Seasons
Information on the astronomical seasons Seasons have been appointed on the basis of observation changes the rhythm of the land of light during the year. They are linked to the Earths axis deviation to the plane of its orbit, making the plane of the equator is inclined to the plane of orbit. Two parallel border have been named: they are Tropic of Cancer and the Tropic of Capricorn. When the sun is in the plane of the equator in the spring begins. This is called the Vernal Equinox Day. And just for the whole day and night on Earth being equal at 12 hours. Sun Jun 21 reaches the Tropic of Cancer starts with the summer - this is the so-called Summer Solstice. And the day is longest and the shortest night. On the Autumnal Equinox on the whole globe day and night are equal at 12 hours. If the sun is over the Tropic of Capricorn begins in the winter - this is the so-called Winter Solstice. And the day is shortest and the longest night. During the spring and summer of astronomical polar day occurs on the northern hemisphere, and during spring and autumn equinox in the southern hemisphere. On spring and autumn equinox day polar is only in poles.