New Insights into the Moon's Core and Formation

Recent research conducted by Paolo A. Sossi, Miki Nakajima, and Amir Khan has provided new insights into the composition, structure, and origin of the Moon. The paper, titled "Composition, Structure and Origin of the Moon," critically examines the geophysical and geochemical properties of the Moon, utilizing existing lunar geophysical data to derive significant findings.

Key findings from the study include:

• The necessity of a lunar core with a radius of approximately 300 ± 20 km, which constitutes about 0.8 to 1.5% of the Moon's mass.
• The analysis indicates that the core densities are consistent with an Earth-like magnesium number (Mg#) of 0.89, suggesting a composition similar to that of an iron-nickel alloy.
• The study reassesses the bulk composition of the Moon across 70 elements, revealing that the lunar core likely formed under specific conditions of pressure and temperature.
• The Moon exhibits a depletion in volatile elements compared to Earth's mantle, with this loss likely occurring at lower temperatures, consistent with stable isotope fractionation.
• The isotopic compositions of the lunar and terrestrial mantles are nearly identical, indicating that both bodies were formed from the same material rather than from an impactor.
• The research suggests that the Moon formed approximately 4.5 billion years ago, with no clear evidence supporting the role of an impactor in its genesis.

These findings challenge previous theories regarding the Moon's formation and suggest alternative scenarios that may explain its origins. The implications of this research could reshape our understanding of lunar geology and the early solar system dynamics.

The full paper can be accessed at arXiv:2408.16840.