Hubblecast 05: Hubble discovers ring of dark matter <br /><br />An international team of astronomers using the NASA/ESA Hubble Space Telescope has discovered a ghostly ring of dark matter formed long ago during a colossal collision between two galaxy clusters. This is the first time that dark matter has been found with a distribution that differs substantially from the distribution of ordinary matter. <br /><br />Credit: <br /><br />ESA/Hubble (M. Kornmesser
