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Russia Meteor Blast Was Largest Detected by Nuclear Monitoring SystemBy Leonard David | SPACE.com – 32 mins ago.. . A far-flung system of detectors that make up a Comprehensive Nuclear-Test-Ban Treaty network made its largest ever detection when a meteor exploded over Russia’s Ural mountains last week. The Vienna, Austria-based Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) runs the International Monitoring System made up of infrasound stations. Infrasound is low frequency sound with a range of less than 10 Hertz. Humans cannot hear the low frequency waves that were emitted by the meteor blast over Russia on Friday (Feb. 15), but they were recorded by the CTBTO’s network of sensors as they travelled across continents. When the space rock detonated, the blast was detected by 17 infrasound stations in the CTBTO’s network that track atomic blasts across Earth. The furthest station to record the sub-audible sound was some 9,320 miles (15,000 kilometers) away in Antarctica. Huge infrasound event Prior to the Russian meteor event, the largest infrasound event registered by 15 stations in the CTBTO’s network was the October 2009 meteor explosion (called a bolide) over Sulawesi, Indonesia. [See video of the intense meteor explosion] In a CTBTO statement discussing the Russian bolide, Pierrick Mialle, an acoustic scientist for the group said: "We saw straight away that the event would be huge, in the same order as the Sulawesi event from 2009. The observations are some of the largest that CTBTO's infrasound stations have detected." The Russian meteor blast picked up by the detectors is not a single explosion, Mialle said. Rather, it is burning, traveling faster than the speed of sound. "That's how we distinguish it from mining blasts or volcanic eruptions," he said. Mialle said that scientists around the world will be using the CTBTO's data to better gauge the object's breakup and discern more about the object's final altitude, energy released and how the meteor disintegrated.Micropressure changes There are currently 45 infrasound stations in the CTBTO's network that measure micropressure changes in the atmosphere generated by infrasonic waves. Infrasound is one of the technologies used in the CTBTO’s network of sensors to monitor the globe for violations of the Comprehensive Nuclear-Test-Ban Treaty that bans all nuclear explosions. Infrasound has been used as part of the CTBTO's tools to detect atomic blasts since April 2001 when the first station came online in Germany. Data from the stations is sent in near real time to Vienna, Austria, for analysis at the CTBTO’s headquarters. Both the raw and analyzed data are provided to all Member States of the CTBTO. CTBTO Member States have spent $1 billion on setting up the CTBTO verification regime. Just days before the meteor explosion over Russia, the CTBTO's seismic network detected a seismic event in North Korea. That event on Feb. 12 measured 4.9 in magnitude. Later that morning, North Korean officials announced that the country had conducted a nuclear test. The event was registered by 94 seismic stations and two infrasound stations in the CTBTO's network.
Russian Meteor's Origin and Size Pinned DownBy Mike Wall | SPACE.com – 7 hrs ago.. .The orbits of the Russian meteor and Asteroid 2012 DA14 are nothing alike meaning they are not related. A meteor that exploded over Russia earlier this month likely hit Earth after a long trip from beyond the orbit of Mars, scientists say. Astronomers and the public were caught off guard by the Russian fireball, which damaged thousands of buildings and wounded more than 1,000 people when it detonated over the city of Chelyabinsk on Feb. 15. But some YouTube-aided detective work suggests that the meteor's parent body belonged to the Apollo family of Earth-crossing asteroids, whose elliptical orbits take them farther than one Earth-sun distance (about 93 million miles, or 150 million kilometers) from our star at some point, researchers said. Jorge Zuluaga and Ignacio Ferrin of the University of Antioquia in Medellin, Colombia, reached this conclusion after analyzing several videos of the Russian meteor, especially one taken in Chelyabinsk's Revolutionary Square and another recorded in the nearby city of Korkino. [Russian Fireball: All You Need to Know (Video)] They also took into account the location of a hole in the ice of Lake Chebarkul, about 43 miles (70 km) from Chelyabinsk. Scientists think the hole was caused by a piece of the space rock that hit Earth on Feb. 15. Using trigonometry, Zuluaga and Ferrin calculated basic elements of the fireball's path through Earth's atmosphere. "According to our estimations, the Chelyabinski meteor started to brighten up when it was between 32 and 47 km up in the atmosphere," they write in their paper, which has been posted to the online astronomy preprint site ArXiv.org. "The velocity of the body predicted by our analysis was between 13 and 19 km/s (relative to the Earth) which encloses the preferred figure of 18 km/s assumed by other researchers." The pair then entered these figures into a software program developed by the United States Naval Observatory called NOVAS (short for Naval Observatory Vector Astrometry), which calculated the likely orbit of the meteor's parent body. Some other scientists agree that this orbit took the space rock relatively far from the sun at times — farther than Mars, in fact. "It came from the asteroid belt, about 2.5 times farther from the sun than Earth," Bill Cooke, of NASA's Meteoroid Environment Office at the Marshall Space Flight Center in Huntsville, Ala., said in a statement. Cooke was not involved in Zuluaga and Ferrin's study. Meanwhile, the size of the meteor's parent object has come into clearer focus, thanks to measurements made by a global network of infrasound sensors operated by the Comprehensive Test Ban Treaty Organization (CTBTO). These sensors monitor extremely low-frequency sound waves, which are a common product of nuclear explosions. As the Russian meteor burned through Earth's atmosphere, it generated the most powerful infrasound signal ever detected by the CTBTO network, researchers said. And this signal revealed a great deal about the asteroid's size, speed and explosive power. "The asteroid was about 17 meters in diameter and weighed approximately 10,000 metric tons," Peter Brown, a physics professor at the University of Western Ontario in Canada, said in a statement. "It struck Earth's atmosphere at 40,000 mph and broke apart about 12 to 15 miles above Earth's surface. The energy of the resulting explosion exceeded 470 kilotons of TNT." That's 30 to 40 times more powerful than the atomic bomb the United States dropped on the Japanese city of Hiroshima during World War II. The Russian fireball likely produced the most powerful such space rock blast since a 130-foot (40 m) object exploded over Siberia in 1908, flattening 825 square miles (2,137 square km) of forest. Preliminary reports suggest that the Chelyabinsk fireball's parent asteroid was composed primarily of stone, with a smidge of iron thrown in. "In other words, [it's] a typical asteroid from beyond the orbit of Mars," Cooke said. "There are millions more just like it." The Russian meteor struck just hours before the 130-foot asteroid 2012 DA14 gave Earth a close shave, missing our planet by just 17,200 miles (27,000 km). But the two space rocks are unrelated, researchers say, making Feb. 15 a day of remarkable cosmic coincidences. You can see the Arxiv paper on the Russian meteor here.
NASA Fireball Website Launches with New Russian Meteor Explosion DetailsBy Leonard David | SPACE.com – 3 hrs ago.. . NASA has launched a new website to share details of meteor explosion events as recorded by U.S. military sensors on secretive spacecraft, kicking off the project with new details of last month's fireball over Chelyabinsk, Russia. The new "Fireball and Bolide Reports" website, overseen by NASA's Near-Earth Object Program, debuted Friday (March 1) with its first entry: a table with a chronological data summary of the Russian meteor explosion of Feb. 15 gleaned from U.S. Government sensor data. Scientists are calling the event a "superbolide," taken from the term "bolide" typically used for fireballs created by meteors. Sharing the information publicly is part of a renewed collaboration between the U.S. military and the scientific community. "And what better way to kick this site off than the Chelyabinsk superbolide … the most energetic recognized-fireball event since Tunguska in 1908," said Don Yeomans, a senior research scientist at the NASA Jet Propulsion Laboratory in Pasadena, Calif. He is also manager of NASA's Near-Earth Object Program Office at JPL. "This website is meant to be the vehicle for future reports of fireballs/bolides as seen by U.S. government sensors," Yeomans told SPACE.com. "This is the first posting of its kind on this site. Future data on bright fireballs will be added to this table. We won't capture every fireball event … only the unusually bright ones," he said. "I consider this a major step forward since these fireball events are by far the most frequent impactors into the Earth's atmosphere," Yeomans said. "And these reports will go a long way toward defining the annual flux of small Earth impactors." [Russian Meteor Explosion Explained (Infographic)] New Russian meteor details The Feb. 15 Russian meteor event is the first entry on this new site, and it provides the following information about the fireball: Time of maximum brightness: 03:20:33 GMT on Feb. 15 Geographic location of maximum brightness: Latitude: 54.8 deg. N Longitude: 61.1 deg. E Altitude of maximum brightness: 23.3 km (14.5 miles) Velocity at peak brightness: 18.6 km/s (11.6 miles/s) Approximate total radiated energy of fireball: 3.75 x 1014 Joules. This is the equivalent of about 90 kilotons of TNT explosives, but it does not represent the total impact energy, which is several times larger than the observed total radiated energy. Approximate total impact energy of the fireball in kilotons of TNT explosives (the energy parameter usually quoted for a fireball): 440 kilotons.New fireball agreement This public release of government detector data was made possible by a newly signed memorandum of agreement (MOA) between NASA’s Science Mission Directorate and Headquarters Air Force Space Command Air, Space and Cyberspace Operations Directorate. The MOA was signed on Jan. 18, said Capt. Chris Sukach, spokesperson for U.S. Air Force Space Command at Peterson Air Force Base in Colorado. For security reasons, the actual MOA is classified, she told SPACE.com. As a result of the agreement, Sukach said, NASA's Near Earth Object (NEO) Program is receiving information on bolide/fireball events based on analysis of data collected by U.S. Government sensors. "Data on the recent Chelyabinsk event has been released," Sukach said. Sukach added that when Air Force Space Command receives data on bolide events, it pushes that data to the NASA Near Earth Object Office. "From then on, it is a NASA-owned process, but our understanding is NASA distributes the information via the publically-accessible Near Earth Object Office website to assist the scientific community’s investigation of bolides," she said. Relatively small asteroid According to Don Yeomans and Paul Chodas, also of the NASA/JPL Near-Earth Object Program office, the Russian fireball was technically a "superbolide" that was observed on the morning of Feb. 15 in the skies near Chelyabinsk, Russia. The object was a relatively small asteroid, approximately 55 to 65 feet (17 to 20 meters) in size. As it roared through the Earth's atmosphere at high speed and a shallow angle, the asteroid released a huge amount of energy. The object broke apart at high altitude, producing a shower of pieces of various sizes that fell to the ground as meteorites. [Russian Meteor Fragments Found (Video)] "The fireball was observed not only by video cameras and low-frequency infrasound detectors, but also by U.S. Government sensors," Yeomans and Chodas said. "As a result, the details of the impact have become clearer. There is no connection between the Russian fireball event and the close approach of asteroid 2012 DA14, which occurred just over 16 hours later."Congress wants to know about NEOs Congressional action on NEOs for this year, spurred in part by the Russian event, was initially slated kick off on March 6 during a House subcommittee hearing, but the meeting was postponed due to weather concerns. The meeting is now scheduled for Tuesday, March 19. The full committee of the House Committee on Science, Space and Technology is expected to hold a multi-panel hearing on "Threats from Space: a Review of U.S. Government Efforts to Track and Mitigate Asteroids and Meteors." Slated to testify on one panel is John Holdren, White House science officer; General William Shelton, commander of the U.S. Air Force Space Command; and Charles Bolden, NASA's chief. More info: NASA's Fireball and Bolide Reports website.
Meteor Over Manhattan: East Coast Fireball Sets Internet AbuzzBy Tariq Malik | SPACE.com – 11 hrs ago...A bright meteor briefly outshined the lights of New York City Friday evening (March 22), according to reports by witnesses who used Twitter and the Internet to report sightings of the fireball streaking over a broad stretch of the U.S. East Coast."Strange Friday night … a meteor passed over my house tonight!" wrote one New Yorker writing as Yanksmom19.The first fireball sightings came at about 8 p.m. EDT (0000 March 23 GMT) and sparked more than 500 witness reports to the American Meteor Society. Reports of the meteor flooded Twitter from New York, Boston and Washington, D.C."The witnesses range from along the Atlantic Coast ranging from Maine to North Carolina," Robert Lunsford, the society's fireball coordinator, wrote in an update. "This object was also seen as far inland as Ohio." [5 Amazing Fireball Videos]The CBS WUSA 9 television news station obtained several security camera videos of the fireball as it lit up the night sky over Washington and parts of Maryland.In New York, some observers reported seeing the meteor low in the sky as it streaked from west to east across the night sky."It shot over Manhattan and broke up over the East Village," observer Ross E. of New York City wrote in his fireball report to the meteor society. In fact, the meteor streaked across hundreds of miles and was visible from many states along the Eastern Seaboard.According to Lunsford, meteors often appear closer than they actually are due to the observer's perspective.Fireballs occur every day and are typically caused by small space rocks about the size of a basketball disintegrating as they streak through Earth's atmosphere, officials with NASA's Asteroid Watch outreach program wrote in a Twitter post.On Feb. 15, a bus-size meteor exploded over Russia near the city of Chelyabinsk, shattering windows in hundreds of buildings and injuring nearly 1,500 people. That rare meteor explosion, which scientists have classified as a superbolide, was the most powerful in more than a century, NASA scientists said.The Earth is bombarded by nearly 100 tons of material from space every day, but most of those objects are tiny dust grains that burn up harmlessly in the atmosphere.NASA scientists and astronomers around the world regularly monitor the night sky for signs of larger asteroids that could pose an impact threat to Earth. Friday night's meteor came just days after back-to-back hearings in the House and Senate about the dangers posed by near-Earth asteroids. Those meetings were scheduled in the wake of the Feb. 15 Russian meteor explosion.Editor's note: If you snapped an amazing photo of the East Coast meteor or any other night sky sight and you'd like to share it for a possible story or image gallery, please send images and comments, including location information, to Managing Editor Tariq Malik at [email protected].
Russian Meteor Fallout: Boosting Asteroid Search May Not Help, Scientist SaysBy Miriam Kramer | SPACE.com – 19 hrs ago...Spending more money on asteroid and meteor detection techniques won't necessarily make the planet safer, according to a planetary scientist.Alexander Deutsch, a professor of planetology at the University of Münster in Germany, explained that the relatively small meteor that exploded over Chelyabinsk, Russia, in February would not have been detected using technologies available around the world today."The problem is that even if they use more of these highly sophisticated observatories, they will not find very small projectiles, but on the other hand, the small projectiles are not very dangerous, and the opinion is that the larger ones or at least most of the larger ones are now known," Deutsch said during a news conference today (April 9) at the European Geosciences Union General Assembly in Vienna. "I don't think more money will produce more data."This idea is contrary to what many scientists, lawmakers and public officials have been saying since the Feb. 15 explosion of the 56-to-66-foot meteor (17 to 20 meters) space rock over Russia's Ural Mountains. [See photos of the Russian meteor explosion]The Russian fireball's blast injured more than 1,000 people, and sparked a series of congressional hearings on asteroid detection in the United States to assess the possible threats posed by asteroids and meteors.NASA also estimates that scientists and amateur astronomers working with the space agency have located and tracked the orbits of 90 percent of the largest near-Earth asteroids that could create a global crisis if the space rocks were to impact the planet.Although the asteroid released the equivalent of 470 kilotons of TNT (30 to 40 times more powerful than the atomic bomb dropped by the United States on the Japanese city of Hiroshima during World War II), the 10,000-metric-ton meteor exploded high enough to shelter those on the ground from the brunt of its impact."What you see now is it doesn't matter if it's Chelyabinsk or London," Deutsch said. "If you have, let's say, good windows and solid structure and [the meteor] exploding very high, then the damage is rather small."Deutsch also pointed out that these events are somewhat rare. Scientists have suggested that a meteor like the one that fell through the atmosphere over Chelyabinsk is expected to happen only once every 50 to 100 years. Before this year, the last meteor that produced such a blast fell over Siberia in 1908, flattening 825 square miles (2,137 square km) of forest.The Russian meteor exploded just before another space rock flew harmlessly past the Earth. Asteroid 2012 DA14 — a 130-foot (40 m) rock — gave the Earth a close shave in astronomical terms, missing the planet's surface by 17,200 miles (27,000 km). The two space rocks, however, were cosmically unrelated.
Russian Meteor Explosion's Dust Cloud Lingered In Atmosphere for MonthsSPACE.com Elizabeth Howell 13 hours agoA portion of Chelyabinsk's dust plume circled Earth in just four days, as shown in this imageWhen a meteor exploded over the Russian city of Chelyabinsk in February, pieces of the bus-sized space rock hit the ground while its detonation shattered windows, set off car alarms and injured more than 1,000 people.Masked in the chaos, however, was an enormous plume of dust that the Russian meteor left behind in Earth's atmosphere. This cloud, which had hundreds of tons of material in it, was still lingering three months after the Feb. 15 explosion, a new study has found. Scientists created a video of the Russian meteor explosion's dust cloud to illustrate the phenomenon."Thirty years ago, we could only state that the plume was embedded in the stratospheric jet stream," Paul Newman, chief scientist for NASA Goddard Space Flight Center's atmospheric science lab, said in a statement. "Today, our models allow us to precisely trace the bolide and understand its evolution as it moves around the globe."Chasing dustThe Russian meteor, which weighed 11,000 metric tons when it hit the atmosphere, detonated about 15 miles (24 kilometers) above Chelyabinsk. The explosion sent out a burst of energy 30 times greater than the atom bomb that leveled Hiroshima during World War II.Some of the asteroid's remnants crashed to the ground, but hundreds of tons of dust remained in the atmosphere. A team led by NASA Goddard atmospheric physicist Nick Gorkavyi, who is from Chelyabinsk, wondered if it was possible to track the cloud using NASA's Suomi NPP satellite."Indeed, we saw the formation of a new dust belt in Earth's stratosphere, and achieved the first space-based observation of the long-term evolution of a bolide plume," Gorkavyi said in a statement.Initial measurements 3.5 hours after the meteor explosion showed the dust 25 miles (40 km) high in the atmosphere, speeding east at 190 mph (306 km/h).Russian officials were still cleaning up in Chelyabinsk when, four days after the explosion, the higher portion of the plume reached all the way around Earth's northern hemisphere. Even three months into the study, Suomi still saw a "detectable belt" of dust circling the globe, researchers said.Putting it in perspectiveTracking the plume also revealed some insights into how particles behave in Earth's atmosphere. Heavier particles, for example, moved more slowly as they dropped closer to Earth in an area with lower wind speeds. Lighter particles maintained speed and altitude, consistent with predictions of wind velocities at their heights.While the plume was easily detectable, it was by no means extraordinarily dense, NASA researchers noted. About 30 metric tons of space dust hits the Earth every day on average. Also, volcanoes and other natural Earth sources contribute far greater numbers of particles to the stratosphere.The study is ongoing, with potential research directions including looking at whether or not meteor debris can affect cloud formation in the stratosphere and mesosphere.A paper based on the work so far has been accepted for publication in the journal Geophysical Research Letters.
"About 30 metric tons of space dust hits the Earth every day on average."
(I may need to make a 'caught being a condescending [male member]' smilie - I'd get some use of one. )
