Mapping the redox conditions of the Solar System using Sm valence state

We aim at measuring the valence state of Sm in materials coming from various parts of the Solar System that have recorded various oxygen fugacities. Recently, we have published data obtained at the L2 absorption edge of Yb in materials covering about 10 orders of magnitude in oxygen fugacity, from terrestrial samples to highly reduced enstatite chondrite meteoriteshaving concentration levels down to the order of few ppm on polished section.We also showed that the redox state of Yb was unaltered by the exposure of the meteorites to the Earth’s surface. Now, we want to expand our investigation of the redox state of the Solar System by combining our Yb data to Sm, another element, for which we have indication of reduction, from experiments performed in our laboratory as well as from anomalies observed in natural meteorite samples. The studied material will consist in our meteorite collection, of Lunar samples, and refractory inclusions, representing the oldest objects of the Solar System.