What causes the seasons?
Earth spins on an axis as it orbits, or travels around, the sun. The axis is an imaginary line running through the North and South Poles. Earth's axis is tilted at an angle. This tilt is the reason why we have seasons. It takes Earth 365 days, or one year, to make a complete orbit of the sun.
During a year, the northern and southern halves, or hemispheres, of Earth will be slightly closer to or farther away from the sun. Each hemisphere will receive more or less sunlight. When one hemisphere is leaning toward the sun, it is summer there, while the other hemisphere, which is leaning away, has winter. In between these seasons are spring and fall. Regions along or near the equator, the imaginary line running around Earth's middle, get the same strength of sunlight all year. These places do not have four seasons. Instead they are warm all year or have only wet and dry seasons.
Earth spins on an axis as it orbits, or travels around, the sun. The axis is an imaginary line running through the North and South Poles. Earth's axis is tilted at an angle. This tilt is the reason why we have seasons. It takes Earth 365 days, or one year, to make a complete orbit of the sun.
During a year, the northern and southern halves, or hemispheres, of Earth will be slightly closer to or farther away from the sun. Each hemisphere will receive more or less sunlight. When one hemisphere is leaning toward the sun, it is summer there, while the other hemisphere, which is leaning away, has winter. In between these seasons are spring and fall. Regions along or near the equator, the imaginary line running around Earth's middle, get the same strength of sunlight all year. These places do not have four seasons. Instead they are warm all year or have only wet and dry seasons.
