An astrolabe is an ancient instrument used for solving problems related to time and the position of celestial bodies. It consists of a flat disk with a rotating arm, called an alidade, which helps users measure angles in the sky. Astrolabes were essential tools for astronomers, navigators, and explorers, allowing them to determine latitude and longitude. Developed in the Hellenistic world, the astrolabe was later refined by Islamic scholars during the Middle Ages. It played a crucial role in the advancement of astronomy and navigation, influencing the work of notable figures like Ptolemy and Ibn al-Haytham.