March 22, 2008 Gamma-Ray Bursts are the most powerful explosive events in the Universe. They thankfully occur in far-off galaxies and hence are usually faint, but on the morning of March 19, 2008 the Swift satellite found a burst which was so bright it could be seen without binoculars or a telescope even though it was seven thousand times further away than the Andromeda galaxy. Put simply, it could be seen with the naked eye from a distance of over twenty billion light years from Earth. It turned out to be a great day for GRB hunters. The Swift satellite typically finds only two GRBs a week, but for the first time found five bursts within 24 hours. The second burst of the day was the new record holder. The enormous energy released in the explosion – brighter than the light from all of the stars in five million Milky Way Galaxies – was caused by the death of a massive star which collapsed to form a black hole.
Read the full article: The largest explosion ever seen