A wide-field map of an ancient celestial city, the USS1558-003 protocluster. The map shows the distances of the three clumps of galaxies from each other relative to the radio galaxy USS1558-003 located at (0,0). More specifically, the horizontal and vertical axes show relative distances in right ascensions and declinations in arcminute units with respect to the radio galaxy. North is up, and east is to the left. The black dots are all galaxies selected in this field. Magenta dots show old, passively evolving galaxies. Blue squares represent star-forming galaxies with H-alpha emission lines, while red ones show red-burning galaxies. Large gray circles show the three clumps of galaxies. // Credit: NAOJ