A study of magnesium stable isotopes in lunar rock samples finds that the oldest known samples contain isotope signatures similar to the known bulk magnesium isotope composition of the Inner Solar System, supporting the theory that the initial impact that formed the Moon did not fractionate magnesium isotopes; samples from subsequent mare basalt regions showed evidence of isotopic fractionation, suggesting that the lunar magma ocean present after impact fractionated magnesium isotopes and that the mare basalt samples reflect the fractionation as re-melted components of the ocean.
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Article #18-11377: "Magnesium stable isotopes support the lunar magma ocean cumulate remelting model for mare basalts," by Fatemeh Sedaghatpour and Stein Jacobsen.
MEDIA CONTACT: Fatemeh Sedaghatpour, Harvard University, Cambridge, MA; tel: 617-384-9335; e-mail: fsedaghatpour@fas.harvard.edu
Proceedings of the National Academy of Sciences