Scientists looking for signs of extraterrestrial life usually have their sights set on the sky, asking if anyone is there …
And it seems that a possible answer has come.
These are radio broadcasts at 982 mega Hertz recorded from the Parkes telescope, in Australia, and whose frequency seems to come, consistently, from the direction of Proxima Centauri, a star 4.2 light years from the Sun.
Experts believe it could be a technology firm, also known as a techno-firm, or technosignature, in English.
For decades, biosignatures have been searched in space – molecules or biochemical elements such as methane and oxygen that suggest that there is life – but until recently they were not looking for techno-signatures, elements or traces that would indicate that there is not only life but there is technology.
The signal “has specific properties that make it comply with several of our filters [de posible inteligencia extraterrestre] and we still can’t explain it“Andrew Siemion, astronomer and principal investigator for Breakthrough Listen, told Scientific American.
Breakthrough Listen was established in 2015 with the encouragement of astrophysicist Stephen Hawking and with funding from billionaire Yuri Milner.
It is the most formal private project of the search for extraterrestrial intelligence (known as SETI by the English search for extraterrestrial intelligence), and is dedicated to renting for a time the use of radio telescopes around the world to see if it is possible to detect something.
The signal has been dubbed BLC-1, acronym in English for Breakthrough Listen Candidate-1, the first candidate for possible techno-signature registered by the project.
The broadcasts were recorded between April and May 2019 during a period of 26 hours of use of the Parkes telescope.
But it was until October 2020 that the people of Breakthrough Listen found among all the information collected the 982 MHz frequency, which is practically never used for human transmissions.
BLC-1 was recorded for periods of half an hour each over five days and only when the telescope was directed towards Proxima.
It was only in December 2020 that it became known that this signal existed, as scientists are finishing their articles for publication in official magazines.
A very ‘forthcoming’ sign
Nature tends to emit different signals at various frequencies, for reasons including the trails of a collapsed star or geomagnetic storms (also called solar storms), like one that hit Earth in 1859.
On other occasions it has also turned out that signals that have been investigated by those looking for extraterrestrial life were caused by earthly issues such as interference by the passage of a satellite. Signals that confused scientists for decades, signals also recorded by the Parkes telescope, turned out to be caused by a microwave oven.
But until now there is no evidence that this emission of radio waves has an earthly or natural origin.
Proxima Centauri is the outer star of our solar system closest to it.
Proxima is surrounded by at least two planets, one gaseous and one terrestrial. The second is called Proxima b, discovered in 2016, and is 17% larger than Earth.
It is in what scientists call the “habitable zone”: when the distance between a planet and its star is such that temperatures let there be water on the surface.
Although it is possible that there are bodies of water in Proxima b does not mean that there are, especially since NASA discovered in 2017 that the star that serves as its sun emits very intense radiation that could destroy, or has already destroyed, the atmosphere planetary.
In addition, Proxima b’s orbit is very short, 11 days, such that one side of the planet is always light and the other is in perpetual darkness, which makes it difficult to have a stable enough climate.
“We have been searching for alien life for so long now, and the idea that it could be almost on our doorstep, in the nearest solar system, is a sum of an improbability added to something improbable”Lewis Dartnell, an astrobiologist at the University of Westminster, told The Guardian.
Siemion himself, from Breakthrough Listen, recognized that the signal could well have an anthropogenic origin (created by humans).
“All SETI experiments are done in the midst of an interference tide, with thousands of signals,” Siemion told National Geographic. “The point is to be able to differentiate between our technology and a distant techno-firm,” he added.
That is why he stressed that the fact that they have not yet been able to establish the possible origin of BLC-1 arouses so much interest.
Siemion noted: “The reason why SETI excites us so much, and why we have dedicated our careers to that search, is the same reason that people of all stripes are excited: aliens, how cool!”
Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.