Gamma ray bursts are one of the current mysteries that are still to be explained.

If we could see gamma ray wavelengths, we would see the sky glow - and much of this is from known sources like pulsars, quasars and so on. However, from time to time we have directly observed sudden pulses of gamma rays for a few seconds at a time.

These pulses pour out massive energy. The mystery is with regard the source of these gamma rays.