by Nola Taylor Redd, SPACE.com Contributor
Powerful and puzzling radio blasts in other galaxies constantly explode across the night sky, a new study suggests.
A team of international astronomers has detected four explosive events, known as fast radio bursts (FRBs), above the plane of our Milky Way Galaxy. Lasting only a few thousandths of a second, these sources send powerful signals across the universe, traveling billions of light-years through space.
"These bursts gave off more energy in a millisecond than the sun does in 300,000 years," said principal investigator Dan Thornton of the University of Manchester in England. [Slideshow: History & Structure of the Universe Explained]
Studying observations by the CSIRO Parkes radio telescope in Australia, Thornton and his team spotted four new point sources across the sky. The bursts ranged from 5.5 to 10 billion light-years away, meaning it took the light from some of them 10 billion years to reach Earth. (The Big Bang that created our universe occurred 13.8 billion years ago.).
These newfound objects allowed the researchers to calculate that an FRB should occur once every 10 seconds.
After the astronomers verified that the objects weren't Earth-based, they questioned whether the new signals came from inside or outside the Milky Way. To do so, they studied how the radio waves were affected by the material they pass through — a technique that could allow these new objects to shed light on the components of space.
As radio waves travel in space, they are stretched and slowed by the ionized material through which they move. Using models, the team concluded that the FRBs traveled billions of light-years — much farther than the edge of Earth's galaxy.
"These are extragalactic in origin — not from the Milky Way — but the source is likely located in another galaxy," Thornton said. ...more