Credit: NASA/GSFC Scientific Visualization Studio
Note: The size and speed of the spiral are greatly exaggerated for clarity.
Polar motion describes the motion of the Earth's spin axis (shown in orange) with respect to the geographic north and south poles (shown in blue). Over time, the geographic poles appear to spin away from the spin axis when viewed from space and then back again. Viewed from the perspective of someone on Earth, the spin axis instead appears to spiral away from the geographic poles and then spiral back. The motion of the spin pole with respect to the geographic poles fixed to the Earth's crust is called polar motion.
