An article published in “The Astrophysical Journal” describes a research on the globular cluster Terzan 5. An international team of astronomers led by Francesco Ferraro from the University of Bologna discovered that the stars of Terzan 5 are divided into two groups, one with an age of 12 billion years and one with an age of around 4.5 billion years, more or less like the Sun. This unique feature can help to better understand the evolution of the Milky Way.