Excessive Water Delivery to Terrestrial Planets by Ice Pebbles in Protoplanetary Disks
Presented by Satoshi Okuzumi
Department of Earth and Planetary Sciences, Tokyo Institute of Technology
Monday, June 15, 2015
12:00 noon in 169-336
The snow line is the location within a protoplanetary disk where water ice sublimates. The small water content in the solar system terrestrial planets implies that they must have formed well inside the snow line. On the other hand, models of protoplanetary disk evolution suggest that the snow line in the solar nebula likely migrated inside Earth's orbit in a late stage of the nebula evolution. We study how much water would have been delivered to terrestrial embryos during this stage by using a global dust evolution model originally developed for the modeling of icy planetesimal formation. We show that the mass accretion rate of ice particles onto planetary embryos is so high that, unless certain conditions are met, rocky embryos quickly evolve into "ocean planets" (water fraction >> 1%) that are inconsistent with the solar system terrestrial planets. Our results provide important constraints on models of solar system formation and solar nebula evolution.
JPL Contact: Neal Turner (3-0049)