Mare clausum defended a "Mare clausum" policy during the age of discovery. This was soon challenged by other European nations. From 30 BC to 117 AD the Roman Empire came to surround the Mediterranean by controlling most of its coasts. Romans started then to name this sea "mare nostrum" (Latin for "our sea"). At those times the period between November and March was considered the most dangerous for navigation, so it was declared ""mare clausum"" (closed sea), although bans on navigation were probably never enforced. In classical law the ocean was not territorial. However, since the Middle Ages maritime republics like the
Mare Moscoviense the first images of the far side were returned by Luna 3 in 1959. The name was approved by the IAU in 1961. The names of maria generally call up psychic states of mind, with a few exceptions. When Mare Moscoviense was discovered, and the name was proposed by the Soviet Union, it was only accepted by the International Astronomical Union with the justification that Moscow is a state of mind. Mare Moscoviense Mare Moscoviense ("Sea of Moscow") is a lunar mare that sits in the Moscoviense basin. It is one of the very few maria on the far side