Iron metal descent to the core during planetary differentiation

Olson, P., and D. Weeraratne, Experiments on metal silicate plumes and core formation, Phil. Trans., R. Soc. A, 366, 4253-4271, 2008. pdf

How does iron differentiate from meteorites and descend to form the liquid iron core ?

Conduit formation behind a sinking metal drop as it descends through a 2 component fluid
(green and red fluid are the same but lit differently).

    Instability of a liquid metal layer at a fluid-fluid interface
(sometimes this required a week or more in the lab!)

When a metal instability begins, it quickly forms a diapir due to the high density
and extreme low viscosity of liquid metal.

A conduit of low density material forms behind each diapir and is temporarily entrained to the bottom of the box.