The meteor was estimated to be about 55 feet and weighing approximately 10,000 tons. The incoming explosion released nearly 500 kilotons of energy and early estimates indicate 1,000 people where injured, primarily from broken glass as windows shattered.
According to the Associated Press,
The explosions broke an estimated 100,000 square meters (more than 1 million square feet) of glass, city officials said.
Chelyabinsk health chief Marina Moskvicheva, said Friday that 985 people in her city had asked for medical assistance. The Interfax news agency quoted her as saying 43 were hospitalized. Athletes at a city sports arena were among those cut up by the flying glass.
NASA stated that such occurrences are to be expected every 30 years or so, and noted that this event and the 2012 DA14 asteroid were unrelated:
"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.
It is understandable that people will conflate the two events occurring on the same day. I would like to know the odds of this event happening.
In a February 14 editorial in The Wall Street Journal, the authors provided additional estimates on the likelihood of future meteor strikes,
The chance of another Tunguska-size impact somewhere on Earth this century is about 30%. That isn't the likelihood that you will be killed by an asteroid, but rather the odds that you will read a news headline about an asteroid impact of this size somewhere on Earth. Unfortunately, that headline could be about the destruction of a city, as opposed to an unpopulated region of Siberia.
The chance in your lifetime of an even bigger asteroid impact on Earth—with explosive energy of 100 megatons of TNT—is about 1%. Such an impact would deliver many times the explosive energy of all the munitions used in World War II, including the atomic bombs. This risk to humanity is similar to an individual's odds of dying in a car accident.
This was published one day before the meteor struck Russia. I wonder if the authors would update their estimates today (or turn in their car keys).
