The annual apparent motion of the sun through the ecliptic and zodiac constellations = one revolution of the earth around the sun 🌞 The Celestial sphere is a conceptual tool used to specify a position of an object in the sky without consideration of its linear distance from the observer. The earth ( the observer) is the center and it’s very useful to locate yourself with the stars. That’s why is used for navigation and astronomy. All objects in the sky can be conceived as being projected upon t