Geological Chronicle
Korolev is a large peak ring basin spanning 423.41 kilometers on the lunar far side, with the northern portion of its floor crossing the equator. Formed during the Nectarian period of the lunar geologic timescale, the basin contains an interior topographic ring and has no central peak at its midpoint.
The outer rim of Korolev is heavily worn and eroded, marked by small craters along the wide rim and low inner wall. Within the basin lies the remains of a second, inner ring roughly half the diameter of the outer wall. Most intact in its eastern half, this ring forms a curving arc of ridges across the floor, where craters Korolev B, Korolev T, and Korolev L lie within its diameter.
During the Apollo 8 mission, a small crater southwest of Korolev L served as control point CP-1, where orbital measurements improved mapping accuracy across the lunar far side. Prior to formal naming in 1970 by the International Astronomical Union in honor of Soviet rocket engineer Sergei Korolev, the feature was designated Basin XV.