The crust is the outer hard layer of the planet. The crust is a part of the Geology/Content/Lithosphere. On Earth, the crust is under the troposphere and above the ocean. It is important to remember that not every geological sphere has a crust. The crust on Earth is being created through a process called Continental Drift, but on the moon it is not being made. The crust has two different parts. One is the continental, and the other is oceanic. The continental crust is thicker, and the oceanic crust is thinner. Thicknesses of the crust can be anywhere from 5-70 km.