Editing Planetary differentiation (section)

===Differentiation through collision===
[[Earth]]'s [[Moon]] probably formed out of material splashed into orbit by the impact of a large body into the early Earth.<ref name=":0">{{Citation|last1=Nimmo|first1=Francis|title=Early Differentiation and Core Formation|date=2015|url=http://dx.doi.org/10.1002/9781118860359.ch5|work=The Early Earth: Accretion and Differentiation|pages=83–102|place=Hoboken, NJ|publisher=John Wiley & Sons, Inc|access-date=|last2=Kleine|first2=Thorsten|series=Geophysical Monograph Series |doi=10.1002/9781118860359.ch5 |isbn=9781118860359 |url-access=subscription}}</ref> Differentiation on Earth had probably already separated many lighter materials toward the surface, so that the impact removed a disproportionate amount of silicate material from Earth, and left the majority of the dense metal behind. The Moon's density is substantially less than that of Earth, due to its lack of a large iron core.<ref name=":0" /> On [[Earth]], physical and chemical differentiation processes led to a crustal density of approximately 2700 kg/m<sup>3</sup> compared to the 3400 kg/m<sup>3</sup> density of the compositionally different mantle just below, and the average density of the planet as a whole is 5515 kg/m<sup>3</sup>.