title: Early formation of the Moon 4.51 billion years ago.
abstract: Establishing the age of the Moon is critical to understanding solar system evolution and the formation of rocky planets, including Earth. However, despite its importance, the age of the Moon has never been accurately determined. We present uranium-lead dating of Apollo 14 zircon fragments that yield highly precise, concordant ages, demonstrating that they are robust against postcrystallization isotopic disturbances. Hafnium isotopic analyses of the same fragments show extremely low initial176Hf/177Hf ratios corrected for cosmic ray exposure that are near the solar system initial value. Our data indicate differentiation of the lunar crust by 4.51 billion years, indicating the formation of the Moon within the first ~60 million years after the birth of the solar system.
authors.affiliation: Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Melanie
authors.initials: M
authors.lastname: Barboni
authors.affiliation: Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA.; Department of the Geophysical Sciences, The University of Chicago, Chicago, IL 60637, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Boehnke
authors.affiliation: Department of Geosciences, Princeton University, Princeton, NJ 08544, USA.; Berkeley Geochronology Center, Berkeley, CA 94709, USA.
authors.forename: Brenhin
authors.initials: B
authors.lastname: Keller
authors.affiliation: Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Issaku E
authors.initials: IE
authors.lastname: Kohl
authors.affiliation: Department of Geosciences, Princeton University, Princeton, NJ 08544, USA.
authors.forename: Blair
authors.identifier: 0000-0001-7092-8590
authors.initials: B
authors.lastname: Schoene
authors.affiliation: Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Edward D
authors.initials: ED
authors.lastname: Young
authors.affiliation: Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: McKeegan
keywords: Age of the moon; Apollo zircons; early earth; early solar system evolution; giant impact; lunar magma ocean; planetary accretion