A long-lived magma ocean on a young Moon

M Maurice; N Tosi; S Schwinger; D Breuer; T Kleine

doi:10.1126/sciadv.aba8949

A long-lived magma ocean on a young Moon

Sci Adv. 2020 Jul 10;6(28):eaba8949. doi: 10.1126/sciadv.aba8949. eCollection 2020 Jul.

Authors

M Maurice^{1

2}, N Tosi^{1

2}, S Schwinger¹, D Breuer¹, T Kleine³

Affiliations

¹ German Aerospace Center (DLR), Rutherfordstr. 2, 12489 Berlin, Germany.
² Department of Astronomy and Astrophysics, Technische Universität Berlin, Berlin, Germany.
³ Institut für Planetologie, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany.

Abstract

A giant impact onto Earth led to the formation of the Moon, resulted in a lunar magma ocean (LMO), and initiated the last event of core segregation on Earth. However, the timing and temporal link of these events remain uncertain. Here, we demonstrate that the low thermal conductivity of the lunar crust combined with heat extraction by partial melting of deep cumulates undergoing convection results in an LMO solidification time scale of 150 to 200 million years. Combining this result with a crystallization model of the LMO and with the ages and isotopic compositions of lunar samples indicates that the Moon formed 4.425 ± 0.025 billion years ago. This age is in remarkable agreement with the U-Pb age of Earth, demonstrating that the U-Pb age dates the final segregation of Earth's core.

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