title: The ancient heritage of water ice in the solar system.
abstract: Identifying the source of Earth's water is central to understanding the origins of life-fostering environments and to assessing the prevalence of such environments in space. Water throughout the solar system exhibits deuterium-to-hydrogen enrichments, a fossil relic of low-temperature, ion-derived chemistry within either (i) the parent molecular cloud or (ii) the solar nebula protoplanetary disk. Using a comprehensive treatment of disk ionization, we find that ion-driven deuterium pathways are inefficient, which curtails the disk's deuterated water formation and its viability as the sole source for the solar system's water. This finding implies that, if the solar system's formation was typical, abundant interstellar ices are available to all nascent planetary systems.
authors.affiliation: Department of Astronomy, University of Michigan, 311 West Hall, 1085 South University Avenue, Ann Arbor, MI 48109, USA. cleeves@umich.edu.
authors.forename: L Ilsedore
authors.initials: LI
authors.lastname: Cleeves
authors.affiliation: Department of Astronomy, University of Michigan, 311 West Hall, 1085 South University Avenue, Ann Arbor, MI 48109, USA.
authors.forename: Edwin A
authors.initials: EA
authors.lastname: Bergin
authors.affiliation: Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA.
authors.forename: Conel M O'D
authors.initials: CM
authors.lastname: Alexander
authors.affiliation: Department of Astronomy, University of Michigan, 311 West Hall, 1085 South University Avenue, Ann Arbor, MI 48109, USA.
authors.forename: Fujun
authors.initials: F
authors.lastname: Du
authors.affiliation: Harvard-Smithsonian Center for Astrophysics, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Dawn
authors.initials: D
authors.lastname: Graninger
authors.affiliation: Harvard-Smithsonian Center for Astrophysics, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Karin I
authors.initials: KI
authors.lastname: Öberg
authors.affiliation: Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK.
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Harries
mesh_terms: D003903:Deuterium / Q000737:chemistry; D018534:Earth, Planet; D007053:Ice; D000069497:Origin of Life; D016082:Solar System
chemical_list: D007053:Ice; D003903:Deuterium