The Earth has four seasons as a result of its revolution on another object – the Sun. Revolution is another type of Earth’s motion aside from rotation – this Earth takes 24 hours to rotate on its axis. Earth doesn’t take 365 days to orbit the sun, but 365.2422 or 365 ¼ days. Revolution happens because the Sun’s gravity pulls Earth and the other planets so they could orbit the Sun. When Earth begins to orbit and as each day passes by, our seasons – winter, spring, summer and fall – also begin to change. A perfect example of Earth’s revolution is this:
When the Northern Hemisphere is closest to the sun, people who are living in that area experience winter and people living in the Southern Hemisphere experience summer. When the Northern Hemisphere is farthest from the sun, people living there experience summer, while people living in the Southern Hemisphere experience winter or cold season.