Purchase includes free access to book updates online and a free trial membership in the publisher's book club where you can select from more than a million books without charge. Chapters: V-Type Asteroid, Asteroid Spectral Types, P-Type Asteroid, C-Type Asteroid, M-Type Asteroid, S-Type Asteroid, X-Type Asteroid, E-Type Asteroid, D-Type Asteroid, K-Type Asteroid, B-Type Asteroid, L-Type Asteroid, G-Type Asteroid, Q-Type Asteroid, R-Type Asteroid, F-Type Asteroid, J-Type Asteroid, T-Type Asteroid, A-Type Asteroid, O-Type Asteroid. Excerpt: Asteroids are assigned a type based on spectral shape, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiated, the surface and internal compositions are presumably similar, while large bodies such as 1 Ceres and 4 Vesta are known to have internal structure. A list of types can be found at asteroid spectral classes. The present-day classification was initiated by Clark R. Chapman, David Morrison, and Ben Zellner in 1975 with three categories: C for dark carbonaceous objects, S for stony (silicaceous) objects, and U for those that did not fit into either C or S. This classification has since been expanded and clarified. A number of classification schemes are currently in existence, and while they strive to retain some mutual consistency, quite a few asteroids are sorted into different classes depending on the particular scheme. This is due to the use of different criteria for each approach. The two most widely used classifications are described below: The most widely used taxonomy for over a decade has been that of David J. Tholen, first proposed in 1984. This classification was developed from broad band spectra (between 0.31m and 1.06m) obtained during the Eight-Color Asteroid Survey (ECAS) in the 1980s, in combination with albedo measurements. The original formulation was based on 978 a. More:
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