Asteroid flies closely past Earth

An asteroid the size of a 10-story building flew past Earth today about twice the distance as the highest Earth-orbiting satellites. Astronomers had known the asteroid was coming and said there was no risk of collision. The vast majority of known asteroids orbit within the main asteroid belt between the orbits of Mars and Jupiter. This belt is currently estimated to contain between 1.1 and 1.9 million asteroids larger than 1 km in diameter. Its believed that an asteroid impact may have contributed to the extinction of the dinosaurs at the end of the Cretaceous Period 65 million years ago.