Structure of a globular cluster

This animation shows the makeup of a globular cluster.

Many of the globular clusters in our Milky Way, and beyond, were found to consist of two different generations of stars in almost equal proportions.

This animation reflects the first generation, in blue, and the second generation of stars polluted with different chemical elements, in green. More information on these clusters and the mystery behind their formation was discussed in Hubblecast 80: The riddle of the missing stars .