The Earth is the fifth largest of the nine planets of our solar system. It revolves about the Sun between the orbits of Venus and Mars. Its mean distance from the Sun is 149.5 million kilometers. Although several other planets have water and an atmosphere, the Earth is the only planet known to support life.
Even if all the continents and oceans of the Earth were drawn out to a level surface, the resulting shape would not be spherical. The centrifugal_force creates a bulge around the equator and flattens the poles. The radius at the equator is 6378 kilometers, while at the poles it is 21 kilometers less.
The Earth and the Moon together follow an eccentric path around the Sun. The Earth moves along this path at a speed of more than 100,000 kilometers per hour. The Earth completes a rotation on its own axis every 23 hours, 56 minutes and 4 seconds. The Earth's_axis is a line drawn through the center-point of the Earth, from the north to the south pole. The Earth rotates around this axis from west to east.
The plane of the Earth's orbit around the Sun (ecliptic) is at an angle of 23.4 degrees to that of the equator. The period of orbit around the Sun is 365. 256 days, or one year. Because of this we experience seasons during each orbit.
The Earth is held in its orbit, moving in the same direction as its own rotation, by gravity. Simultaneously, it is orbited by the Moon.
