Galaxies on the Move (image) University of Iowa Share Print E-Mail Caption This image shows three instances of merging galaxies located at least a billion light years from Earth. Each galaxy is as large as the Milky Way and contains about 100 billion stars. Violent gravitational interactions created the tidal tails shown and triggered massive black hole accretion at the galactic nuclei. These systems were first confirmed by Hai Fu in 2015 and published in Astrophysical Journal Letters. Credit Hai Fu, University of Iowa Usage Restrictions None Share Print E-Mail 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.