āBeautiful Nebula discovered between the Balance [Libra] & the Serpent [Serpens] ā¦ā is how the description of the 5th entry in 18th century astronomer Charles Messierās famous catalog of nebulae and star clusters begins. Although to him it appeared to be fuzzy, round and without stars, Messier 5 (M5) is now known to be a globular star cluster, 100,000 stars or more, bound by gravity and packed into a region around 165 light-years in diameter. It lies about 25,000 light-years away. Roaming the halo of our galaxy, globular star clusters are ancient members of the Milky Way. M5 is one of the oldest, its stars estimated to be nearly 13 billion years old.
Image Credit & Copyright: Adam Block, Mt. Lemmon SkyCenter, University of Arizona









