Astronomy · a Light

An observatory in Iran hired astronomers from as far as China

Nasir al-Din al-Tusi persuaded the Mongol ruler Hulagu to fund an observatory at Maragha in northwest Iran, begun in 1259. It was not one instrument but an institution: a staff drawn from Damascus, Mosul, Tus and Andalusia, a Chinese astronomer among them, a library, a workshop for making instruments, and thirty years of funding. The star tables produced there, the Zij-i Ilkhani, were finished in 1272 and used for centuries. The astronomers of Maragha also built new geometric models to fix the parts of Ptolemy they thought incoherent, and the same devices turn up later in Copernicus. How they reached him is still argued, and no document of the transmission has been found.

Maragha, Iran · founded 1259