[Hundreds of Galaxies in the Perseus Cluster]

This image shows the central region of the Perseus cluster, which contains hundreds of galaxies, even more invisible dark matter, and is one of the most massive objects in the universe. Each orange dot in this map is a galaxy. In all, the SDSS imaging map shown here contains more than a trillion pixels, each one imaged in five colors. The image was taken using the 2.5 meter telescope at Apache Point Observatory and is part of the Sloan Digital Sky Survey, of which Vanderbilt is a partner institution.