Spaceweather.com has a report on an event that happened maybe 2.4 billion years ago – and just affected us a few days ago:
Oct. 17, 2022: Astronomers have never seen anything quite like it. On Oct. 9, 2022, Earth-orbiting satellites detected the strongest gamma-ray burst (GRB) in modern history: GRB221009A. How strong was it? It caused electrical currents to flow through the surface of our planet.
Yeow! And then that age thing:
Researchers have since pinpointed the burst. It came from a dusty galaxy 2.4 billion light years away, almost certainly triggered by a supernova explosion giving birth to a black hole. This is actually the closest GRB ever recorded, thus accounting for its extreme intensity.
I see that, by contrast, NASA is estimating 1.9 billion light years. And gamma rays are potentially dangerous, as the Wikipedia page notes. I wonder how much damage we’d sustain if that gamma ray burst had happened within our home galaxy, the Milky Way.
