Early Water Delivery to Terrestrial Planet Regions during the Stages of Jupiter’s Formation and Migration in the Grand Tack Model

Abstract

The formation and subsequent migration of gas giants could significantly affect the material mixing in the solar system. In this study, we use N -body simulations to investigate how much water is transported into the region of the terrestrial planet formation during the growth and migration phases of Jupiter in the Grand Tack model. We found that Jupiter’s growth was accompanied by significant mass transport and that a substantial amount of water (about 10 times Earth’s ocean mass for the initial planetesimal distribution based on the minimum-mass solar nebula) was transported into the terrestrial planet region. The total amount delivered increased further during Jupiter’s migration phase (totaling about 10–40 times Earth’s ocean mass), which was less dependent on simulation parameters. In addition, at these stages, terrestrial planets were not fully grown. Therefore, water supplied during these early stages could interact with metallic iron during the core formation of protoplanets and/or growing Earth. Since hydrogen in water molecules can dissolve into their cores, this could explain the density deficit observed in the current Earth core. Notably, Jupiter could play an important role as a “barrier” in explaining the dichotomy of the isotopic compositions between noncarbonaceous (NC) and carbonaceous (CC) meteorites. This study’s results show that Jupiter’s growth necessitates some mixing of NC and CC materials.

Keywords

• Planet formation
• Planetary dynamics
• Solar system