ACT-CLJ0102-4915 is located approximately 7.2 billion light-years from Earth.

This galaxy cluster is almost as massive as 3 million billion Suns — so it’s little wonder that it has earned the nickname of ‘El Gordo’ (‘the Fat One’ in Spanish).

In 2012, observations from ESO’s Very Large Telescope, NASA’s Chandra X-ray Observatory and the Atacama Cosmology Telescope showed that ACT-CLJ0102-4915 is actually composed of two galaxy clusters colliding at millions of miles per hour.

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