Our planet Earth

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Our planet has one moon. It is about one-quarter the size of the Earth.

The moon takes about 27days and 7 and a half hours to orbit the Earth once.

Earth spins on its axis in an anti-clockwise direction and takes 23 hours 56 minutes to rotate (turn) once.

Because of its position in the Solar System, and because its atmosphere contains oxygen, hydrogen and carbon, Earth is the only planet where life is known to exist.

Scientists believe that the planet is 4.54 billion years old.

Structure of the Earth

The Earth is made up of several layers. There is an outer solid crust, then a mantle, then a liquid outer core, and finally a solid inner core.

The atmosphere, the layer of gases that surround the planet, contains, nitrogen, oxygen, water vapor, carbon dioxide and small amounts of other gases.

This atmosphere protects life on the planet from harmful ultra-violet rays from the Sun.

Planet Earth Facts:

  • Mass: 5,972,190,000,000,000 billion kg
  • Equatorial Diameter: 12,756 km
  • Polar Diameter: 12,714 km
  • Equatorial Circumference: 40,030 km
  • Known Moons: 1
  • Orbit Period: 365.26 Earth days
  • Surface Temperature: -88 to 58°C

Read more about the Earth's core :

http://en.wikipedia.org/wiki/Structure_of_the_Earth

Watch an animation video about how the Earth was formed