Figure 1-16 The Ecliptic and the Ecliptic Plane (a) As seen from Earth, the Sun appears to move around the celestial sphere along a circular path called the ecliptic. Earth takes a year to complete one orbit around the Sun, so as seen by us the Sun takes a year to make a complete trip around the ecliptic. (b) The ecliptic plane is the plane in which Earth moves around the Sun.