The internal structure of the Earth is made up of the asthenosphere, the upper mantle, the lower mantle, the outer core and the inner core. These structures support the crust of the Earth. More »

As of 2014, The Great Wall of China is the largest man-made structure on Earth, stretching over 4,000 miles from the Shanghai Pass to the Bohai Sea. The Great Wall started as individual walls built over several dynasties... More »

Scientists agree that the Earth formed about 4.6 billion years ago out of accreted matter from the solar nebula. All planets in the solar system formed the same way. Once the proto-Earth was formed, many changes occurred... More »

The four layers of the Earth are called the inner core, the outer core, the mantle and the crust. In addition, there are two different types of crust. The continental crust is the part that is under land, and the oceanic... More »

The key characteristics of the Earth's layers are the thinness of the crust, the rigidity of the upper mantle and the viscosity of the lower mantle and the asthenosphere. Other characteristics are the liquid state of the... More »

The layer on Earth with the most mass in the mantle, which is made up of silicate compounds, iron, silicon, magnesium, oxygen and aluminum. The mantle is a solid mass that generates heat reaching over 1,832 degrees Fahre... More »

The center of the Earth is called its inner core, which is solid and surrounded by the liquid outer core. The outer core is surrounded by the solid mantle layer, which moves in response to a temperature difference of at ... More »