M75

M75 is a compact, luminous globular cluster in Sagittarius, about 67,500 light-years from Earth — one of the most distant and most concentrated Messier globulars. It has a concentration class I, meaning it has an extremely dense core. The cluster spans about 130 light-years.

Located about 8 degrees south-southwest of Theta Capricorni, in a rather isolated area between Sagittarius and Capricornus. In binoculars it appears as a faint, star-like fuzzy point. A 6-inch telescope shows a small, very concentrated glow. Resolving individual stars is extremely difficult even in large amateur telescopes due to its distance and tight concentration. Best observed from August through October.

Discovered by Pierre Mechain on August 27, 1780. Charles Messier observed it on October 5, 1780, describing it as a 'nebula without stars.' Due to its great distance and compact nature, it remained unresolved for a long time.