Hubble Photographs Double Einstein Ring
Einstein's theory of general relativity includes many predictions about the behavior of light in the presence of gravitational fields. One prediction defined gravitational lensing, where two super massive objects are directly in line with one another such that the object in the foreground will bend all of the background light around it to form a "ring" of light. Statistically, astronomers put the odds of seeing one at 1 in 10,000. Using the SLACS (Sloan Lens Advanced Camera for Surveys) on the Hubble Space Telescope, astronomers have already been able to quadruple the number of known Einstein Rings. A recent discovery, however, is a photograph of a double Einstein Ring where three galaxies were lined up perfectly in order to create concentric rings of light from the gravitational lens effect of object SDSSJ0946+1006.