M-type asteroids

M-type asteroids

A class of asteroids that is fairly common in the main belt, having featureless spectra that are distinguished by high albedo. Their surfaces have a metallic composition (nickel and iron) plus a varying amount of silicates. (16) Psyche, 250 km in diameter, is the largest of the M-Type asteroids.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006