The Earth’s axis – the imaginary line around which the Earth turns daily is titled at an angle of to the plane of its orbit. The seasons are caused by this tilt and by the fact that the Earth’s axis always holds the same orientation in space. As the Earth travels round the Sun, the North Pole is sometimes directed towards the Sun and sometimes directed away from it. When the North Pole is directed towards the Sun, sunray’s strike the northern hemisphere almost directly. This causes summer in the northern hemisphere and the southern hemisphere has winter. Three months later, the North Pole begins to slant away from the Sun. This causes the northern autumn and southern spring. After another three months the North Pole it tilted away from the Sun, this causes winter in the north and summer in the south. Finally the North Pole tilts towards the Sun again, bringing spring to north and autumn to south.
