The giant elliptical galaxy Messier 87 is surrounded by a huge halo. An increase in brightness in the top-right part of this halo and the motion of planetary nebulae in the galaxy are the last remaining signs of a medium-sized galaxy that collided with M87.
This wide field image also contains many other galaxies forming the Virgo Cluster, of which Messier 87 is the largest member. The two galaxies at the edge of the top right of the frame are nicknamed “the Eyes.”
Image Credit: ESO