title: Solar wind neon from Genesis: implications for the lunar noble gas record.
abstract: Lunar soils have been thought to contain two solar noble gas components with distinct isotopic composition. One has been identified as implanted solar wind, the other as higher-energy solar particles. The latter was puzzling because its relative amounts were much too large compared with present-day fluxes, suggesting periodic, very high solar activity in the past. Here we show that the depth-dependent isotopic composition of neon in a metallic glass exposed on NASA's Genesis mission agrees with the expected depth profile for solar wind neon with uniform isotopic composition. Our results strongly indicate that no extra high-energy component is required and that the solar neon isotope composition of lunar samples can be explained as implantation-fractionated solar wind.
authors.affiliation: Isotope Geology and Mineral Resources, ETH Zürich NW, Clausiusstrasse 25, CH-8092 Zürich, Switzerland. grimberg@erdw.ethz.ch
authors.forename: Ansgar
authors.initials: A
authors.lastname: Grimberg
authors.forename: Heinrich
authors.initials: H
authors.lastname: Baur
authors.forename: Peter
authors.initials: P
authors.lastname: Bochsler
authors.forename: Fritz
authors.initials: F
authors.lastname: Bühler
authors.forename: Donald S
authors.initials: DS
authors.lastname: Burnett
authors.forename: Charles C
authors.initials: CC
authors.lastname: Hays
authors.forename: Veronika S
authors.initials: VS
authors.lastname: Heber
authors.forename: Amy J G
authors.initials: AJ
authors.lastname: Jurewicz
authors.forename: Rainer
authors.initials: R
authors.lastname: Wieler