Astronomers spot 1 of the most powerful 'sonic booms' in the universe as massive galaxy crashes into its neighbors Livescience.com2-million-mile-per-hour galactic crash reawakens a dangerous 'cosmic crossroads' Space.comPowerful telescope captures rogue galaxy colliding with another at 2 million mph Yahoo! VoicesGalaxies colliding at 2 million miles per hour observed in unprecedented detail Earth.comA Galaxy Crashes at 2 Million MPH, Creating One of the Most Powerful Shock Waves Ever Seen The Daily Galaxy --Great Discoveries Channel