Two years ago, astronomers detected a star cluster in the Crater constellation, which lies south of Leo on the sky. Intrigued by this they began using images and data collected from the Hubble Space Telescope to learn more about the stars.The Crater cluster is of interest because it is a type of globular cluster , and most of these are in the galactic center. The Crater cluster is atypically situated on the edge of the spiral rim. A globular cluster is a spherical collection of stars ; they are compact, and tightly tethered through gravity. Compared with other regions of the galaxy, globular clusters are contain considerably more stars and are much older compared with other star clusters.The Crater cluster is 470,000 light years away from the galactic center and this position struck astronomers as unusual. This led to the theory that the star group was not originally from the Milky Way, but rather it had been dragged in at some point in the past. Speaking with New Scientist magazine , Daniel Weisz, an astronomer at the University of Washington in Seattle, stated: "It’s almost certainly not from the Milky Way." Hubble data suggests the Crater cluster is cluster some 7.5 billion years old. This makes it far younger than the other globular clusters in the Milky Way. It is reasoned that the stars were pulled away from the Small Magellanic Cloud , which is a far smaller ("dwarf") galaxy.