Earth's daily rotation
To an observer in the Northern Hemisphere, for example, in the European part of Russia, the Sun usual rises in the east and rises to the south, taking in the afternoon the highest position in the sky, then bends to the west and liesbeyond the horizon.This movement of the sun is only visible and caused by the Earth's rotation around its axis.When viewed from above the Earth in the direction of the North pole, then it will rotate counterclockwise.The sun at this is in place, the appearance of motion is created by the rotation of the Earth.
annual rotation of the earth
around the Sun as the Earth rotates counterclockwise: if you look at the planet from above, from the North Pole.Since the Earth's axis i
s tilted relative to the plane of rotation, as the Earth's rotation around the sun, it illuminates it unevenly.In one area of sunlight falls more than on others - less.Because of this there is a change of the seasons and changes in day length.
vernal and autumnal equinoxes
Twice a year, March 21 and 23 September, the same sun illuminates the Northern and Southern Hemispheres.These points are known as the vernal and autumnal equinoxes.In March in the northern hemisphere spring begins in the South - autumn.In September, on the contrary, in the northern hemisphere autumn comes, and in the South - spring.
summer and winter solstice
In the Northern Hemisphere on June 22 the sun is highest above the horizon.Day has the largest duration and the night hours in the shortest.The winter solstice occurs on December 22 - the day has the shortest duration, and the maximum length of night.In the southern hemisphere this is reversed.
Because of the tilt of the Earth axis polar and polar regions of the Northern Hemisphere during the winter months are without sunshine - the sun never rises above the horizon.This phenomenon is known as the polar night.Similar polar night there and the polar regions of the southern hemisphere, the difference between them is exactly six months.
What gives earth its rotation around the sun
Planet can not revolve around their stars - otherwise they would simply have been attracted and burned.The uniqueness of Earth lies in the fact that the inclination of its axis in 23,44o proved optimal for the origin of all the variety of life on the planet.
It is thanks to the inclination of the axis there is a change of the seasons, there are different climate zones, which provided diversity of Earth's flora and fauna.Change heating the Earth's surface provides the movement of air masses, and hence precipitation in the form of rain and snow.
distance from Earth to the Sun in 149.6 million km also proved optimal.A little further on, and the water on Earth would be only in the form of ice.A little closer, and the temperature would be too high.The very origin of life on earth and the diversity of its forms is made possible thanks to the unique concurrence of so many factors.