Gan De (甘德) was an ancient Chinese astronomer. According to other Chinese astronomer Xi Zezong, his observation of a "small reddish star" near the planet Jupiter was its moon Ganymede. His observation was made almost 2,000 years before Galileo Galilei's observation of the satellite, making him the true discoverer of Ganymede.
- Zezong, Xi, "The Discovery of Jupiter's Satellite Made by Gan De 2000 years Before Galileo", Chinese Physics 2 (3) (1982): 664–67.
As a reminder, article comments are only for discussions on how to improve the article. Please direct other comments to a user's talk page. Please be formal and do not use excessive uppercase. Please be advised you may receive an automatic block if you break the article comments policy. For information regarding what is acceptable/not acceptable in article comments, please message Joey (talk), Natalia (talk), ynoss (talk), or Daniel (older account/talk).