Left panel: comparison between the spectra of 1 Ceres obtained in this study and the average spectrum from the DAWN spacecraft (de Sanctis et al. 2018). Middle panel: comparison between the sp06 spectrum of 1 Ceres obtained in this study and spectra of the Occator crater (De Sanctis et al. 2016). Five regions are located in the ∼90 km Occator crater on 1 Ceres. Spectra 5 and 1 correspond to the brightest area and dark floor in Occator, respectively. As the numbers in the spectrum become smaller, their reflectances are decreasing (e.g., absolute reflectance values of craters 5, 4, 3, 2, and 1 at 1.0 μm are 0.25, 0.13, 0.10, 0.05, and 0.03, respectively). Right panel: comparison between the sp06 spectrum of 1 Ceres obtained in this study and spectra of exposed water-rich areas (Combe et al. 2019).