Alien hunters have finally resolved the mystery of what they called ‘the weird signal from Parkes’ which had researchers worldwide excited about finding life on another planet.

A Search for Extra-Terrestrial Intelligence (SETI) team at the University of California Berkeley pitched in to run tests on a signal detected by Australia’s Parkes radio telescope while it was looking at the Proxima Centauri system in 2019.

Proxima Centauri is the closest star to our solar system and has an Earth-like planet, Proxima b, in a so-called habitable zone.

It is 4.22 light years away which would take around 73,000 years to reach using our current spacecraft technologies.

Many international researchers hoped the signal, which had all the signs they hoped for, was a ‘technosignature’, a marker which could signal the presence of life.

After weeks of tests the Berkeley team decided it was probably a type of distortion called ‘intermodulation’.

In the case of the Parkes’ signal, it was radio interference caused by the interaction of two frequencies used by devices on Earth.

Berkeley researcher Sofia Sheikh said her team called it ‘the weird signal from Parkes’ before it attracted the attention of the Breakthrough Listen program.

It was given the name Breakthrough Listen Candidate-1 (BLC-1) – signifying its importance.

There was a lot of international excitement about BLC-1, but unfortunately the hype did not lead to the discovery of aliens.

‘[It was] two different Earth-bound transmitters mixing with each other. Definitely not aliens,’ Ms Sheikh said.

Curtin University researcher Danny Price, part of the Parkes program, likened the sound to ‘a guitar amp being deliberately overdriven’.

The finding wasn’t all bad news.

Mr Price said the sensitivity of equipment used and the cooperative research effort shows the search for extra-terrestrial life using radio waves is functioning as it should.

‘Regardless of what caused BLC-1, it was not the technosignature we were looking for. It did, however, make for an excellent case study, and showed that our detection pipelines are working and picking up unusual signals,’ said Mr Price.

A research paper published in the journal of Nature Astronomy called BLC-1 ‘compelling’.

‘It’s disappointing to have our hopes of finding other intelligent life out there dashed yet again,’ Flinders University space archaeologist and Space Industry Association advisory council member Dr Alice Gorman told news.com.au.

‘Because the team approached the analysis with such rigour, we know that if there is a future signal which suggests a technosignature, we can rely on the evidence. Now we know a little bit more about what not to look for.’