The elite of the electromagnetic spectrum, gamma rays are the most potent packets of energy produced by the interplay of atoms and atomic particles. They’re powerful enough to travel billions of light-years across the universe without flagging and to turn DNA into a mutated mess. But while this ferocious source of radiation regularly bathes our solar system, gamma rays are absorbed quite efficiently by Earth’s protective atmosphere. That may be fortunate for those who value the health of their chromosomes, but it’s frustrating for astrophysicists.
Frustrating because gamma rays bring news of the most sensational events in the history of the universe. They fly from star collisions and explosions, matter-antimatter annihilations, the frenzied burning of quasars, and the cataclysmic eating habits of black holes. Until recently, these violent cosmic events have simply teased gamma-ray researchers, who’ve been restricted to lofting short-term probes above the atmosphere on balloons, rockets, or brief orbiting missions.
