Why do we have seasons and why do the seasons change?
The sun is important to the earth because it acts like a heater. When we receive a lot of heat from the sun, we get hotter, and when we receive little, we get colder. In other words, the changing seasons are related to the movement of the earth and the sun.
The earth rotates once a day and revolves around the sun once a year. However, because the earth orbits the sun in a slightly tilted position, the heat received from the sun differs from place to place. At certain times of the year, the northern hemisphere of the earth receives more sunlight and it is summer. At the same time, the southern hemisphere receives less sunlight, resulting in winter. When it is mid-summer in Japan, it is mid-winter in Australia. In this way, the northern and southern hemispheres alternate between summer and winter as the earth rotates around the sun over the course of a year.
