why does the earth have four seasons

Many people think that some parts of the year are hotter because we're nearer to the Sun, but the real reason is that
the Earth is wonky (tilted). Why do we have seasons? We have seasons because the earth is tilted (wonky) as it makes its yearly journey around the sun. The Earth's tilt The Earth's axis is tilted at an angle of 23. 5 degrees. This means that the Earth is always pointing to one side as it goes around the Sun. So, sometimes the Sun is in the direction that the Earth is pointing, but not at other times. The varying amounts of sunlight around the Earth during the year, creates the seasons. The tilt of the Earth's AXIS is the most important reason why seasons occur. We have hot summers and cold winters because of the tilt of the Earth's axis. The tilt of the Earth means the Earth will lean towards the Sun (Summer) or lean away from the Sun (Winter) 6 months later. In between these, Spring and Autumn will occur. The Earth revolves around the Sun. The North pole always points the same way as the Earth revolves around the Sun. The Earth's movement around the sun causes the seasons. The Earth takes 365. 24 days to orbit the sun. As we move around the Sun during the year, the amount of light each area of the planet receives varies in length. 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. It is Summer time in countries in the Northern Hemisphere. It is Winter time in countries in the Southern Hemisphere. It is Winter time in countries in the Northern Hemisphere. It is Summer time in countries in the Southern Hemisphere. Since the tilt of the axis is 23 1/2 degrees, the north pole never points directly at the Sun. The north pole begins to move away from the Sun. The Sun rises lower in the sky so the days start getting shorter. When the Sun is at its mid-point in the sky, we reach the ' ', around 22 September. Day and night are both 12 hours long and its the beginning of autumn. The Earth continues on its path, and our north pole starts moving towards the Sun again. The Sun moves upwards in our skies and the days continue getting longer. Again, we reach a midpoint when day and night are both 12 hours long. This is called the ' ' and happens around 21 March.


Did you know? The Earth's movement around the sun causes the seasons, but it does not affect the temperatures during the seasons. Many people believe that the temperature changes because the Earth is closer to the sun in summer and farther from the sun in winter. In fact, the Earth is farthest from the sun in July and is closest to the sun at the beginning of January! The height of the sun in the sky varies with the seasons. The sun is at its heighest at 12:00pm (noon) on any gven day. In the summer the sun is higher than it is in the other three seasons. Summer Months Summer is warmer and winter is colder because of the length of our days and nights. In the summer daylight lasts longer and night time is shorter. Winter Months In winter the days are shorter and the nights longer. There is more time for the sun to warm us during long summer days. And short winter days have long, cold nights. Revolution - The Earth revolves around the Sun. Watch a video of why we have seasons Nearly everyone enjoys the change of seasons on Earth from winter to spring, from summer to fall. But why do our seasons change? Some assume our planet s changing distance from the sun causes the change in the seasons. That s logical, but not the case, for Earth. Instead, Earth has seasons because our planet s axis of rotation is tilted at an angle of 23. 5 degrees relative to our orbital plane the plane of Earth s orbit around the sun. The tilt in the axis of the Earth is called its obliquity by scientists. Over the course of a year, the angle of tilt does not vary. In other words, Earth s northern axis is always pointing the same direction in space. At this time, that direction is more or less toward the star we call. But the orientation of Earth s tilt with respect to the sun our source of light and warmth does change as we orbit the sun. In other words, the Northern Hemisphere is oriented toward the sun for half of the year and away from the sun for the other half. The same is true of the Southern Hemisphere. When the Northern Hemisphere is oriented toward the sun, that region of Earth warms because of the corresponding increase in solar radiation. The sun s rays are striking that part of Earth at a more direct angle. It s summer. When the Northern Hemisphere is oriented away from the sun, the sun s rays are less direct, and that part of Earth cools.


It s winter. Seasons in the southern hemisphere occur at opposite times of the year from those in the northern hemisphere. Northern summer = southern winter. The tilt in Earth s axis is strongly influenced by the way mass is distributed over the planet. Large amounts of land mass and ice sheets in the northern hemisphere make Earth top-heavy. An is imagining what would happen if you were to spin a ball with a piece of bubble gum stuck near the top. The extra weight would cause the ball to tilt when spun. Over long periods of geological time, the angle of Earth s obliquity cycles between. This cycle lasts approximately 41,000 years and is thought to play a key role in the formation of ice ages a scientific theory proposed by in 1930. The Earth is currently decreasing in obliquity. Decreases in obliquity can set the stage for more moderate seasons (cooler summers and warmer winters) while increases in obliquity create more extreme seasons (hotter summers and colder winters). Glaciers tend to grow when the Earth has many cool summers that fail to melt back the winter snows. Remember, we re talking about a 41,000-year cycle here, so these changes in obliquity are not the primary driver of Earth s climate in the century ahead. Temperatures on Earth are influenced not just by obliquity, but also by many more factors which drive our complex climate system and the global temperatures we experience from year to year. P Other planets in our solar system also tilt at various degrees. Uranus rotates almost sideways at 97 degrees and has. The axial tilt on Venus is 177. 3 degrees. Hence, Venus has very little in the way of seasons. Earth s does change throughout the year, and it s logical to assume that an increase or decrease in a sun-planet distance could cause a cyclical change in the seasons. But in the case of our planet this change is too small to cause this change. Our seasons change due to our planet s angle of tilt 23. 5 degrees relative to our orbit around the sun. If Earth did not tilt at all, but instead orbited exactly upright with respect to our orbit around the sun, there would be minor variations in temperature throughout each year as Earth moved slightly closer to the sun and then slightly farther away.


And there would be temperature differences from Earth s equatorial region to the poles. But, without Earth s tilt, we d lack Earth s wonderful seasonal changes and our association of them with the various times of year associating a fresh feeling in the air with springtime, for example. It s easy to imagine a planet that has a more pronounced change in its distance from its star as the planet orbits the star. Some extrasolar planets planets orbiting distant stars have been found with more extreme orbits. And even in our own solar system, for example, the planet Mars has a more elliptical orbit than Earth does. It s distance from the sun changes more dramatically through its year than Earth s does, and the change in Mars distance from the sun does cause some more pronounced cyclical changes on this red desert world. Bottom line: It s logical to assume our planet s changing distance from the sun causes the change in the seasons. But Earth s distance from the sun doesn t change enough to cause seasonal differences. Instead, our seasons change because Earth tilts on its axis, and the angle of tilt causes the Northern and Southern Hemisphere to trade places throughout the year in receiving the sun s light and warmth most directly. Many people think that some parts of the year are hotter because we're nearer to the Sun, but the real reason is that the Earth is wonky (tilted). Why do we have seasons? We have seasons because the earth is tilted (wonky) as it makes its yearly journey around the sun. The Earth's tilt The Earth's axis is tilted at an angle of 23. 5 degrees. This means that the Earth is always pointing to one side as it goes around the Sun. So, sometimes the Sun is in the direction that the Earth is pointing, but not at other times. The varying amounts of sunlight around the Earth during the year, creates the seasons. The tilt of the Earth's AXIS is the most important reason why seasons occur. We have hot summers and cold winters because of the tilt of the Earth's axis. The tilt of the Earth means the Earth will lean towards the Sun (Summer) or lean away from the Sun (Winter) 6 months later. In between these, Spring and Autumn will occur. The Earth revolves around the Sun. The North pole always points the same way as the Earth revolves around the Sun.


The Earth's movement around the sun causes the seasons. The Earth takes 365. 24 days to orbit the sun. As we move around the Sun during the year, the amount of light each area of the planet receives varies in length. 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. It is Summer time in countries in the Northern Hemisphere. It is Winter time in countries in the Southern Hemisphere. It is Winter time in countries in the Northern Hemisphere. It is Summer time in countries in the Southern Hemisphere. Since the tilt of the axis is 23 1/2 degrees, the north pole never points directly at the Sun. The north pole begins to move away from the Sun. The Sun rises lower in the sky so the days start getting shorter. When the Sun is at its mid-point in the sky, we reach the ' ', around 22 September. Day and night are both 12 hours long and its the beginning of autumn. The Earth continues on its path, and our north pole starts moving towards the Sun again. The Sun moves upwards in our skies and the days continue getting longer. Again, we reach a midpoint when day and night are both 12 hours long. This is called the ' ' and happens around 21 March. Did you know? The Earth's movement around the sun causes the seasons, but it does not affect the temperatures during the seasons. Many people believe that the temperature changes because the Earth is closer to the sun in summer and farther from the sun in winter. In fact, the Earth is farthest from the sun in July and is closest to the sun at the beginning of January! The height of the sun in the sky varies with the seasons. The sun is at its heighest at 12:00pm (noon) on any gven day. In the summer the sun is higher than it is in the other three seasons. Summer Months Summer is warmer and winter is colder because of the length of our days and nights. In the summer daylight lasts longer and night time is shorter. Winter Months In winter the days are shorter and the nights longer. There is more time for the sun to warm us during long summer days. And short winter days have long, cold nights. Revolution - The Earth revolves around the Sun. Watch a video of why we have seasons

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