The early instability scenario: Mars' mass explained by Jupiter's orbit

Abstract

The formation of the solar system's giant planets predated the ultimate epoch of massive impacts that concluded the process of terrestrial planet formation. Following their formation, the giant planets' orbits evolved through an episode of dynamical instability. Several qualities of the solar system have recently been interpreted as evidence of this event transpiring within the first ~100 Myr after the Sun's birth; around the same time as the final assembly of the inner planets. In a series of recent papers we argued that such an early instability could resolve several problems revealed in classic numerical studies of terrestrial planet formation; namely the small masses of Mars and the asteroid belt. In this paper, we revisit the early instability scenario with a large suite of simulations specifically designed to understand the degree to which Earth and Mars' formation are sensitive to the specific evolution of Jupiter and Saturn's orbits. By deriving our initial terrestrial disks directly from recent high-resolution simulations of planetesimal accretion, our results largely confirm our previous findings regarding the instability's efficiency of truncating the terrestrial disk outside of the Earth-forming region in simulations that best replicate the outer solar system. Moreover, our work validates the primordial 2:1 Jupiter-Saturn resonance within the early instability framework as a viable evolutionary path for the solar system. While our simulations elucidate the fragility of the terrestrial system during the epoch of giant planet migration, many realizations yield outstanding solar system analogs when scrutinized against a number of observational constraints. Finally, we highlight the inability of models to form adequate Mercury-analogs and the low eccentricities of Earth and Venus as the most significant outstanding problems for future numerical studies to resolve.

24 pages, 10 figures, 6 tables, accepted for publication in Icarus

References in corpus (30)

• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• Building Terrestrial Planets
• Origin of the Structure of the Kuiper Belt during a Dynamical Instability in the Orbits of Uranus and Neptune
• Dynamics of the giant planets of the solar system in the gaseous proto-planetary disk and relationship to the current orbital architecture
• The timeline of the Lunar bombardment - revisited
• Close-in planetesimal formation by pile-up of drifting pebbles
• Constraints on resonant-trapping for two planets embedded in a protoplanetary disc
• Lunar and Terrestrial Planet Formation in the Grand Tack Scenario
• The early instability scenario: terrestrial planet formation during the giant planet instability, and the effect of collisional fragmentation
• The GENGA Code: Gravitational Encounters in N-body simulations with GPU Acceleration
• Dynamical evidence for an early giant planet instability
• Formation, stratification, and mixing of the cores of Earth and Venus
• The Feeding Zones of Terrestrial Planets and Insights into Moon Formation
• Constraining the giant planets' initial configuration from their evolution: implications for the timing of the planetary instability
• Chaotic Disintegration of the Inner Solar System
• Outward migration of Jupiter and Saturn in 3:2 or 2:1 resonance in radiative disks: implications for the Grand Tack and Nice models
• Formation and accretion history of terrestrial planets from runaway growth through to late time: implications for orbital eccentricity
• 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
• Terrestrial Planet Formation from an Annulus
• An ancient and a primordial collisional family as the main sources of X-type asteroids of the inner Main Belt
• The Asteroid Belt as a Relic From a Chaotic Early Solar System
• Excitation of the Orbital Inclination of Iapetus during Planetary Encounters
• A record of the final phase of giant planet migration fossilized in the asteroid belt's orbital structure
• Growing Mars fast: High-resolution GPU simulations of embryo formation
• Constraints on the pre-impact orbits of Solar System giant impactors
• Instabilities in the Early Solar System due to a Self-gravitating Disk
• Dynamical Constraints on Mercury's Collisional Origin
• Constraints on terrestrial planet formation timescales and equilibration processes in the Grand Tack scenario from Hf-W isotopic evolution
• Eccentric Early Migration of Neptune

Cited by in corpus (1)

• The terrestrial planet formation paradox inferred from high-resolution N-body simulations