This false-color mosaic of the central region of the Coma cluster of galaxies combines infrared and visible-light images to reveal thousands of faint objects (green). Follow-up observations showed many of these objects are dwarf galaxies belonging to the cluster. Two large elliptical galaxies, NGC 4889 and NGC 4874, dominate the cluster's center.
NASA/JPL-Caltech/L. Jenkins (GSFC)