Lunar and Terrestrial Planet Formation in the Grand Tack Scenario

Abstract

We present conclusions from a large number of N-body simulations of the giant impact phase of terrestrial planet formation. We focus on new results obtained from the recently proposed Grand Tack model, which couples the gas-driven migration of giant planets to the accretion of the terrestrial planets. The giant impact phase follows the oligarchic growth phase, which builds a bi-modal mass distribution within the disc of embryos and planetesimals. By varying the ratio of the total mass in the embryo population to the total mass in the planetesimal population and the mass of the individual embryos, we explore how different disc conditions control the final planets. The total mass ratio of embryos to planetesimals controls the timing of the last giant (Moon forming) impact and its violence. The initial embryo mass sets the size of the lunar impactor and the growth rate of Mars. After comparing our simulated outcomes with the actual orbits of the terrestrial planets (angular momentum deficit, mass concentration) and taking into account independent geochemical constraints on the mass accreted by the Earth after the Moon forming event and on the timescale for the growth of Mars, we conclude that the protoplanetary disc at the beginning of the giant impact phase must have had most of its mass in Mars-sized embryos and only a small fraction of the total disc mass in the planetesimal population. From this, we infer that the Moon forming event occurred between $\sim$60 and $\sim$130 My after the formation of the first solids, and was caused most likely by an object with a mass similar to that of Mars.

26 pages, 10 Figures, Accepted in Philosophical Transactions

References in corpus (5)

• The origins and concentrations of water, carbon, nitrogen and noble gases on Earth
• Building Terrestrial Planets
• Water Delivery and Giant Impacts in the 'Grand Tack' Scenario
• Highly Siderophile Elements in the Earth's Mantle as a Clock for the Moon-forming Impact
• Constraints on resonant-trapping for two planets embedded in a protoplanetary disc

Cited by in corpus (51)

• Origin of water in the inner Solar System: Planetesimals scattered inward during Jupiter and Saturn's rapid gas accretion
• Water Delivery and Giant Impacts in the 'Grand Tack' Scenario
• Formation of planetary systems by pebble accretion and migration: How the radial pebble flux determines a terrestrial-planet or super-Earth growth mode
• The timeline of the Lunar bombardment - revisited
• Challenges in Planet Formation
• Multiple Impact Origin for the Moon
• Highly siderophile elements were stripped from Earth's mantle by iron sulfide segregation
• A primordial origin for the composition similarity between the Earth and the Moon
• Formation, stratification, and mixing of the cores of Earth and Venus
• The Feeding Zones of Terrestrial Planets and Insights into Moon Formation
• Lunar Exploration: Opening a Window into the History and Evolution of the Inner Solar System
• Reconciling Magma-Ocean Crystallization Models with the present-day Structure of the Earth's mantle
• Thermodynamics of Element Volatility and its Application to Planetary Processes
• The Grand Tack model: a critical review
• Formation, tidal evolution and habitability of the Kepler-186 system
• Impact bombardment chronology of the terrestrial planets from 4.5 Ga to 3.5 Ga
• Terrestrial Planet Formation from an Annulus
• The Role of Early Giant Planet Instability in the Terrestrial Planet Formation
• The Asteroid Belt as a Relic From a Chaotic Early Solar System
• Stochastic accretion of the Earth
• The Lunar Gravitational-wave Antenna: Mission Studies and Science Case
• The formation of the Galilean moons and Titan in the Grand Tack scenario
• Growing Mars fast: High-resolution GPU simulations of embryo formation
• Formation of terrestrial planets in disks evolving via disk winds and implications for the origin of the solar system's terrestrial planets
• A Martian Origin for the Mars Trojan Asteroids
• Metal-silicate partitioning of W and Mo and the role of carbon in controlling their abundances in the Bulk Silicate Earth
• The terrestrial planet formation paradox inferred from high-resolution N-body simulations
• Terrestrial planet formation from a ring
• Possible Atmospheric Diversity of Low Mass Exoplanets, some Central Aspects
• Dynamical Evolution of the Earth-Moon Progenitors - Whence Theia?
• Impact Induced Atmosphere-Mantle Exchange Sets the Volatile Elemental Ratios on Primitive Earths
• Migration processes in the Solar System and their role in the evolution of the Earth and planets
• Dynamical avenues for Mercury's origin I: The lone survivor of a primordial generation of short-period proto-planets
• Born extra-eccentric: A broad spectrum of primordial configurations of the gas giants that match their present-day orbits
• Constraints on terrestrial planet formation timescales and equilibration processes in the Grand Tack scenario from Hf-W isotopic evolution
• The early instability scenario: Mars' mass explained by Jupiter's orbit
• Dynamical avenues for Mercury's origin II: in-situ formation in the inner terrestrial disk
• Interior Controls on the Habitability of Rocky Planets
• Comparisons of the core and mantle compositions of earth analogs from different terrestrial planet formation scenarios
• Quantitative estimates of impact induced crustal erosion during accretion and its influence on the Sm/Nd ratio of the Earth
• How much water was delivered from the asteroid belt to the Earth after its formation?
• How the presence of a giant planet affects the outcome of terrestrial planet formation simulations
• Can narrow disks in the inner solar system explain the four terrestrial planets?
• Born Dry or Born Wet? A Palette of Water Growth Histories in TRAPPIST-1 Analogs and Compact Planetary Systems
• Constraining the Origin of Mars via Simulations of Multi-Stage Core Formation
• The effect of collisional erosion on the composition of Earth-analog planets in Grand Tack models: Implications for the formation of the Earth
• Interactions Among Non-Interacting Particles in Planet Formation Simulations
• Formation of the four terrestrial planets in the Jupiter-Saturn chaotic excitation scenario: fundamental properties and water delivery
• Probabilities of collisions of bodies ejected from forming Earth with the terrestrial planets
• Early Initiation of Inner Solar System Formation at Dead-Zone Inner Edge
• Magnitude of stable iron isotope fractionation limited by multiple stages of terrestrial core formation