Origin Theories of the Moon

The origin of the Moon remains an unsolved problem of the planetary science. Researchers engaged in celestial dynamics, geophysics, and geochemistry are still discussing various models of creation of our closest cosmic neighbour. The most popular scenario, the impact hypothesis involving a collision early in the Earth's history, has been substantially challenged by the new data. The birth and development of a planet-moon system always plays a role in the formation of an entire planetary system around our Sun or around another star. This way, the story of our Moon acquires broader ramifications for one of the hottest topics of the modern scholarship. All this has motivated the authors of this book to consider a new concept and to compare the currently discussed theories, analyzing their advantages and shortcomings in explaining the experimental data.

Auteur

Professor Erik M. Galimov, Vernadsky Institute of Geochemistry and Analytical Chemistry, Russia;
Professor Anton M. Krivtsov, St. Petersburg State Polytechnical University, Russia.

Contenu

I The Moon

History of study.
The Moon as a celestial body.
Structure, chemical composition and mineralogy.
Lunar geology.
Data on the age of the Moon.

II Solar system

Beginning of the Solar system.
Extrosolar planetary systems.
Possible scenarios of accumulation of planets.

III Hypotheses of the Moon's origin

The giant impact model.
Other models.

IV The model of formation of the Earth-Moon system via fragmentation of the initial gas-dust concentration

Enrichment of the Moon in refractory elements and depletion in volatiles.
Volatility of iron.
Evaporation of particles during contraction of the initial cloud is a crucial factor for both: dynamic of its fragmentation and depletion of the Moon in iron.
Geochemical consequences following from the model and how they are reconciled with the observations.

V Isotope constraints for evolution of the gas-dust cloud initial for Earth and Moon and again of their formation

Stable isotopes

VI Dynamics of the Earth-Moon formation
Existing models for simulation of the dynamics of the Earth-Moon formation.
Modelling of the Earth-Moon system formation using particles.
Sequential stages of Earth-Moon system formation.
Formation of the gas-dust cloud.
Rotational collapse.
Accumulation growth of the Earth and Moon embryos.
Results of the dynamics simulation and analysis of their dependence on the model parameters and conditions of the computations.
Analysis of the composition of Earth and Moon obtained from the dynamical model.

Summary

References