Why are the seasons opposite in the Northern and Southern Hemispheres?

• A. The tilt of Earth's axis causes opposite heating in the hemispheres during different times of the year
• B. The Earth is closer to the Sun in one hemisphere's summer
• C. Each hemisphere tilts toward or away from the Sun opposite to the other as Earth orbits
• D. Differences in atmospheric pressure between hemispheres

Answer: (C)

Seasons come from the tilt of Earth’s axis relative to its orbit around the Sun. The axis stays pointed in roughly the same direction, so as Earth travels around the Sun, different hemispheres tilt toward or away from the Sun. When the Northern Hemisphere tilts toward the Sun, it receives more direct sunlight and longer days, making it summer there, while the Southern Hemisphere tilts away and gets less direct sunlight and shorter days, making it winter there. About six months later, the situation reverses, so the Southern Hemisphere experiences summer while the Northern Hemisphere experiences winter. Distance to the Sun changes only a little and isn’t what creates the seasons, and atmospheric pressure differences don’t drive the seasonal change.