Which motion describes the spinning of the Earth on its axis?

Which motion describes the spinning of the Earth on its axis?

• A. Revolution
• B. Orbit
• C. Rotation
• D. Precession

Answer: (C)

Spinning on its own axis is rotation. The Earth turns around an imaginary line through the North and South Poles, so every point on Earth completes a turn as the planet spins. This rotation is what creates day and night, since different parts of the planet face toward or away from the Sun over about a 24-hour cycle. It’s different from revolution, which is the Earth’s path around the Sun over a year, or precession, which is a slow wobble of the axis direction over thousands of years. So the motion described—the Earth turning about its axis—is rotation.

Spinning on its own axis is rotation. The Earth turns around an imaginary line through the North and South Poles, so every point on Earth completes a turn as the planet spins. This rotation is what creates day and night, since different parts of the planet face toward or away from the Sun over about a 24-hour cycle. It’s different from revolution, which is the Earth’s path around the Sun over a year, or precession, which is a slow wobble of the axis direction over thousands of years. So the motion described—the Earth turning about its axis—is rotation.