Scientists have found evidence of a "catastrophic event" in the distant past that they believe was responsible for halting the birth of stars in the early universe. Physicists at Durham University have observed a galaxy as it would have appeared 3 billion years after the Big Bang, when the Universe was a quarter of its present age. According to their findings, the galaxy exploded in a series of blasts trillions of times more powerful than an atomic bomb. The blasts happened every second for millions of years. The explosions scattered the gas needed to form new stars by helping it escape the gravitational pull of the galaxy, with this loss limiting the system's expansion.