Planispheric Astrolabe

An astrolabe is an early scientific instrument representing a two-dimensional model of the celestial sphere. These instruments trace back to the Hellenistic period between 220 and 150 BCE but became popular as complex tools in Europe and the Islamic world from the early Middle Ages. Constructed as inscribed discs, usually made of metal, such as brass or iron, astrolabes were used for measuring time (the time of the day and night, the month or the year), determining altitude and latitude or for observational purposes. They were, therefore, extremely useful in solving problems in the fields of geography, surveying and astronomy. This type of astrolabe, known as a ‘planispheric astrolabe’, allowed astronomers to calculate the position of the sun and other prominent stars.

This gilded brass planispheric astrolabe was made by the famous artist Muhammad Mahdi ibn Muhammad Amin al-Yazdi in Isfahan in the year 1065 AH (1654-1655 CE) during the Safavid period. It is exquisitely decorated with leaves, inscribed with different types of calligraphy and engraved with scientific information.