One of the most massive black holes in the universe lurks at the center of the Cosmic Horseshoe

In 2007, astronomers discovered the Cosmic Horseshoe, a gravitationally lensed system of galaxies about 5.5 billion light-years away. The foreground galaxy's mass magnifies and distorts the image of a distant background galaxy whose light has traveled for billions of years before reaching us. The foreground and background galaxies are in such perfect alignment that they create an Einstein ring.