Terrestrial Planet Formation from an Annulus

Abstract

It has been shown that some aspects of the terrestrial planets can be explained, particularly the Earth/Mars mass ratio, when they form from a truncated disk with an outer edge near 1.0 au (Hansen 2009). This has been previously modeled starting from an intermediate stage of growth utilizing pre-formed planetary embryos. We present simulations that were designed to test this idea by following the growth process from km-sized objects located between 0.7 to 1.0 au up to terrestrial planets. The simulations explore initial conditions where the solids in the disk are planetesimals with radii initially between 3 and 300 km, alternately including effects from a dissipating gaseous solar nebula and collisional fragmentation. We use a new Lagrangian code known as LIPAD (Levison et al. 2012), which is a particle-based code that models the fragmentation, accretion and dynamical evolution of a large number of planetesimals, and can model the entire growth process from km-sizes up to planets. A suite of large (Mars mass) planetary embryos is complete in only 1 Myr, containing most of the system mass. A quiescent period then persists for 10-20 Myr characterized by slow diffusion of the orbits and continued accretion of the remaining planetesimals. This is interupted by an instability that leads to embryos crossing orbits and embyro-embryo impacts that eventually produce the final set of planets. While this evolution is different than that found in other works exploring an annulus, the final planetary systems are similar, with roughly the correct number of planets and good Mars-analogs.

23 pages, 15 figs

References in corpus (3)

• Building Terrestrial Planets
• Water Delivery and Giant Impacts in the 'Grand Tack' Scenario
• Lunar and Terrestrial Planet Formation in the Grand Tack Scenario

Cited by in corpus (19)

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• The early instability scenario: terrestrial planet formation during the giant planet instability, and the effect of collisional fragmentation
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• Impact bombardment chronology of the terrestrial planets from 4.5 Ga to 3.5 Ga
• The Role of Early Giant Planet Instability in the Terrestrial Planet Formation
• Formation of Venus, Earth and Mars: Constrained by isotopes
• A record of the final phase of giant planet migration fossilized in the asteroid belt's orbital structure
• Dynamical Constraints on Mercury's Collisional Origin
• Terrestrial planet formation from a ring
• Implications of Jupiter Inward Gas-Driven Migration for the Inner Solar System
• The early instability scenario: Mars' mass explained by Jupiter's orbit
• Compound chondrule formation in optically thin shock waves
• Escape and accretion by cratering impacts: Formulation of scaling relations for high-speed ejecta
• Rethinking the role of the giant planet instability in terrestrial planet formation models
• Mercury's formation within the Early Instability Scenario
• A dynamical context for the origin of Phobos and Deimos
• Can narrow disks in the inner solar system explain the four terrestrial planets?