Is ET trying to phone or fly home? Scientists tend to think not, but they are hoping to find out more about extremely powerful and bright radio signals in outer space.

Key points: Search for aliens detects extremely powerful and bright radio signal

Search for aliens detects extremely powerful and bright radio signal Astronomical community abuzz after discovering more mysterious blips

Astronomical community abuzz after discovering more mysterious blips Scientists say extra terrestrial life theory must be considered as "a last resort"

The Breakthrough Listen project discovered what is called a Fast Radio Burst while scanning the skies from Australia as part of the biggest search for extra terrestrial life in the Milky Way and nearby stars.

Breakthrough Listen scientist Danny Price said it was exciting when the burst from billions of light years away was picked up, but it was unlikely aliens were behind it.

"There are lots of theories out there, there are some theories that they are from extra terrestrial propulsion systems; these theories you have to go to as a last resort," Dr Price said.

He said astrophysical events had to be ruled out first.

It is not the first burst to be detected, with the CSIRO Parkes Radio Telescope picking up the first one in 2001.

The bursts last for about a millisecond, and sound like an ambulance driving past when picked up by special receivers.

Scientists say it is unlikely aliens are behind the rare signals. (Breakthrough Listen team)

Some believe the powerful burst could be a cataclysmic event, similar to a blackhole or star exploding.

While it is not as Earth-shattering as finding signs of an intelligent alien civilisation, it has still created a buzz in the astronomical community.

"We're in on the very ground floor where a new field of radio astronomy research is opening up for us for the first time and are able to perhaps identify something new, something that we haven't observed before and that is really exciting," CSIRO scientist John Sarkissian said.



While about two dozen of the signals have been picked up in almost as many years at the Dish, there is optimism Australia will continue to help lead the way in astronomical discoveries.

"What would have taken 10 million years, now only takes one year for us to survey so it is really fantastic how quickly technology has progressed," Mr Price said.

As for finding other intelligent civilisations, we will have to wait.

"The search will never really end until we find something because we keep on getting so much better," Mr Price said.

Many will be hoping scientists heed the late Stephen Hawking's advice when the search does end — do not return ET's phone call, just listen to the message.

