A sprawling galaxy cluster nine billion light years from Earth lurks in the constellation Draco. The combined gravity of its many member galaxies warps the space in and around the cluster, bending and magnifying the light from galaxies in the remote background along the line of sight from Earth. eMACS J1823.1+7822, seen here, is one of five exceptionally massive galaxy clusters studied by the Hubble Space Telescope to learn more about the strength of gravitational lensing and the distribution of dark matter in such galactic assemblies. Other than a handful of foreground stars marked by tell-tale diffraction spikes, every object in the image is a galaxy. The numerous arc-like streaks are the gravitationally magnified and distorted light from more distant background galaxies. This multi-wavelength image incorporates data from eight filters and two instruments – the Advanced Camera or Surveys and the Wide Field Camera 3.
