Astronomers are familiar with seeing amazing things through their telescopes. But nothing prepared them for an incredible explosion detected early Wednesday morning by NASA’s Swift satellite. At 2:12 a.m. EDT, Swift detected an explosion from deep space that was so powerful that its afterglow was briefly visible to the naked eye.

In 2002, when astronomers first detected cosmic gamma rays - the most energetic form of light known - coming from the constellation Cygnus they were surprised and perplexed. The region lacked the extreme electromagnetic fields that they thought were required to produce such energetic rays.