About this image

These illustrations demonstrate how two galaxies coalesce in a slow dance that lasts about a billion years.

The graphics are taken from a simulation astronomers created to determine how long it takes for galaxies to complete a merger. By understanding the time it takes for two merging systems to become one normal-looking galaxy, astronomers can calculate how many galaxy encounters happen over time. This information yields important clues about how galaxies have changed throughout the universe's history.

COSMOS, Deep Fields, Galaxies, GOODS, Hubble Telescope, Hubble Ultra Deep Field, Illustrations, Interacting Galaxies, Survey


Credit: P. Jonsson (Harvard-Smithsonian Center for Astrophysics), G. Novak (Princeton University), and T.J. Cox (Carnegie Observatories, Pasadena, Calif.)