Abstract
Recent studies (Chiang & Goldreich, 1997; Chiang et al., 2002) imply that the interior of the solar nebula is shadowed from direct exposure to sunlight, so that the H2O ice is prevented from sublimation even at the formation zone of terrestrial planets. In such circumstances, the planetesimals formed through the gravitational instability are mainly composed of ice. It is possible that the H2O in the icy planetesimals contributes the supply of water to the terrestrial planets. In this study, we investigate the evolution of icy planetesimals in the solar nebular. The collisional growth and the sublimation of icy planetesimals are especially important to estimate the abundance of H2O that survives until the formation of protoplanets. To estimate the amount of sublimation of icy planetesimals, the radiative transfer around the equatorial plane of the disk is considered. For the collisional growth of icy planetesimals, we adopt the statistical approach based on Inaba et al. (2001). We calculate the evolution of icy planetesimals considering their sublimation and collisional growth simultaneously.
