Elizabeth goes to Russia in search of a meteorite for a film documentary.

By Elizabeth Pearson, an astronomer at Cardiff University and presenter for science made simple.

On 15th February 2013 an explosion was heard in the air above Chelyabinsk, Russia, blowing out windows and doors for miles around. It was not, as many locals thought, a bomb going off but the shock wave created when a huge asteroid hit the earth’s atmosphere. News carriers around the world quickly picked up on the story, inviting experts to come and talk about the meteorite. Experts like me! I was contacted and asked whether or not I’d like to go to Russia to film a documentary on the meteor. I, of course, said yes. After several manic days of trying to get visas and cold weather gear, whilst still performing my Maths Apps shows for science made simple, I was off.

It was great to be in the place where the meteor actually struck down. It’s the first time something like this has happened and has been caught on camera. By looking at the footage scientists were quickly able to work out what direction the asteroid came from and how fast it was going. The best estimates put it somewhere around the 40,000mph mark.

 

Meteoroids are small particles of space rock, ranging from dust grains all the way up to kilometre sized asteroids. Meteoroids hit the Earth’s atmosphere all the time, around 50,000 tonnes of them a year. When this happens, they become known as meteors. Most are small and burn up in the atmosphere, meaning they’re only dust when they reach the ground. By using stations across the globe designed to listen out for nuclear bombs, astronomers managed to work out how much energy the meteor created when it exploded, putting the size of the meteor at about 10,000 tonnes. Meteors of this size are thought to hit the planet once every 100 years or so. While it’s sad that so many people got hurt, it was really fortunate to have the event caught on so many cameras.

The day after we arrived we headed out into the countryside to ground zero: the spot directly underneath where the asteroid exploded. The fact that the area is covered in snow was actually a huge help to us meteorite hunters. I had to look for tiny holes in the snow, made by the meteorite as they showered from above. When you found a hole you had to dig around it, clearing a ring. Then I had to sift through the snow in the middle and hopefully find a meteorite. A lot of the holes were from mice or bits of tree but eventually me and the team got lucky and we found one! It was about the size of a jelly bean, covered in black crust, and it felt really heavy.

We took the fragment to Urals Federal University, where they were looking at the fragments already found. They discovered that the meteor was actually a rather average meteor, with about 7-10% iron, which was why the rock felt so heavy. I even got to look at a piece in a travelling electron microscope.

Despite the devastation that this meteor caused it was actually quite small, probably only 15m across; around the size of a house. The one that killed the dinosaurs was about 10km in size. Luckily those only happen every few million years and we would probably see it coming. Projects like Pan-STARRS regularly scan the sky and can find nearly all asteroids that would risk wiping out all life on the planet. It hasn’t found any that are on a collision course with Earth, so there’s no need to worry. We’re not going the way of the dinosaurs anytime soon.

See an interview with Elizabeth by the BBC about the meteors in Russia here.

Here is an article about her written by the BBC.

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