Astrolabes are scientific instruments used for reckoning time and for observational purposes.
They were developed by Islamic and European astronomers and mariners during the Middle Ages. An astronomer would rotate plates with coordinates on them and align a straight ruler with an object in the sky. A system developed by people through the ages to forecast earthly and human events by observing and interpreting the Sun, moon, stars, and planets. The science of understanding the origin, evolution, composition, distance, and motion of all bodies in the universe, including the sun, Moon, planets, solar system, comets, stars, galaxies, and interstellar dust. An axis is an imaginary line running through a planet or other celestial body around which it rotates.