This is a moderately eroded crater, with the satellite crater Nagaoka W overlapping the northwestern rim. The remainder of the rim remains well-defined, although it is overlain by several tiny craters. The inner wall has slumped in places, forming terrace-like shelves. A few small craters lie within the crater interior.
The crater was named after Japanese physicist Hantaro Nagaoka by the IAU in 1970.[1]
Satellite craters
By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Nagaoka.
Menzel, D. H.; Minnaert, M.; Levin, B.; Dollfus, A.; Bell, B. (1971). "Report on Lunar Nomenclature by the Working Group of Commission 17 of the IAU". Space Science Reviews12 (2): 136–186. doi:10.1007/BF00171763. Bibcode: 1971SSRv...12..136M.