The source of a mysterious signal coming from deep within the Universe has finally been discovered. 

Fast Radio Bursts, or FRBs, have been an enigma for scientists since they were first discovered in 2007. They are very short but powerful radio waves that only last for a millisecond. They have only been heard 18 times and until now, nobody knew where they were coming from or how they might be triggered. 

They were first heard by Australia's Parkes telescope in 2007 and have been heard 17 times since then but only once has the signal been heard repeatedly. That repeated burst has been studied by scientists for six months and they think they've finally discovered its source. 

The team of scientists have revealed that the signal seems to be coming from a faint dwarf galaxy more than three billion lightyears away. 

Dr Shriharsh Tendulkar, a member of the team from McGill University in Montreal, Canada, said: "Before we knew the distance to any FRBs, several proposed explanations for their origins said they could be coming from within or near our own Milky Way galaxy. We now have ruled out those explanations, at least for this FRB."

While the team has narrowed down the source location of the signal, what produced it remains a mystery. One likely candidate is a super-dense neutron star, or "magnetar." Other alternatives are jets of material shooting out of a black hole or, if you listen to the conspiracy theorists - aliens. 

Co-author Dr Shami Chatterjee, from Cornell University in the US, said: "Finding the host galaxy of this FRB, and its distance, is a big step forward, but we still have much more to do before we fully understand what these things are."

Via Independent UK