title: An asteroidal origin for water in the Moon.
abstract: The Apollo-derived tenet of an anhydrous Moon has been contested following measurement of water in several lunar samples that require water to be present in the lunar interior. However, significant uncertainties exist regarding the flux, sources and timing of water delivery to the Moon. Here we address those fundamental issues by constraining the mass of water accreted to the Moon and modelling the relative proportions of asteroidal and cometary sources for water that are consistent with measured isotopic compositions of lunar samples. We determine that a combination of carbonaceous chondrite-type materials were responsible for the majority of water (and nitrogen) delivered to the Earth-Moon system. Crucially, we conclude that comets containing water enriched in deuterium contributed significantly <20% of the water in the Moon. Therefore, our work places important constraints on the types of objects impacting the Moon ∼4.5-4.3 billion years ago and on the origin of water in the inner Solar System.
authors.affiliation: Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK.
authors.forename: Jessica J
authors.initials: JJ
authors.lastname: Barnes
authors.affiliation: Lunar and Planetary Institute, 3600 Bay Area Boulevard, Houston, Texas 77058, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Kring
authors.affiliation: Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK.|Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Muséum National d'Histoire Naturelle, Sorbonne Universités, CNRS, UMPC &IRD, Paris 75005, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Tartèse
authors.affiliation: Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Franchi
authors.affiliation: Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK.|Earth Sciences Department, Natural History Museum, Cromwell Road, London SW7 5BD, UK.
authors.forename: Mahesh
authors.initials: M
authors.lastname: Anand
authors.affiliation: Earth Sciences Department, Natural History Museum, Cromwell Road, London SW7 5BD, UK.
authors.forename: Sara S
authors.initials: SS
authors.lastname: Russell