Grimberg Ansgar, Baur Heinrich, Bochsler Peter, Bühler Fritz, Burnett Donald S, Hays Charles C, Heber Veronika S, Jurewicz Amy J G, Wieler Rainer
Isotope Geology and Mineral Resources, ETH Zürich NW, Clausiusstrasse 25, CH-8092 Zürich, Switzerland.
Science. 2006 Nov 17;314(5802):1133-5. doi: 10.1126/science.1133568.
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.
月球土壤被认为含有两种具有不同同位素组成的太阳稀有气体成分。一种已被确定为注入的太阳风，另一种为高能太阳粒子。后者令人困惑，因为与现今的通量相比，其相对含量过大，这表明过去存在周期性的、非常高的太阳活动。在这里，我们表明，美国国家航空航天局“起源”任务中暴露的金属玻璃中氖的深度依赖同位素组成与具有均匀同位素组成的太阳风氖的预期深度分布一致。我们的结果有力地表明，不需要额外的高能成分，月球样品的太阳氖同位素组成可以解释为注入分馏的太阳风。
