This Hubble Space Telescope image shows the core of Messier 5, a globular star cluster about 25,000 light-years away in Serpens, the snake. The cluster contains hundreds of thousands of stars all packed into a spherical region about 165 light-years across. The cluster formed about 13 billion years ago, when the universe was less than one billion years old, making it one of the oldest members of the Milky Way Galaxy. [ESA Hubble/NASA]