¹Hairuo Fu, ¹Stein B. Jacobsen
Earth and Planetary Science Letters 672, 119697 Link to Article [https://doi.org/10.1016/j.epsl.2025.119697]
¹Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USA
Copyright Elsevier

Emerging evidence of strikingly similar Earth–Moon refractory lithophile element compositions provides a key constraint on lunar origin, underscoring the need for a novel framework to test competing Moon formation models. Here, we evaluate whether the canonical giant-impact hypothesis can account for this compositional similarity. We model depth-dependent refractory element heterogeneity within the differentiated Moon-forming impactor and proto-Earth and integrate these chemical signatures with the canonical giant-impact sampling to predict the Moon’s composition. Our modeling shows that the canonical model would lead to a highly fractionated proto-lunar disk composition relative toEarth’s mantle and cannot reproduce the observed Earth–Moon similarity, when mantle compositional differentiation within the pre-impact bodies is considered. This result holds true irrespective of whether density-driven mantle overturn occurred in the pre-impact bodies. Instead, the observed similarity favors extensive post-impact homogenization of the proto-lunar disk, a process consistent with a high-energy giant-impact Moon formation scenario (e.g., Synestia).