- Signals recorded by a team working under the Breakthrough Listen project
- It was founded by Stephen Hawking to explore intelligent alien life
- The 10-year programme will survey the 1,000,000 closest stars to Earth
Vishal Gajjar is part of the team working under the Breakthrough Listen project - set up by Hawking, one of the world's best-known scientists, and Russian billionaire Yuri Milner - to discover the truth about the universe.
The latest fast radio bursts (FRBs) prove their equipment is working well and ready to pick up signs of life if they exist.
"We really have no idea about where they come from," Gajjar, one of the scientists from the University of California Berkeley Research Centre, told The Daily Telegraph.
He noted: "If some form of life would like to produce a signal that is detectable to another civilisation this could be a way to do it, but I don't think they are coming from intelligent civilisations.
"There are more theories than the number of sources. We have opened more questions than answers. As we do more study we find more weird things," he said.
Breakthrough Listen is a USD 100-million global astronomical initiative launched in 2015 by Hawking and Miller and has teams around the world using their telescopes to look for evidence of life.
The initial 10-year programme will survey the 1,000,000 closest stars to Earth, scanning the entire galactic plane of the Milky Way.
Announcing the project at the time at a press conference in London, Hawking said it was time to commit to finding the answer to life beyond Earth.
"Somewhere in the universe intelligent life may be watching the lights of ours aware of what they mean," he said.
Explanations for the latest signals detected range from rotating neutron stars with extremely magnetic fields, to energy sources used by extraterrestrial civilisations to power spacecraft.
Whatever they are they left their galaxy when our Solar System was just two billion years old and life was just getting going on Earth.
At first scientists thought the signals were the fallout from a catastrophic event in space, like a supernova, but then they repeated again in 2015 and 2016 suggesting the whatever object produced them was still there.
In the fresh experiment, which will be elaborated upon in scientific journals in future, University of California, Berkeley, experts scanned the same galaxy at a higher frequency than which had been used to see the original bursts, and found 15 more.