noun
orbital motion
Technical astronomy term for the movement of a celestial body along its orbit.
地球の公転運動は約365日で一周する。
The Earth's orbital motion completes one revolution in about 365 days.
自転運動 refers to rotation about an internal axis, while 公転運動 refers to revolution around an external body.
Compound of 公転 (revolution) and 運動 (motion).