Australian scientists have helped detect a second set of ripples in space and time, building on a century-old theory by Albert Einstein.
The gravitational waves - created when two black holes collided about 1.4 billion years ago - were detected in December, scientists announced in San Diego on Thursday.
A team of more than 1000 researchers worldwide detected the phenomenon for the first time in September.
These space-time warps were predicted in Einstein's general theory of relativity.
"There's an explosion somewhere in the universe. You imagine dropping a rock in a pond," University of Adelaide head of physics Peter Veitch told AAP.
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"The ripples are the gravitational waves. There are very likely to be more of these coming towards us.
"They might have already been seen by a civilisation that happened to be closer to the source of the explosion."
Gravitational waves are important because they allow scientists to read the universe in a new way.
"A normal (traditional) signal looks at things that are hot like gamma rays whereas gravitational waves looks at it in a completely different way ... with a signal you otherwise can't see," Prof Veitch said.
"It's about us understanding our place in the universe, how it evolved, what we find ourselves in now and what might be out there."
