Local Group Dark Matter (IMAGE) Durham University Caption Description: The visible galaxies in the Local Group simulation, shown in the lower right, only trace a tiny fraction of the vast number of dark matter halos, revealed in the upper left. Credit Credit: John Helly, Till Sawala, James Trayford, Durham University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.