Image credit: Google Earth, NASA/JPL-Caltech › Larger view
From the WSJ (NASA JPL Statement follows):
The meteor that crashed to earth in Russia was about 55 feet in diameter, weighed around 10,000 tons and was made from a stony material, scientists said, making it the largest such object to hit the Earth in more than a century.
Large pieces of the meteor have yet to be found. However, a team from the Urals Federal University, which is based in Yekaterinburg, collected 53 fragments, the largest of which was 7 millimeters, according to Viktor Grokhovsky, a scientist at the university.
Data from a global network of sensors indicated that the disintegration of the Russia fireball unleashed nearly 500 kilotons of energy, more than 30 times the energy of the Hiroshima atomic bomb.
It is the largest reported meteor since the one that hit Tunguska, Siberia, in 1908, according to the U.S. National Aeronautics and Space Administration. The agency’s new gauge of the meteor’s size was a marked increase from its initial estimate.
==============================================================
Here is the NASA JPL statement:
New information provided by a worldwide network of sensors has allowed scientists to refine their estimates for the size of the object that entered that atmosphere and disintegrated in the skies over Chelyabinsk, Russia, at 7:20:26 p.m. PST, or 10:20:26 p.m. EST on Feb. 14 (3:20:26 UTC on Feb. 15).
The estimated size of the object, prior to entering Earth’s atmosphere, has been revised upward from 49 feet (15 meters) to 55 feet (17 meters), and its estimated mass has increased from 7,000 to 10,000 tons. Also, the estimate for energy released during the event has increased by 30 kilotons to nearly 500 kilotons of energy released. These new estimates were generated using new data that had been collected by five additional infrasound stations located around the world – the first recording of the event being in Alaska, over 6,500 kilometers away from Chelyabinsk. The infrasound data indicates that the event, from atmospheric entry to the meteor’s airborne disintegration took 32.5 seconds. The calculations using the infrasound data were performed by Peter Brown at the University of Western Ontario, Canada.
“We would expect an event of this magnitude to occur once every 100 years on average,” said Paul Chodas of NASA’s Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif. “When you have a fireball of this size we would expect a large number of meteorites to reach the surface and in this case there were probably some large ones.”
The trajectory of the Russia meteor was significantly different than the trajectory of the asteroid 2012 DA14, which hours later made its flyby of Earth, making it a completely unrelated object. The Russia meteor is the largest reported since 1908, when a meteor hit Tunguska, Siberia.
Source: http://www.nasa.gov/mission_pages/asteroids/news/asteroid20130215.html
Preliminary information indicates that a meteor in Chelyabinsk, Russia, is not related to asteroid 2012 DA14, which is flying by Earth safely today.
The Russia meteor is the largest reported since 1908, when a meteor hit Tunguska, Siberia. The meteor entered the atmosphere at about 40,000 mph (18 kilometers per second). The impact time was 7:20:26 p.m. PST, or 10:20:26 p.m. EST on Feb. 14 (3:20:26 UTC on Feb. 15), and the energy released by the impact was in the hundreds of kilotons.
Based on the duration of the event, it was a very shallow entry. It was larger than the meteor over Indonesia on Oct. 8, 2009. Measurements are still coming in, and a more precise measure of the energy may be available later. The size of the object before hitting the atmosphere was about 49 feet (15 meters) and had a mass of about 7,000 tons.
The meteor, which was about one-third the diameter of asteroid 2012 DA14, was brighter than the sun. Its trail was visible for about 30 seconds, so it was a grazing impact through the atmosphere.
It is important to note that this estimate is preliminary, and may be revised as more data is obtained.
http://www.nasa.gov/topics/solarsystem/features/asteroidflyby.html
Jet Propulsion Laboratory, Pasadena, Calif.
agle@jpl.nasa.gov
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michaeljmcfadden says:
February 18, 2013 at 9:14 pm
This Island Earth. http://en.wikipedia.org/wiki/This_Island_Earth
Ahh! FOUND IT! 🙂 “This Island Earth” — an excellent 1950s genre sci-fi movie!
http://en.wikipedia.org/wiki/This_Island_Earth
The movie your thinking of is: This Island Earth – 1955
No, there may or may not be a huge crater. Prelimanry reports say this was a stony meteor. There are three general types of meteors in space: stony, metallic (usually iron-nickel), andd mixed stony and iron-nickel/metallic. The stony types tend to explode into a myriad of fragments while still in the upper reaches of the atmosphere. When the meteors plunge into the Earth’s atmosphere, they are usually moving at tremendously high speeds. At such high speeds the impact with the atmosphere 70 to 20 miles above the Earth is like running into a steel armor wall. The impact and friction vaporizes the material at the foreside of the object as the kinetic energy at the rearside of the object is trying to force its way through the object to its frontside. This sudden shockwave through the meteorite can compress, heat, and stress the near zero cold material inside to the point where it must fracture and explode into a showeer of pieces. Stony meteors/meteorites have the least internal strength and are most prone to such fracturing., while some iron-nickel meteors/meteorites can survive in large enough chunks to punch a crater into the ground. The stony object is like a high explosive shell hitting the armor of a tank and fragmenting at the surface, whereas an armor piercing shell with a hard metallic sabot melts and pierces through the tank armor to strike the interior.
Sooner or later this will get put down to ‘galaxy warming’
lol
Take an object with a mass of about 10,000 tons, accelerate it to a high velocity by imparting large amounts of kinetic energy, decelerate the object to less than 10 percent of its high velocity in only a number of seconds in time, watch the forend decelerate faster than the rearend, observie the internal compression disrupt the internal molecular bonds of the object and resultant heating, add the heat from the friction with the atmosphere and vaporization of the foreend material, and you get an object fracturing and vaporizing with a force commensurate with the kinetic energy applied against the resisting forces in the atmosphere and the object.
Spacecraft have already been successfully sent to land upon asteroids and comets. Specially designed spacecraft can do the same, land, and deploy very large and lightwieght aluminized reflectors or sails. Given sufficient time (weeks, months, years, or decades in different cases), the reflectors or sails can use Solar light pressure to impart a steady increase and/or decrease in velocity needed to deorbit the asteroid into the Sun, accelerate it out of the Earth’s orbit, or accelerate it out of the Solar System. Other methods such as converting Solar energy into electricity to create jets of vaporized asteroid steadily propelling it in the desired directions. The principal problem now is having sufficient warning, time, and money. Changing the orbit of an asteroid is possible now with present technology, and it will be much less costly and easier when off-planet mining and manufacturing becomes routine and economical.
Wow! Well, we’ve certainly determined ONE thing for sure! There are a lot of 1950s movie sci-fi fans among WUWT readership! :> I’ve got hundreds of them recorded on VHS tapes in my living room (VHS is something the younger kiddies may not know about… it’s sorta like biblical scrolls and cave paintings. Nothing to fret about. Go back to your iPhones…)
– MJM
P.S. Matt, thanks for the dartboard note! Heh, I *knew* “cardboard” wasn’t quite right but my sleep-deprived brain refused to pop the cork!
Naw, they’ll just accuse us of causing black holes which will one day swallow the Sun and the Earth, end the Mayan calendar, melt the mountain snows to wash away the Tibetan monestaries, and ruin the Academy Award ceremonies.
Meteorites and bolides of this size put out light brighter than the Sun in their brief flash through the atmosphere. This flash of light can be much brighter than the nuclear detonations the military satellites are monitoring for on the Earth’s surface. There was another substantial meteorite and bolide fall over Africa in recent years, and the satellites captured images of the event from above in space. You can see the image/s on Youtube.
“500 kilotons of energy”
Somebody was nodding-off in their school physics lessons.
People always seem to say stuff like that … now imagine actually doing that … on an object that is spinning.
michaeljmcfadden says:
February 18, 2013 at 9:14 pm
Hmm… I am distressed. I can NOT remember the name of the 1950s sci-fi film where some earth scientists were taken to a planet “millions of miles away” which was under attack by enemies who basically guided meteorites down through the atmosphere to strike at their majestic alien cities. I had *thought* it was “20 million miles to earth” but IMDB shows that as being some sort of giant lizard movie that I know I’ve never even seen.
The movie was This Island Earth, complete with kinetic weapons, bug eyed monsters, and screaming damsels.
which had little relation to the short story it was “based” on.
The original plot was a replay of ww2 with two empires at war and the Earth acting as a South Pacific island.
problem was how to get the “good guys” to defend Earth when their computers told them it was an unimportant military target. Turns out the bad guys had been nibbleing away at the good guys for hundreds of years by attacking “unimportant” targets.
All of the impact rate calculations are liable to go up in smoke when the Solar System encounters a region of interstellar space littered with a dense field or band of asteroids not orbiting the Sun.
before anyone objects to their existence, it should be noted that it is not impossibel for the late heavy Bombardment and the formation of the Soalr system to have been associated with just such events.
Werner Borzek says
In a scientific paper it should be. But for popular science this is good enough. It is strictly ‘500 KT of TNT equivalent’.
But the unit is widely enough known and understood to be a convenient shorthand for the general reader. And ‘thirty times Hiroshima’ is pretty graphic.
There are 3 speeds that I am aware of associated with the earth. The speed of the meteor is quoted as relative to earth’s surface, which is what matters to us. But what was the actual speed of this meteor? The speed of the surface at the equator is about 1000 km/hr, the speed of the Earth around the sun is 100,000 km/hr. The third speed is our galaxy speed, which I assume the meteor shares the same reference frame.
The Tunguska Event was also an airburst. See photos taken some years later.
http://en.wikipedia.org/wiki/Tunguska_event
A 55 ft meteorite (not ter mention a fly by asteroid at the same time?)
‘We would expect an event of this magnitude will occur every 100 years
on average.’ says NASA Paul CHodas. Yes if yer livin’ in a gaussian
Mediocristan. ) ref Nassim Taleb ‘The Black Swan.’
The post dropped the word “reported”, but suppose there should be some share of similar events having gone unreported, over the vast southern seas for example?
“It is important to note that this estimate is preliminary, and may be revised as more data is obtained.”
Why am I not surprised by this rider?
D. Patterson says:
February 19, 2013 at 12:03 am
Doug Huffman says:
February 18, 2013 at 5:42 pm
All of the impact rate calculations are liable to go up in smoke when the Solar System encounters a region of interstellar space littered with a dense field or band of asteroids not orbiting the Sun.
before anyone objects to their existence, it should be noted that it is not impossibel for the late heavy Bombardment and the formation of the Soalr system to have been associated with just such events.
*************
One of the interesting studies done after Pioneer(s) were launched was where would they first enter another stellar system.
The stars are constantly moving, each with its own trajectory. The neighbor of today is just a memory a million years hense,
So a study was done of closest approaches by stars over the next few million years,
Turns out that in the year 600,000 AD there was a ( very small ) star that would pass WITHIN our sun’s OORT cloud. Needless to say this will disrupt the orbits of comets, asteroids, and possibly even planets.! ( and another 10 that would be within 4 LY CPA)
Since the other star’s cloud will be on the other side of Sol / bearing down on the planets. We may even end up recreating the conditions of the Hadean Era.
( rule of thumb for mariners — if constant bearing, first order prediction is that your are going to collide)
There was a more recent collection of stellar proper motions but I have seen no revision to who what and when.
The stars rarely direcly collide but they can have their planets stripped away to drift aimlessly in space with no heat or life.
OssQss says:
February 18, 2013 at 7:29 pm
Please see: http://english.pravda.ru/society/anomal/20-07-2012/121694-tunguska_meteorite-0/
Quote: “Researchers from Bologna led by a specialist in marine geology Luca Gasperini ran into another “crater” in 2007. The Italians drew attention to the taiga Lake Cheko that lies eight kilometers north-west of the alleged epicenter of the explosion. The location of the reservoir coincides with the flight path of a giant body that later without good grounds became known as the Tunguska meteorite. It is interesting that Lake Cheko is not observed on any map made before 1929, and according to the testimony of local residents, prior to the crash in 1908 it simply did not exist.
Under The project “Tunguska 99,” Gasperini and his colleagues conducted a study of the lake on the ground. First of all, they were struck by its nearly hemispherical form. It was also found that the bottom of the reservoir has the shape of a cone, and its maximum depth is about 50 meters. This may indicate that something huge had struck the tunnel at this point and sank into the ground. Indeed, the ground penetrating radar recorded a large object at a depth of 10 meters below the bottom of the lake.
The Italian scientists suggest that the “culprit” was a fragment of an exploded cosmic body. The weight of the “fragment” is about 1,5 × 10(high)6 kilograms.” – Unquote.
Where’s a will, there’s a way – and where’s a meteorite, there’s a crater (well: almost always, at least…)
!0,000 tonnes is too much. I calculate 5600 tonnes. 8M rad. and a SG of 2.6 since this was a stoney meteorite. Do the math.
A metallic meteorite may not have exploded like this did and with a SG of 3.4 would have weighed more, far more kinetic energy, reached the ground and done far more damage.
Any asteroids that size that hit earth at or near perpendicular would in all probability go completely undetected. Any radar trace would only remain for a few seconds and would probably be put down to a UFO and ignored. If 50 perpendicular impacts happened each century, only one or two would by chance be near populations. A huge asteroid hitting the deep ocean would not trigger a tsunami, but it would trigger short wavelength, high amplitude “rogue” waves that coudl travel a fair old distance. The spin of the Earth would make perpendicular impacts rare for smaller objects one would assume, but huge objects certainly coudl retain their trajectory…. so I reckon these are more common than we think….
NASA :”The trajectory of the Russia meteor was significantly different than the trajectory of the asteroid 2012 DA14, which hours later made its flyby of Earth, making it a completely unrelated object. ”
Since no one saw it coming, it was not tracked and all we have are a few dashboard cameras to record its “trajectory” I really don’t see what they have to make such definitive statements.
Of course it had a “significantly different trajectory” by the time it hit Russia, But that really tells us very little about what it’s tragectory was before it encountered the Earth’s gravitational field unless we can pin down its direction very precisely. You don’t do that with a dash camera.
The odds on the two events happening within hours of each other would be long enough to get the chair if it was DNA in a murder trial.