Condensation and fractionation in the protoplanetary disk: the enstatite meteorite perspective

The enstatite meteorites are a unique set of rocks that span a range of compositions from primitive (unchanged) to processed (melted and fractionated). They formed in a region of the solar nebula close to the sun where conditions were highly reducing, resulting in the meteorites having a very unusual mineralogy. Many species are presnt as sulphides, rather than silicates, and iron-nickel metal is abundant. Because of their metal-rich condition and reduced nature, it has been suggested that enstatite meteorites are the closest analogy that we have to the planet Mercury. We will carry out a complete and thorough analysis of opaque minerals from a suite of enstatite meteorites. We will examine metal, sulphides, phosphides and chromites by optical and electron microscopy, as well as measuring the iron, nickel, copper, sulphur and noble gas compositions by mass spectrometry. The purpose of this research project is to find out how the enstatite meteorites formed and evolved, and whether they can be used to prepare for ESA's Bepi-Colombo mission to Mercury.