Vocabulary Axis – imaginary line around which Earth spins; drawn from the north geographic pole through Earth to the south geographic pole Rotation – spinning of Earth on its axis, which causes day and night; it takes 24 hours for Earth to complete one rotation Revolution – the motion of Earth around the Sun, which takes about 365 ¼ days, or one year, to complete Orbit – curved path followed by Earth as it moves around the Sun Equinox – twice-yearly time when the Sun is directly above Earth’s equator and there are equal hours of day and night Solstices – time when the Sun reaches its greatest distance north or south of the equator

Vocabulary Hemisphere – one half of a sphere Equator – imaginary line that separates Earth into 2 hemispheres. Latitude – imaginary lines measuring the distance north or south of the equator. Sphere – round, solid figure Seasons – changes in weather patterns and daylight hours resulting from the Earth’s tilt and its revolution around the sun. Vernal – spring