Why the Earth Has Seasons?

The main reason of earth having four seasons is that it is tilt on its axis. An axis is an imaginary line passing through the poles. An angle of 23.5 degrees is formed to the perpendicular of the earth’s orbit and axis always points in the same direction throughout the year.

The sun rays hit at a smaller angle as compared to the other parts of the globe. When the northern hemisphere is away from the sun, it means that it is leaning away from the sun and then the light received in the northern hemisphere is distributed in large area thus receiving less heat. At this time there will be winter in the northern hemisphere because of less heat and there will be summer in the southern hemisphere. Exactly same happens when southern hemisphere leans away from the sun. There will be winter and there will be summer in the northern hemisphere during the other half of the year. It means the different parts of the earth receives different amount of sunlight which is the reason of having four seasons.

fourseasons Why the Earth Has Seasons?

When the northern hemisphere is nearest to the sun it will be Summer Solstice. The sun is in its highest point in the sky during this time so it takes more time to cross sky. That is the obvious reason that the longest day in a year is somewhere around 21 June.

When the North Pole moves away from the sun then it starts rising lower in the sky. Gradually the days get shorter and when it reaches the midpoint, it is called Autumn Equinox which is somewhere around 22 September.

When the North Pole leans further away from the sun, it rises in lower point crossing the sky faster. This is the shortest day that is somewhere around 22 December and it is called Winter Solstice.

When the northern hemisphere moves near the sun, the sun starts rising upward every day and when it reaches the midpoint, it is called Spring Equinox. This is somewhere around 21st of March.

No seasons would have been experienced If the axis was at zero degree and the sun rays would reach the earth in same way throughout the year.

A misconception which is most common about seasons is that when the earth moves closer to the sun, it will be summer and when it would move further it will be winter. The orbit of earth is an ellipse that is not in a perfect circle but very near to circle hardly having any effect on the seasons.

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