14:45 〜 15:00
[PPS03-15] JSCEモデルにおける地球型惑星の構成要素と小惑星帯の形成の解明
キーワード：太陽系、地球型惑星 、小惑星帯、水、火星、水星
The Jupiter–Saturn chaotic excitation (JSCE) scenario offers a plausible explanation for several observed properties of the inner solar system. Still, simultaneously replicating the four terrestrial planets’ orbits/masses, the asteroid belt’s main properties, and other inner solar system constraints remains a tremendous challenge.
Here, we investigated the simultaneous formation of the four terrestrial planets (Mercury, Venus, Earth, and Mars) and the asteroid belt in the context of the JSCE scenario. We found that our terrestrial systems satisfied several inner solar system constraints.
A comprehensive analysis of 37 optimally formed terrestrial planet systems allowed us to constrain the planets’ building blocks, accretion history, and other fundamental properties. First, the obtained terrestrial planets acquired orbits and masses very similar to those observed in our solar system. In addition, other key results include Moon-forming giant impacts occurring within ~60 Myr, terrestrial planets’ bombardment of late impactors represented by disk objects formed within 2 au, and bulk water acquired during the first 10–20 Myr of Earth’s formation. In particular, achieving Earth’s estimated bulk water content required the disk to initially contain sufficient water mass in objects beyond ~1–1.5 au. This requirement implies that Mercury, Venus, and Mars acquired water similar to the amount on Earth during their formation.
Finally, our model asteroid belt explained the asteroid belt’s orbital structure, small mass, and taxonomy (S-, C- and D/P-types). The current asteroids represent a mixture of local asteroids that survived the dynamical depletion of the primordial asteroid belt by JSCE and captured asteroids from trans-Jovian reservoirs during the giant-planet instability/migration.
Here, we investigated the simultaneous formation of the four terrestrial planets (Mercury, Venus, Earth, and Mars) and the asteroid belt in the context of the JSCE scenario. We found that our terrestrial systems satisfied several inner solar system constraints.
A comprehensive analysis of 37 optimally formed terrestrial planet systems allowed us to constrain the planets’ building blocks, accretion history, and other fundamental properties. First, the obtained terrestrial planets acquired orbits and masses very similar to those observed in our solar system. In addition, other key results include Moon-forming giant impacts occurring within ~60 Myr, terrestrial planets’ bombardment of late impactors represented by disk objects formed within 2 au, and bulk water acquired during the first 10–20 Myr of Earth’s formation. In particular, achieving Earth’s estimated bulk water content required the disk to initially contain sufficient water mass in objects beyond ~1–1.5 au. This requirement implies that Mercury, Venus, and Mars acquired water similar to the amount on Earth during their formation.
Finally, our model asteroid belt explained the asteroid belt’s orbital structure, small mass, and taxonomy (S-, C- and D/P-types). The current asteroids represent a mixture of local asteroids that survived the dynamical depletion of the primordial asteroid belt by JSCE and captured asteroids from trans-Jovian reservoirs during the giant-planet instability/migration.