Seas Mare Moscoviense Origin of the name "Sea of Muscovy." When to observe it On the far side: it never faces the Earth. Only spacecraft have seen it. Nearby Titov 70 km Tereshkova 118 km Komarov 139 km Belyaev 187 km Feoktistov 228 km Shatalov 228 km Leonov 249 km Nikolaev 250 km