Astronomers using the High-Resolution Echelle Spectrometer (HIRES) on the Keck I telescope at W. M. Keck Observatory and the Canada-France-Hawaii Telescope (CFHT) have discovered a massive globular cluster in the Andromeda Galaxy, RBC EXT8, that is extremely poor in heavy elements — chemical elements heavier than hydrogen and helium. The cluster’s iron abundance is about 800 times lower than that of the Sun, and about three times lower than...