'Alien' Radio Signal 5.5 Billion Light Years From Earth Caught In Real Time In Australia

For the first time, an Australian scientist has seen live a radio signal from space beyond our Milky Way galaxy, which could be 5.5 billion light years away.

PhD student Emily Petroff of the Swinburne University of Technology saw the fast radio burst, flash of radio waves from an unknown source, using the 64-meter Parkes radio telescope of the Commonwealth Scientific and Industrial Research Organisation in eastern Australia.

The first such radio burst, lasting only milliseconds, was discovered back in 2007 by astronomers looking through old Parkes data archive.

The Australian scientific body said six more radio bursts outside the galaxy were detected using the telescope and a seventh by an Aracebi telescope in Puerto Rico.

"These bursts were generally discovered week, months or even more than a decade after they happened. We are the first to catch one in real time," said Petroff.

Petroff had an international team of astronomers to make follow-up observations.

When the burst went off, the team swung into action on 12 telescopes in Australia, California, Canary Islands, Chile, Germany, Hawaii and India, and the Swift Gamma Ray Burst Explorer in space.

"We can rule out some ideas because no counterparts were seen in the optical, infrared, ultraviolet or X-ray," said Dr. Simon Johnston, assistant director of Astrophysics of the Commonwealth Scientific and Industrial Research Organisation.

"However, the neat idea that we are seeing a neutron star imploding into a black hole remains a possibility," he said.

The distance of the fast radio bursts are still unknown but it is estimated that it could be up to 5.5 billion light years away.

"This means it could have given off as much energy in a few milliseconds as the Sun does in a day," said Petroff, adding that the origin of the fast radio bursts could be identified.

"We've set the trap. Now we just have to wait for another burst to fall into it."

The findings have been published in the monthly notices of the Royal Astronomical Society.