Hubble Observes Ancient Galaxies

This image of the central portion of a remote cluster of galaxies (CL 0939+4713) as it looked when the universe was two-thirds of its present age. The HST picture confirms that billions of years ago, clusters of galaxies contained not only the types of galaxies dominating their descendant clusters today, but also several times as many spiral galaxies. These spiral galaxies have since disappeared through mergers and disruptions, as evident in the HST image.