What are gamma-ray bursts?
Q: What are gamma-ray bursts?
A: Gamma-ray bursts (GRBs) are flashes of gamma rays from extremely energetic explosions.
Q: How long do GRBs typically last?
A: GRBs can last from milliseconds to several minutes, although a typical burst lasts a few seconds.
Q: What is the source of most GRBs?
A: Most GRBs are a narrow beam of intense radiation released during a supernova, as a huge rapidly spinning star collapses to form a black hole.
Q: Where do most observed GRBs come from?
A: All observed GRBs have come from outside the Milky Way galaxy.
Q: How much energy does an average burst release?
A: A typical burst releases as much energy in a few seconds as the Sun will in its entire 10 billion year lifetime.
Q: How rare are GRB events?
A: They are very rare (a few per galaxy per million years).
Q: Could there be any danger posed by gamma-ray bursts within our own galaxy?
A: It has been suggested that a gamma-ray burst in the Milky Way could cause a mass extinction on Earth, but no such case is known.
