Posted on 02/17/2013 1:01:22 AM PST by neverdem
Current and planned efforts focus on larger objects
Scientists have begun piecing together the characteristics of the meteor that exploded over Russia on the morning of February 15, using data from seismic instruments that track earthquakes and microphones designed to detect sonic booms from nuclear explosions. Unlike the asteroid DA14, which narrowly but predictably missed Earth later that day, the meteor was too small to detect before its contrail appeared in the dawn skies over the Russian city of Chelyabinsk.
Yet even an object too small to detect can produce an impressive amount of destruction. The meteor was 15 meters across (compared with 50 meters for 2012 DA14) and weighed more than 7,000 metric tons when it entered Earth’s atmosphere, says Margaret Campbell-Brown, an astronomer at Western University in London, Ontario. She estimates that it was streaking through the sky at supersonic speeds of about 18 kilometers a second before exploding at an altitude of 15 to 20 kilometers, creating a shock wave that shattered glass in a deafening boom once it reached the surface. Various news sources have reported hundreds of buildings damaged and about 1,200 injuries.
Coincidentally, the largest observed meteor to enter the atmosphere since 1908 arrived just hours before a much larger object passed the planet uneventfully at a distance of about 27,000 kilometers.
“The fireball is not related in any way to 2012 DA14,” says Paul Chodas, a planetary scientist with NASA’s Near Earth Object Program at the Jet Propulsion Laboratory in Pasadena, Calif. Among other reasons, the meteor buzzed through the sky from north to south, the opposite trajectory of DA14.
The explosion had the equivalent of up to 500,000 tons of TNT, Campbell-Brown says. That’s about 30 times the energy output of the Hiroshima atomic bomb but only 5 percent of the energy...
(Excerpt) Read more at sciencenews.org ...
Hmmm, I think I'll wait for the above to be confirmed. That seems a bit large to me.
If the UN wanted to do one useful thing;this would be it.
Check sf stOry “trigger man”. By j f. BOne
Are you talking about the asteroid 2012 DA14?
Based on some internet comments the wall in question is on a VERY old building.
If a window could be broken, an old, un-reinforced brick wall with nothing behind it (and possibly poorly constructed) could be knocked down.
Here’s the FR word of the day!
BOLIDE - a meteor and meteorite related term, with specific definitions from several groups. One definition describes them as fireballs reaching magnitude -14 or brighter.[1] In geology the term is used “to imply that we do not know the precise nature of the impacting body ... whether it is a rocky or metallic asteroid, or an icy comet, for example”.[2]
An especially bright meteor, a bolide (in astronomy).
The word bolide comes from the Greek (bolis), which can mean a missile.
The IAU has no official definition of “bolide”, and generally considers the term synonymous with “fireball”. However, the term generally applies to fireballs reaching magnitude -14 or brighter.[1] Astronomers tend to use “bolide” to identify an exceptionally bright fireball, particularly one that explodes (sometimes called a detonating fireball). It may also be used to mean a fireball which creates audible sounds.
If the magnitude of a bolide reaches -17 or brighter it is known as a superbolide.
http://en.wikipedia.org/wiki/Bolide
Depending upon the makeup of the object itself, there could be ill effects from the smoke or smaller fragments breaking off. The notion of meteorites being toxic isn’t entirely a creation of comic books and science fiction.
http://news.yahoo.com/russian-meteor-blast-bigger-thought-nasa-says-234920189.html
“But late Friday, NASA revised its estimates on the size and power of the devastating meteor explosion. The meteor’s size is now thought to be slightly larger — about 55 feet (17 m) wide — with the power of the blast estimate of about 500 kilotons, 30 kilotons higher than before, NASA officials said in a statement.”
“The meteor was also substantially more massive than thought as well. Initial estimated pegged the space rock’s mass at about 7,000 tons. Scientists at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., now say the meteor weighed about 10,000 tons and was travelling 40,000 mph (64,373 km/h) when it exploded.”
There was another meteorite that hit Cuber!
February 16, 2013 - Another February 14th Meteor Report -
This One Over Cuba.
Before the big space rock exploded with the force of 300 TNT kilotons and crashed into central Russia at 9:20 PM local time on February 14 (3:20 AM GMT), another fireball was videotaped over Rodas near Cienfuegos, Cuba, around 8 PM local time (1 AM GMT), six thousand miles from the exploded meteor impact sites in Chelyabinsk east of the Ural Mountains. Rodos residents described a roaring sound in the sky and a moving bright light that exploded and shook some houses, but no damage or injuries were reported. Cuban media report that scientists are trying to find pieces of that explosion.
Video here:
http://www.youtube.com/watch?v=gGJsv1WYXEM
News article in Spanish with video.
http://www.cubasi.cu/cubasi-noticias-cuba-mundo-ultima-hora/item/14384-en-video-el-meteorito-de-cienfuegos
If those fragments happen to be a carbonaceous chondrite it is worth $10,000 per gram if found.
If it were to contain enough cyanogen the person or persons who found it wouldn’t live long enough to enjoy any payoff.
I’ve never heard of c2n2 showing up in meteorites. Used in rocketry? Yes! Have any links on that?
Many meteor showers are associated with the orbits of comets, therefore the origin of some meteors would be comet fragmentation. Many comets contain cyanogen, so many meteorite showers associated with their orbits will as well.
As a for instance, fairly recently, a meteor struck near a Peruvian village, emitted a very strong odor, sickening hundreds of villagers as well as police. Investigators wearing gas masks reported strong nasal and respiratory irritation through their gas masks.
Some attribute the respiratory distress and illness to cyanogen. Others attribute it to the heat of the meteorite fusing elements in the soil itself along with a high water table, emitting steam containing arsenic among other substances.
http://astronomer.proboards.com/index.cgi?board=meteors&action=display&thread=319
I wasn’t even considering the potential toxicity - I was wondering just about the physical effects of a large hypersonic object passing low “overhead”.
Bizarre weather would be an effect in the wake of a large one grazing the atmosphere, I’d think. Possibly cyclonic.
Thanks for the info, guess I am incorrect, it was that big. Russia got very lucky the meteorite did not hit dirt. That would have been a BIG bang. Seems there are lots of fireballs in the sky lately. Wonder what is up with that?
However assuming the impossible the effects of such a fly by would depend on the composition of the meteor. The "sonic boom" of a mile wide object traveling 60,000 mph one mile overhead would be very impressive, lol. Sadly it is above my pay grade to do the math on that. Fluid Dynamics is not my thing.
Proteins behind mad-cow disease also help brain to develop
A tantalising prospect: Exotic, useful metals such as titanium are about to become cheap & plentiful
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Proteins behind mad-cow disease also help brain to develop
A tantalising prospect: Exotic, useful metals such as titanium are about to become cheap & plentiful
Pop Vitamin C Tablets, Get a Kidney Stone
FReepmail me if you want on or off my health and science ping list.
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