An Einstein Cross reveals the presence of a huge gravitational lens in the distant reaches of the universe. Astronomers discovered this gravitational lens in 1985 using survey maps of the sky obtained with the Hubble Space Telescope (HST). The bright object at the center of the image is a distant galaxy. The four bright objects surrounding it are actually multiple images of a single quasar that lies far beyond the galaxy. The lens was named the Einstein Cross in honor of Albert Einstein, whose relativity theory predicted the phenomena decades before the first gravitational lens was observed in 1979.
Space Telescope Science Institute/Nasa/Science Source/Photo Researchers, Inc.