Catalogue and alternative designations M22, NGC 6656   Type Globular Cluster  Position  18 36.4, -23 54 Constellation Sagittarius Camera and Telescope STL11000M and 31.75 cm Ritchey Chretien Focal Ratio F9 Exposure Details LRGB =60:50:50:50 with Astrodon filters all 1x1 Description M22 is one of the nearer globular clusters at a distance of 3100 parsecs.  Although there is a lot of absorption in the area it is quite bright at magnitude 5.1 and should be visible to the naked eye in a dark sky.  Measured in terms of brightness alone, M22 ranks third after Omega Centauri and 47 Tucanae.