A pair of nearby supermassive black holes are heading for a collision

A newly discovered pair of supermassive black holes is closer to Earth than any known so far. The two are only 1,600 light years apart, so astronomers predict they will smash together in a mere 250 million years. One sits at the centre of the galaxy NGC 7727, with the other just off to the side. Many more off-centre black holes could be hiding throughout the Universe, say astronomers — in which case, the cosmos might contain up to 30% more of the celestial objects than previously thought.