The giant cluster of elliptical galaxies in the center of this image contains so much dark matter mass that its gravitational field bends light. This means that for distant galaxies in the background, the cluster acts as a magnifying glass, bending and concentrating the distant object’s light towards Hubble. These gravitational lenses are one tool astronomers can use to extend Hubble’s vision beyond what it would normally be capable of seeing.
NASA/ESA/J. Richard (CRAL) and J.P. Kneib (LAM); acknowledgement: Marc Postman (STScI)