Our year is divided up by four different seasons. These are, winter, spring, summer and autumn and every year, without fail, we can expect to experience these four seasons. The reason we have four seasons is because as the earth orbits the sun, different parts of the planet face towards or way from it. As this happens the different parts of the earth receive varying amounts of heat. The earth is tilted at an angle and always tilts the same way. This means that when the earth is on one side of the sun, the Northern Hemisphere leans towards the sun and experiences what we know as summer. At the same time, the Southern Hemisphere, or the other side of the earth, is leaning away from the sun, and so is having the opposite climate effect, so it would be winter on this part of the world. Approximately six months later, the earth is on the other side of the sun and the situations are reversed. Spring begins in a hemisphere at the moment at which it starts to lean towards the sun, which is why after the winter months, we begin to feel warmer and plants start to bud. As the earth moves slowly away from the sun, it is then that we begin to feel the air cooling down, which is what we call autumn, or fall if you are American. For those who grumble about the hot weather, it would be important to remember that without the earth orbiting the sun, we wouldn't have a planet because the sun is our vital source of energy.
As the earth spins on its axis, producing night and day, it also moves about the sun in an elliptical (elongated circle) orbit that requires about 365 1/4 days to complete. The earth's spin axis is tilted with respect to its orbital plane. This is what causes the seasons. When the Earth's axis points towards the Sun, it is summer for that hemisphere. When the Earth's axis points away, winter can be expected. Since the tilt of the axis is 23 1/2 degrees, the north pole never points directly at the Sun, but on the summer solstice it points as close as it can, and on the winter solstice as far as it can. Midway between these two times, in spring and autumn, the spin axis of the Earth points 90 degrees away from the Sun. This means that on this date, day and night have about the same length: 12 hours each, more or less.
Why should this tilt of the Earth's axis matter to our climate? To understand this, take a piece of paper and a flashlight. Shine the light from the flashlight straight onto the paper, so you see an illuminated circle. All the light from the flashlight is in that circle. Now slowly tilt the paper, so the circle elongates into an ellipse. All the light is still in that ellipse, but the ellipse is spread out over more paper. The density of light drops. In other words, the amount of light per square centimeter drops (the number of square centimeters increases, while the total amount of light stays the same).
The same is true on the Earth. When the Sun is overhead, the light is falling straight on you, and so more light (and more heat) hit each square centimeter of the ground. When the Sun is lower in the sky, the light gets more spread out over the surface of the Earth, and less heat (per square centimeter) can be absorbed. Since the Earth's axis is tilted, the Sun is higher when you are on the part of the Earth where the axis points towards the Sun, and lower on the part of the Earth where the axis points away from the Sun.
For the Northern Hemisphere, the axis points most toward the Sun in June (specifically around June 21), and away from the Sun around December 21. This corresponds to the Winter and Summer Solstice (solstice is Latin for "the sun stands"), or the midpoints of winter and summer. For the Southern Hemisphere, this is reversed.
For both hemispheres, the Earth is 90 degrees away from the sun around March 21 and then again around September 21. This corresponds to the Fall and Spring Equinox (equinox is Latin for "equal night"). Everyplace in the world has about 12 hours of daylight and 12 hours of night.
The earth has different seasons because of how close it is to the sun. The earth moves in ellipses, which are like ovals or stretched out circles. The sun is not at the center of these ellipses, but rather towards one side of them. Within 365 days (or one earth year), earth moves around the entire ellipse once. During the part of the ellipse where the earth is closest to the sun, people on earth experience what is summer. When the planet earth is farthest from the sun, that is what we perceive as winter. The earth also rotates on the polar caps, not perpendicular to the ellipse, but slightly ascew (look up "equator" to see what the rotation looks like). As for spring and fall, those are just climate changes based on going from hot to cold and cold to hot.
Thanks for asking such a great question! I had fun answering it! :)
The seasons occur because the axis on which Earth turns is tilted with respect to the plane of Earth’s orbit around the Sun. Earth’s tilt causes the North Pole to be tilted toward the Sun for half of the year, and the South Pole to be tilted toward the Sun for the other half of the year. The hemisphere that is tilted toward the Sun has a longer day, receives more of the Sun’s rays, and receives the Sun’s rays more directly than the hemisphere tilted away from the Sun.
Read Gen.1:14-18 God created lights to divide day and night, for seasons, signs, and days, and years. The greater light the sun the lessor light the moon. The moon is not a ball of fire like the sun, it gets its light reflected from the sun.Gen.1:16. The stars are really suns to other solar systems. The sun, the moon and the stars are the rulers of day and night. Each one having its own unique government in their functions as God created them for His purpose! 1Cor.15:39-41. All functioning perfectly by His will and spoken Word! How glorious!!!...Genaveve
Earth experiences fall, winter, spring and summer every year. When we wonder why, they only answer that comes to our head is that, earth is round and it revolves around the sun. Every time its position changes, the weather changes. To simply put it, when ever it is directly facing the sun we experience summer and when it is not we experience winter. But have you ever imagines that when you are experiencing summer, another part of the world is experiencing winter as they are not facing the sun. This is because the earth not only makes revolutions around the sun but also rotates in circles. This way, the earth is divided in to the southern and northern hemisphere. So when the either of the Hemispheres is experiencing winter the other will experience summer. The four seasons are basically caused due to the tilt of the earth on it axis. This causes the earth's orbit around the sun and cause different seasons.
The Earth's axial tilt causes the Sunlight fall on it at a certain slant and as the Earth rotates around the sun in an elliptical orbit it's distance from the Sun varies. When the Earth gets close to the Sun the average global temperature is increased and we have Summers and as the Earth moves away from the Sun we end up having winters as the cumulative effect of Sunlight decreases.
