Editing Planetary differentiation (section)

==Core formation mechanisms==
Core formation utilizes several mechanisms in order to control the movement of metals into the interior of a planetary body. <ref name=":0" /> Examples include [[percolation]], [[Dike (geology)|diking]], diapirism, and the direct delivery of impacts are mechanisms involved in this process.<ref name=":0" /> The metal to silicate density difference causes percolation or the movement of a metal downward. Diking is a process in which a new rock formation forms within a fracture of a pre-existing rock body. For example, if minerals are cold and brittle, transport can occur through fluid cracks.<ref name=":0" /> A sufficient amount of pressure must be met for a metal to successfully travel through the fracture toughness of the surrounding material. The size of the metal intruding and the viscosity of the surrounding material determines the rate of the sinking process.<ref name=":0" /> The direct delivery of impacts occurs when an impactor of similar proportions strikes the target planetary body.<ref name=":0" /> During the impact, there is an exchange of pre-existing cores containing metallic material.<ref name=":0" />           

The planetary differentiation event is said to have most likely happened after the accretion process of either the asteroid or a planetary body. Terrestrial bodies and iron meteorites consist of Fe-Ni alloys.<ref name=":1" /> The Earth's core is primarily composed Fe-Ni alloys. Based on the studies of short lived [[Radionuclide|radionuclides]], the results suggest that core formation process occurred during an early stage of the [[Solar System]].<ref name=":1" /> Siderophile elements such as [[nickel]] and [[cobalt]] can dissolve in molten iron; these elements help the differentiation of iron alloys.<ref name=":1" />            

The first stages of accretion set up the groundwork for core formation. First, terrestrial planetary bodies enter a neighboring planet's orbit. Next, a collision would take place and the terrestrial body could either grow or shrink. However, in most cases, accretion requires multiple collisions of similar sized objects to have a major difference in the planet's growth.<ref name=":0" /> Feeding zones and hit and run events are characteristics that can result after accretion.<ref name=":0" />