Scientists have detected evidence of a colossal explosion in space - five times bigger than anything observed before. The huge release of energy is thought to have emanated from a supermassive black hole some 390 million light years from Earth. The eruption is said to have left a giant dent in the Ophiuchus galaxy cluster. Researchers reported their findings in The Astrophysical Journal. "I've tried to put this explosion into human terms and it's really, really difficult," co-author Melanie Johnston-Hollitt told BBC News.