Pairs and mergers
Images of galaxy pairs
Despite the millions of light-years separating neighbouring galaxies, the force of gravitation exerts on these huge and massive systems. Pairs get formed by breaking away from the surrounding expansion.
Images of interacting and merging galaxies
Galaxies in pairs are to collide and merge. This may take billions of years, and leads to the formation of a more massive galaxy. Like beacons, luminous bursts of star formation light up the new galaxy.