A multiple-impact origin for the Moon

  title={A multiple-impact origin for the Moon},
  author={Raluca Rufu and Oded Aharonson and Hagai B. Perets},
  journal={Nature Geoscience},
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… 
Moonfalls: collisions between the Earth and its past moons
During the last stages of the terrestrial planet formation, planets grow mainly through giant-impacts with large planetary embryos. The Earth's Moon was suggested to form through one of these
Terrestrial magma ocean origin of the Moon
A conceptual framework for the origin of the Moon must explain both the chemical and the mechanical characteristics of the Earth–Moon system to be viable. The classic concept of an oblique giant
The Role of Multiple Giant Impacts in the Formation of the Earth–Moon System
The Earth–Moon system is suggested to have formed through a single giant collision, in which the Moon accreted from the impact-generated debris disk. However, such giant impacts are rare, and during
Impact Dynamics of Moons Within a Planetary Potential
Current lunar origin scenarios suggest that Earth's Moon may have resulted from the merger of two (or more) smaller moonlets. Dynamical studies of multiple moons find that these satellite systems are
The Origin of the Moon Within a Terrestrial Synestia
The giant impact hypothesis remains the leading theory for lunar origin. However, current models struggle to explain the Moon's composition and isotopic similarity with Earth. Here we present a new
A Magnetized, Moon-forming Giant Impact
The Moon is believed to have formed in the aftermath of a giant impact between a planetary-mass body and the proto-Earth. In a typical giant impact scenario, a disk of vapor, liquid, and solid debris
Geochemical Constraints on the Origin of the Moon and Preservation of Ancient Terrestrial Heterogeneities
The Moon forming giant impact marks the end of the main stage of Earth’s accretion and sets the stage for the subsequent evolution of our planet. The giant impact theory has been the accepted model
Large planets may not form fractionally large moons
One of the unique aspects of Earth is that it has a fractionally large Moon, which is thought to have formed from a Moon-forming disk generated by a giant impact. The Moon stabilizes the Earth’s spin
Creating an isotopically similar Earth–Moon system with correct angular momentum from a giant impact
The giant impact hypothesis is the dominant theory explaining the formation of our Moon. However, the inability to produce an isotopically similar Earth–Moon system with correct angular momentum has
Primordial Earth Mantle Heterogeneity Caused by the Moon-forming Giant Impact?
The giant impact hypothesis for Moon formation successfully explains the dynamic properties of the Earth–Moon system but remains challenged by the similarity of isotopic fingerprints of the


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
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
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
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
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.