Meteor explodes over Russia, nearly 1,000 injured

[Buster's Uncle]

How about having female members showing a female SMAC(X) citizen icon instead of a male one? At least when in the initial stages of their stay here (lower post count)?

I could create a "Female Woman" (or something) membergroup, and do an icon as you say, but I don't have server access to install the icon, else I'd have had some fun with it when I started throwing people into novelty membergroups.

Good idea, though.

[Geo]

Just something that might avoid confusion, and have female members with a character their way. 

[Buster's Uncle]

I agree - Mylochka's thinking it over now, and I'll ask Valka.

[Buster's Uncle]

Stunning New Details From The Largest Asteroid Impact In A Century
By Dina Spector | Business Insider – 1 hour 43 minutes ago



Science/AAAS  The main mass of the Chelyabinsk fall is seen at the Chelyabinsk State Museum of Local History shortly after recovery from Chebarkul Lake.



New details about the origin, structure, and impact of the meteor that exploded over the Russian city of Chelyabinsk on Feb. 13, 2013, are reported in three separate papers published Wednesday.

Thanks to cell phones, dashboard video cameras, and other recording devices, researchers have been able to collect a large amount of data about the Chelyabinsk meteor — the largest impact over land since the 1908 explosion over Tunguska in Siberia. That event, believed to have been caused by a comet, was much larger but not well-observed.

Below are some of the key details from the studies. For clarity, a meteoroid is the original object (an asteroid is a larger meteoroid), a meteor is that same rock as it burns up in the atmosphere, also known as a "shooting star"; and a meteorite is the rock once it hits the ground.

Size and speed
•Researchers who published their results in the journal Nature estimate that the asteroid was originally 19 meters (62 feet) wide before it hit Earth's atmosphere and broke apart.
•The meteoroid entered Earth's atmosphere at 19 kilometers per second (42,500 mph), which is slightly faster than previously reported, according to a study in the journal Science.
•A study led by Jirí Borovicka from the Academy of Sciences found that the Chelyabinsk asteroid had a very similar orbit to the 1.2-mile-wide near-Earth asteroid 86039. This suggests that the two were once part of the same object.
•The Chelyabinsk asteroid was probably ejected from asteroid 86039 when it collided with another asteroid.
•Borovicka and colleagues believe that the asteroid broke up into small pieces between 30 and 45 kilometers (19-28 miles) above the ground, based on the timing of secondary sonic booms heard on videos.
•The main body remained intact and quite massive at around 1,000 kilograms (2,200 pounds) until an altitude of 22 kilometers (13.6 miles) above the ground.
•A large dust trail, which started at an altitude of 68 km (42.3 miles) was left in the atmosphere after the meteor passed and extended to 18 km (11.2 miles) above the ground.



Jiri Borovicka  This map shows the ground projection of the trajectory of the Chelyabinsk meteor (red – main body, orange – fragment F1) and the location of the impact hole (Crater) in the ice of Lake Chebarkul. The bright meteor moved from right to left.


When the meteoroid broke apart in the atmosphere it produced a fireball — also known as an airburst — that released about the same amount of energy as 500 kilotons of exploding TNT.

•At its peak, the airburst appeared 30 times brighter than the sun. It was captured by more than 400 video cameras and other seismic and infrasound instruments almost 700 kilometers (430 miles) away.
•The airburst created a shockwave — known as an airblast — that traveled down through the air and struck the Russian city of Chelyabinsk below. The shockwave shattered thousands of windows and injured more than 1,000 people, mostly from flying glass.
•The airblast that reached the city was generated around 24 to 30 kilometers (15-19 miles) above the ground.

Damage
•Olga Popova of the Russian Academy of Sciences and NASA meteor astronomer Peter Jenniskens visited 50 villages in the area to collect information about damage caused by the shockwave.
•In Chelyabinsk itself, 3,613 apartment buildings (around 44%) had shattered and broken glass. The shockwave was also strong enough to blow people off their feet.
•People also found it painful to look at the fireball. In an Internet survey of 1,113 people who were outside at the time, 25 were sunburned (2.2%), 315 felt hot (28%), and 415 warm (37%).

Meteorite Recovery
•Scientists found fewer fragments larger than 100 grams (0.22 pounds) than they expected.
•However, a 7-8 meter (23-36 feet)-sized hole was discovered in 70-cm (2.3 feet) thick ice on Lake Chebarkul, 43 miles west of Chelyabinsk. A security video camera at the site also recorded the impact.
•Researchers estimate that 76% of the meteoroid evaporated, and much of the remaining mass was turned into dust. Only 0.03-0.05% of the initial mass survived.
•Jenniskens and colleagues believe that "shock veins" in the original asteroid caused by an impact hundreds of millions of years ago probably weakened the asteroid and caused it to break up easily.
•This team also found that the Chelyabinsk asteroid belongs to a common type of meteorite known as LL chondrite. It was 4.452 billion years old.
•The Chelyabinsk asteroid was possibly once part of a bigger "rubble pile" asteroid that broke apart 1.2 million years ago, according to Jenniskens.

Detection
•In its aftermath, many people wondered why scientists had not detected the meteor ahead of time. A study led by Borovicka reports that before impact, the asteroid had spent at least six weeks within a region of sky that could not be seen by Earth-based telescopes. Before that, it was too faint to be seen.

Future Hazards
•A study led by Peter Brown from the University of Western Ontario found that hazards from small-sized meteoroids are greater than previously thought.
•Telescopic surveys have only discovered about 500 near-Earth asteroids that are comparable in size to Chelyabinsk —10 to 20 meters (33-66 feet) wide — but the population could be much bigger.


http://finance.yahoo.com/news/stunning-details-largest-asteroid-impact-180053787.html

[Buster's Uncle]

Russian fireball shows meteor risk may be bigger
Associated Press
By SETH BORENSTEIN 1 hour ago



In this frame grab made from dashboard camera vide shows a meteor streaking through the sky over Chelyabinsk, about 930 miles east of Moscow, Friday, Feb. 15, 2013. After a surprise meteor hit Earth at 42,000 mph and exploded over a Russian city in February, smashing windows and causing minor injuries, scientists studying the aftermath say the threat of space rocks hurtling toward our planet is bigger than they had thought. Meteors like the one that exploded over Chelyabinsk _ and those that are even bigger and more dangerous _ are probably four to five times more likely to hit Earth than scientists thought before the February mid-air explosion, according to three studies released Wednesday in the journals Nature and Science. (AP Photo/AP Video)


WASHINGTON (AP) — Scientists studying the terrifying meteor that exploded without warning over a Russian city last winter say the threat of space rocks smashing into Earth is bigger than they thought.

Meteors about the size of the one that streaked through the sky at 42,000 mph and burst over Chelyabinsk in February — and ones even larger and more dangerous — are probably four to five times more likely to hit the planet than scientists believed before the fireball, according to three studies published Wednesday in the journals Nature and Science.

Until Chelyabinsk, NASA had looked only for space rocks about 100 feet wide and bigger, figuring there was little danger below that.

This meteor was only 62 feet across but burst with the force of about 40 Hiroshima-type atom bombs, scientists say. Its shock wave shattered thousands of windows, and its flash temporarily blinded 70 people and caused dozens of skin-peeling sunburns just after dawn in icy Russia. More than 1,600 people in all were injured.

Up until then, scientists had figured a meteor causing an airburst like that was a once-in-150-years event, based on how many space rocks have been identified in orbit. But one of the studies now says it is likely to happen once every 30 years or so, based on how often these things are actually hitting.

By readjusting how often these rocks strike and how damaging even small ones can be, "those two things together can increase the risk by an order of magnitude," said Mark Boslough, a Sandia National Lab physicist, co-author of one of the studies.

Lindley Johnson, manager of NASA's Near Earth Object program, said the space agency is reassessing what size space rocks to look for and how often they are likely to hit.



Maps show how scientists will narrow the field of impact in the weeks approaching the time of impact


The U.S. government gained a new sense of urgency after Chelyabinsk, quietly holding a disaster drill earlier this year in Washington that was meant to simulate what would happen if a slightly bigger space rock threatened the East Coast.

After the drill, NASA and Federal Emergency Management Agency officials said they should look at the need for evacuations, figure out ways of keeping the public informed without scaring them, and handle meteor threats in a way comparable to how they deal with hurricanes bearing down on the coast.

During the drill, when it looked as if the meteor would hit just outside the nation's capital, experts predicted 78,000 people could die. But when the mock meteor ended up in the ocean, the fake damage featured a 49-foot tsunami and shortages of supplies along the East Coast, according to an after-action report obtained by The Associated Press.

The exercise and the studies show there's a risk from smaller space rocks that strike before they are detected — not just from the giant, long-seen-in-advance ones like in the movie "Armageddon," said Bill Ailor, a space debris expert at the Aerospace Corporation who helped coordinate the drill.

"The biggest hazard from asteroids right now is the city-busting airbursts, not the civilization-busting impacts from 1-kilometer-diameter objects that has so far been the target of most astronomical surveys," Purdue University astronomer Jay Melosh, who wasn't part of the studies, wrote in an email.

"Old-fashioned civil defense, not Bruce Willis and his atom bombs, might be the best insurance against hazards of this kind."



This photo provided by The Field Museum in Chicago, taken April 9, 2013, shows pieces of a meteor


Scientists said a 1908 giant blast over Siberia, a 1963 airborne explosion off the coast of South Africa, and others were of the type that is supposed to happen less than once a century, or in the case of Siberia, once every 8,000 years, yet they all occurred in a 105-year timespan.

Because more than two-thirds of Earth is covered with water and other vast expanses are uninhabited deserts and ice, other past fireballs could have gone unnoticed.

This week, NASA got a wake-up call on those bigger space rocks that astronomers thought they had a handle on, discovering two 12-mile-wide space rocks and a 1.2-mile-wide one that had escaped their notice until this month.

The three objects won't hit Earth, but their discovery raises the question of why they weren't seen until now.

The last time a 12-mile-wide rock had been discovered was about 30 years ago, and two popped into scientists' view just now, NASA asteroid scientist Donald Yeomans said. He said NASA had thought it had already seen 95 percent of the large space rocks that come near Earth.

Asteroids are space rocks that circle the sun as leftovers of failed attempts to form planets billions of years ago. When asteroids enter Earth's atmosphere, they become meteors. (When they hit the ground, they are called meteorites.)



FILE - In this Feb. 15, 2013 file photo provided by Chelyabinsk.ru, shows a meteorite contrail


The studies said the Chelyabinsk meteor probably split off from a much bigger space rock.

What happened in the Russian city of 1 million people is altering how astronomers look at a space rocks. With first-of-its-kind video, photos, satellite imagery and the broken-up rock, scientists have been able to piece together the best picture yet of what happens when an asteroid careens into Earth's atmosphere. It's not pretty.

"I certainly never expected to see something of this scale or this magnitude," said University of Western Ontario physicist Peter Brown, lead author of one study. "It's certainly scary."

Scientists said the unusually shallow entry of the space rock spread out its powerful explosion, limiting its worst damage but making a wider area feel the effects. When it burst it released 500 kilotons of energy, scientists calculated.

"We were lucky. This could have easily gone the other way. It was really dangerous," said NASA meteor astronomer Peter Jenniskens, co-author of one of the papers. "This was clearly extraordinary. Just stunning."

___

Online:

NASA's Near Earth Object Program: http://neo.jpl.nasa.gov

Nature: http://www.nature.com/nature

The journal Science: http://www.sciencemag.org


http://news.yahoo.com/russian-fireball-shows-meteor-risk-may-bigger-180350480.html

[Buster's Uncle]

Chelyabinsk Eyewitnesses Help Scientists Resolve Meteor Mysteries
Scientific American
By Clara Moskowitz 4 hours ago



On February 15, 2013, people near Chelyabinsk, Russia felt the ground shake, smelled the sour stench of sulfur, heard windows shatter into sprays of glass and had to look away from a fireball in the sky so bright it hurt their eyes. The meteor that caused all this havoc largely dissolved into a cloud of dust during its passage through Earth’s atmosphere, so scientists are turning to clues on the ground and the memories of eyewitnesses to piece together  what happened that day. Around 1,500 people were injured, although no one was killed. In the city of Chelyabinsk alone, more than 3,500 buildings were damaged, and the researchers found shockwave destruction as far as 100 kilometers away from the impact site.

Based on testimony from people near the impact zone as well as the copious video footage caught by residents’ dashboard cameras and security video feeds, scientists have calculated the precise trajectory of the inbound Chelyabinsk meteor, as well as the power of the atmospheric explosion and the dynamics of its shockwave. The findings are detailed in three papers published this week in Nature and Science. (Scientific American is part of Nature Publishing Group.)

A team led by Olga Popova of the Russian Academy of Sciences visited 50 villages surrounding the blast area in the month after the event to speak to residents and photograph the broken windows and other damage from the meteor. “Typically we’d go into a village and first find out where the local grocery market is, and we’d talk to the people behind the counter because they’d just listened for the past three weeks to what other people had experienced,” says research team member Peter Jenniskens of the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View, Calif. “They’d summarize for us, and then we’d go into the streets and talk to people. Everybody had a story to tell.” The scientists met people who were blown off their feet by the meteor’s shockwave, and others who were sunburned by ultraviolet light from the fireball. “There was one person who said his skin even flaked afterward,” Jenniskens says. The team found that it was often the village schools, which tended to have the biggest windows, that suffered the most window damage. The scientists compiled the data from their visits and interviews, as well as from an online survey of residents, to calculate damage and injury patterns around the Chelyabinsk area.

Both Popova’s team and a second group, led by Jirí Borovicka of the Academy of Sciences of the Czech Republic and Peter Brown of the University of Western Ontario, used video footage to calculate the meteor’s trajectory. (Popova’s findings were reported in Science and Borovicka and Brown each led papers published in Nature). The researchers visited the locations where amateur videos had been filmed, and photographed the stars in the sky to calibrate the meteor’s precise location and the path it took through the atmosphere. Both calculations agree well with a trajectory computed from satellite images of the meteor by Colorado State University meteorologist Steven Miller and his colleagues, which was published October 21 in Proceedings of the National Academy of Sciences. “It was nice to see that confirmation,” Miller says.

Borovicka and Brown’s team found that the rock started out about 19 meters wide, and broke into small pieces as it descended from 45 to 30 kilometers over Earth. The meteor's airburst packed an energy equivalent to 500 kilotons of TNT, they calculated. The relatively small asteroid had escaped detection prior to impact, but by computing the meteor’s original velocity and direction of flight, the scientists were able to deduce the rock’s orbit around the sun, which proved to be markedly similar to the orbit of a known, much larger asteroid—a two-kilometer-wide object called 86039 (1999 NC43).

“After statistical analysis we found it’s very unlikely that the proximity of the orbits is only by chance,” Borovicka says. “So we cannot prove it, but we suggest this Chelyabinsk asteroid and this big asteroid were one time in the past part of the same body.” If an earlier collision broke the two apart, their orbits probably would have diverged over time, so such a break-up would have to have occurred relatively recently, says Nick Gorkavyi of NASA Goddard Space Flight Center, who was not involved in the new studies. “It’s an interesting possibility, but of course right now it’s just a hypothesis,” he says. NASA planetary scientist Don Yeomans of the Jet Propulsion Laboratory agrees that the idea is “quite possible” but notes that researchers must now look for compositional similarities between the two objects. “I would say the jury is still out … until the asteroid's spectral characteristics can be matched with the Chelyabinsk meteorites,” he says.

The new analyses also suggest that events like Chelyabinsk might be more common than had been assumed. Based on telescopic observations of asteroids, researchers had previously estimated that a Chelyabinsk-scale impact took place every 150 years, on average. But after analyzing various historic surveys and the new information about the February meteor, Brown’s team estimates that such objects might smack Earth as often as once every few decades. “There may be more of these airburst-type events, things like Chelyabinsk, than we previously thought,” Brown says. Even though most impacts of this size do not cause serious damage, and the vast majority will hit over ocean rather than land, the finding is nonetheless sobering. “We may well in our lifetime see another one like Chelyabinsk,” Brown warns.


http://news.yahoo.com/chelyabinsk-eyewitnesses-help-scientists-resolve-meteor-mysteries-180000821.html

[Buster's Uncle]

Smaller Asteroids Pose Bigger Threat
Well-Documented Explosion Over Russia in February Offers Clues on Origin, Structure
By Gautam Naik  Updated Nov. 6, 2013 2:44 p.m. ET


 
The asteroid that exploded over Russia in February has raised the prospect that relatively small space rocks crashing to Earth may pose a bigger danger than had been previously believed.

Astronomers have mapped about 1,000 such objects—between 10 meters and 50 meters (33 feet to 165 feet) in diameter—in near-earth orbit, similar to the asteroid that exploded over Chelyabinsk, Russia.

"But we estimate that there are a million of them out there," said Margaret Campbell-Brown, a meteor physicist at the University of Western Ontario. She added that today's Earth-based astronomical surveys can't spot most of these smaller rocks because they are too faint.



 

The Russian asteroid detonation was an unprecedented modern-day event not just for the destruction caused but also because the fiery descent was captured in detail by hundreds of amateur video cameras and an array of scientific instruments.

With the help of that data, as well as laboratory analyses of rock fragments and witness accounts from around Chelyabinsk, three research teams have now compiled a comprehensive view of the asteroid's possible origin, flight path and structure. Crucially, the findings help explain why a space rock just 20 meters in diameter generated such a powerful shock wave.

Two studies about the asteroid's impact were published on Wednesday in the journal Nature and a third appeared in Science. Together, they serve as a stark reminder about the potential violence of such events and could help astronomers assess future threats.

Until the Russia event, an Earthbound asteroid was only deemed to be a big danger "if it was a kilometer in diameter," said Qing-Zhu Yin, a meteor astronomer at the University of California, Davis, and one of 59 authors of the Science paper. "But now, we know we ought to worry even if it's a few meters in size."

One of the Nature papers noted that while most near-Earth asteroids more than one kilometer in diameter are known, the unexpected explosive force of the Chelyabinsk event has shifted more of the concern to smaller bodies with diameters between 10 and 50 meters, which could trigger "nuclear-weapon-sized detonations" in the atmosphere.

The Chelyabinsk strike was the largest since a similar event over Siberia in 1908. The disintegration—which lasted less than 30 seconds— generated a blast that blew out windows miles away, knocked some people off their feet and sent more than 1,000 people to the hospital.

At one point, the flaming meteor appeared 30 times as bright as the sun. Several people were severely sunburned by the radiation, according to a team of researchers who toured 50 villages in the area.
 
 

A meteor contrail was seen over Chelyabinsk, Russia, in February. Chelyabinsk.ru/Associated Press


"What's surprising was the fragility of the asteroid body and how only a small fraction of the original mass reached the ground," said Jiri Borovicka of the Academy of Sciences of the Czech Republic and a co-author of both Nature papers. "Theoretical papers had predicted that more than 10% would reach the ground for an asteroid of this size."

The UC Davis team estimated that only 4,000 to 6,000 kilograms, or less than 0.05%, fell to earth.

The clue to that mystery—why the rock's destruction was so comprehensive—may lie in its origin.

The asteroid may have been born when a collision broke off a chunk of rock from asteroid 86039, an object that is one kilometer in diameter and lies beyond the orbit of Venus. Dr. Borovicka said he suspects this to be the case because the orbits of both seem to match.

At some point, the orbit of the Chelyabinsk asteroid intersected with earth's orbit and fell into the planet's gravitational thrall. On Feb. 15, the rock began to streak through earth's atmosphere toward Russia's Ural Mountains.

"Chelyabinsk came from the direction of the sun," said Dr. Campbell-Brown, co-author of one of the Nature studies. "Even if we'd known where to look we wouldn't have seen it because it's hard to see faint objects in the glare."

The fireball was first recorded at an altitude of 97 kilometers, around 9:20 a.m. local time. At 90 kilometers, a shock wave began to develop.

The rock's subsequent destruction was captured globally by a range of instruments, including infrasound, seismic U.S. government sensors and more than 400 video cameras at ranges as many as 700 kilometers away.

Large pieces began to break off at a height of 40 kilometers. The entire disintegration unleashed about 500 kilotons of energy, more than 30 times the energy of the Hiroshima atomic bomb.

The shock wave shattered windows and injured hundreds of people. A statue of 19th century Russian author Alexander Pushkin in a library was cracked by a blown-out window frame. The roof of a zinc factory collapsed.

The fireball was at its hottest and brightest when it was about 30 kilometers above the earth. It was then hurtling at more than 40,000 miles an hour. But by the time it reached a height of 15 kilometers, much of it had evaporated.

UC Davis scientists believe the rock broke up unusually quickly because it was weakened by cracks in its material. Divers later fished out a 1,430-pound chunk from a lake.


http://online.wsj.com/news/articles/SB10001424052702304448204579181823461263590

[Buster's Uncle]

Russian Fireball Fallout: Huge Asteroid Numbers Raise Stakes of Impact Threat
SPACE.com
By Mike Wall, Senior Writer  5 hours ago






The number of asteroids zooming close to Earth is far greater than previously believed, highlighting the need to ramp up efforts to find and track these potentially dangerous space rocks, experts say.

A new analysis of the Russian meteor explosion that injured more than 1,000 people in the city of Chelyabinsk this past February estimates that similar impacts occur about seven times more often than previously thought.

That means there could be more than 20 million near-Earth asteroids roughly 62 feet (19 meters) wide — the size of the Chelyabinsk object — rather than three or four million, scientists say, adding to the Russian meteor explosion's importance as a teachable moment.

"It has attracted more attention to the threat," Lindley Johnson, program executive for NASA's Near-Earth Object (NEO) Observations Program, said of the Chelyabinsk event in a teleconference with reporters Wednesday (Nov. 6).

The Russian meteor explosion is a "great advertisement," he added, "that this is really something that we do need to be dealing with, and addressing the improvement in capabilities to detect, track and characterize these objects."



Impact site of the main mass of the Chelyabinsk meteorite in the ice of Lake Chebarkul


Out of the blue

The Russian meteor caught scientists and citizens of Chelyabinsk by surprise, exploding without warning on Feb. 15. The shock wave created by the blast — which was equivalent to about 500 kilotons of TNT — shattered windows throughout the area, sending more than 1,200 people to the hospital. (There were no fatalities.)

It's not terribly surprising that the Chelyabinsk airburst came out of the blue. Scientists have discovered just 10,000 or so near-Earth objects to date, out of a total population that numbers in the millions.

And that population is likely significantly larger than scientists had realized, suggests the new study, which was published Wednesday (Nov. 6) in the journal Nature.



Main mass of the Chelyabinsk fall at the Chelyabinsk State Museum of Local History


The researchers, led by Peter Brown of the University of Western Ontario in Canada, performed a global survey of recent airbursts packing at least 1 kiloton of energy. They concluded that the number of Chelyabinsk-like events — and, by extension, Chelyabinsk-meteor-size asteroids — appears to be about seven times greater than previously estimated.

While this calculation must be taken with a grain of salt because it's based on a small sample size, it does imply that the number of near-Earth asteroids in the 50- to 100-foot-range (15 to 30 meters) has likely been underestimated in the past, other researchers say.

"I'm uncomfortable to go out on a quote saying that it's actually seven times more at that size range," said Paul Chodas, a research scientist with the NEO Program Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif., who was not involved in the study. "But I would say it appears to be several times more."


Hunting for asteroids



This graphic depicts the orbit of the asteroid that exploded over Chelyabinsk, Russia on Feb. 15, 2013


Astronomers have spotted 95 percent of the 980 near-Earth asteroids at least 0.6 miles (1 km) wide, which might end civilization if they hit us. But if they want to start making real progress in detecting smaller objects like the Chelyabinsk impactor, new tools will likely be needed.

At the top of many scientists' wish list is an infrared space telescope that would hunt for asteroids from inside the orbit of Earth, so it could stare out at our planet's neighborhood without having to fight the glare of the sun.

Such an instrument is already on the drawing board. The nonprofit B612 Foundation, which is dedicated to helping protect Earth against catastrophic asteroid impacts, aims to launch its Sentinel Space Telescope to a Venus-like orbit in 2018. Sentinel should find about 500,000 near-Earth asteroids in less than six years of operation, B612 officials have said.

But defending the planet effectively against space rocks involves more than the launch of one telescope, researchers say. Rather, detecting dangerous asteroids — and eventually deflecting them away from Earth — will require a concerted and sustained international effort, which has likely gotten a boost from the drama in the skies over Chelyabinsk on Feb. 15.

"It's provided, certainly, incentive by not only the U.S. government but nations around the world and the United Nations to improve our coordination of capabilities against this natural threat to the Earth," Johnson said.





http://news.yahoo.com/russian-fireball-fallout-huge-asteroid-numbers-raise-stakes-121747077.html

[Buster's Uncle]

Brighter than the sun: stunning new details on the meteor that exploded over Russia
Thanks largely to eyewitnesses and video footage, researchers have documented Chelyabinsk with incredible detail
By Katie Drummond on November 8, 2013 11:30 am






It was the blast felt around the world: when the Chelyabinsk meteor exploded over Russia in February, its shock wave was powerful enough to emit subsonic waves to far-flung regions across the planet.
 
Now, scientists know a little bit more about that mysterious space rock — which, at 12,000 tons, was the biggest meteor to explode over Earth in more than a century. In a new study published in this week’s Science, researchers led by the Russian Academy of Scientists relied on an unprecedented volume of information — courtesy of surveillance cameras, cell phones, seismic instruments, and eyewitness observations — to assemble heaps of data about the freaky incident. "Our goal," said study co-author Peter Jenniskens, "was to understand all circumstances that resulted in the damaging shock wave that sent over 1,200 people to hospitals in the Chelyabinsk Oblast area that day."

By watching various amateur video clips of the rock as it soared towards Earth, the team was able to determine key details, shown in the illustration below. Among them are the meteor’s precise trajectory, its speed upon entering the atmosphere, exactly where it fragmented into smaller pieces, and the point at which that explosion shone most powerfully. That moment — a searingly bright flash 30 times stronger than the sun — actually caused severe sunburns among some bystanders.

Shockwaves from the fireball, the team concluded, caused damage in areas up to 50 miles from the meteor’s trajectory on either side. Fortunately, the largest fragment from the explosion, a 1,250-pound meteorite, hit a frozen lake. The team was able to recover that piece, and their subsequent analysis reveals that the rock — a relatively ordinary "chondrite" space rock — was more than 4,400 million years old.

Now, experts hope that their analysis of the Chelyabinsk incident can help detect and track future space-based threats — and calculate the potential havoc they might wreak upon planet Earth. And it looks like they might be making more such calculations than previously anticipated: yet another new study, published this week in Nature, warns that the likelihood of events like Chelyabinsk is 10 times higher than experts had thought — making the phenomenon one we can expect every 25 years or so.





http://www.theverge.com/2013/11/8/5078430/new-details-on-russian-meteor-chelyabinsk

[ariete]

http://www.allworldwars.com/news-commentary-reviews/2013/02/24/its-good-to-have-aliens-on-our-side-chelyabinsk-meter-shot-down-15-february-2013/

[Geo]

Ridicilous.

[ariete]

me  ... you don't believe in god/s ?

[Geo]

I was forced into the Catholic Church when only a few days old. You tell me.

[ariete]

  me too geo, and i think we are been lucky for this ...

[Geo]

Why's that?