Mars' formation can constrain the primordial orbits of the gas giants

Abstract

Recent high precision meteoritic data infers that Mars finished its accretion rapidly within 10 Myr of the beginning of the Solar system and had an accretion zone that did not entirely overlap with the Earth's. Here we present a detailed study of the accretion zone of planetary embryos from high resolution simulations of planetesimals in a disc. We found that all simulations with Jupiter and Saturn on their current eccentric orbits (EJS) result in a similar accretion zone between fast-forming Mars and Earth region embryos. Assuming more circular orbits for Jupiter and Saturn (CJS), on the other hand, has a significantly higher chance of forming Mars with an accretion zone not entirely dominated by Earth and Venus region embryos, however CJS in general forms Mars slower than in EJS. By further quantifying the degree of overlap between accretion zones of embryos in different regions with the average overlap coefficient (OVL), we found that the OVL of CJS shows a better match with the OVL from a chondritic isotopic mixing model of Earth and Mars, which indicates that the giant planets are likely to have resided on more circular orbits than today during gas disc dissipation, matching their suggested pre-instability orbits. More samples, including those from Mercury and Venus, could potentially confirm this hypothesis.

References in corpus (7)

• The GENGA Code: Gravitational Encounters in N-body simulations with GPU Acceleration
• Dynamical evidence for an early giant planet instability
• Accretion of Terrestrial Planets from Oligarchs in a Turbulent Disk
• The Feeding Zones of Terrestrial Planets and Insights into Moon Formation
• Outward migration of Jupiter and Saturn in 3:2 or 2:1 resonance in radiative disks: implications for the Grand Tack and Nice models
• Growing Mars fast: High-resolution GPU simulations of embryo formation
• Isotopically distinct terrestrial planets via local accretion

Cited by in corpus (7)

• The terrestrial planet formation paradox inferred from high-resolution N-body simulations
• Born extra-eccentric: A broad spectrum of primordial configurations of the gas giants that match their present-day orbits
• Collision Chains among the Terrestrial Planets. II. An Asymmetry between Earth and Venus
• Rethinking the role of the giant planet instability in terrestrial planet formation models
• Mercury's formation within the Early Instability Scenario
• Accretion regions of meteorite parent bodies inferred from a two-endmember isotopic mixing model
• Spatial distribution of isotopes and compositional mixing in the inner protoplanetary disk