Earth is the only planet in the Solar System that is rich in water and oxygen. It is sometimes known as the Blue Planet because 70% of the surface is covered by water.

The atmosphere is made up mainly of nitrogen and oxygen which is necessary for organic life. The thickness of the atmosphere also protects life from deadly solar radiation.

Distance from Sun (million km): 149.6 57.9
Year (time to go round the Sun): 365.26 Earth days 88 Earth days
Day (time to revolve round axis): 23 hours 56 minutes
Diameter at equator (km): 12,765
Known moons: 1
Mass (Earth = 1): 1(5,980 billion tonnes)
Gravity at surface (Earth = 1): 1(9.81 metres per second)