This image shows a sequence illustrating the formation of streams of stars around the Milky Way galaxy. The Milky Way galaxy, and others, are surrounded by vast streams of stars. These are now known to be the remnants of dwarf galaxies. These are small galaxies in orbit around the parent galaxy. As they orbit, they experience gravitational forces which, in time, stretch out the dwarf galaxy to form star streams. Satellite galaxies of the Milky Way, such as the Magellanic Clouds, already have stars streams associated with them, indicating that the tidal forces have already been working.