He was the first to take notice of Ganymede, which at that time he described as a small reddish “star” around Jupiter.
The Chinese have one of the most detailed documentation of astronomical observations. Gan De is one of the most notable astronomers in Ancient China. He was the first to take notice of Ganymede, which at that time he described as a small reddish “star” around Jupiter. Shi Shen also created one of the most detailed and oldest catalogs of the stars – Star Catalogue of Shi.