Collision Chains among the Terrestrial Planets. II. An Asymmetry between Earth and Venus
arXiv:2110.00221 · doi:10.3847/PSJ/ac19b1
Abstract
During the late stage of terrestrial planet formation, hit-and-run collisions are about as common as accretionary mergers, for expected velocities and angles of giant impacts. Average hit-and-runs leave two major remnants plus debris: the target and impactor, somewhat modified through erosion, escaping at lower relative velocity. Here we continue our study of the dynamical effects of such collisions. We compare the dynamical fates of intact runners that start from hit-and-runs with proto-Venus at 0.7 AU and proto-Earth at 1.0 AU. We follow the orbital evolutions of the runners, including the other terrestrial planets, Jupiter, and Saturn, in an N-body code. We find that the accretion of these runners can take 10 Myr (depending on the egress velocity of the first collision) and can involve successive collisions with the original target planet or with other planets. We treat successive collisions that the runner experiences using surrogate models from machine learning, as in previous work, and evolve subsequent hit-and-runs in a similar fashion. We identify asymmetries in the capture, loss, and interchange of runners in the growth of Venus and Earth. Hit-and-run is a more probable outcome at proto-Venus, being smaller and faster orbiting than proto-Earth. But Venus acts as a sink, eventually accreting most of its runners, assuming typical events, whereas proto-Earth loses about half, many of those continuing to Venus. This leads to a disparity in the style of late-stage accretion that could have led to significant differences in geology, composition, and satellite formation at Earth and Venus.
arXiv comment18 pages, 9 figures, 4 tables. Published in PSJ, article available at https://iopscience.iop.org/article/10.3847/PSJ/ac19b1
References in corpus (37)
- HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
- Building the Terrestrial Planets: Constrained Accretion in the Inner Solar System
- Accretion and differentiation of the terrestrial planets with implications for the compositions of early-formed Solar System bodies and accretion of water
- Collisions Between Gravity-Dominated Bodies: 1. Outcome Regimes and Scaling Laws
- Collisions between Gravity-Dominated Bodies: 2. The Diversity of Impact Outcomes during the End Stage of Planet Formation
- High-resolution simulations of the final assembly of Earth-like planets 1: terrestrial accretion and dynamics
- Formation of the Terrestrial Planets from a Narrow Annulus
- A hit-and-run Giant Impact scenario
- Astrophysical Smooth Particle Hydrodynamics
- Mars' Growth Stunted by an Early Giant Planet Instability
- Merging Criteria for Giant Impacts of Protoplanets
- Formation of Terrestrial Planets from Protoplanets under a Realistic Accretion Condition
- The Frequency of Giant impacts on Earth-like Worlds
- Two-Dimensional Transport of Solids in Viscous Protoplanetary Disks
- The Formation of the Collisional Family around the Dwarf Planet Haumea
- Migration-driven diversity of super-Earth compositions
- Dynamical evidence for an early giant planet instability
- Formation, stratification, and mixing of the cores of Earth and Venus
- Forming Mercury by Giant Impacts
- Bifurcation in the history of Uranus and Neptune: the role of giant impacts
- Numerical aspects of Giant Impact simulations
- SPH calculations of Mars-scale collisions: the role of the Equation of State, material rheologies, and numerical effects
- Signatures of a planet-planet impacts phase in exoplanetary systems hosting giant planets
- Realistic On-the-fly Outcomes of Planetary Collisions II: Bringing Machine Learning to N-body Simulations
- The rotation of planets hosting atmospheric tides: from Venus to habitable super-earths
- Realistic On-The-Fly Outcomes of Planetary Collisions: Machine Learning Applied to Simulations of Giant Impacts
- Constraints on the pre-impact orbits of Solar System giant impactors
- Collision Chains among the Terrestrial Planets. III. Formation of the Moon
- The Effect of Inefficient Accretion on Planetary Differentiation
- Fate of the runner in hit-and-run collisions
- Machine learning applied to simulations of collisions between rotating, differentiated planets
- Studying the Evolution of Warm Dust Encircling BD +20 307 Using SOFIA
- Importance of Giant Impact Ejecta for Orbits of Planets Formed during the Giant Impact Era
- Graze-and-Merge Collisions under External Perturbers
- Mars' formation can constrain the primordial orbits of the gas giants
- A Survey for Satellites of Venus
- A pebble accretion model for the formation of the terrestrial planets in the Solar System
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- A race against the clock: Constraining the timing of cometary bombardment relative to Earth's growth
- Probabilities of collisions of bodies ejected from forming Earth with the terrestrial planets