Planet Earth is made up of three concentric zones of rocks that are either solid or liquid (molten). The innermost zone is the core. The core has two parts: a solid inner core and a molten outer core. The inner core is composed mostly of nickel and iron and is solid due to the tremendous pressure from overlying matter. The outer core is composed mostly of iron, also mixed with nickel as well as some lighter elements, and is semi-solid due to lower pressure. Surrounding the outer core is the mantle, which is made mostly of solid rock. Near the top of the mantle lies a layer of slowly flowing rock called the asthenosphere. The lithosphere, a thin, rigid layer of rock, is the Earth's outer shell. The lithosphere includes the rigid upper mantle above the asthenosphere and the crust, the solid surface of the Earth. Think of it as floating atop the asthenosphere like a cracker atop a thick layer of hot pudding.🏁

Planet Earth is made up of three concentric zones of rocks that are either solid or liquid (molten). The innermost zone is the core. The core has two parts: a solid inner core and a molten outer core. The inner core is composed mostly of nickel and iron and is solid due to the tremendous pressure from overlying matter. The outer core is composed mostly of iron, also mixed with nickel as well as some lighter elements, and is semi-solid due to lower pressure. Surrounding the outer core is the mantle, which is made mostly of solid rock. Near the top of the mantle lies a layer of slowly flowing rock called the asthenosphere. The lithosphere, a thin, rigid layer of rock, is the Earth's outer shell. The lithosphere includes the rigid upper mantle above the asthenosphere and the crust, the solid surface of the Earth. Think of it as floating atop the asthenosphere like a cracker atop a thick layer of hot pudding.🏁