The circle of the earth can be estimated on the longest parallel - the equator. However the last results of measurements of this parameter show that the standard idea of it not always is true.
It is known that on Earth there are four seasons: winter, spring, summer and fall. And, season in the Northern hemisphere is always opposite to season of the Southern hemisphere. Why on the planet there is regularly a change of seasons?
Studying astronomy (science about celestial bodies), you will repeatedly meet mentions of the Milky Way. The Milky Way is a congestion of stars, a so-called star system in which we live.
The cycle time of a body which moves on the closed trajectory can be measured by means of hours. If the address happens too quickly, it becomes after change of some number of full addresses. If the body rotates on a circle, and its linear speed is known, this size is calculated by a formula. The cycle time of the planet pays off under the third law of Kepler.
The Neptune is considered the most remote planet of the Solar system if not to consider Pluto excluded in 2006 from the list of planets. The Neptune enters into group of giant planets, his orbit is located in 4491.1 million km from the Sun.