Figure 2. Composition of the core of the giant impact after equilibration in the magma ocean, and its effect of Earth’s core composition.

(a) The composition of the hybridized impactor core (HIC), plotted as a function of impactor mass. Smaller impactors interact and equilibrate with larger relative amounts of magma ocean material; they “swell” (see Extended Data Fig. 7) and become very enriched in Mg, Si, and O. (b) The compositional imprint of the giant impact on the core; between 2 and 8% of the core’s total mass consist of mantle material transported by the HIC. The Si and O concentrations added to the core are lower than the amounts present in the core prior to the impact²³. This shows that the giant impact’s significant contribution to core chemistry is the magnesium influx. The 10% Mars-size impact¹⁹ and 2.5% “fast-spinning” impact²⁰ are highlighted by circles.