The geosphere refers to the solid parts of our planet. It is the portion of the Earth’s internal system that includes rocks, minerals, landforms and the general processes that shape our planet’s surface. Geodesy, which is the formal study of the geosphere, is a fundamental science, that is critical for creating maps and understanding satellite orbits. The geosphere consists of the hydrosphere, the cryosphere, the lithosphere and the atmosphere.
The crust of the Earth is what everyone walks on and mines. Even the world's deepest mines do not penetrate below the crust.
The Earth's interior consists of a series of layers that changes in mineral composition, thickness and density with depth. Directly below the crust is the mantle. The mantle consists of two parts; the upper layer is less dense and more brittle compared to the inner layer. The upper mantle combined with the crust forms the Earth’s lithosphere.
The mantle possesses the largest volume of the interior, and the region directly below the mantle is Earth’s core, which consists of two distinct parts: the liquid outer core, which is roughly 2250 kilometers thick, and the solid inner core, which is roughly 1200 kilometers thick. The core consists of iron, with traces of nickel.