Task: Question Generation
Input (English): Pole star -- The identity of the pole stars gradually changes over time because the celestial poles exhibit a slow continuous drift through the star field. The primary reason for this is the precession of Earth's rotational axis, which causes its orientation to change over time. Precession causes the celestial poles to trace out circles on the celestial sphere approximately once every 26,000 years, passing close to different stars at different times (with an additional slight shift due to the proper motion of the stars).
Output (English): has polaris always been the north star also known as the pole star