CoGeNT gives further backing to annual dark-matter variation

A long-standing and controversial claim by the DAMA collaboration in Italy that it has observed dark matter has received fresh support from a US-based experiment. Like DAMA, the CoGeNT collaboration says that it continues to see a seasonal variation in the number of events registered in its detector. Such a variation would be expected if the Milky Way galaxy were shrouded in a "halo" of dark matter, but several other dark-matter searches have failed to see the effect.