Dark matter mapped by ghostly star

First globular cluster stellar stream ever identified Most of the stars in our Milky Way galaxy sit neatly on a flat plane. But the space around our galaxy is much more chaotic. Rogue bands of stars called "stellar streams" orbit the Milky Way much like planets in our solar system orbit the sun. A ghostly stream of stars beyond the Milky Way is giving astronomers a new way to map the universe’s…