The shaping of the terrestrial planet’s interiors by late accretions

Terrestrial planets—Mercury, Venus, Earth and Mars—formed by the accretion of smaller objects, each planet with their own timescale. The Earth was probably the latest terrestrial planet to form and reached about 99% of its final mass within about 60–100 Myr after condensation of the first solids in the Solar System. This contribution examines the disproportionate role of the last approximately 1% of Earth’s growth, or late accretion, in controlling its long-term interior evolution, and in particular metal-silicate mixing and bulk volatile budget. 

The coupling of impact and geodynamical simulations reveals underappreciated consequences of Earth’s late accretion with implications for a correct interpretation of the geochemical and geodynamical properties of the present Earth’s mantle. Similar implications are expected for Venus and Mars, and are also likely to occur and modulate the interior evolution of rocky exoplanets.