Host: The Japanese Society for Planetary Sciences: Local Organizing Committee for 2006 Fall Meeting
Recent studies (Chiang & Goldreich, 1997; Chiang et al., 2002) imply that the interior of the protoplanetary disk is shadowed from direct exposure to sunlight, so that the H2O ice is prevented from sublimation even at the formation region of terrestrial planets. If planetesimals are formed in such opaque protoplanetary disks, they should be mainly composed of H2O ice. We call such planetesimals icy planetesimals hereafter.
We have investigated the evolution of icy planetesimals at the formation region of terrestrial planets. 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. In addition, the internal structure and the thermal history of icy planetesimals have strong effects on the water supply to the planets.
In this study, we investigate the thermal history of icy planetesimals heated by short-lived radioactive elements such as 26Al.
