C-type asteroids are carbonaceous asteroids. They form 75% of known asteroids, and are extremely dark (albedo 0.03), similar to carbonaceous chondrite meteorites (types CI and CM). They dominate the outer belt beyond 2.7 AU. These asteroids have approximately the same chemical composition as the Sun, except that they do not contain hydrogen, helium and other volatiles. The spectra of these asteroids have relatively blue colours, slightly reddish longwards of 0.4 µm, but otherwise fairly flat and featureless with an ultraviolet absorption feature shortwards of 0.4 µm.
C-type asteroids are further subdivided into the following classifications:
See also
