What causes the seasons?

What causes the seasons?

• A. The distance between Earth and Sun.
• B. The tilt of the Earth's axis relative to its orbit around the Sun.
• C. The Earth's speed.
• D. The Moon's gravity.

Answer: (B)

The seasons change mainly because the tilt of Earth’s axis relative to its orbit around the Sun changes how sunlight hits different parts of the planet throughout the year. When a hemisphere is tilted toward the Sun, days are longer and the Sun’s rays hit more directly, warming that hemisphere (summer). When that same hemisphere is tilted away, days are shorter and sunlight is softer, leading to colder conditions (winter). The opposite happens in the other hemisphere, so it’s summer there when it’s winter here. This tilt, not distance from the Sun, is what drives the seasonal pattern. The Sun-Earth distance changes a bit as we orbit, and Earth’s speed in orbit varies, but those factors don’t determine the seasons. The Moon’s gravity doesn’t control seasons either.

The seasons change mainly because the tilt of Earth’s axis relative to its orbit around the Sun changes how sunlight hits different parts of the planet throughout the year. When a hemisphere is tilted toward the Sun, days are longer and the Sun’s rays hit more directly, warming that hemisphere (summer). When that same hemisphere is tilted away, days are shorter and sunlight is softer, leading to colder conditions (winter). The opposite happens in the other hemisphere, so it’s summer there when it’s winter here. This tilt, not distance from the Sun, is what drives the seasonal pattern. The Sun-Earth distance changes a bit as we orbit, and Earth’s speed in orbit varies, but those factors don’t determine the seasons. The Moon’s gravity doesn’t control seasons either.