Celestial navigation Celestial navigation Celestial navigation, also known as astronavigation, is the ancient and modern practice of position fixing that enables a navigator to transition through a space without having to rely on estimated calculations, or dead reckoning, to know their position. Celestial navigation uses "sights", or angular measurements taken between a celestial body (e.g. the Sun, the Moon, a planet, or a star) and the visible horizon. The Sun is most commonly used, but navigators can also use the Moon, a planet, Polaris, or one of 57 other navigational stars whose coordinates are tabulated in the nautical almanac and air almanacs.
Dynamics of the celestial spheres associating an angel with each of the spheres. Moreover, Aquinas rejected the idea that celestial bodies are moved by an internal nature, similar to the heaviness and lightness that moves terrestrial bodies. Attributing souls to the spheres was theologically controversial, as that could make them animals. After the Condemnations of 1277, most philosophers came to reject the idea that the celestial spheres had souls. Robert Kilwardby (c. 1215–1279) discussed three alternative explanations of the motions of the celestial spheres, rejecting the views that celestial bodies are animated and are moved by their own spirits or souls, or that the celestial