Facts About the Earth

Age : About 4.6 billion years
Mass of Earth : 10²⁴ kg
Density of Earth: 5.515 times that of water.
Volume of Earth: 1,083,208,840,000 cubic km.
Surface area : 51,00,66,100 sq. km.
Land surface : 14,89,00,000 sq. km. or (29.8 percent of the surface area)
Water surface : 36,12,00,000 sq. km.
Equatorial circumference : 40,076 km.
Polar circumference : 40,008 km.
Equatorial diameter: 12,756 km.
Polar diameter: 12,713 km
Mean distance from the Sun: 14,95,98,900 km.
Time of rotation on its axis: 23 hrs. 56 min. and 4.09 sec.
Period of rotation round the Sun : 365 days 5 hrs. 48 min. and 45.51 sec.
Population : 6.7 Billion (2007)



TEN FACTS ABOUT EARTHFact One:Earth is the only planet in the Solar System to have water in its three states of matter: as a solid (ice), a liquid (sea, rain, etc.) and as a gas (clouds). These are all shown below. Water is, of course, the most important liquid for life.

Fact Two:
Earth is almost five billion years old, although life (resembling life as we know it) has only existed on the planet for the last 150 million to 200 million years. This means that life has only been present on Earth for only 5%-10% of its lifetime.

Fact Three:
Earth and Mercury are the two most dense planets in the Solar System. This means that particles inside the planet are most closely packed together.

Fact Four:
The length of time it takes for Earth to orbit the Sun is 365 and a quarter days. To make up this extra quarter which isn't counted at the end of a year, we have an extra day every four years on 29th February. This year, 2000, is a Leap Year. The next Leap Year will be in 2004.

Fact Five:
Earth is gradually slowing down. Every few years, an extra second is added to make up for lost time. Millions of years ago, a day on Earth will have been 20 hours long. It is believed that, in millions of years time, a day on Earth will be 27 hours long.

Fact Six:
The centre of the Earth, its core, is molten. This means that it is liquid rock which sometimes erupts onto the surface through volcanic eruptions. This core is 7,500°c, hotter than the surface of the Sun!

Fact Seven:
Earth is the only planet in the Solar System not to be named after a mythical God.

Fact Eight:
Despite being called Earth, only 29% of the surface is actually 'earth.' The rest of the planet's surface (71%) is made up of water.

Fact Nine:
From a distance, Earth would be the brightest of the 9 planets. This is because sunlight is reflected by the planet's water.

Fact Ten:
Earth is the only planet in the Solar System known to be geologically active, with Earthquakes and volcanoes forming the landscape, replenishing carbon dioxide into the atmosphere and erasing impact craters from meteors.