Earth its the 3rd planet from the sun; the planet on which we live; "the Earth moves around the sun"(Web,1)
Earth (planet), one of the planets in the solar system, the third in distance from the sun and the fifth largest of the planets in diameter. The mean distance of the earth from the sun is 149,503,000 km (92,897,000 mi). It is the only planet known to support life, although some of the other planets have atmospheres and contain water.
The diameter of the earth, measured around the equator, is about 12756 km (7926 mi). The earth is not a perfect sphere but is slightly oblate, or flattened at the poles. Because of this flattening, the diameter of the earth measured around the North Pole and the South Pole is about 12713 km (7899 mi) — 43 km (27 mi) less than the equatorial diameter.(Encarta,2003)
Despite its own special conditions, the Earth is in some ways similar to the other inner planets the group of planets nearer to the sun. Of these planets, Mercury is the closest to the sun; Venus is second; the Earth is third ;and Mars is fourth. All of these planets, including the Earth, are basically balls of rock. Mercury is the smallest in size. Its diameter is about two thirds the greatest width of the Atlantic Ocean. Mars is larger than Mercury, but its diameter is only a little more than half that of the Earth.
Venus, with a diameter of roughly 7,600 miles (12,000 kms),is almost as large as the Earth. Four of the five outer planets are much bigger than any of the inner Planets. The largest, Jupiter , has a diameter more than 11 times as great as that of the Earth. These four outer planets are also much less dense than the inner planets.......
