Imagine taking a time-lapse photograph of a clear sky at night. The photograph will be filled with circular arcs of light that reflect the motion of the stars in the sky as the Earth rotates around its axis. These paths have been the subject of human wonder since the time of ancient civilisations, and our precise mathematical knowledge of the positions of stars has enabled us to navigate our way home from long journeys across vast oceans.
Now imagine we are on a distant planet, whose rotation is not so regular or predictable. It may have a cycle of rotation
