Abstract
The main characteristics that distinguish the Moon from Earth are (i) a smaller core, (ii) a more pronounced deficit in volatile elements, and (iii) identical isotopic anomalies. After reviewing historical models of the Moon’s formation, we will examine why the giant impact model has gained acceptance within the scientific community. However, the isotopic identity between the Earth and the Moon remains difficult to explain. We will therefore examine the various variants of the impact model proposed to account for this, as well as a model based on isotopic equilibration between the Earth and the protolunar disk. Finally, the existence of the Moon demonstrates that the Earth’s formation was not limited to the accretion of small bodies but also involved large impacts, with profound consequences for its core-mantle differentiation.
