The Hercules Cluster (M13) is often cited as the grandest globular cluster north of the celestial equator. Located 25,000 light- years away, it hosts more than 100,000 stars crammed into a volume of space roughly 150 light-years in diameter.
Although it is visible to the naked eye on dark, transparent nights, it seemingly went undocumented until Edmond Halley first laid eyes on it in 1714. Charles Messier subsequently added it to his famed catalog (as entry 13) a century later, but he only des