The biggest cosmic explosion EVER seen: 'Monster' gamma ray burst blasts into space 3.7 billion light years away The cosmic explosion happened 3.7 billion light years away in April 2013 It created energy bursts five times stronger than the largest known blast Gamma ray bursts happen when stars die and collapse into black holes Astronomers believe the only bigger display would have been the Big Bang If the burst had happened closer to Earth it could've destroyed the planet The largest and brightest cosmic explosion ever witnessed has been captured 3.7 billion light years away. Astronomers have called the gamma ray burst 'the monster' because it created five times more energy than the largest previously-known blast and if it had been closer to Earth, our planet could have been destroyed. Orbiting telescopes spotted the blast in April and it is believed that the only bigger display astronomers know of is the Big Bang. The cosmic explosion happened 3.7 billion light years away in April 2013. Nasa said the blast created energy bursts five times stronger than the largest known blast and the only larger display astronomers known of was the Big Bang A gamma ray burst happens when a massive star dies, collapses into a brand-new black hole, explodes in what's called a supernova and ejects energetic radiation. The radiation is as bright as can be as it travels across the universe at the speed of light. A planet caught in one of these bursts would lose its atmosphere instantly and would be left a burnt cinder, astronomers say. Scientists might be able to detect warning signs of an impending gamma ray burst but if a burst were headed for Earth there wouldn't be anything anybody could do about it. However, astronomers put the chances of that happening at around 1 in 10 million. 'This burst was a once-in-a-century cosmic event,' said Nasa astrophysics chief Paul Hertz. Nasa telescopes have been seeing bursts of various sizes for more than two decades, spotting one every couple of days. However, this one, witnessed on 27 April this year, set records, according to four studies published in the journal Science. Researchers say it took the light from this event 3.7 billion years to reach us. The burst is said to have flooded Nasa monitoring instruments with five times the energy of its nearest competitor, a 1999 blast, said University of Alabama at Huntsville astrophysicist Rob Preece, author of one of the studies. It started with a star that had 20 to 30 times the mass of our sun but was only a couple of times wider, meaning it was incredibly dense. Researchers claimed it exploded in a certain violent way. In general, gamma ray bursts are 'the most titanic explosions in the universe,' and this one was so big that some of the telescope instruments hit their peak, continued Preece. I call it the monster. One of the main reasons the April burst was so bright was that relative to the thousands of other gamma ray bursts astronomers have seen, it was pretty close by cosmic standards. The burst is said to have flooded Nasa monitoring instruments with five times the energy of its nearest competitor, a blast from 1999. It started with a star that had 20 to 30 times the mass of our sun but was only a couple of times wider, meaning it was incredibly dense A light-year is almost 6 trillion miles (almost 10 trillion kilometers) and most of the bursts Nasa telescopes have seen have been twice as distant as this one. This burst was so bright telescopes on Earth saw a brief flash in the constellation Leo. For scientists, this was a wow moment: 'These are really neat explosions,' said Peter Michelson, a Stanford physicist who is the chief scientist for one of the instruments on a Nasa gamma ray burst-spotting telescope. The gamma-ray burst is extremely bright and is the most luminous object in the field, as seen in the image on the left. The right image is a close-up of the gamma-ray burst, taken by the ultraviolet/optical telescope on the Swift satellite 'If you like fireworks, you can't beat these. Other than the Big Bang itself, these are the biggest there are. The burst 'is part of the cycle of birth and life and death in the universe,' Professor Michelson added. You and I are made of the stuff that came from a supernova. Some claim that a mass extinction on Earth 450 million years ago was caused by a gamma ray burst in a nearby part of our galaxy. The Swift satellite has three instruments on board. They work together to get as much information about each gamma-ray burst as possible