An International Workshop on "one Century of Mars Observations" is planned to take place at Meudon observatory on the 17-20 September 2009. Its main objective is to gather amateur astronomers and professional interested in the study of the red planet. This will also celebrate the 100th anniversary of the observations of Mars that E. Antoniadi made with the great Meudon refractor which definitely proved the absence of Mars channels. Session devoted to the history of Mars observations as well as modern techniques and space missions are planned.
