Earth and Space Science

Earth's Structure

• Earth has three main layers: the core, mantle, and crust
• The core is divided into a solid inner core and a liquid outer core
• The inner core is solid due to immense pressure, while the outer core is liquid due to high temperatures

Earth's Core

• The core is made up of a mixture of metals, mostly nickel and iron
• Scientists used seismic waves generated by earthquakes to determine the core's composition
• The inner core is solid, while the outer core is liquid due to high temperatures

Earth's Mantle

• The mantle is Earth's thickest layer, lying between the core and crust
• The mantle is made of solid rock that can flow very slowly over time due to high temperatures and pressure
• The mantle can be divided into two parts: the upper mantle and the lower mantle

Earth's Crust

• The crust is Earth's thin outer layer, ranging from 0-100 km thick
• The crust is made of a variety of rocks and has two types: continental crust and oceanic crust
• Continental crust forms the continents and shallow seas, covering about 40% of Earth's surface
• Oceanic crust is formed in Earth's ocean basins, covering about 60% of Earth's surface

Lithosphere

• The lithosphere is Earth's rigid, rocky outer zone, including the crust and upper mantle
• The lithosphere is made up of tectonic plates that 'float' and move around on a viscous zone called the asthenosphere
• Rocks in the asthenosphere are almost at their melting point, allowing tectonic plates to move and cause earthquakes and volcanoes at Earth's surface

Additional Facts

• The oldest rock in Earth's crust is the Acasta Gneiss, approximately 3.96 billion years old
• Earth is approximately 4.5 billion years old, formed from a ball of molten rock that cooled and separated into three main layers
• The Acasta Gneiss was originally granite, formed when molten rock solidified about 4.2 billion years ago

Earth's Structure

• Earth has three main layers: the core, mantle, and crust
• The core is divided into a solid inner core and a liquid outer core
• The inner core is solid due to immense pressure, while the outer core is liquid due to high temperatures

Earth's Core

• The core is made up of a mixture of metals, mostly nickel and iron
• Scientists used seismic waves generated by earthquakes to determine the core's composition
• The inner core is solid, while the outer core is liquid due to high temperatures

Earth's Mantle

• The mantle is Earth's thickest layer, lying between the core and crust
• The mantle is made of solid rock that can flow very slowly over time due to high temperatures and pressure
• The mantle can be divided into two parts: the upper mantle and the lower mantle

Earth's Crust

• The crust is Earth's thin outer layer, ranging from 0-100 km thick
• The crust is made of a variety of rocks and has two types: continental crust and oceanic crust
• Continental crust forms the continents and shallow seas, covering about 40% of Earth's surface
• Oceanic crust is formed in Earth's ocean basins, covering about 60% of Earth's surface

Lithosphere

• The lithosphere is Earth's rigid, rocky outer zone, including the crust and upper mantle
• The lithosphere is made up of tectonic plates that 'float' and move around on a viscous zone called the asthenosphere
• Rocks in the asthenosphere are almost at their melting point, allowing tectonic plates to move and cause earthquakes and volcanoes at Earth's surface

Additional Facts

• The oldest rock in Earth's crust is the Acasta Gneiss, approximately 3.96 billion years old
• Earth is approximately 4.5 billion years old, formed from a ball of molten rock that cooled and separated into three main layers
• The Acasta Gneiss was originally granite, formed when molten rock solidified about 4.2 billion years ago