Hubble Captures a 'Five-Star' Rated Gravitational Lens

NASA's Hubble Space Telescope has captured the first-ever picture of a group of five star-like images of a single distant quasar. The multiple-image effect seen in the Hubble picture is produced by a process called gravitational lensing, in which the gravitational field of a massive object -- in this case, a cluster of galaxies -- bends and amplifies light from an object -- in this case, a quasar -- farther behind it. The galaxy cluster creating the lens is known as SDSS J1004 4112 and was discovered in the Sloan Digital Sky Survey. It is one of the more distant clusters known (seven billion light-years away), and is seen as it appeared when the universe was half its present age. Credit: ESA, NASA, K. Sharon (Tel Aviv University) and E. Ofek (Caltech)