Saturday, March 2, 2013

It Came From the Sky!

This post will also be found in Tehachapi's The Loop Newspaper.

A couple weeks ago I wrote about the asteroid that was going to fly by the Earth. Which it did, since we're all still here to read this. But at almost the same time, February 15th, a meteor did come down on Chelyabinsk area of Russia (in the Ural Mountains). And it was big, though not particularly huge, at about 55 feet and weighing in at about 10,000 tons. It was certainly big enough to cause a lot of injuries and damage.

Rather than strike the ground the meteor exploded about 10 miles up, which spread the damage over a wider area, but did keep the overall severity of the damage down. The amount of energy that was released, was somewhere close to 500 kilotons, which is about 30 times the size of the Atomic Bomb that was used on Hiroshima.

Somewhere around 1,500 people were injured by the meteor, however almost all the injuries were pretty minor. Most of them caused by flying pieces of glass. But some injuries were more severe with a small number of people hospitalized briefly.

The meteor took a considerable amount of time to fly across the sky, giving many people a chance to capture video of the event. If you are interested some of these are available of YouTube, one link is With the brightness of the explosion the fireball was seen for a large distance. (Exploding meteors are sometimes called bolides. I was exposed to one many years ago in Texas. I say exposed rather than saw, since I was facing the other direction and saw the light, and my shadow on the ground in front of me. My friends that were facing me actually got to see the explosion.)

Given how well observed this particular meteor was, it is no wonder that it wasn't long before people had tracked down fragments of the meteor. Some fragments (at least purported fragments) are available to buy on Ebay (prices vary by size). Other fragments have been sent to various scientific centers to undergo investigation.

These fragments have shown that the meteor was of a type known as a chondrite. Chondrites are rocky meteors, made up of dust and small grains that came out of the cloud of material that formed the early solar system billions of years ago. This means they are basically unchanged from the types of things that first made up the planets and larger asteroids. Most meteors are chondrites. These small pieces of rock contain examples of minerals such as olivine and pyroxene, which aren't formed on planets.

So a small piece of rock (relatively small at least) hits the Earth. Russian entrepreneurs are making money on Ebay selling fragments, scientists get some new samples of the early solar system to study. Almost all the injuries were pretty minor. The economic impact is only about $30 million. Life is good. But let's keep science looking up, even a little warning might have helped to prevent some of those injuries. Such meteor strikes are rare events, so we probably have time before the next one, but let's not gamble with the whole nest egg.   

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