# The Earth's rotation

Earth's rotation around its axis and the sun continuously.Many phenomena depend on this movement.So, the day follows night, one season another in different areas set different climate.

rotation of the earth, according to scientists, is 23 hours, 56 minutes, 4.09 seconds.Thus, there is one full turn.With a speed of about 1 670 km / h makes the movement of the planet around its axis.For the poles the speed is reduced to zero.

Man does not notice the Earth's rotation.This is due to the fact that all objects that are close to it, move simultaneously and in parallel with the same speed.

Earth's rotation around the sun made its orbit.It is located on an imaginary surface passing through the center of the planet and the brightest star.This surface is referred to as the plane of the orbit.

Earth passes through the center of an imaginary line between the poles - axis.This line is not perpendicular to the orbital plane.Axis inclination is approximately 23.5 degrees.The angle of inclination is always the same.The line, which moves around the Earth is always tilted to one side.

orbiting the planet takes a year.The Earth's rotation is then carried out counterclockwise.It should be noted that the orbit is not perfectly circular.The average distance from the Sun about one hundred and fifty million kilometers.It (distance) changes in the average of three million kilometers, forming thus a slight orbital oval.

turnover Earth's orbit is 957 million. Km.It overcomes the distance of the planet three hundred sixty-five days, six hours, nine minutes and nine and a half seconds.According to estimates, the rotation of the Earth in its orbit at a speed of 29 occurs kilometers per second.

Scientists have found that the motion of the planet is slowing.This is due mainly to tidal braking.On the surface of the Earth under the influence of the attraction of the moon (mainly) and the Sun formed tidal trees.They move from east to west (after these celestial bodies), in the opposite direction of the movement of our planet.

Less importance is attached to the tides in the Earth's lithosphere.Thus there is a deformation of a solid body in the form of several delayed tidal wave.It provokes braking torque that helps to ensure that the Earth's rotation is slowing down.

should be noted that the tides in the lithosphere affect the process of braking of the planet by only 3%, the remaining 97% accounted for by tides.These data were obtained in the establishment cards waves lunar and solar tides.

The rate affects Earth and atmospheric circulation.It is considered the main cause of seasonal non-uniform motion of the planet.The movement of the atmosphere going from east to west at low latitudes, and from the west to the east - in the high and middle latitudes.At the same time western winds momentum of positive and negative in the eastern winds, and it is estimated that several times smaller than the first.This difference is redistributed between the Earth and the atmosphere.In strengthening or weakening of the westerly winds east at atmospheric angular momentum increases and decreases that of the Earth.Thus, the motion of the planet is slowing.With easterly winds strengthening and weakening of the western, respectively, in the atmosphere decreases the angular momentum.Thus, the motion of the Earth becomes faster.The total angular momentum of the atmosphere and the planet at a constant value.

Scientists were able to determine that the lengthening days before 1620, took place an average of 2.4 milliseconds in a hundred years.After that, the value decreased by almost half and began to be 1.4 milliseconds in a hundred years.However, according to some recent calculations and observations, slowing of the Earth occurs on average by 2.25 milliseconds in a hundred years.