Streams of stars that are being ripped to shreds as they spiral into the Milky Way have been imaged in unprecedented detail using data from the Sloan Digital Sky Survey. The so-called Field of Streams suggests the halo of dark matter that cocoons our galaxy is spherical – not squashed like an American football as previously thought. Galaxies are thought to have massive dark matter halos that extend many times farther than the galaxies themselves. Theories predict that the halos are flattened – ellipsoid – in shape, but different observations of gas and stars in the Milky Way have suggested different shapes for its halo.
Site – http://www.newscientist.com