One of geology's basic principles is that the Earth is made up of four layers: the crust, the mantle, the outer core, and the inner core. But this may be squashed in light of a
new study that suggests Earth actually has a distinct fifth layer that's been under our feet all along.
Researchers at the Australian National University (ANU) say that the new layer they uncovered is located within Earth's inner core. Deeper analysis of this discovery could help scientists better understand our planet's history and evolution.
A peek inside Earth
Approximately 4.6 billion years ago, the Earth formed. The story starts with the planet's interior or
rocky core, which formed through the collision of heavy elements. The core, found at the center of the Earth, is made up of two parts. The outer layer, comprised of liquid iron alloy, is about 1,355 miles thick. The outer core is also thought to be responsible for Earth’s magnetic field. In contrast, the inner core is made up of solid iron alloy with a radius of 760 miles.
Next comes the mantle, which sits directly above the core. This layer is composed of mostly silicate rocks that are rich in magnesium and iron. The mantle has a thickness of about 1,793 miles, making it Earth's thickest layer. The thinnest and most brittle layer is the crust, however. It varies between 18.6 to 43.5 miles in thickness and forms the outermost layer of our home planet.