Solar Wind in the Lunar Soil

In a recent Letter to Nature, we report the discovery of an unusual oxygen isotopic composition that has not been encountered previously in the solar system. Moreover, this composition is preserved below the surface of the grains consistent with implantation from the solar wind. It therefore appears that the Sun has an oxygen isotope composition that is much heavier (enriched in O-17 and O-18) relative to the rocky components of the solar system that we can sample (i.e. from planets and asteroids). Such a situation could arise from the distribution of oxygen between the solid components (dust, ice) versus the gaseous component (dominated by CO). For more information contact Trevor Ireland.