Related to major near-Earth asteroid set to graze planet Friday? UPDATED: Euro Space Agency says event unrelated...
By Brad Friedman on 2/14/2013, 11:44pm PT  

At this hour, just after 11pm PT, this story is labeled as "BREAKING NEWS" at Russia's state-owned RT website.

RT is reporting "Up to 100 people sought medical attention as a result of the incident, according to the Russian Interior Ministry. No serious injuries have been reported, with most of the injuries caused by broken glass and minor concussions."

[Update: AP now pegs the number as "more than 400 people" injured, according to a Russian Interior Ministry spokesperson. || Later Update: Washington Post now reports "985 people sought medical help for injuries and 43 were hospitalized."]

But take a look at some of the remarkable video...

Here's the beginning of RT's coverage explaining what seems to be going on...

A series of explosions in the skies of Russia’s Urals region, reportedly caused by a meteorite shower, has sparked panic in three major cities. Witnesses said that houses shuddered, windows were blown out and cellphones have stopped working.

According to unconfirmed reports, the meteorite was intercepted by an air defense unit at the Urzhumka settlement near Chelyabinsk. A missile salvo reportedly blew the meteorite to pieces at an altitude of 20 kilometers.

A bright flash was seen in the Chelyabinsk, Tyumen and Sverdlovsk regions, Russia’s Republic of Bashkiria and in northern Kazakhstan.

Lifenews tabloid said that at least one piece of the fallen object caused damage on the ground in Chelyabinsk. According to preliminary reports, it crashed into a wall near a zinc factory, disrupting the city's Internet and mobile service.

The Emergency Ministry reported that 20,000 rescue workers are operating in the region. Three aircraft were deployed to survey the area and locate other possible impact locations.

Witnesses said the explosion was so loud that it seemed like an earthquake and thunder had struck at the same time, and that there were huge trails of smoke across the sky. Others reported seeing burning objects fall to earth.

Police in the Chelyabinsk region are reportedly on high alert, and have begun ‘Operation Fortress’ in order to protect vital infrastructure.

This certainly seems like a hoax, but apparently it is not, as U.S. news sites are now picking this up as well. See RT's page for more details.

Here are a few of the photos they have posted, said to have been published by Twitter users, and one possible explanation for what seems to be going on...

RT goes on to report that "It is believed that the incident may be connected to asteroid 2012 DA14, which measures 45 to 95 meters in diameter and will be passing by Earth tonight at around 19:25 GMT at the record close range of 27,000 kilometers."

They don't specify who "believes" that, but, indeed, 2012 DA14 is set to fly by Earth on Friday in what NASA describes as "a record close approach for a known object of this size."

"Small near-Earth asteroid 2012 DA14 will pass very close to Earth on February 15," NASA reports, "so close that it will pass inside the ring of geosynchronous weather and communications satellites. NASA's Near-Earth Object Program Office can accurately predict the asteroid's path with the observations obtained, and it is therefore known that there is no chance that the asteroid might be on a collision course with Earth. Nevertheless, the flyby will provide a unique opportunity for researchers to study a near-Earth object up close."

Could be an interesting day...

* * *

UPDATE 10:02am PT, 2/15/2013: NASA's Jet Propulsion Laboratory tweets to say that the "Russian meteor appears to be a fireball". They point us to this American Meteor Society FAQ on fireballs, which, among other information, describes a fireball as "another term for a very bright meteor, generally brighter than magnitude -4, which is about the same magnitude of the planet Venus in the morning or evening sky."

The FAQ goes on to say: "Several thousand meteors of fireball magnitude occur in the Earth’s atmosphere each day. The vast majority of these, however, occur over the oceans and uninhabited regions, and a good many are masked by daylight. Those that occur at night also stand little chance of being detected due to the relatively low numbers of persons out to notice them. ... Additionally, the brighter the fireball, the more rare is the event."

According to the European Space Agency, the Russian meteor was not related to the asteroid 2012 DA14 which is passing the Earth today in one of the closest near misses on record for an asteroid of this size. You can watch the asteroid pass by Earth, as it happens, via this JPL live video stream.

UPDATE 10:50am PT, 2/15/2013: Dan Vergano at USA Today adds this context to all of the above:

The Russian meteor burst apart in air, creating a pressure wave strong enough to blast out windows across a region of central Russia. [Purdue University asteroid impact expert Jay] Melosh estimates the impact energy of an asteroid the size of 2012 DA14, were it to hit Earth, at about 4 megatons, a bit higher than NASA estimates. Soviet city buster nuclear bombs were about 20 megatons, for context, while the 1945 Hiroshima atomic bomb that killed about 150,000 people was only about 15 kilotons. (A kiloton has the equivalent explosive force of 1,000 tons of TNT. A megaton explodes like 1 million tons of TNT.) NASA's Donald Yeomans compared the blast from such an object to the 1908 Tunguska (tun-GUS-kuh) event in Siberia. "This impact of an asteroid just slightly smaller than 2012 DA14 is believed to have flattened about 750 square miles of forest," Yeomans says.
...
The Russian meteor's damage was from the air pressure wave it created as it zoomed into the atmosphere, says [MIT asteroid expert Richard] Binzel, who estimates the object was likely, "about the size of an SUV." An asteroid the size of 2012 DA14 would break up at about 30,000 feet in altitude if it ran into the Earth, Melosh estimates. Unfortunately this is the "optimal" height in military terms, he says, for delivering the full force of its blast to the surface. "It's tempting to spin out these terrible scenarios where it happens over Moscow or London, which would be devastating, but the truth is that cities are not covering that much of the Earth, and so it is very unlikely that one would be hit," Melosh says. Plus, we would have at least a month to evacuate a city or region that appeared at risk under circumstances similar to 2012 DA14's discovery.

So...rest easy and have a great, non-apocalyptic day!