A stronomers just detected what may be the most powerful flash of light ever seen. The gammaray burst, the most energetic type of electromagnetic explosion known to exist in the universe, was first spotted by telescopes on 9 October. Gamma-ray bursts, which were discovered accidentally by US military satellites in the 1960s, are likely produced when giant stars explode at the ends of their lives before collapsing into black holes, or when ultradense stellar remnants known as neutron stars
