A Distant Cluster of Galaxies.

In this 1994 Hubble Space Telescope photograph , every bright object is a galaxy . Oddly - most of them are spiral galaxies. This rich cluster of galaxies , named CL 0939+4713 , is almost half way across the visible universe . Photos like this indicate that clusters in the past contained a higher fraction of spirals than do nearby clusters which are usually dominated by elliptical galaxies .