M22 taken from my Creedmoor site on July 28th 2016 is a magnificent globular cluster located in the constellation of Sagittarius. With a magnitude of +5.1, the cluster is visible to the naked eye under dark skies and is also the brightest globular in Messier's catalogue. Only the two great southern globulars Omega Centauri (NGC 5139) and 47 Tucanae (NGC 104) are more brilliant, however both are too far south in the sky to have been seen by Messier. With an apparent diameter extending 32 arc-minutes, M22 covers more sky than the Full Moon.
The main reason why M22 appears so large and bright is because it's close, only 10,400 light-years distant. It's also probably the first globular to have been discovered - by Abraham Ihle in 1665 - although it has been suggested that Hevelius may have seen it earlier. M22 was included in Edmund Halley's list of 6 objects published in 1715 and then catalogued by Charles Messier on the June 5, 1764.