The term "crust" refers to the outermost shell of a terrestrial planet.
Understanding Planetary Crusts
Planets with solid surfaces, like Earth, Mars, and Venus, have a crust as their outermost layer. This layer is distinct from the planet's mantle and core. The crust's composition and characteristics can vary significantly from one planet to another.
Earth's Crust
Our planet's crust is quite complex and is typically divided into two types:
- Continental Crust: This is the older and thicker portion of Earth's crust, forming the landmasses we inhabit.
- Oceanic Crust: Younger and denser than continental crust, it lies beneath the oceans.
Crust Characteristics
| Feature | Continental Crust | Oceanic Crust |
|---|---|---|
| Age | Older | Younger |
| Thickness | Thicker | Thinner |
| Density | Less Dense | More Dense |
| Location | Landmasses | Beneath Oceans |
Why is it Important?
The crust is essential to a planet's geology and evolution. It dictates:
- The formation of mountains, valleys and other landforms.
- The movement of tectonic plates.
- The availability of resources like minerals and fossil fuels.
Summary
The term crust applies to the outermost layer of a terrestrial planet and on Earth, it is further classified into oceanic and continental.
