A multiple-impact origin for the Moon

@article{Rufu2017AMO,
  title={A multiple-impact origin for the Moon},
  author={Raluca Rufu and Oded Aharonson and Hagai B. Perets},
  journal={Nature Geoscience},
  year={2017},
  volume={10},
  pages={89-94}
}
The hypothesis of lunar origin by a single giant impact can explain some aspects of the Earth–Moon system. However, it is difficult to reconcile giant-impact models with the compositional similarity of the Earth and Moon without violating angular momentum constraints. Furthermore, successful giant-impact scenarios require very specific conditions such that they have a low probability of occurring. Here we present numerical simulations suggesting that the Moon could instead be the product of a… 
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References

SHOWING 1-10 OF 50 REFERENCES
High-Resolution Simulations of a Moon-forming Impact and Postimpact Evolution
In order to examine the "giant impact hypothesis" for the formation of the Moon, we run the first grid-based, high-resolution hydrodynamic simulations of an impact between proto-Earth and a
Forming a Moon with an Earth-like Composition via a Giant Impact
TLDR
Computer simulations show that a giant impact on early Earth could lead to a Moon with a composition similar to Earth’s, and simulate impacts involving larger impactors than previously considered that can produce a disk with the same composition as the planet's mantle, consistent with Earth-Moon compositional similarities.
Making the Moon from a Fast-Spinning Earth: A Giant Impact Followed by Resonant Despinning
TLDR
Computer simulations show that a giant impact on early Earth could lead to a Moon with a composition similar to Earth’s, and shows that a faster-spinning early Earth-Moon system can lose angular momentum and reach the present state through an orbital resonance between the Sun and Moon.
Collisionless encounters and the origin of the lunar inclination
TLDR
It is shown that the modern lunar orbit provides a sensitive record of gravitational interactions with Earth-crossing planetesimals that were not yet accreted at the time of the Moon-forming event, and obviates the need for previously proposed excitation mechanisms and constrains the pristineness of the dynamical state of the Earth–Moon system.
Evolution of a Terrestrial Multiple-Moon System
The currently favored theory of lunar origin is the giant-impact hypothesis. Recent work that has modeled accretional growth in impact-generated disks has found that systems with one or two large
Accretion of the Moon from non-canonical discs
  • J. SalmonR. Canup
  • Physics, Geology
    Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
  • 2014
TLDR
It is found that the Moon's semi-major axis at the end of its accretion is approximately 7R⊕, which is comparable to the location of the evection resonance for a post-impact Earth with a 2.5 h rotation period in the absence of a disc.
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