Asteroids, chunks of rock and metal that orbit the Sun, sometimes collide with the Earth. This is one possible explanation for the extinction of dinosaurs.
|Asteroid Fact Sheet|
Asteroids are chunks of rock and metal that orbit the Sun. They can be different shapes and sizes.
There are three major types of asteroids: C-Carbonaceous (comprised of ancient carbon silicates), S-Silicates (made of rocky silicates and iron), and M-Types (rich in metals, mostly nickel and iron).
Asteroids can be as small as the size of a pebble. The largest known asteroid is Ceres, which is around 597 miles (960 kilometers) in diameter.
The largest population of asteroids lies between the orbits of Mars and Jupiter. However, a significant amount of asteroids are found within the orbits of Mars, Earth, Venus, and Mercury. Less than 200 asteroids orbit close enough to Earth to be considered a threat. These bodies are known as near-Earth objects.