The International Astronomical Union (IAU) is an international association of professional astronomers who are in charge of naming celestial bodies. It was founded in Brussels, but its head office is currently in Paris.
The association names everything: from small craters on Mars to the satellites of Jupiter.
On July 1 in 2009, the IAU named a crater on Mars after Ehden. It measures 57.4 km in diameter. In fact, craters are cavities on celestial objects.
There are plenty of other craters that are named after cities around the world: Bordeaux, Charlieu, and Apt are named after regions in France, for example.
The craters are not named randomly. According to sources, the large ones are dedicated to the deceased scientists and writers who have contributed to the study of Mars.
The small craters are dedicated to towns and villages that have a population of 100,000 or less. Other features are named after rivers and the name of Mars in various languages.