806px-17._Celestial_sphere,_showing_equator_and_ecliptic_(22722076956) Published December 21, 2018 at 806 × 768 in Why Use the Tropical Zodiac? Intersection of the Equator and Ecliptic (public domain) 806px-17._Celestial_sphere,_showing_equator_and_ecliptic_(22722076956)