What is a Gamma Ray Burst?
A gamma-ray burst (GRB) is a brief flash of gamma rays coming from an astrophysical source at great distances from us, often from hundreds of millions of light years away. Gamma rays are a kind of light (like visible light, microwaves, or X-rays) that is very energetic, and whatever produces gamma rays must therefore contain (and unleash) a large amount of energy in a very short amount of time. Thus the study of gamma ray bursts is a study of some of the most violent events in the universe. GRBs were discovered in the late 1960s and early 1970s by Earth-orbiting satellites designed to keep watch against covert nuclear weapons testing, but it was quickly realized they originate well outside our solar system. Their origins remained mysterious for several decades because they came and went so quickly — often within a few seconds — and because their position couldn’t be pinpointed to better than a few degrees on the sky. For comparison, the full Moon is about 0.5 degrees across, and a te
