The Limited Role of the Streaming Instability During Moon and Exomoon Formation
arXiv:2404.18145 · doi:10.3847/PSJ/ad4863
Abstract
It is generally accepted that the Moon accreted from the disk formed by an impact between the proto-Earth and impactor, but its details are highly debated. Some models suggest that a Mars-sized impactor formed a silicate melt-rich (vapor-poor) disk around Earth, whereas other models suggest that a highly energetic impact produced a silicate vapor-rich disk. Such a vapor-rich disk, however, may not be suitable for the Moon formation, because moonlets, building blocks of the Moon, of 100 m-100 km may experience strong gas drag and fall onto Earth on a short timescale, failing to grow further. This problem may be avoided if large moonlets ( km) form very quickly by streaming instability, which is a process to concentrate particles enough to cause gravitational collapse and rapid formation of planetesimals or moonlets. Here, we investigate the effect of the streaming instability in the Moon-forming disk for the first time and find that this instability can quickly form km-sized moonlets. However, these moonlets are not large enough to avoid strong drag and they still fall onto Earth quickly. This suggests that the vapor-rich disks may not form the large Moon, and therefore the models that produce vapor-poor disks are supported. This result is applicable to general impact-induced moon-forming disks, supporting the previous suggestion that small planets () are good candidates to host large moons because their impact-induced disks would be likely vapor-poor. We find a limited role of streaming instability in a satellite formation in an impact-induced disk, whereas it plays a key role during planet formation.
Accepted for Publication in PSJ
References in corpus (24)
- Athena: A New Code for Astrophysical MHD
- Equilibration in the Aftermath of the Lunar-Forming Giant Impact
- How to form planetesimals from mm-sized chondrules and chondrule aggregates
- Melting and Mixing States of the Earth's Mantle after the Moon-Forming Impact
- Thresholds for Particle Clumping by the Streaming Instability
- Multiple Impact Origin for the Moon
- A giant impact as the likely origin of different twins in the Kepler-107 exoplanet system
- Large Impacts around a Solar Analog Star in the Era of Terrestrial Planet Formation
- Streaming Instability for Particle-Size Distributions
- Volatile loss following cooling and accretion of the Moon revealed by chromium isotopes
- Vapor drainage in the protolunar disk as the cause for the depletion in volatile elements of the Moon
- Inefficient volatile loss from the Moon-forming disk: reconciling the giant impact hypothesis and a wet Moon
- Streaming Instability with Multiple Dust Species: II. Turbulence and Dust-Gas Dynamics at Nonlinear Saturation
- Non-linear Development of Secular Gravitational Instability in Protoplanetary Disks
- Tidal Evolution of the Evection Resonance/Quasi-Resonance and the Angular Momentum of the Earth-Moon System
- Immediate origin of the Moon as a post-impact satellite
- Large planets may not form fractionally large moons
- Satellitesimal Formation via Collisional Dust Growth in Steady Circumplanetary Disks
- Collision Chains among the Terrestrial Planets. III. Formation of the Moon
- A Magnetized, Moon-Forming Giant Impact
- Studying the Evolution of Warm Dust Encircling BD +20 307 Using SOFIA
- Kepler-1708 b-i is likely undetectable with HST
- Analytical Model for the Tidal Evolution of the Evection Resonance and the Timing of Resonance Escape
- Effect of Equation of State and Cutoff Density in Smoothed Particle Hydrodynamics Simulations of the Moon-Forming Giant Impact