This diagram illustrates the comparative scale of the differentiated layers of Mercury
1. Rapid growth of an embryo by pebble accretion to reach a mass of 2.25 × Mercury
in 13 m.y.
2. Differentiation of proto-Mercury to form an upper mantle, lower mantle, and core.
3. A severe impact with another planetary embryo due to the migration of Jupiter
within 5 m.y., prior to nebula gas dissipation and mantle overturn on proto-Mercury.
4. The two cores merged, the larger fragments derived from the volatile-rich upper
mantle of proto-Mercury were re-accreted, and the Mg-rich lower mantle material
was vaporized and lost to the Sun due to aerodynamic drag.
5. Si was redistributed from the core to the mantle due to the lower pressures.