2:45 PM - 3:00 PM
[PPS03-15] Revealing the building blocks of the terrestrial planets and the origin of asteroids in the Jupiter-Saturn chaotic excitation (JSCE) model
Keywords:solar system , terrestrial planets , asteroid belt , water, Mars , Mercury
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.