MNN - Mother Nature Network

Once every 2,000 years or so, an asteroid the size of a football field comes in contact with the Earth. This can cause significant damage to the planet. Then, every few million years, an impact event happens on our planet. This is when an object big enough to end life as we know it collides with the planet. Scientists generally agree that an asteroid impact eliminated dinosaurs from the planet about 65 million years ago. Here are seven amazing images of known asteroid impact craters from all over the globe.