Hubblecast 05: Hubble finds ring of dark matter

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. Read more at: http://www.spacetelescope.org/news/