December 12
Galaxy Cluster SDSS J1004+4112
Observed in 2005
This picture captures a galaxy cluster called SDSS J1004+4112 that's so massive that its gravity bends light from galaxies behind it. The light of a distant quasar (the brilliant core of an active galaxy) has been bent around the cluster, appearing in five places in this image.
Image credit: NASA, ESA, Hubble Space Telescope