Just over three and a half billion years ago, in the direction of the constellation Leo the Lion, something big happened – something very, very big. That very big something caused a beam of intensely energetic (yet invisible) light to fly our way. It's been traveling toward us all this time, as our Earth evolved and changed, until finally, on April 27, 2013, it reached our planet.
On that date, astronomers operating telescopes in orbit around the Earth recorded the most powerful gamma ray burst they'd seen in decades. Now those same astronomers are anxiously watching the same patch of sky for what they believe must follow, a giant stellar explosion called a supernova. If they can spot it, they will learn much about stars, their moments of death, and the origin of us all.
So what's the big deal about gamma rays?