INCOMING!: метеорита в Челябинске, Russian Meteor - February 2013 |
INCOMING!: метеорита в Челябинске, Russian Meteor - February 2013 |
Feb 15 2013, 07:01 AM
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#1
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Senior Member Group: Moderator Posts: 3241 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
Looks like a small meteoroid decided to spoil 2012 DA14's big day by exploding over Russia...
http://zyalt.livejournal.com/722930.html?nojs=1 -------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
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Feb 15 2013, 07:18 AM
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#2
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Senior Member Group: Members Posts: 2106 Joined: 13-February 10 From: Ontario Member No.: 5221 |
Depends on one's definition of 'small'! Phil Plait has an early summary/videos: http://www.youtube.com/watch?feature=playe...p;v=rflTN4XAt34
The biggest over a populated area in a long time... |
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Feb 15 2013, 08:16 AM
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#3
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Member Group: Members Posts: 293 Joined: 22-September 08 From: Spain Member No.: 4350 |
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Feb 15 2013, 08:27 AM
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#4
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Clearly a major event. I hope that the reported injuries are mild, and that there are no fatalites.
Caution all to be objective (as all have been thus far) and most of all respectful since there does seem to be a possibility of direct effects on people here, okay? All that being said: There is no amount of 'wow' I can adequately express. Looking forward to the final analysis of this. -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Feb 15 2013, 08:43 AM
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#5
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Senior Member Group: Members Posts: 2106 Joined: 13-February 10 From: Ontario Member No.: 5221 |
Direct hit on factory? http://www.youtube.com/watch?v=DgZ0aA7RUhE
Crews clearing rubble like just another day at work. i know that statistically Russia is the most likely country to get hit since it's got the greatest surface area, but literally a half day before this other rock is a real coincidence. |
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Feb 15 2013, 11:15 AM
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#6
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Member Group: Members Posts: 796 Joined: 27-February 08 From: Heart of Europe Member No.: 4057 |
Chelyabinsk's bolid from Meteosat.
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Feb 15 2013, 11:50 AM
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#7
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Russia is the most likely country to get hit since it's got the greatest surface area, but literally a half day before this other rock is a real coincidence. And that's in fact what it is precisely. Preliminary reports indicate that the object entered from a completely different azimuth than what would be possible for something associated with that asteroid during the upcoming encounter. -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Feb 15 2013, 01:01 PM
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#8
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Member Group: Members Posts: 813 Joined: 29-December 05 From: NE Oh, USA Member No.: 627 |
WOW!...
Hope injuries not serious. Analysis of this should be fascinating.... a mini-Tunguska. Craig |
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Feb 15 2013, 01:10 PM
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#9
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Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
The best of the videos I've seen show the contrail ending well above the ground, suggesting that the impactor disintegrated in the air. I'm wondering whether the bolide actually hit the ground, or whether the damage was caused by an over-pressure wave pushed ahead of it.
-the other Doug -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Feb 15 2013, 01:26 PM
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#10
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Senior Member Group: Members Posts: 2492 Joined: 15-January 05 From: center Italy Member No.: 150 |
An hour ago, Italian television told about russain military attempt to intercept/destroy the meteorite in flight, through a non-armed missile... I am very skeptical, did someone heared such a story? They showed also an impressive video with a ground explotion near an highway (metoerite fragment hitting ground?)
-------------------- I always think before posting! - Marco -
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Feb 15 2013, 03:33 PM
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#11
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Member Group: Members Posts: 796 Joined: 27-February 08 From: Heart of Europe Member No.: 4057 |
Dilo, today's SAMs cannot hit and destroy such asteroid. Radar has limited range and limited reaction time and even ABM missiles cannot cope with object with speed more than ~7 km/s. It's total nonsense.
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Feb 15 2013, 03:46 PM
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#12
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Senior Member Group: Members Posts: 2492 Joined: 15-January 05 From: center Italy Member No.: 150 |
Yes, machi, I know and I said I was skeptical! in fact, it seems such rumor was officially denied...
-------------------- I always think before posting! - Marco -
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Feb 15 2013, 03:56 PM
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#13
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Member Group: Members Posts: 495 Joined: 12-February 12 Member No.: 6336 |
The best of the videos I've seen show the contrail ending well above the ground, suggesting that the impactor disintegrated in the air. I'm wondering whether the bolide actually hit the ground, or whether the damage was caused by an over-pressure wave pushed ahead of it. -the other Doug Several pieces did hit the ground, images of that factory shown above is only one that might have been a smaller piece. A somewhat larger impacted near a highway. And one piece thought to have been larger is said to have ended up in a lake quite far from the city according to my teletext news here. @dilo: Hard to say, my teletext feed states that there initially were one alert for one possible nuclear strike, but it reads as that alert came after the actual impact so I guess the Italians have elaborated on that fact a bit. @nprev: The teletext say about 900 wounded, mostly from shattered glass, and a number (no numbers given) hospitalized. But still no mention of any casualties so lets hope there were none. |
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Feb 15 2013, 04:05 PM
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#14
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Solar System Cartographer Group: Members Posts: 10227 Joined: 5-April 05 From: Canada Member No.: 227 |
The story about intercepting the meteorite is almost certainly a journalist's confusion between the current event and stories about future asteroid deflection missions, which are being discussed in Russia.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PDF: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Feb 15 2013, 04:08 PM
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#15
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Member Group: Members Posts: 723 Joined: 13-June 04 Member No.: 82 |
I am trying to get an estimate of the size of the meteoroid and explosion. Assuming a dense rocky composition with a density around 3 tonnes per cubic metre, I keep getting sizes much larger than the estimate of around 10 tonnes that I have heard. The calculation below results in a mass of around 73,000 tonnes.
The overpressure from the blast wave was sufficient to shatter thousands of windows (and in fact some videos I have watched appear to show that every window in view was smashed) and caused the partial collapse of a zinc factory. This implies that the overpressure was between 1 kPA (shatters many windows) and 5 kPa (partial collapse of some buildings), let's assume that the zinc factory was poorly maintained and the overpressure was 3 kPa. Early reports give an entry velocity of around 30 km/s. According to this site, the diameter of a rocky object that produces a 3.1 kPa overpressure at a distance of 30 km from directly under the main explosion (as appears to be roughly the distance from the videos) would be about 36m, producing a 5.26 MT airburst at an altitude of 18.2 km. Earth Impact Effects Program Robert Marcus, H. Jay Melosh, and Gareth Collins Please note: the results below are estimates based on current (limited) understanding of the impact process and come with large uncertainties; they should be used with caution, particularly in the case of peculiar input parameters. All values are given to three significant figures but this does not reflect the precision of the estimate. For more information about the uncertainty associated with our calculations and a full discussion of this program, please refer to this article Your Inputs: Distance from Impact: 30.00 km ( = 18.60 miles ) Projectile diameter: 36.00 meters ( = 118.00 feet ) Projectile Density: 3000 kg/m3 Impact Velocity: 30.00 km per second ( = 18.60 miles per second ) Energy: Energy before atmospheric entry: 3.30 x 10^16 Joules = 7.88 MegaTons TNT The average interval between impacts of this size somewhere on Earth is 539.1 years Major Global Changes: The Earth is not strongly disturbed by the impact and loses negligible mass. The impact does not make a noticeable change in the tilt of Earth's axis (< 5 hundreths of a degree). The impact does not shift the Earth's orbit noticeably. Atmospheric Entry: The projectile begins to breakup at an altitude of 63100 meters = 207000 ft The projectile bursts into a cloud of fragments at an altitude of 18200 meters = 59600 ft The residual velocity of the projectile fragments after the burst is 17.3 km/s = 10.7 miles/s The energy of the airburst is 2.20 x 10^16 Joules = 5.26 MegaTons. No crater is formed, although large fragments may strike the surface. Air Blast: The air blast will arrive approximately 1.77 minutes after impact. Peak Overpressure: 3100 Pa = 0.031 bars = 0.44 psi Max wind velocity: 7.21 m/s = 16.1 mph Sound Intensity: 70 dB (Loud as heavy traffic) edit -- Assuming that the distance from ground zero was 15km instead of 30km, and with an overpressure of 2 kPa, the website gives the following (calculated initial mass 51,000 tonnes): Your Inputs: Distance from Impact: 15.00 km ( = 9.32 miles ) Projectile diameter: 32.00 meters ( = 105.00 feet ) Projectile Density: 3000 kg/m3 Impact Velocity: 30.00 km per second ( = 18.60 miles per second ) Energy: Energy before atmospheric entry: 2.32 x 10^16 Joules = 5.53 MegaTons TNT The average interval between impacts of this size somewhere on Earth is 410.7 years Major Global Changes: The Earth is not strongly disturbed by the impact and loses negligible mass. The impact does not make a noticeable change in the tilt of Earth's axis (< 5 hundreths of a degree). The impact does not shift the Earth's orbit noticeably. Atmospheric Entry: The projectile begins to breakup at an altitude of 63100 meters = 207000 ft The projectile bursts into a cloud of fragments at an altitude of 19900 meters = 65400 ft The residual velocity of the projectile fragments after the burst is 18.3 km/s = 11.4 miles/s The energy of the airburst is 1.45 x 10^16 Joules = 3.47 MegaTons. No crater is formed, although large fragments may strike the surface. Air Blast: The air blast will arrive approximately 1.26 minutes after impact. Peak Overpressure: 2120 Pa = 0.0212 bars = 0.301 psi Max wind velocity: 4.96 m/s = 11.1 mph Sound Intensity: 67 dB (Loud as heavy traffic) another edit -- this is the minimum value that reliably breaks windows, it still results in a calculated airburst energy of 1.9 MT with an initial mass of 31,000 tonnes. I doubt that the airburst was this close to overhead, it appeared closer to the horizon in the videos. Your Inputs: Distance from Impact: 10.00 km ( = 6.21 miles ) Projectile diameter: 27.00 meters ( = 88.60 feet ) Projectile Density: 3000 kg/m3 Impact Velocity: 30.00 km per second ( = 18.60 miles per second ) Energy: Energy before atmospheric entry: 1.39 x 10^16 Joules = 3.32 MegaTons TNT The average interval between impacts of this size somewhere on Earth is 277.4 years Major Global Changes: The Earth is not strongly disturbed by the impact and loses negligible mass. The impact does not make a noticeable change in the tilt of Earth's axis (< 5 hundreths of a degree). The impact does not shift the Earth's orbit noticeably. Atmospheric Entry: The projectile begins to breakup at an altitude of 63100 meters = 207000 ft The projectile bursts into a cloud of fragments at an altitude of 22500 meters = 73700 ft The residual velocity of the projectile fragments after the burst is 19.6 km/s = 12.2 miles/s The energy of the airburst is 7.95 x 10^15 Joules = 1.90 MegaTons. No crater is formed, although large fragments may strike the surface. Air Blast: The air blast will arrive approximately 1.24 minutes after impact. Peak Overpressure: 994 Pa = 0.00994 bars = 0.141 psi Max wind velocity: 2.33 m/s = 5.22 mph Sound Intensity: 60 dB (Loud as heavy traffic) |
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