The three main types of asteroids are C-Type, M-Type, and S-Type. Asteroids are categorized according to their compositions. C-Type asteroids are carbonaceous, M type asteroids are metallic, and S-Type asteroids are smilacaceous. Dark C Type asteroids are found in the portion of the asteroid belt facing away from the sun. M Type asteroids are found in the middle of the belt, and most of the metal in M Type asteroids consist of iron and nickel.
The S-Type asteroids reside in the inner area of the asteroid belt. When an asteroid impacts with the Earth, it is called a meteorite. Small meteorites do very little damage. Large ones infiltrating the atmosphere create shock waves and other conditions that are potentially hazardous. These meteorites are thought to be behind some extinction events.