Human have long feared things falling from the sky. Objects from space that make it through Earth's atmosphere are generally meteorites, which are small particles from asteroids or comets that orbit the sun.

 

Once every 2,000 years or so, an asteroid the size of a football field comes in contact with the Earth. Then, every few million years, our planet experiences an impact event. This is when an object big enough to end life as we know it collides with Earth. Scientists generally agree that an asteroid impact eliminated the dinosaurs about 65 million years ago.

 

Not only have these impacts shaped evolution, they have created important ore deposits and land disturbances. Impacts have even helped shape and form our oceans. Here are seven images of known asteroid impact craters around the planet. (Text: Katherine Butler)