Aspects of this topic are discussed in the following places at Britannica.
Asteroids of the B, C, F, and G classes have low albedos and spectral reflectances similar to those of carbonaceous chondritic meteorites and their constituent assemblages produced by hydrothermal alteration and/or metamorphism of carbonaceous precursor materials. Some C-class asteroids are known to have hydrated minerals on their surfaces, whereas Ceres, a G-class asteroid, probably has water...
We welcome your comments. Any revisions or updates suggested for this article will be reviewed by our editorial staff. Contact us here.
Regular users of Britannica may notice that this comments feature is less robust than in the past. This is only temporary, while we make the transition to a dramatically new and richer site. The functionality of the system will be restored soon.