Transcript: Globular clusters are the largest, most massive, and oldest groups of stars we know of in the Milky Way. Typical ages are eight to ten billion years, but some globular clusters are as young as five billion years old and some are as old as twelve billion years. The stars are dim and red as might be expected from an old stellar system where there’s no ongoing star formation. Most of the massive stars have long ago left the main sequence. Heavy element abundances are far lower than in the Sun or the stars in the solar neighborhood. In the globular clusters we find most stars to be nearly three times older than the Sun.