https://scienceblogs.com/startswithabang/2012/11/12/messier-monday-an-ancient-globular-cluster-m15
Messier Monday: An Ancient Globular Cluster, M15 | ScienceBlogs
"When your friends begin to flatter you on how young you look, it's a sure sign you're getting old." -Mark Twain
globular cluster m15messiermondayancientscienceblogs