A huge meteor streaked through the sky over Chelyabinsk, Russia today and then exploded, raining molten debris across the area that damaged buildings and caused hundreds of injuries.
Multiple eyewitness video captured of the event, showing the meteor lighting up the sky like a second Sun before erupting into a blinding explosion above the city.
From the footage, it appears as though only a few small fragments of the meteor managed to survive the explosion to continue on its original trajectory, with the bulk of the meteor shattering in all directions to rain down on the ground.
Many large meteors that enter our atmosphere suffer this fate, and it's only the truly massive ones that survive to hit the ground (relatively) intact.
Traveling at least 11 km/s (that's 40,000 km/h) as they encounter the atmosphere, the friction generated as they pass through the air heats meteors to incredible temperatures. Smaller ones quickly burn up, leaving behind a harmless glowing trail in the upper atmosphere, or they shatter and the resulting smaller pieces burn up harmlessly.
When meteors of a certain size encounter the Earth, though, such as this one, they're big enough to survive entry into the atmosphere. As they travel through the atmosphere, friction and pressure from the air cause the leading side of the meteor to reach temperatures much higher than the trailing side of the meteor. This temperature difference causes internal pressures that can shatter the rock cause it to explode.
This particular meteor was estimated at about 10 tons, and was apparently travelling at between 15-30 km/s (that's 54,000-108,000 km/h!), according to the Russian Academy of Sciences. Its passage through the air set off massive sonic booms, and when the pressure and heat from the friction with the air became too much for it to hold together, it went off like a bomb.
The resulting fireball rained flaming debris down across the city, and the powerful pressure wave from the explosion shattered windows and reportedly crumpled the store fronts of several buildings in the city centre. One large building, a zinc factory, apparently suffered a partial collapse.
- Is this a prelude to 2012 DA14?
- Russian meteor trail as seen from space
- Gallery: Meteorite hits Russia
- Asteroid near-miss only a hint of what's really out there
With attention already on the sky today, as asteroid 2012 DA14 makes its extremely close pass by the Earth in just a few hours, there are likely concerns that this morning's meteor strike is some kind of prelude to 2012 DA14 actually hitting the planet. However, according to NASA officials, the two events are not related, with the separation in time between this meteor entering the atmosphere and the passage of 2012 DA14 being very significant.
I think far more eyes will be on the sky and on the internet sites that will be showing the passage of 2012 DA14, though, just to be sure.
Check out my article from the other day (click here) to read up more on 2012 DA14 and follow the links at the bottom of the article to watch as it flies by the Earth this afternoon.
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