Planet Earth - blue life giving


General Information

Average distance from the Sun

150 million km
(93 million miles)

Length of year

365 Earth days

Length of solar day

24 Hours

Rotation period relative to stars

23 hours 56 minutes
4 seconds

Diameter at equator

12,760 km
(7,930 miles)

Approximate surface temperatures

22 0C
(72 0F)

Viewed from space, planet Earth has blue oceans, white clouds and polar ice caps, and dark areas of land. It is the only planet we know that has life. Life on Earth only thrives because there is a balance between animals, which use up oxygen and release carbon dioxide; and plants, which take in carbon dioxide and produce oxygen.

The Earth's crust contains over 2000 different minerals. Only about 20 of these minerals account for over 90 per cent of the crust. Minerals are made up of different chemical elements. Just eight elements make up 99 per cent of the Earth's crust.

Area of land : 148,326,000 km2 (57,268,900 square miles), equals 29 per cent of the total surface of the earth.

Area of water : 361,740,000 km2 (139,668,500 square miles), equals 31 per cent of the total surface of the Earth.

About a fifth of the Earth's land surface is mountainous and a further eighth is covered by deserts. Earth is the only planet in the Solar System with liquid water. Of all the water on Earth, 97 per cent is saltwater. Only 3 per cent is freshwater and two-thirds of this is frozen into ice. Only 1 per cent of all the Earth's water is in lakes, rivers or underground.