  We present a global spectrophotometric characterization of the Ceres surface
using Dawn Framing Camera (FC) images. We identify the photometric model that
yields the best results for photometrically correcting images. Corrected FC
images acquired on approach to Ceres were assembled into global maps of albedo
and color. Generally, albedo and color variations on Ceres are muted. The
albedo map is dominated by a large, circular feature in Vendimia Planitia,
known from HST images (Li et al., 2006), and dotted by smaller bright features
mostly associated with fresh-looking craters. The dominant color variation over
the surface is represented by the presence of "blue" material in and around
such craters, which has a negative spectral slope over the visible wavelength
range when compared to average terrain. We also mapped variations of the phase
curve by employing an exponential photometric model, a technique previously
applied to asteroid Vesta (Schr\"oder et al., 2013b). The surface of Ceres
scatters light differently from Vesta in the sense that the ejecta of several
fresh-looking craters may be physically smooth rather than rough. High albedo,
blue color, and physical smoothness all appear to be indicators of youth. The
blue color may result from the desiccation of ejected material that is similar
to the phyllosilicates/water ice mixtures in the experiments of Poch et al.
(2016). The physical smoothness of some blue terrains would be consistent with
an initially liquid condition, perhaps as a consequence of impact melting of
subsurface water ice. We find red terrain (positive spectral slope) near
Ernutet crater, where De Sanctis et al. (2017) detected organic material. The
spectrophotometric properties of the large Vendimia Planitia feature suggest it
is a palimpsest, consistent with the Marchi et al. (2016) impact basin
hypothesis. The central bright area in Occator crater, Cerealia...

Earth and Planetary Astrophysics