Animation of a cutaway of the Antikythera Mechanism, an analogue computer from the Classical Greek Era. The device acted as a portable planetarium, and turning the handle moved a succession of intricate gears within, calculating the relative positions of the Sun, Earth, Moon, the dates of eclipses, and possibly the positions of the planets at any given point in the future. Such technology was not thought to have been possible at the time of its creation before the discovery and subsequent study of the device. The Antikythera Mechanism was discovered in a first-century-BCE Roman shipwreck in 1901, but the exact details of its construction and purpose have only been elucidated with the help of modern high-resolution X-ray imaging, due to its heavily-corroded state after two millennia in seawater. It is thought that the device was designed and built by Archimedes in the third century BCE.