Astronomers have achieved a major breakthrough by detecting a hidden magnetic signal from one of the most powerful explosions in the universe. Gamma-ray bursts are the brightest and most energetic explosions known in the universe. Although astronomers have studied gamma-ray bursts for decades, measuring the magnetic fields around them has been extremely difficult. The amount of twisting reveals valuable information about the strength and structure of the magnetic fields along its path. The measurements showed magnetic fields that were thousands of times stronger than could be explained by our own Milky Way or the space between galaxies.