Artist’s impression of dark matter clumps around a Milky Way-like galaxyV. Belokurov, D. Erkal, S.E. Koposov (IoA, Cambridge). Photo: Color image of M31 from Adam Evans. Dark matter clumps from Aquarius, Volker Springel (HITS)By Adam MannA one-two punch of dark matter may have knocked holes in a stream of stars out past the edge of the Milky Way. If...