Why do we have seasons?

Why do we have different seasons on the northern and southern hemisphere, and what is the explanation for why we have seasons?

Distance to the Sun does not determine seasons. Seasons change is connected with the fact that Earth is constantly moving in relation to the Sun.

At first, one would think that it becomes warmest when the Earth comes closest to the Sun in its elliptical path, but it does not.

The distance between the two celestial bodies varies so little during our one-year course around the Sun, that in practice it is irrelevant to the temperature of the Earth.

The slope of the earth gives us seasons

why do we have different seasons on different parts of the earth

The reason for the seasons change is the slope of the earth.

As the Earth rotates around the Sun, it also rotates itself in an axis that cuts about 23.5 °.

So; this slope changes how the northern and southern hemispheres point toward the Sun and that is the exact reason for seasons. So when the northern hemisphere points to the Sun, we get more sunlight and the extra solar energy warms the earth and the air – which is resulted in spring and summer.

Half a year later, the Earth is redirected to the the sun with the other side of the Earth, and now it is the southern hemisphere pointing towards the Sun while the northern hemisphere is in shadow.

Therefore, spring and summer will be in, for example, Australia and South America, while we have fall and winter in Europe.

Seasons effect animal and plant life cycle

If the axis of the Earth were straight, we would have the same amount of sunshine every day and everywhere.

Locally speaking, it would be perceived that the sun rose and went down at the same time all year round. The weather would not change on our latitudes.

Under such circumstances, life here on Earth would be very different from what we experience now. The lifecycle of many animals and plants is dependent on the  seasons change.

Changing seasons in the Space

It is not only Earth that has seasons. Despite the average temperature of minus 180 ° C on the surface, the Satan Moon Titan also has seasons where icebergs of methane melt during the summer.