What are Gamma-Ray Bursts and how Did we Discover Them?

Gamma-ray bursts (GRBs) are flashes of gamma rays (electromagnetic radiation of high frequency) that come from energetic explosions in distant galaxies. They are known to be the most radiating electromagnetic events in the Universe. The bursts can last from ten milliseconds to several minutes (a typical burst lasts 20-40 seconds). GRBs were discovered in the lats 1960s; however, this was not an intentional discovery. They were discovered by the U.S. Vela satellites that were actually built to detect gamma radiation pulses emitted by nuclear weapons tested in Space. Why? Well, the USA suspected that the USSR might attempt to conduct secret nuclear tests after signing the Nuclear Test Ban Treaty in 1963.

Learn about how they were discovered at:
http://www.fromquarkstoquasars.com/what-are-gamma-ray-bursts-and-how-did-we-discover-them/

Image source:
http://www.nsf.gov/news/news_images.jsp?cntn_id=104440&org=NSF