A new image from the Hubble Space Telescope takes a look at Messier 22: the closest, brightest and most spectacular globular cluster in our local part of the Milky Way Galaxy; It can be found approximately 11,000 light-years away from Earth in the constellation of Sagittarius.
Otherwise known as NGC 6656, Messier 22 spans around 70 light-years across, and boasts a combined mass of 500,000 Suns. Given its size, and close proximity, it’s easily the most prominent globular cluster in our sky (one of a small number that can be seen by the naked eye), but oddly enough, it’s not nearly as bright as one would expect it to be. You see, the cluster is situated in a section of the galaxy that contains significant quantities of obscuring interstellar gas and dust. Instead of its light traveling from point a to point b without obstruction, it encounters this interstellar material, which absorbs and deflects some of the light.
Messier 22 also has several other quirks. Perhaps most noteworthy is the fact that it’s one of only three globular clusters known to harbor a planetary nebula—that is, a nebula spawned after a star with the mass of the Sun died. Additionally, it has not one, but two black holes, and around 6 “planet-sized objects” that seem to orbit said black holes.
See a larger image here.