30th May 2019
Speaker: Tim Elliot, University of Bristol

The main ingredients usually invoked to make planets are primitive meteorites, the chondrites. Although believed to be broadly representative of the solar disk from which planets grew, there are subtle differences in the compositions of different chondrite groups.

An important question has therefore been, what quantities of the different chondrites are needed to make the Earth. It transpires that one answer is obtained by considering elemental compositions and another using their isotopic characteristics.

Time argues that this dilemma is resolved if elemental abundances are modified by vapour loss as a natural consequence of the energetic process of collisional planetary accretion. So overall, a respectable Earth can be made from a starting composition of enstatite chondrite that has been wantonly over-cooked.

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