Space Telescope Science Institute
Cluster MACS J1206.2-0847 (or MACS 1206 for short) is one of the first targets in a Hubble Space Telescope survey that will allow astronomers to construct the highly detailed dark matter maps of more galaxy clusters than ever before. These maps are being used to test previous but surprising results that suggest that dark matter is more densely packed inside galaxy clusters than some models predict. This might mean that galaxy cluster assembly began earlier than commonly thought. The multiwavelength survey, called the Cluster Lensing And Supernova survey with Hubble (CLASH), probes, with unparalleled precision, the distribution of dark matter in 25 massive clusters of galaxies. So far, the CLASH team has completed observations of six of the 25 clusters. MACS 1206 lies 4.5 billion light-years from Earth. This image was taken with Hubble's Advanced Camera for Surveys and the Wide Field Camera 3 in April 2011 through July 2011.