| The age of earth has been estimated to be around 4.54 billion years. |
| Equatorial circumference of the earth is 40,067 km and equatorial diameter is 12,757 km |
| Polar circumference of the earth is 40,000 km polar diameter is 12,714 km |
| The total surface area of the earth is 510,100,500 sq km |
| The Hydrosphere (sea) comprises 70.8% of the surface area and Lithosphere (land) is 29.2% |
| The percentage of fresh water on earth is 3% while 97% of hydrosphere is salty water. |
| The earth is made up of three layers – crust (outermost), mantle and core (innermost). |
| The period of rotation of the earth is 23 hrs 56 mts 4.091 secs |
| The speed of rotation at the equator is 1674 kmph |
| The time taken by the earth to rotate about its axis so that the distant stars appear in the same position in the sky is known as Sidereal Day. |
| The time taken by the earth to rotate about its axis so that the sun appears in the same position in the sky is known as Solar Day. A sidereal day is shorter than a solar day. |
| The escape velocity on earth 11.186 km/sec |
| The highest point on earth is Mt Everest at 8,848 meters |
| The deepest point on earth is Challenger Deep in the Pacific Ocean at 11,034 meters |