Wikipedia
Tsiolkovskiy (crater)
Tsiolkovskiy is a large lunar impact crater that is located on the far side of the Moon. Named for Russian scientist Konstantin Tsiolkovsky, it lies in the southern hemisphere, to the west of the large crater Gagarin, and northwest of Milne. Just to the south is Waterman, with Neujmin to the south-southwest. The crater protrudes into the neighbouring Fermi, an older crater of comparable size that does not have a lava-flooded floor.