Eugène Michel Antoniadi

"Antoniadi" redirects here. For other uses, see Antoniadi (disambiguation).

Eugène Michel Antoniadi (March 1, 1870 – February 10, 1944) was a Greek astronomer, born in Asia Minor, who spent most of his life in France. He was also known as Eugenios Antoniadis. His name is also sometimes given as Eugène Michael Antoniadi or even incorrectly Eugène Marie Antoniadi. He became a highly reputed observer of Mars, and at first supported the notion of Martian canals, but after using the 83 centimeter telescope at Meudon Observatory during the 1909 opposition of Mars, he came to the conclusion that canals were an optical illusion. He also observed Venus and Mercury. He made the first attempts to draw a map of Mercury, but his maps were flawed by his incorrect assumption that Mercury had synchronous rotation with the Sun. A crater on Mars and the Antoniadi crater on the Moon were named in his honor, as well as Antoniadi Dorsum on Mercury itself. He is also famed for creating the Antoniadi scale of seeing, which is commonly used by Amateur astronomers. He was also a strong chess player. His best result was equal first with Frank Marshall in a tournament in Paris in 1907, a point ahead of Savielly Tartakower.