3:30 PM - 3:45 PM
[PPS07-16] Difficulty in the Grand Tack planetary migration
Keywords:Jupiter, Mars, asteroid, planet formation
The grand tack hypothesis claims that Jupiter and Saturn migrated inward in the solar nebula, and after Jupiter reached around 1.5AU, they changed the direction of migration outward to reach their present positions. This migration of Jupiter sculpted out most objects in the asteroid belt and Mars-forming regions, which can explain, for example, the current small masses of Mars and the asteroid belt. Many studies have reported that the grand tack model also explains the origin of many other solar-system bodies. However, several difficulties have been pointed out for the migration of Jupiter and Saturn assumed in the grand tack model, and it is difficult to believe that the grand tack planetary migration had occurred. In this talk, I will explain the difficulties of the grand tack planetary migration.
The most serious problem in the grand tack planetary migration is the growth of the giant planets by gas accretion. Both the processes of planetary migration and gas accretion onto the giant planet are hydrodynamical processes induced by the planetary gravitational force acting on the disk gas around the Hill radius, and they always proceed simultaneously. However, most hydrodynamical simulations of the Grand Tack planet migration ignored the gas accretion onto the giant planets. All hydrodynamical simulations also including the gas accretion showed that Saturn rapidly grows to the Jupiter mass before sufficient migration. In this talk, I will discuss the difficulty of the Grand Tack planetary migration based on previous and recent hydrodynamical simulations of planetary migration and gas accretion.
The most serious problem in the grand tack planetary migration is the growth of the giant planets by gas accretion. Both the processes of planetary migration and gas accretion onto the giant planet are hydrodynamical processes induced by the planetary gravitational force acting on the disk gas around the Hill radius, and they always proceed simultaneously. However, most hydrodynamical simulations of the Grand Tack planet migration ignored the gas accretion onto the giant planets. All hydrodynamical simulations also including the gas accretion showed that Saturn rapidly grows to the Jupiter mass before sufficient migration. In this talk, I will discuss the difficulty of the Grand Tack planetary migration based on previous and recent hydrodynamical simulations of planetary migration and gas accretion.