Image Source: Pearson Prentice Hall, Inc.

Outermost layer of a differentiated planet, asteroid or moon, usually consisting of silicate rock and extending no more than 10s of km from the surface. The term is also applied to icy bodies, in which case it is composed of ices, frozen gases, and accumulated meteoritic material.

On Earth, the continental crust consists predominantly of granite and related rocks while oceanic crust consists mostly of basalt.