sol2 4B

​On a clear night, you can often see meteors - space rocks - as they fall towards the Earth. Each rock is smaller than an apple, but they look as bright as stars in the night sky, so people call them shooting stars. Larger meteors are much rarer, but their effects are far more spectacular.

In 2013, a meteor exploded in the sky above the city of Chelyabinsk in Russia. The explosion was more powerful than the 1945 Hiroshima atomic bomb, but its effect was not as devastating as the bomb because the meteor exploded much further from the ground. Scientists compared the Chelyabinsk meteor to an earlier - and far bigger - explosion: the Tunguska Event.