New insight into the origin of the Moon’s depletion of volatile elements
The Moon's arid surface, devoid of liquid water and subject to extreme temperature variations, has long intrigued observers. These characteristics indicate a marked lack of volatile elements, such as water and certain gases. Recent work by doctoral student Wei Dai, under the supervision of Frédéric Moynier, and their CNRS colleagues in the CAGE (Cosmochemistry, Astrophysics and Experimental Geophysics) team at the Paris Institut de Physique du Globe (CNRS/IPGP/Université Paris Cité), has provided some clues as to the origin of this depletion, while confirming a degree of chemical homogeneity on a lunar scale. These results were published on 28 May in the journal PNAS.
Lunar meteorite sample
Publication date: 28/05/2025
Research
Related teams :
Cosmochemistry, Astrophysics and Experimental Geophysics (CAGE)
Samples brought back by the Apollo missions had already revealed this poverty of volatiles, without its origin being fully understood. Thanks to the use of new-generation isotopic methods, the researchers were able to show that this depletion was the result of significant evaporation following a giant impact between the Earth and another celestial body, an event that is now considered to have been responsible for the formation of the Moon.
A detailed analysis of lunar meteorites
In order to gain a better understanding of the extent of this phenomenon, the research team examined lunar meteorites, which come from impacts that threw fragments of the Moon down to Earth. These samples, which are different from those from the Apollo missions, have slightly different compositions. Nevertheless, their analysis revealed isotopic and chemical consistency with the lunar samples already known, which tends to show that the depletion in volatiles is global and not limited to certain areas.
New perspectives for the study of the Moon
Frédéric Moynier emphasises: “These results provide a better understanding of the conditions under which the Moon was formed and the thermal processes that may have influenced its composition. The fact that such homogeneity can be found between different types of samples is a major step forward in assessing the overall composition of our satellite and in validating models of its formation.
Towards new confirmations with the Chang’e 6 mission
The Chang’e 6 mission, which recently enabled the return of previously unseen samples from the far side of the Moon, will provide an opportunity to test these conclusions on materials that have never been analysed before. These data will enrich our understanding of the Moon’s chemical and isotopic history, and could confirm the hypotheses put forward by the research team.
Source :
A whole scale volatile depleted lunar interior, PNAS
DOI: https://www.pnas.org/doi/10.1073/pnas.2422726122
Contacts :
IPGP : Pierre-Yves Clausse I I + 33 (0)6 51 67 84 83
CNRS : Bureau de presse I I +33 (0)1 44 96 51 51
