Day, Night & Seasons

Earth's rotation and revolution create our daily and yearly cycles

Earth rotates on its axis once every 24 hours, causing day and night. The side facing the Sun experiences day; the opposite side experiences night. Earth also revolves around the Sun once every 365.25 days. Earth's axis is tilted at 23.5° relative to its orbital plane. This tilt causes seasons: when the Northern Hemisphere tilts toward the Sun (summer), it receives more direct sunlight and has longer days. When tilted away (winter), it receives indirect, weaker sunlight and shorter days. At the equinoxes (March and September), day and night are approximately equal everywhere. The distance from the Sun is NOT the primary cause of seasons — Earth is actually closest to the Sun in January (during Northern Hemisphere winter).