The sky appears to drift overhead from east to west, completing a full circuit around the sky in 24 (Sidereal) hours. This phenomenon is due to the spinning of the Earth on its axis. The Earth's spin axis intersects the Celestial Sphere at two points. These points are the Celestial Poles. As the Earth spins; they remain fixed in the sky, and all other points seem to rotate around them. The celestial poles are also the poles of the Equatorial Coordinate System, meaning they have Declinations of +90 degrees and -90 degrees (for the North and South celestial poles, respectively).
O ceo parece desprazarse por riba das nosas cabezas de leste a oeste, completando un circuíto completo do ceo en 24 (horas sidéreas). Este fenómeno débese á rotación da Terra sobre o seu eixo. O eixo de rotación da Terra intersecciona a esfera celeste en dous puntos. Estes puntos son os polos celestes. Segundo a terra xira, estes fican fixos no ceo e todos os demais puntos parecen rotar arredor deles. Os polos celestes son tamén os polos do sistema de coordenadas ecuatorial, o que quere dicir que teñen declinacións de +90 graos e - 90 graos (polos norte e sul, respectivamente).