If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?: Seventy-Five Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life

by Stephen Webb

Another intriguing candidate is GCRT J1745-3009, a radio source that emitted five bursts of low frequency radiation in October 2002. Each burst was equally bright, lasted about ten minutes, and occurred every 77 minutes. A similar burst was observed a year later. Six months after that, astronomers observed a weaker burst. There has been nothing since.

Wow