What is the astrolabe? (2 points)
1) The astrolabe is an ancient astronomical instrument that was used to measure the altitude of celestial objects, such as the Sun, Moon, and stars. It allowed astronomers and navigators to determine their positions and navigate accurately.
2) It was invented in the Hellenistic period and became widely used in the Islamic Golden Age. The astrolabe was a multi-purpose tool with various components, including a graduated plate, called a zodiacal ring, which represented the celestial sphere, and a rete, which was a rotating star map. It also had a sighting device, called an alidade, that allowed the user to align the instrument with a celestial object for measurement.