As the Earth spins on its axis, its shadow moves based on the position of the sun and the tilt of the Earth. Sun up occurs when the Earth's surface and the Sun (at noon) meet at a 90 degree angle. On March 21 or 22, the Sun overhead hits the equator. The Northern Hemisphere experiences the Spring Equinox, while the Southern Hemisphere experiences the Autumnal Equinox. During this period, days and nights last the same amount of time everywhere on Earth, and both hemispheres receive the same amount of solar radiation. After the equinox, the days become longer in the Northern Hemisphere as the season moves into spring, and shorter in the Southern Hemisphere as it moves into autumn. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay On June 21 or 22, or the summer solstice, the Sun overhead directly strikes the Tropic of Cancer. The Northern Hemisphere is tilted towards the Sun, on the summer solstice, and the Southern Hemisphere is tilted away from the Sun, on the winter solstice. During the solstice the days are longest in the North and shortest in the South, with 24 hours of light at the North Pole and 24 hours of darkness at the South Pole. When the Sun returns to the equator on September 22 or 23, the Northern Hemisphere it is found on the autumnal equinox and the southern equinox on the spring equinox. As in March, the hemispheres receive similar amounts of solar radiation and the length of day and night is the same everywhere on Earth. However, after the equinox, the days in the North become shorter and those in the South become longer. For the winter solstice, December 21 or 22, the Sun overhead directly hits the Tropic of Capricorn. Now the Northern Hemisphere is tilted away from the Sun, and the Southern Hemisphere is tilted towards the Sun, pushing them into winter and summer respectively. Days are longer in the South and shorter in the North, with 24 hours of darkness in the Arctic Circle (in the North) and 24 hours of daylight in the Antarctic Circle (in the South). Essentially, as the angle of the Sun and the tilt of the Earth changes, the hemispheres experience seasons. The sunlight received by each hemisphere depends on whether it is tilted away from the Sun, towards the Sun, or hit directly at the equator. Please note: this is just an example. Get a custom paper from our expert writers now. Customize essay