Revelle said. Los Alamos scientists have now installed low-frequency sound detectors to watch for bolides exploding over Los Angeles, Utah, Wyoming and at the Nevada nuclear weapon test site near Las Vegas.
Milton Garces, a physicist at the University of Hawaii, is studying how infrasound detectors might be useful to warn when volcanoes are ready to erupt -- because the lava moving up their throats emits powerful bursts of infrasound.
Those signals could give as much as a 30-minute warning of an eruption, Garces said. His group recently installed three detectors near the smaller erupting volcanic vents on the flanks of Kilauea, on the island of Hawaii.
"Each volcano has its own voice," Garces said. "A volcano that's quiet is purring, but when it's really ready to go, its infrasound voice gets louder and louder."
Of Elephants And Infrasound
One unusual but charming aspect of infrasound is that several species of animals use it to communicate, particularly in environments where visibility is difficult, as in the ocean or in dense forests.
Scientists have studied infrasound communication among whales and, more recently, land animals including giraffes, rhinos and elephants. Katy Payne, a Cornell University bioacoustics researcher, recently described what she observed among a group of elephants in Central Africa.
Payne first suspected that elephants might be using infrasound to communicate when she noticed "a throbbing in the air that I couldn't attribute to anything around me." She was always near the elephant cages when she felt the throbbing.
Biologists, she noted, had never studied the possibility of land animals making sounds below the frequencies people can hear.
"I thought maybe the elephants were generating that throbbing by making really powerful calls that were so low pitched that people couldn't hear them, " she said.
What she found is that elephants indeed have "an extensive vocabulary, including lots of sounds that are very rich in infrasound."
Low frequency sound travels much farther than sounds humans can hear. Perhaps, she wondered, infrasound is the basis for a long-distance communication system. That would explain all kinds of mysterious behaviors observed in elephants.
Payne and her colleagues are still investigating it, but she has described some of her field research on elephant infrasound in "Silent Thunder," a powerful plea for protecting the remarkable animals.
Infrasound At A Glance
Infrasound is a low frequency sound below the range of human hearing. It is produced by a variety of natural events - including earthquakes, volcanoes, avalanches, severe weather, ocean waves - and some man-made sources - including aircraft and explosions. It is also used by some animal species to communicate.
How is it different from audible sound?
One of the most interesting properties of infrasound waves is that they travel over global distances without losing their strength. So an instrument in Colorado can detect the sound of ocean waves hitting the coast in California or the roar of a typhoon halfway around the world.
How is it detected?
Infrasound wavelengths are so long that they can be detected only by sensors that take up a large ground area.
What is it used for?
A global infrasound sensor system is being deployed to detect nuclear weapons testing. Scientists are also studying ways to use infrasound to provide advance warning of natural disasters.
Avalanches rumbling down mountainsides, the seething magma inside volcanoes as eruptions near, the violent twisting air of tornadoes and even the crash of ocean waves -- all send out ultra-long-wave, low-frequency vibrations known as infrasound.
Using sensitive instruments, scientists are studying whether detection of infrasound can provide advance warning of these natural disasters. They also are using infrasound to detect the nuclear weapon tests of enemy nations.
Infrasound is the opposite of the extreme high-frequency whistles that dogs can hear but humans can't, or the high-pitched ultrasound echolocation that bats use home in on their prey or that modern physicians use to create images of a fetus in the womb.
All sound waves are actually pulses of air pressure -- rapid pulses in the case of high-frequency sounds, and very slow-moving pressure waves with extremely long wavelengths in the infrasound ranges.
The frequency of sound waves are measured in hertz, after the 19th century German physicist Heinrch R. Hertz, who first measured them. The human ear can normally discern sounds ranging from a low of 20 Hz to a high of 20,000 Hz. Infrasound signals start below 20 Hz, but can be detected at frequencies as low as a hundredth, or even a thousandth of a hertz.
While ultrasound signals have a relatively short range and last only briefly, the long-lasting pressure waves of infrasound can be picked up by sensitive barometers at extraordinarily long distances.
When the giant Indonesian volcano Krakatoa erupted in 1883, for example, its infrasound waves were detected traveling more than three times around the globe. And two years ago, waves churned up by a tropical storm off Mexico generated infrasound signals that were detected by stations in Boulder, Colo.
At the annual meeting of the American Association for the Advancement of Science last week, Alfred J. Bedard Jr. described how he and his colleagues at the federal Environmental Technology Laboratory in Boulder are trying to use a network of infrasound detectors to warn of oncoming tornadoes.
The funnel-shaped columns twist powerfully and emit strong infrasound signals as they race above the countryside, threatening small towns and farms in the Midwest. Infrasound can signal their approach many minutes before they reach the ground, Bedard said.
Bedard's laboratory is also contracting with commercial firms to apply the technology at ski areas in the Rockies and the Sierra Nevada where inaudible rumblings from early avalanche movements can warn back-country skiers to stay away from the early buildup of downslope snow movements.
Most recently, Bedard and his colleagues reviewed infrasound data to see if they could detect anomalies in the infrasonic boom of the doomed space shuttle Columbia during its re-entry into Earth's atmosphere over California.
The most sensitive infrasound detection network is used to listen for nuclear weapon tests around the world. As the threat of such testing grows, more stations are being built, said Douglas Christie of the United Nation's Comprehensive Nuclear Test Ban Treaty Organization, known as the CTBTO.
Nearly 100 nations have ratified the treaty, and another 59 have signed it. Although the United States signed it during the Clinton administration, the Senate has refused to ratify it.
More than 60 test ban monitoring stations operate on every continent and even on small islands around the world, Christie said. Another half-dozen are under construction. The stations include a variety of instruments, including seismographs that can pick up signals from nuclear weapon blasts underground.
The U.N. nuclear test ban agency has tested the sensitivity of the infrasound detectors by recording the low-frequency rumbles of exploding meteors, known as bolides, as they enter the Earth's atmosphere.
Bolides explode with enormous energy. Douglas O. ReVelle, a meteorologist at Los Alamos National Laboratory, estimates that every year at least one bolide explodes over the Earth's surface with the force of 15 kilotons, or 15, 000 tons of TNT. (The atomic bomb dropped on Hiroshima in World War II was equivalent to about 12,500 tons of TNT).
Infrasound signals from at least five such bolides have been detected and located nearly 5,000 miles away, Revelle said. Los Alamos scientists have now installed low-frequency sound detectors to watch for bolides exploding over Los Angeles, Utah, Wyoming and at the Nevada nuclear weapon test site near Las Vegas.
Milton Garces, a physicist at the University of Hawaii, is studying how infrasound detectors might be useful to warn when volcanoes are ready to erupt -- because the lava moving up their throats emits powerful bursts of infrasound.
Those signals could give as much as a 30-minute warning of an eruption, Garces said. His group recently installed three detectors near the smaller erupting volcanic vents on the flanks of Kilauea, on the island of Hawaii.
"Each volcano has its own voice," Garces said. "A volcano that's quiet is purring, but when it's really ready to go, its infrasound voice gets louder and louder."
Of Elephants And Infrasound
One unusual but charming aspect of infrasound is that several species of animals use it to communicate, particularly in environments where visibility is difficult, as in the ocean or in dense forests.
Scientists have studied infrasound communication among whales and, more recently, land animals including giraffes, rhinos and elephants. Katy Payne, a Cornell University bioacoustics researcher, recently described what she observed among a group of elephants in Central Africa.
Payne first suspected that elephants might be using infrasound to communicate when she noticed "a throbbing in the air that I couldn't attribute to anything around me." She was always near the elephant cages when she felt the throbbing.
Biologists, she noted, had never studied the possibility of land animals making sounds below the frequencies people can hear.
"I thought maybe the elephants were generating that throbbing by making really powerful calls that were so low pitched that people couldn't hear them, " she said.
What she found is that elephants indeed have "an extensive vocabulary, including lots of sounds that are very rich in infrasound."
Low frequency sound travels much farther than sounds humans can hear. Perhaps, she wondered, infrasound is the basis for a long-distance communication system. That would explain all kinds of mysterious behaviors observed in elephants.
Payne and her colleagues are still investigating it, but she has described some of her field research on elephant infrasound in "Silent Thunder," a powerful plea for protecting the remarkable animals.
Infrasound At A Glance
Infrasound is a low frequency sound below the range of human hearing. It is produced by a variety of natural events - including earthquakes, volcanoes, avalanches, severe weather, ocean waves - and some man-made sources - including aircraft and explosions. It is also used by some animal species to communicate.
How is it different from audible sound?
One of the most interesting properties of infrasound waves is that they travel over global distances without losing their strength. So an instrument in Colorado can detect the sound of ocean waves hitting the coast in California or the roar of a typhoon halfway around the world.
How is it detected?
Infrasound wavelengths are so long that they can be detected only by sensors that take up a large ground area.
What is it used for?
A global infrasound sensor system is being deployed to detect nuclear weapons testing. Scientists are also studying ways to use infrasound to provide advance warning of natural disasters.
CNN
Wed, 23 May 2001 18:10 UTC
Intelligence
scientists listening for covert nuclear blasts had their ears rattled
by other explosive sounds -- the detonation of meteors as they streaked
over the Pacific Ocean.
The Earth eavesdropping, conducted by researchers at the Los Alamos National Laboratory in New Mexico, was intended to detect atomic weapons tests by rogue nations or organizations in remote locations.
Instead, the Los Alamos listening stations picked up the sound of two large meteors as they plunged into the atmosphere off the coast of Mexico, the Los Alamos lab said this week.
The space rocks raced across the sky in April and August. But the lab waited to announce its findings until other U.S. space scientists last week confirmed the two objects.
The meteors were unusually big, between 6 and 10 feet in diameter. The first one created an explosive pressure wave with as much energy as 2,000 to 3,000 tons of TNT, according to Los Alamos researchers. The second, larger one could have produced a shock wave equivalent to 8,000 tons of TNT.
"Had anyone seen the April 23 event, they would have seen quite a show. That meteor was one of the five brightest ever recorded," Los Alamos scientist Doug ReVelle said.
Each year, listening stations at the lab record an average of 10 meteors 6 feet in diameter or greater. Those that appear as huge fireballs in the sky, like the April and August specimens, are known as bolides.
Bolides make dazzling displays dozens of miles above the planet. Fortunately, most explode into thousands of pieces or burn up entirely before they reach the surface. If these two survived, they probably smacked into the ocean, well away from populated regions, the scientists said.
The destructive capability of bolides that strike land is considerable. An extremely large one blasted the huge Meteor Crater in Arizona.
The unaided human ear cannot detect the low frequency pressure waves when at a great distance. But specialized microphones at four Los Alamos monitoring stations in the United States can both detect the infrasonic waves and help plot their locations.
The infrasonic information takes minutes or hours to reach the stations, which therefore cannot provide advance warning about approaching large meteors.
However, the Los Alamos scientists welcome the opportunity to monitor falling space rocks, which allows them to fine tune the instruments to use to detect nuclear blasts.
Comment: See Space.com's report: Best of the Web: Military Hush-Up: Incoming Space Rocks Now Classified
We propose that the witholding of information is because key authorities know that the risk of catastrophic impact from comet debris recently took at sharp upturn from possible to probable:
What are they hiding? Flight 447 and Tunguska Type Events
Comment: Let's not downplay the catastrophic effect that a "pebble from space" could have on those of us living on this planet.
A meteor exploding above the planet just may be what brought down Flight 447.
.
The Earth eavesdropping, conducted by researchers at the Los Alamos National Laboratory in New Mexico, was intended to detect atomic weapons tests by rogue nations or organizations in remote locations.
Instead, the Los Alamos listening stations picked up the sound of two large meteors as they plunged into the atmosphere off the coast of Mexico, the Los Alamos lab said this week.
The space rocks raced across the sky in April and August. But the lab waited to announce its findings until other U.S. space scientists last week confirmed the two objects.
The meteors were unusually big, between 6 and 10 feet in diameter. The first one created an explosive pressure wave with as much energy as 2,000 to 3,000 tons of TNT, according to Los Alamos researchers. The second, larger one could have produced a shock wave equivalent to 8,000 tons of TNT.
"Had anyone seen the April 23 event, they would have seen quite a show. That meteor was one of the five brightest ever recorded," Los Alamos scientist Doug ReVelle said.
Each year, listening stations at the lab record an average of 10 meteors 6 feet in diameter or greater. Those that appear as huge fireballs in the sky, like the April and August specimens, are known as bolides.
Bolides make dazzling displays dozens of miles above the planet. Fortunately, most explode into thousands of pieces or burn up entirely before they reach the surface. If these two survived, they probably smacked into the ocean, well away from populated regions, the scientists said.
The destructive capability of bolides that strike land is considerable. An extremely large one blasted the huge Meteor Crater in Arizona.
The unaided human ear cannot detect the low frequency pressure waves when at a great distance. But specialized microphones at four Los Alamos monitoring stations in the United States can both detect the infrasonic waves and help plot their locations.
The infrasonic information takes minutes or hours to reach the stations, which therefore cannot provide advance warning about approaching large meteors.
However, the Los Alamos scientists welcome the opportunity to monitor falling space rocks, which allows them to fine tune the instruments to use to detect nuclear blasts.
Geoff Brumfiel
Nature News
Fri, 12 Jun 2009 02:46 UTC
Satellite information on incoming meteors is blocked
The
US military has abruptly ended an informal arrangement that allowed
scientists access to data on incoming meteors from classified
surveillance satellites.
The change is a blow to the astronomers and planetary scientists who used the information to track space rocks, especially those that burn up over the oceans or in other remote locations. "These systems are extremely useful," says Peter Brown, an astronomer at the University of Western Ontario in London, Canada. "I think the scientific community benefited enormously."
When the policy changed is unclear. The website Space.com reported the end of the relationship on 10 June, but Brown says that he was told at the beginning of this year that there would be no further data releases. Mark Boslough, a physicist at Sandia National Laboratories in Albuquerque, New Mexico, says he was told this spring that he could no longer publicly discuss the classified data to which he had some access.
Neither scientist could give a reason for the end of the arrangement, and the United States Air Force, which operates the satellites, did not respond in time for Nature's deadline. The Air Force did issue a 16 March memo on the military classification of fireball data, but Nature could not confirm its contents.
The Defense Support Program satellite network is part of the Pentagon's early-warning system. Since 1970, 23 infrared satellites in the series have been launched into geosynchronous orbit to monitor the globe for missile launches or atmospheric nuclear blasts.
But the same infrared sensors were perfect for spotting fireballs as they streaked across the atmosphere, according to Brian Weeden, a former Air Force captain who now works at the Secure World Foundation, a non-profit organization based in Superior, Colorado. The satellites could precisely detect the time, position, altitude and brightness of meteors as they entered Earth's atmosphere. Weeden, who left the Air Force in 2007, says that the military didn't consider that information particularly useful, or classified. "It was being dropped on the floor," he says.
Under an informal arrangement, at least some of the data seem to have been provided on an ad-hoc basis to scientists studying meteorites. Often it came in the form of an anonymous, tersely worded e-mail describing the coordinates, altitude and size of a fireball. Brown, who has collected the data since 1994, declined to specify who sent the reports.
Even the short descriptions of events were enormously helpful. In 2002, Brown and his colleagues used a larger data set from the satellites to quantify the number of objects striking Earth each year (P. Brown et al. Nature 420, 294-296; 2002). Last year, they were used to narrow the search for remnants of the asteroid 2008 TC3 in the Sahara Desert in North Africa, and they were also crucial in recovering a meteorite fragment in 2000 from Tagish Lake in northern Canada. "In both of those cases it's hard to say whether this would have been picked up without
the satellite data," Boslough says.
The data also provide a useful check against ground-based instruments monitoring low-frequency sound waves and dust from the fireball explosions, says Brown.
Although the reason for ending the arrangement remains unclear, Weeden notes that it coincides with the launch of a new generation of surveillance satellites. The US$10-billion-plus Space-Based Infrared System will provide a more detailed infrared picture of Earth for battlefield surveillance, early-warning alerts and the US missile defence programme.
The first of these satellites was launched in 2006 in a highly elliptical orbit and entered operational service in November 2008, a month after Brown received his last report. In its final configuration, the system will include at least two satellites in highly elliptical orbit and three or more geosynchronous satellites for a whole-Earth view.
Weeden speculates that the Pentagon may not want details of the new satellites' capabilities to be made public, or it may simply lack the expensive software needed to handle classified and declassified data simultaneously. "The decision may have been made that it was perhaps too difficult to disclose just these data," he says.
Brown says that whatever the reason, the end of the relationship has left the tight-knit meteorite community smarting. The global reach of the satellites and the data they supplied were unparalleled, he says. "There's nothing else that even comes close," he says.
The change is a blow to the astronomers and planetary scientists who used the information to track space rocks, especially those that burn up over the oceans or in other remote locations. "These systems are extremely useful," says Peter Brown, an astronomer at the University of Western Ontario in London, Canada. "I think the scientific community benefited enormously."
When the policy changed is unclear. The website Space.com reported the end of the relationship on 10 June, but Brown says that he was told at the beginning of this year that there would be no further data releases. Mark Boslough, a physicist at Sandia National Laboratories in Albuquerque, New Mexico, says he was told this spring that he could no longer publicly discuss the classified data to which he had some access.
Neither scientist could give a reason for the end of the arrangement, and the United States Air Force, which operates the satellites, did not respond in time for Nature's deadline. The Air Force did issue a 16 March memo on the military classification of fireball data, but Nature could not confirm its contents.
The Defense Support Program satellite network is part of the Pentagon's early-warning system. Since 1970, 23 infrared satellites in the series have been launched into geosynchronous orbit to monitor the globe for missile launches or atmospheric nuclear blasts.
But the same infrared sensors were perfect for spotting fireballs as they streaked across the atmosphere, according to Brian Weeden, a former Air Force captain who now works at the Secure World Foundation, a non-profit organization based in Superior, Colorado. The satellites could precisely detect the time, position, altitude and brightness of meteors as they entered Earth's atmosphere. Weeden, who left the Air Force in 2007, says that the military didn't consider that information particularly useful, or classified. "It was being dropped on the floor," he says.
Under an informal arrangement, at least some of the data seem to have been provided on an ad-hoc basis to scientists studying meteorites. Often it came in the form of an anonymous, tersely worded e-mail describing the coordinates, altitude and size of a fireball. Brown, who has collected the data since 1994, declined to specify who sent the reports.
Even the short descriptions of events were enormously helpful. In 2002, Brown and his colleagues used a larger data set from the satellites to quantify the number of objects striking Earth each year (P. Brown et al. Nature 420, 294-296; 2002). Last year, they were used to narrow the search for remnants of the asteroid 2008 TC3 in the Sahara Desert in North Africa, and they were also crucial in recovering a meteorite fragment in 2000 from Tagish Lake in northern Canada. "In both of those cases it's hard to say whether this would have been picked up without
the satellite data," Boslough says.
The data also provide a useful check against ground-based instruments monitoring low-frequency sound waves and dust from the fireball explosions, says Brown.
Although the reason for ending the arrangement remains unclear, Weeden notes that it coincides with the launch of a new generation of surveillance satellites. The US$10-billion-plus Space-Based Infrared System will provide a more detailed infrared picture of Earth for battlefield surveillance, early-warning alerts and the US missile defence programme.
The first of these satellites was launched in 2006 in a highly elliptical orbit and entered operational service in November 2008, a month after Brown received his last report. In its final configuration, the system will include at least two satellites in highly elliptical orbit and three or more geosynchronous satellites for a whole-Earth view.
Weeden speculates that the Pentagon may not want details of the new satellites' capabilities to be made public, or it may simply lack the expensive software needed to handle classified and declassified data simultaneously. "The decision may have been made that it was perhaps too difficult to disclose just these data," he says.
Brown says that whatever the reason, the end of the relationship has left the tight-knit meteorite community smarting. The global reach of the satellites and the data they supplied were unparalleled, he says. "There's nothing else that even comes close," he says.
Comment: See Space.com's report: Best of the Web: Military Hush-Up: Incoming Space Rocks Now Classified
We propose that the witholding of information is because key authorities know that the risk of catastrophic impact from comet debris recently took at sharp upturn from possible to probable:
What are they hiding? Flight 447 and Tunguska Type Events
Jadyn Cassidy
All News Web
Sat, 20 Jun 2009 15:33 UTC
Something fell from the sky today and landed on a mountain near the
town of Gin-Gin in central Queensland in Australia. The object or UFO,
described by witnesses as a fireball, set nearby trees alight. A
subsequent search of the area failed to find any remains of whatever it
was that impacted the bush.
Most are declaring the object to be either space junk or a very small meteor that had entered the earth's atmosphere, however others are not sure. Is it possible that it was a UFO of extra-terrestrial origin?
According to Australian ufologist Michael Cohen 'unmanned' probes sent by an extra-terrestrial civilization to explore earth and other planets are entering the atmosphere through specific UFO vortex exits located at various points throughout the world. These vortex exits are currently being studied by government scientists. No such exits are believed to be located in the skies above Australia; however the super-fast travelling probes that enter earth through them are exploring all continents.
'This incident might well have been caused by one of these UFO probes' Cohen noted 'It might have run out of energy, failed for other reasons or been struck by lightning. Much about this incident is similar to other confirmed UFO crashes that are known have occurred on other continents, such as Asia and South America.'
'The probes generally disintegrate on impact, however thorough forensic sifting of the exact location of the crash might yield debris. Locals should keep an eye on who appears at the site over the next few days searching for remains. If the event seems to be attracting more attention than should a pebble from space, start suspecting something more exotic' Cohen concluded.
Most are declaring the object to be either space junk or a very small meteor that had entered the earth's atmosphere, however others are not sure. Is it possible that it was a UFO of extra-terrestrial origin?
According to Australian ufologist Michael Cohen 'unmanned' probes sent by an extra-terrestrial civilization to explore earth and other planets are entering the atmosphere through specific UFO vortex exits located at various points throughout the world. These vortex exits are currently being studied by government scientists. No such exits are believed to be located in the skies above Australia; however the super-fast travelling probes that enter earth through them are exploring all continents.
'This incident might well have been caused by one of these UFO probes' Cohen noted 'It might have run out of energy, failed for other reasons or been struck by lightning. Much about this incident is similar to other confirmed UFO crashes that are known have occurred on other continents, such as Asia and South America.'
'The probes generally disintegrate on impact, however thorough forensic sifting of the exact location of the crash might yield debris. Locals should keep an eye on who appears at the site over the next few days searching for remains. If the event seems to be attracting more attention than should a pebble from space, start suspecting something more exotic' Cohen concluded.
Comment: Let's not downplay the catastrophic effect that a "pebble from space" could have on those of us living on this planet.
A meteor exploding above the planet just may be what brought down Flight 447.
YouTube
Sat, 20 Jun 2009 03:03 UTC
.
Lee Williams
Star-Telegram
Mon, 22 Jun 2009 23:36 UTC
While most of the Metroplex was asleep early Monday a fireball shot across the sky, startling those who were still awake.
"It was huge," said Austin Babek, 18, who observed the light show from outside his south Arlington home. "It actually scared me it was so big."
Babek said he and a friend saw the fireball at 12:56 a.m. He said it lasted about five seconds and was bright orange with a long blue and green tail.
"I've seen shooting stars before but never anything like this," he said.
In an e-mail to the Star-Telegram, Lynda Edwards of Fort Worth described it as "so bright I could see it through the branches and leaves of my large pecan tree. It emerged on the other side of the tree and burnt out in the northwest sky."
Ron Dilulio, planetarium and astronomy lab director at the University of North Texas, is out of town on a field trip, but said based on descriptions, it was "more than likely a meteor."
Posted: June 22, 2009
Date: May 30 2009
Time: 11pm round about
Number of witnesses: 4
Number of objects: 3
Shape of objects: Ball
Weather Conditions: No wind no cloud
Description: My neighbour called me up on the phone to get me to look out in the sky from my back garden, she thought it could be some sort of flare. When I had a look it looked very much like a orange ball of fire. Thought maybe a meteor, none that I have ever seen before. Too big to be a helicopter in the distance, no flashing lights, def not a plane. It seemed to stop for a little while as if hovering then changed its course, did a semi circle. No sooner had it faded another one appeared doing the same thing. Although as this one hovered, another one appeared. I would have took a pic but I could not pull myself away from watching them. Any clue what they could have been?
Comment: Here is the original report on this incident.
The
mysterious 1908 Tunguska explosion that leveled 830 square miles of
Siberian forest was almost certainly caused by a comet entering the
Earth's atmosphere, says new Cornell University research. The
conclusion is supported by an unlikely source: the exhaust plume from
the NASA space shuttle launched a century later.
The research, accepted for publication (June 24, 2009) by the journal Geophysical Research Letters, published by the American Geophysical Union, connects the two events by what followed each about a day later: brilliant, night-visible clouds, or noctilucent clouds, that are made up of ice particles and only form at very high altitudes and in extremely cold temperatures.
"It's almost like putting together a 100-year-old murder mystery," said Michael Kelley, the James A. Friend Family Distinguished Professor of Engineering at Cornell who led the research team. "The evidence is pretty strong that the Earth was hit by a comet in 1908." Previous speculation had ranged from comets to meteors.
The researchers contend that the massive amount of water vapor spewed into the atmosphere by the comet's icy nucleus was caught up in swirling eddies with tremendous energy by a process called two-dimensional turbulence, which explains why the noctilucent clouds formed a day later many thousands of miles away.
Noctilucent clouds are the
Earth's highest clouds, forming naturally in the mesosphere at about 55
miles over the polar regions during the summer months when the
mesosphere is around minus 180 degrees Fahrenheit (minus 117 degrees
Celsius).
The space shuttle exhaust plume, the researchers say, resembled the comet's action.
A single space shuttle flight injects 300 metric tons of water vapor into the Earth's thermosphere, and the water particles have been found to travel to the Arctic and Antarctic regions, where they form the clouds after settling into the mesosphere.
Kelley and collaborators saw the noctilucent cloud phenomenon days after the space shuttle Endeavour (STS-118) launched on Aug. 8, 2007. Similar cloud formations had been observed following launches in 1997 and 2003.
Following the 1908 explosion, known as the Tunguska Event, the night skies shone brightly for several days across Europe, particularly Great Britain -- more than 3,000 miles away.
Kelley said he became intrigued by the historical eyewitness accounts of the aftermath, and concluded that the bright skies must have been the result of noctilucent clouds. The comet would have started to break up at about the same altitude as the release of the exhaust plume from the space shuttle following launch. In both cases, water vapor was injected into the atmosphere.
The scientists have attempted to answer how this water vapor traveled so far without scattering and diffusing, as conventional physics would predict.
"There is a mean transport of this material for tens of thousands of kilometers in a very short time, and there is no model that predicts that," Kelley said. "It's totally new and unexpected physics."
This "new" physics, the researchers contend, is tied up in counter-rotating eddies with extreme energy. Once the water vapor got caught up in these eddies, the water traveled very quickly -- close to 300 feet per second.
Scientists have long tried to study the wind structure in these upper regions of the atmosphere, which is difficult to do by such traditional means as sounding rockets, balloon launches and satellites, explained Charlie Seyler, Cornell professor of electrical engineering and paper co-author.
"Our observations show that current understanding of the mesosphere-lower thermosphere region is quite poor," Seyler said. The thermosphere is the layer of the atmosphere above the mesosphere.
The paper is also co-authored by physicist Miguel Larsen, Ph.D. '79, of Clemson University, and former student of Kelley. The work performed at Cornell was funded by the Atmospheric Science Section of the National Science Foundation.
On July 1, Kelley will give a lecture, "Two-dimensional Turbulence, Space Shuttle Plume Transport in the Thermosphere, and a Possible Relation to the Great Siberian Impact Event," at a plenary session of the annual meeting of Coupling, Energetics and Dynamics of Atmospheric Regions in Sante Fe, N.M.
The paper is available here
"It was huge," said Austin Babek, 18, who observed the light show from outside his south Arlington home. "It actually scared me it was so big."
Babek said he and a friend saw the fireball at 12:56 a.m. He said it lasted about five seconds and was bright orange with a long blue and green tail.
"I've seen shooting stars before but never anything like this," he said.
In an e-mail to the Star-Telegram, Lynda Edwards of Fort Worth described it as "so bright I could see it through the branches and leaves of my large pecan tree. It emerged on the other side of the tree and burnt out in the northwest sky."
Ron Dilulio, planetarium and astronomy lab director at the University of North Texas, is out of town on a field trip, but said based on descriptions, it was "more than likely a meteor."
UFOINFO
Mon, 22 Jun 2009 12:52 UTC
Date: May 30 2009
Time: 11pm round about
Number of witnesses: 4
Number of objects: 3
Shape of objects: Ball
Weather Conditions: No wind no cloud
Description: My neighbour called me up on the phone to get me to look out in the sky from my back garden, she thought it could be some sort of flare. When I had a look it looked very much like a orange ball of fire. Thought maybe a meteor, none that I have ever seen before. Too big to be a helicopter in the distance, no flashing lights, def not a plane. It seemed to stop for a little while as if hovering then changed its course, did a semi circle. No sooner had it faded another one appeared doing the same thing. Although as this one hovered, another one appeared. I would have took a pic but I could not pull myself away from watching them. Any clue what they could have been?
Kalleen Buchanan
News Mail
Mon, 22 Jun 2009 15:27 UTC
The mystery fire on Hazle Marland's Gaeta property is still burning - just like the questions about what started it.
On Friday emergency crews rushed to Mrs Marland's property after reports something had fallen from the sky and started a fire.
Crews were quick to rule out the possibility of a plane crash, but speculation about the cause goes on.
"It's still a mystery, there are a lot of rumours floating around but because it is so inaccessible I really don't think that we're ever going to get to the bottom of it," Mrs Marland said.
She said she had been inundated with phone calls on Saturday from media organisations and spectators wanting to go up to the site, as the news of the fallen object spread around the world.
"I was just astonished that they would show such interest," Mrs Marland said.
She said she hoped life would return to normal on the property, which is used for grazing cattle.
"I'm not encouraging anybody (to visit the site), because there is nothing to see," Mrs Marland said.
"We're just hoping it isn't anything to be worried about and we don't think it is."
Bundaberg Astronomical Society member Don Gray said he suspected the mystery object was a meteor, and the lack of an impact crater did not rule it out.
"It would be very small, depending on the weight of it or what it was, whether it was metallic or just rock, whether when it hit the ground it exploded and dug up a lot of earth," Mr Gray said.
"But it all burns, and that disguises things a bit."
He said tens of thousands of meteors, dust and space junk fell to earth every year, from pieces of old satellites to tools dropped by astronauts working on space stations.
"Most of it has never been found," he said.
"If they find it they'll be able to determine what it is - some of these meteorites are made of a glass-like substance, some are made from iron."
A spokeswoman from UFO Research Queensland said her members had heard reports of flashes of lights and falling objects, but there was no clue what it may have been.
On Friday emergency crews rushed to Mrs Marland's property after reports something had fallen from the sky and started a fire.
Crews were quick to rule out the possibility of a plane crash, but speculation about the cause goes on.
"It's still a mystery, there are a lot of rumours floating around but because it is so inaccessible I really don't think that we're ever going to get to the bottom of it," Mrs Marland said.
She said she had been inundated with phone calls on Saturday from media organisations and spectators wanting to go up to the site, as the news of the fallen object spread around the world.
"I was just astonished that they would show such interest," Mrs Marland said.
She said she hoped life would return to normal on the property, which is used for grazing cattle.
"I'm not encouraging anybody (to visit the site), because there is nothing to see," Mrs Marland said.
"We're just hoping it isn't anything to be worried about and we don't think it is."
Bundaberg Astronomical Society member Don Gray said he suspected the mystery object was a meteor, and the lack of an impact crater did not rule it out.
"It would be very small, depending on the weight of it or what it was, whether it was metallic or just rock, whether when it hit the ground it exploded and dug up a lot of earth," Mr Gray said.
"But it all burns, and that disguises things a bit."
He said tens of thousands of meteors, dust and space junk fell to earth every year, from pieces of old satellites to tools dropped by astronauts working on space stations.
"Most of it has never been found," he said.
"If they find it they'll be able to determine what it is - some of these meteorites are made of a glass-like substance, some are made from iron."
A spokeswoman from UFO Research Queensland said her members had heard reports of flashes of lights and falling objects, but there was no clue what it may have been.
Comment: Here is the original report on this incident.
Peter Davenport
NUFORC
Tue, 09 Jun 2009 18:18 UTC
Occurred: 6/7/2009 02:00 (Entered as : 06/07.09 2:00)
Reported: 6/6/2009 11:45:44 PM 23:45
Posted: 6/9/2009
Location: Brooksville, Florida
Shape: Fireball
Duration: 2-3 seconds
Blue fireball falling; disappears before reaching horizon
I was driving north of Highway 41 entering southern Brooksville. I saw a large, bright blue fireball fall straight from the sky in the distance to the north. It disappeared BEFORE reaching the horizon like a comet fading. However, this thing moved much slower and was much bigger than a comet. It looked like space debris but it was too large and moved too fast.
It just looked... unnatural. I've seen many comets and seen space debris but this was somewhere... in between. The people driving in the next lane over were both pointing and looking in that direction afterwards... I'm sure one of them saw it too.
It wasn't "messy" like a fireball, but more like a perfect blue sphere. No trail.
Reported: 6/6/2009 11:45:44 PM 23:45
Posted: 6/9/2009
Location: Brooksville, Florida
Shape: Fireball
Duration: 2-3 seconds
Blue fireball falling; disappears before reaching horizon
I was driving north of Highway 41 entering southern Brooksville. I saw a large, bright blue fireball fall straight from the sky in the distance to the north. It disappeared BEFORE reaching the horizon like a comet fading. However, this thing moved much slower and was much bigger than a comet. It looked like space debris but it was too large and moved too fast.
It just looked... unnatural. I've seen many comets and seen space debris but this was somewhere... in between. The people driving in the next lane over were both pointing and looking in that direction afterwards... I'm sure one of them saw it too.
It wasn't "messy" like a fireball, but more like a perfect blue sphere. No trail.
Blaine Friedlander
Cornell University
Wed, 24 Jun 2009 23:37 UTC
© Wikimedia
Trees were levelled in Siberia after what is thought to have been an impact from space in 1908
Trees were levelled in Siberia after what is thought to have been an impact from space in 1908
The research, accepted for publication (June 24, 2009) by the journal Geophysical Research Letters, published by the American Geophysical Union, connects the two events by what followed each about a day later: brilliant, night-visible clouds, or noctilucent clouds, that are made up of ice particles and only form at very high altitudes and in extremely cold temperatures.
"It's almost like putting together a 100-year-old murder mystery," said Michael Kelley, the James A. Friend Family Distinguished Professor of Engineering at Cornell who led the research team. "The evidence is pretty strong that the Earth was hit by a comet in 1908." Previous speculation had ranged from comets to meteors.
The researchers contend that the massive amount of water vapor spewed into the atmosphere by the comet's icy nucleus was caught up in swirling eddies with tremendous energy by a process called two-dimensional turbulence, which explains why the noctilucent clouds formed a day later many thousands of miles away.
© John C McConnell
Noctilucent clouds, like these imaged on 29 May from Northern Ireland, are so high up that they reflect sunlight even after the sun has set. Strange, glowing clouds that were likely noctilucent clouds were seen soon after the Tunguska explosion
Noctilucent clouds, like these imaged on 29 May from Northern Ireland, are so high up that they reflect sunlight even after the sun has set. Strange, glowing clouds that were likely noctilucent clouds were seen soon after the Tunguska explosion
The space shuttle exhaust plume, the researchers say, resembled the comet's action.
A single space shuttle flight injects 300 metric tons of water vapor into the Earth's thermosphere, and the water particles have been found to travel to the Arctic and Antarctic regions, where they form the clouds after settling into the mesosphere.
Kelley and collaborators saw the noctilucent cloud phenomenon days after the space shuttle Endeavour (STS-118) launched on Aug. 8, 2007. Similar cloud formations had been observed following launches in 1997 and 2003.
Following the 1908 explosion, known as the Tunguska Event, the night skies shone brightly for several days across Europe, particularly Great Britain -- more than 3,000 miles away.
Kelley said he became intrigued by the historical eyewitness accounts of the aftermath, and concluded that the bright skies must have been the result of noctilucent clouds. The comet would have started to break up at about the same altitude as the release of the exhaust plume from the space shuttle following launch. In both cases, water vapor was injected into the atmosphere.
The scientists have attempted to answer how this water vapor traveled so far without scattering and diffusing, as conventional physics would predict.
"There is a mean transport of this material for tens of thousands of kilometers in a very short time, and there is no model that predicts that," Kelley said. "It's totally new and unexpected physics."
This "new" physics, the researchers contend, is tied up in counter-rotating eddies with extreme energy. Once the water vapor got caught up in these eddies, the water traveled very quickly -- close to 300 feet per second.
Scientists have long tried to study the wind structure in these upper regions of the atmosphere, which is difficult to do by such traditional means as sounding rockets, balloon launches and satellites, explained Charlie Seyler, Cornell professor of electrical engineering and paper co-author.
"Our observations show that current understanding of the mesosphere-lower thermosphere region is quite poor," Seyler said. The thermosphere is the layer of the atmosphere above the mesosphere.
The paper is also co-authored by physicist Miguel Larsen, Ph.D. '79, of Clemson University, and former student of Kelley. The work performed at Cornell was funded by the Atmospheric Science Section of the National Science Foundation.
On July 1, Kelley will give a lecture, "Two-dimensional Turbulence, Space Shuttle Plume Transport in the Thermosphere, and a Possible Relation to the Great Siberian Impact Event," at a plenary session of the annual meeting of Coupling, Energetics and Dynamics of Atmospheric Regions in Sante Fe, N.M.
The paper is available here
Derek Jordan and Ted Morris
The Sierra Vista Herald
Thu, 25 Jun 2009 13:09 UTC
Loud boom heard, bright streak seen across the region late Tuesday
Sierra Vista - A number of southeastern Arizona residents reported seeing a bright meteor in the night sky Tuesday, followed by a loud explosion-like sound as it fell to Earth.
At his home off of Highway 191, about seven miles south of Interstate 10, Wayne Crane said he saw the shooting star just as it lit up the sky shortly before 9:30 p.m.
"I was facing probably southwest, and I just happened to look up, and I saw a glowing object," Crane said. The object appeared very bright and very large, "like a moon against the sky."
The meteor was visible only briefly, said Crane, who is the public relations manager for Sulphur Springs Valley Electric Cooperative.
"It was only there for about a second and a half before it was gone. Almost, in fact, before I had realized what I had seen," Crane said.
In Sierra Vista, several people report seeing and hearing the same object as it entered the atmosphere.
"The sky lit up and looked like fireworks or something," said Cody Bastian. "It lasted maybe three seconds, and then shortly after I saw it, we heard a big crash or boom."
Bastian and friend Amanda LaValley were walking along Calle Portal when they saw the meteor.
"It looked blue to me," LaValley said. "It seemed to be sparkling."
Said Bastian, "It looked like it fell somewhere toward Huachuca City."
Their friend Carol Captain also saw the meteor from her driveway off of Lenzner Avenue.
"I thought it was a shooting star or something like that," Captain said. "It looked white and very bright, but then, after it fell, there was a large boom. It looked like it fell somewhere between Fort Huachuca or Whetstone."
Hereford resident Gini Hoffmeyer said she heard the noise from her home.
"I was sitting here about 9:20 p.m., and there was just this loud boom, and all the windows rattled and shook," Hoffmeyer said. As she didn't witness the meteor herself, Hoffmeyer said she was initially unsure what could have caused such a noise. "I looked outside to make sure nobody's house had blown up," she said.
Neal Galt, writer of the Backyard Astronomer column for the Herald/Review, said that the likelihood of any remains of the meteor reaching the planet's surface depends on various factors, including the composition of the object.
"You can have things that are light and stony, and they break up very easily," Galt said, "and then you have things made of iron, and those seem to stay together." The velocity of the object also plays a part, he said.
The exceptional brightness of the meteor would classify it in astronomy circles as a "bolide," he said. Typically, meteors such as the one that passed over southeastern Arizona Tuesday night are visible no farther than 100 miles away, he said.
Dr. Jack Schrader, a Sierra Vista dentist who has hunted for meteorites for 15 years, is eager to search for possible fragments from Tuesday's event. "When you have a sonic boom, then there is a very good indication that there are pieces that have reached the Earth's surface," Schrader said.
He said he has received calls from fellow meteorite hunters in places like Prescott who plan to visit this area soon to hunt for fragments.
Schrader said a meteorite often looks like a charcoal briquette. It is not always shiny. The blackness is attributed to a fusion crust that forms during meteor's fiery descent through the Earth's atmosphere.
A meteorite can range from the size of a pea to a football. They are often cold after falling out of the sky and sometimes warm. They are not radioactive and are safe to handle, Schrader said.
"It's super exciting," the dentist said, noting he has been waiting for a long time for something like this to happen in this area. If anyone has information, call Schrader at 458-2419.
Comment: Sott.net has an alternative theory - incoming space debris:
Meteorites, Asteroids, and Comets: Damages, Disasters, Injuries, Deaths, and Very Close Calls
What are they hiding? Flight 447 and Tunguska Type Events
Signs Meteor Supplement
Sierra Vista - A number of southeastern Arizona residents reported seeing a bright meteor in the night sky Tuesday, followed by a loud explosion-like sound as it fell to Earth.
At his home off of Highway 191, about seven miles south of Interstate 10, Wayne Crane said he saw the shooting star just as it lit up the sky shortly before 9:30 p.m.
"I was facing probably southwest, and I just happened to look up, and I saw a glowing object," Crane said. The object appeared very bright and very large, "like a moon against the sky."
The meteor was visible only briefly, said Crane, who is the public relations manager for Sulphur Springs Valley Electric Cooperative.
"It was only there for about a second and a half before it was gone. Almost, in fact, before I had realized what I had seen," Crane said.
In Sierra Vista, several people report seeing and hearing the same object as it entered the atmosphere.
"The sky lit up and looked like fireworks or something," said Cody Bastian. "It lasted maybe three seconds, and then shortly after I saw it, we heard a big crash or boom."
Bastian and friend Amanda LaValley were walking along Calle Portal when they saw the meteor.
"It looked blue to me," LaValley said. "It seemed to be sparkling."
Said Bastian, "It looked like it fell somewhere toward Huachuca City."
Their friend Carol Captain also saw the meteor from her driveway off of Lenzner Avenue.
"I thought it was a shooting star or something like that," Captain said. "It looked white and very bright, but then, after it fell, there was a large boom. It looked like it fell somewhere between Fort Huachuca or Whetstone."
Hereford resident Gini Hoffmeyer said she heard the noise from her home.
"I was sitting here about 9:20 p.m., and there was just this loud boom, and all the windows rattled and shook," Hoffmeyer said. As she didn't witness the meteor herself, Hoffmeyer said she was initially unsure what could have caused such a noise. "I looked outside to make sure nobody's house had blown up," she said.
Neal Galt, writer of the Backyard Astronomer column for the Herald/Review, said that the likelihood of any remains of the meteor reaching the planet's surface depends on various factors, including the composition of the object.
"You can have things that are light and stony, and they break up very easily," Galt said, "and then you have things made of iron, and those seem to stay together." The velocity of the object also plays a part, he said.
The exceptional brightness of the meteor would classify it in astronomy circles as a "bolide," he said. Typically, meteors such as the one that passed over southeastern Arizona Tuesday night are visible no farther than 100 miles away, he said.
Dr. Jack Schrader, a Sierra Vista dentist who has hunted for meteorites for 15 years, is eager to search for possible fragments from Tuesday's event. "When you have a sonic boom, then there is a very good indication that there are pieces that have reached the Earth's surface," Schrader said.
He said he has received calls from fellow meteorite hunters in places like Prescott who plan to visit this area soon to hunt for fragments.
Schrader said a meteorite often looks like a charcoal briquette. It is not always shiny. The blackness is attributed to a fusion crust that forms during meteor's fiery descent through the Earth's atmosphere.
A meteorite can range from the size of a pea to a football. They are often cold after falling out of the sky and sometimes warm. They are not radioactive and are safe to handle, Schrader said.
"It's super exciting," the dentist said, noting he has been waiting for a long time for something like this to happen in this area. If anyone has information, call Schrader at 458-2419.
Sat, 27 Jun 2009 05:09 UTC
Science Hub
An amateur videographer has filmed an impressive fireball that
travelled the skies of France in June 2009. The ball of fire then
disappeared from view behind trees. According to their comments it is
not an airplane. This fireball is like having an object coming through
the atmosphere... unless it is an airplane? Could it be a UFO? I did
not find more information on this video.
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Comment: Sott.net has an alternative theory - incoming space debris:
Meteorites, Asteroids, and Comets: Damages, Disasters, Injuries, Deaths, and Very Close Calls
What are they hiding? Flight 447 and Tunguska Type Events
Signs Meteor Supplement
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