Messier 12 is a globular cluster discovered by Charles Messier on 30 May 1764, known to astronomers as NGC 6218.
It has a magnitude of 6.7 and is 23,000 light-years away in the constellation of Ophiuchus. Its apparent diameter is 14.5 minutes of arc, and its real diameter is estimated to be 68 light-years.
Like the 200 other clusters in our galaxy, Messier 12 describes an elongated elliptical orbit that has it periodically approaching the highly populated regions of the Milky Way.
In February 2006, a team of Italian ESA astronomers using the VLT spectrograph showed that the Messier 12 globular cluster had probably lost nearly a million low mass stars to the Milky Way. By coming too close to very dense areas of the Milky Way, where the disturbances are intense, the low mass stars in the globular cluster would simply have been "ejected" before wandering in its trail or being lost in the halo of our galaxy.