Terrain A appears to be the ubiquitous background on most of Ida, while Terrain B is correlated with some small craters Galileo SSI color data between 0.4 and 1.0 m demonstrate as well as with possible ejecta from the 10-km Azzurra that both Ida and Dactyl are S-type asteroids with similar, but impact structure. Because of these trends, it is less likely distinct spectra. Small but definite color variations are also that differences between Terrains A and B are caused by an observed on Ida itself and involve both the blue part of the original compositional inhomogeneity within the body of Ida, spectrum and the depth of the 1-m pyroxene-olivine band. although they do fall within the range known to occur within Ida's surface can be classified into two color terrains: Terrain the Koronis family.
A has a shallower 1-m absorption and a steeper visible red
The spectrum of Dactyl is similar to, but definitely different slope than does Terrain B. Qualitatively, the color-albedo from, that of Terrain B on Ida. It does not conform to the systematics of these two terrains follow those noted for color pattern that obtains between the colors and albedos of Terrains units on Gaspra and the variations in 1-m band depth with A and B: the satellite's 1-m band is deeper than that of weathering described by Gaffey et al. (Gaffey, M. J., J. F. Bell, Terrain B, but its albedo is lower, rather than higher. By R. H. Brown, T. H. Burbine, J. Piatek, K. L. Reed, and D. A. itself, the deeper band depth could be interpreted, following Chaky 1993. Icarus 106, 573-602). Terrain A, with its slightly Gaffey et al., to mean that Dactyl is a less weathered version lower albedo, its shallower 1-m band, and its slightly steeper of Terrain B on Ida, but such an interpretation is at odds visible red slope relative to Terrain B could be interpreted as the with Dactyl's redder spectral slope. Thus, the explanation ''more processed,'' ''more mature,'' or the ''more weathered'' of for the color difference between Dactyl and Ida is likely to be different from that which accounts for the differences the two terrains. Consistent with this interpretation is that