Earth's Crust:
* The outermost solid layer of the Earth. It's a relatively thin layer compared to the other layers, ranging from 3 to 45 kilometers in thickness.
* Composed primarily of igneous, sedimentary, and metamorphic rocks.
* Divided into two types:
* Oceanic Crust: Thinner, denser, and composed mainly of basalt. Found beneath the oceans.
* Continental Crust: Thicker, less dense, and composed primarily of granite. Found under continents.
Crust of Other Celestial Bodies:
* The solid outermost layer of a planet or moon. This definition is broader and can include various types of solid material depending on the celestial body.
* Examples:
* Moon's Crust: Composed of anorthosite, a type of feldspar-rich rock.
* Mars' Crust: Mostly composed of basalt with some areas of sedimentary rock.
In summary:
The scientific definition of crust refers to the outermost solid layer of a celestial body. For Earth, the crust is further divided into oceanic and continental crust, each with distinct properties and compositions.
