Lower left corner: Hubble sits looking toward the upper-right corner where there is a spiral galaxy. Between the two is an image of a large galaxy cluster. Lines drawn from the spiral at upper-right to Hubble illustrate the gravitational lens created by the galaxy cluster.

Illustration showing gravitational lensing producing supernova i

Large galaxy clusters contain both dark matter and normal matter. The immense gravity of all this material warps the space around the cluster, causing the light from objects located behind the cluster to be distorted and magnified. This phenomenon is called gravitational lensing. This sketch shows paths of light from a distant galaxy that is being gravitationally lensed by a foreground cluster.

Credits: NASA, ESA