Riddle of the radio waves in outer space
Unexplained signal seems to come from nearby star
A MYSTERIOUS radio signal from a nearby star has excited a team of alien-hunting astronomers.
Researchers believe the waves are coming from the area around Proxima Centauri, the closest star to Earth except the sun.
A narrow beam was spotted by the Parkes radio telescope in Australia in spring this year and, unlike previous radio bursts, it has not been attributed to any natural or human-created source, such as a passing satellite.
The team, from the Breakthrough Listen Project – a £70million initiative to find alien life through radio telescopes – said it is one of the most exciting discoveries in decades.
It has been compared to the ‘WOW! signal’ of 1977 – a short narrowband radio signal picked up by the Big Ear Radio Observatory, in Ohio. That gained its name after astronomer Jerry Ehman wrote ‘Wow!’ next to the data.
‘[This] is the first serious candidate since the “Wow! signal”,’ an astronomer told The Guardian.
The new beam appears to originate from close to Proxima Centauri, which sits 4.2 light years from Earth with two confirmed planets, a Jupiter-like gas giant and a rocky world, Proxima b.
Proxima b is an Earth-like world that orbits within the ‘habitable zone’ of Proxima Centauri, an area where liquid water could flow on the surface of the planet, scientists believe.
However, as Proxima Centauri is a red dwarf, the smallest and coolest kind of star, the habitable zone is very close to the star. This means it is probably tidally locked like the moon, with half of the planet in constant daylight, and the other in everlasting darkness. The planet is also therefore likely exposed to intense radiation so any civilisation is unlikely, at least on the surface.
Lewis Dartnell, an astrobiologist from the University of Westminster, said: ‘It’s hard to imagine how you can have a stable climatic system and all the things you need to get from bacteria, which are hardy, up to intelligent animal life forms, which certainly are not. But I’d love to be proved wrong.’
The radio signal was detected in the 980MHz range, and shifts in the frequency detected by the Parkes telescope are consistent with the movement of a planet. This suggests it could be evidence of a third planet within the system, experts say, rather than ‘very unlikely’ signs of an alien civilisation.
David Rothery, professor of planetary geosciences at the Open University, said it was very unlikely ‘that there is someone on the planet with a radio beacon sending an alien signal’. He added: ‘ It would be a very freakish coincidence if aliens on the nearest exoplanet to us just happened to have developed radio technology at around the same time, given we got it only about 120 years ago.’
‘A freakish coincidence’