Here is a bit more on this mysterious phenomenon:

Now, for the first time, the mysterious phenomenon has been observed happening live.
Exactly what may be causing the signal is hotly debated by scientists. Possibilities range from evaporating black holes to alien communication and merging neutron stars

“These events are one of the biggest mysteries in the universe,” said Carnegie Observatories’ acting director John Mulchaey.
“Until now, astronomers were not able to catch one of these events in the act.

One of the comments on the video is very clever and E C poses this question this:

Aliens civilisations probably exist, but they’re likely to be quiet. Why would an intelligent civilisations broadcast themselves across the universe? It seems reckless. They likely evolved on a planet where intergalactic communication was completely unnecessary for survival. However, like us, they may have produced faint radio signals which were never intended for communication with foreign civilisations. I like to imagine future ‘humans’ as altruistic beings, cautiously helping conscious creatures in their galactic neighbourhood. (like a cosmic ‘Doctors without borders’). However, empathy may not be common among advanced civilisations: beware.

What do you think?  Feel free to comment on your thoughts and theories!

thanks to the telegraph for the great info