Although the speed of the earth around the sun is a periodic motion but not rotational motion
If the motion of a moving object is such that it passes repeatedly through a definite point in the same direction in the same manner in a definite interval of time, then this motion is called a periodic motion. Earth revolves around the Sun in the same direction in a parabolic path in every 1 year or 365 days, so the motion of Earth is periodic motion. Again, when a body rotates about a particular point or a line, keeping the distance of the particles of the body unchanged, it is called circular motion. Since orbit of Earth is parabolic, so the distance between Earth and Sun isn't always same, this distance is different at different times of the period. So, motion of Earth is not circular motion.
