This produced one of the most consistent sets of negative results in the history of science. For more than 60 years, researchers have tried to find a single piece of convincing evidence to support the idea that we share the universe with other intelligent beings. Despite these decades of efforts, they have failed to make contact of any kind.
But the search for alien civilizations may be entering a new era, researchers say. Scientists with Breakthrough Listen, the world’s largest scientific research program aimed at finding alien civilizations, say a host of technological developments are poised to transform the search for intelligent life in the cosmos.
These innovations will be detailed at the group’s annual conference, which is being held for the first time in the UK this week in Oxford. Several hundred scientists, from astronomers to zoologists, are expected to attend.
Astronomer Steve Croft, a project scientist with Breakthrough Listen, said: “There are incredible technologies under development, such as the construction of large new telescopes in Chile, Africa and Australia, as well as developments in AI. They are going to change how we look for alien civilizations.”
Among these new instruments are the Square Kilometer Arraywhich consists of hundreds of radio telescopes now being built in South Africa and Australia, and the Vera Rubin Observatory which is being built in Chile. The former will become the world’s most powerful radio astronomy facility while the latter, the world’s largest camera, will be able to image the entire visible sky every three or four nights, and is expected to help discover millions of new galaxies and stars.
Both facilities will begin observations in the next few years and both will provide data for Breakthrough Listening. Using AI to analyze these vast streams of information for subtle patterns that would reveal evidence of intelligent life will give added power to the search for alien civilizations, Croft added.
“Until now, we have been limited to looking for signals deliberately sent out by aliens to advertise their existence. The new techniques are going to be so sensitive that for the first time we will be able to detect inadvertent transmissions as opposed to intentional transmissions and will be able to detect alien airport radar, or powerful TV transmitters – things like it.”
The importance of detecting civilizations from the signatures of their everyday activities is supported by astrophysicist Prof Adam Frank of the University of Rochester in New York. “By looking for signatures of an alien society’s daily activities—a techno-signature—we are building entirely new toolkits for finding intelligent, civilization-building life,” he writes in his new book, The little book of strangers.
All sorts of techno-signs have been suggested as indicators of the presence of alien civilizations, from artificial lighting to atmospheric pollution. Some scientists have even suggested that alien civilizations can be spotted from the solar panels they have built. Solar panels absorb visible light, but strongly reflect ultraviolet and infrared radiation, which could be detected with a powerful telescope.
However, it would only be possible to spot if large parts of a planet’s surface were covered in solar fields and hundreds of hours of observation time were dedicated to such a search, says astrobiologist Lewis Dartnell. write in the latest edition of the BBC Sky at night magazine.
to newsletter promotion
However, other alien efforts to capture solar radiation may be even more elaborate and conspicuous. The American physicist Freeman Dyson once suggested that some civilizations might be advanced enough to build large arrays of solar panels surrounding their home stars. These large orbiting structures – known as Dyson spheres – would be detectable from Earth, and several candidates have been proposed, including Boyajian’s star, in the constellation Cygnus, whose output of light is sporadic and unpredictable. Some have suggested that it could be caused by a Dyson sphere, although recent observations have ruled out the possibility.
The search for alien civilizations has been a cornerstone of cinematic science spectacles of E.T on Contact, Arrival and District 9. However, extraterrestrial life forms have remained the stuff of fiction, despite efforts that began in earnest in 1960 when astronomer Frank Drake used a 26-meter radio telescope to search for possible signals from the stars Tau Ceti and Epsilon Eridani. None were detected – a state of affairs that has persisted despite vast increases in the power and sophistication of modern telescopes.
Whether this stream of negative results continues remains to be seen. Croft remains optimistic that we will soon manage to make contact. “We know that the conditions for life are everywhere, we know that the ingredients for life are everywhere.
“I think it would be very strange if it turns out that we are the only inhabited planet in the galaxy or in the universe. But you know, it’s possible.”
