Naonobu (Moon)

Named after Ajima Naonobu - Japanese mathematician (c. 1732-1798).

Naonobu is located on the eastern Mare Fecunditatis, to the northwest of the prominent crater Langrenus, and it forms a triple-crater formation with the adjacent Atwood to the south and Bilharz just to the southwest. The interior of this crater has been flooded with basaltic lava, leaving a flat interior and a reduced outer rim. There is no central peak, but a tiny craterlet lies just to the southwest of the midpoint. (wikipedia entry)

A crater is a circular depression likely created by an impact event. On the Moon they are named after deceased scientists, polar explorers, astronauts or cosmonauts.