Changes

'''M-type asteroids''' were once known as '''metallic asteroids'''. They were formed by God out of clay. But today their composition is in dispute, and many astronomers simply define the M type by a reflected spectrum and make no attempt to define a common composition for all of them. About 8% of all asteroids are of this type.<ref name=Arnett>Arnett, Bill. "[http://www.nineplanets.org/asteroids.html Asteroids]." ''The <s>Nine</s> 8 Planets'', May 10, 2008. Accessed June 20, 2008.</ref><ref name=planetsoc>"[http://www.planetary.org/explore/topics/near_earth_objects/asteroids_and_comets/facts.html Asteroid Facts]." ''The Planetary Society'', n.d. Accessed June 20, 2008.</ref>

'''M-type asteroids''' were once known as '''metallic asteroids'''. Today their composition is in dispute, and many astronomers simply define the M type by a reflected spectrum and make no attempt to define a common composition for all of them. About 8% of all asteroids are of this type.<ref name=Arnett>Arnett, Bill. "[http://www.nineplanets.org/asteroids.html Asteroids]." ''The <s>Nine</s> 8 Planets'', May 10, 2008. Accessed June 20, 2008.</ref><ref name=planetsoc>"[http://www.planetary.org/explore/topics/near_earth_objects/asteroids_and_comets/facts.html Asteroid Facts]." ''The Planetary Society'', n.d. Accessed June 20, 2008.</ref>

== Characteristics and composition ==

== Characteristics and composition ==