The evolution of material in the inner solar system: Elucidating the history of enstatite chondrites

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The solar system formed from a disk of dust and gas, and this can be analysed using meteorites that date from this time. The student will undertake a detailed study of materials that date from this time and place - specifically the enstatite meteorites, which may have originated in the innermost part of the disk.Chondritic meteorites are relicts from the early solar system composed largely of sub-spherical um-to-mm sized objects called chondrules. Enstatite chondrites are isotopic twins to the Earth-Moon system, suggesting a genetic connection.In addition, recent orbital data from the MESSENGER mission to Mercury have shown that it has chemical similarities to the enstatite chondrites, for example high sulphur abundances and Mg/Si ratios.This rare meteorite group (only around 500 enstatite meteorites are known) are therefore highly likely to be products of the inner solar system; if not direct ancestors then possible 'aunts' to the terrestrial planets.The enstatite chondrites are remarkable for their extremely reduced mineralogy; sulphides and metal are very abundant and the main silicate is FeO-poor enstatite. Reduced C and N bearing minerals such as SiC, graphite and nierite (Si3N4) are relatively abundant. High temperature solids such as calcium aluminium-rich inclusions (CAIs) are rare.The student will analyse the chemistry and isotope systematics of individual, pristine, chondrules, CAIs and isolated sulphide grains from the most primitive available enstatite chondrites.