The Earth

The Earth is the third planet out from the Sun, 149.6 million km away on average. On 3 January, at the nearest point of its orbit (called the perihelion), the Earth is 147,097 ,800 km away from the Sun. On 4 July, at its furthest (the aphelion) , it is 152,098,200 km away.

He is the fifth largest planet in the Solar System, with a diameter of 12,756 km and a circumference of 40,024 km at the Equator.

The Earth is one of four rocky planets, along with Mercury, Venus and Mars. It is made mostly of rocks, with a core of iron and nickel. No other planet in the solar system has water on its surface, which is why Earth is uniquely suitable for life. Over 70% of Earth's surface is under water.

The Earth's atmosphere is mainly harmless nitrogen and life-giving oxygen, and it is over 700 km deep. The oxygen has been made and maintained by plants over billions of years.

Did you know?

• The Earth is protected from Sun's radiation by a magnetic field which streches 60,000 km out into space.
  
  
• The Earth's orbit around the Sun is 939,886,400 km long and takes 365.242 days.
  
  
• The Earth is tilted at an angle of 23.5°. Even so, it orbits the Sun in a level plane, called the
  plane of the ecliptic.