The sphere that extends from the core to the crust is the mantle.

Here's a breakdown of Earth's layers:

* Core: The innermost layer, composed primarily of iron and nickel. It has a solid inner core and a liquid outer core.

* Mantle: The thickest layer, located between the core and the crust. It's mostly solid rock, but behaves like a very viscous fluid over long periods.

* Crust: The outermost layer, thin and solid, and composed of various types of rock.

Let me know if you have any other questions!