The Astrolabe was originally invented by Greek astrologers around 150 BC. This particular astrolabe is a Persian Planispheric Astrolabe from Hajji Ali, Isfahan, Iran, that dates back to 1790. The plaque that accompanies this item at the Mariner’s Museum states that during the late 13th century it became widely used by Mediterranean mariners for navigation. Astrolabes were used to tell time and show the movement of the sun and stars as they moved across the horizon. Interestingly, by the time of this astrolabe’s creation, they had been used for almost 2000 years.