What causes the seasons on Earth?

The seasons on Earth are primarily caused by the tilt of the Earth's axis. As the Earth orbits the Sun throughout the year, its axial tilt remains at an angle of about 23.5 degrees. This tilt means that different parts of the Earth receive varying amounts of sunlight at different times of the year.

During summer in the Northern Hemisphere, for instance, the North Pole is tilted toward the Sun, causing that hemisphere to receive more direct sunlight and longer days. Conversely, during winter, the North Pole is tilted away from the Sun, leading to less direct sunlight and shorter days. This variation in sunlight intensity and duration is what brings about the changes in temperature and weather patterns that we identify as the seasons.

The rotation of the Earth on its axis contributes to the cycle of day and night but does not influence seasonal changes. The Earth's distance from the Sun does vary slightly throughout the year due to its elliptical orbit, but this variation is not significant enough to cause the seasons. Furthermore, while the gravitational pull of the Moon affects ocean tides, it has no direct effect on the Earth's seasonal changes.