Astrolabes were early scientific instruments that can be traced back to the 6th century AD. They were used for reckoning time as well as astronomical exploration, navigation and astrology. In medieval Europe, astrolabes were widely used for astrological purposes. By the mid-15th century, sailors adopted the device to navigate at sea. It enabled the determination of the position of the sun and prominent stars in relation to both the horizon and the meridian. Astrolabes represent a unique blend of science and myth that reveals the logic of an earlier time, when humans were still trying to make sense of the natural world.