It has produced one of the most consistent sets of negative results in the history of science. For over 60 years, researchers have been trying to find a single compelling piece of evidence to support the idea that we share the universe with other intelligent beings. Despite these decades of effort, they have not been able to make any contact.
But the hunt for alien civilizations may be entering a new era, researchers believe. Scientists at Breakthrough Listen, the world’s largest scientific research program dedicated to finding extraterrestrial civilizations, say a series of technological advances are poised to transform the search for intelligent life in the cosmos.
These innovations are being outlined at the group’s annual conference, being held in the UK for the first time this week, in Oxford. Hundreds of scientists, from astronomers to zoologists, are expected to attend.
Astronomer Steve Croft, a project scientist at Breakthrough Listen, said: “There are amazing technologies in development, like the construction of huge new telescopes in Chile, Africa and Australia, and developments in AI. They are going to transform the way we search for extraterrestrial civilisations.”
These new instruments include the Square Kilometre Array, consisting of hundreds of radio telescopes now under construction in South Africa and Australia, and the Vera Rubin Observatory under construction in Chile. The former will be 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 coming years, and both will provide data for Breakthrough Listen. Using AI to analyze these vast streams of information for subtle patterns that could reveal evidence of intelligent life will give added power to the search for alien civilizations, Croft added.
“Until now, we’ve been limited to looking for signals deliberately broadcast by aliens to advertise their existence. The new techniques are becoming so sensitive that for the first time we can detect unintentional transmissions rather than intentional ones, and we can spot alien airport radars or powerful TV transmitters — things like that.”
The importance of being able to detect civilizations by the signatures of their daily 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 technosignature – we are building entirely new toolkits to find intelligent, civilization-building life,” he writes in his new book, The Little Book of Aliens.
All sorts of technosignatures have been proposed as indicators of the presence of alien civilizations, from artificial light to air pollution. Some scientists have even suggested that alien civilizations could be detected by the solar panels they have built. Solar panels absorb visible light, but strongly reflect ultraviolet and infrared radiation, which can be detected with a powerful telescope.
However, this would only be possible if large parts of a planet’s surface were covered with solar farms and hundreds of hours of observing time were devoted to such a search, astrobiologist Lewis Dartnell says in the latest edition of the BBC. Sky at night magazine.
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Other extraterrestrial attempts to harvest solar radiation, however, could be even more elaborate and striking. American physicist Freeman Dyson once proposed that some civilizations might be advanced enough to build vast arrays of solar panels that surround their home stars. These large, rotating 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 light output is sporadic and unpredictable. Some have suggested that this could be caused by a Dyson sphere, although recent observations have ruled out that possibility.
The hunt for alien civilizations is a cornerstone of spectacular science fiction films of the 1960s. AND Unpleasant Contact, Arrival And District 9. Extraterrestrial life forms, however, have remained a 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. No signals were detected – a situation 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 succeed in making 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 Milky Way or in the universe. But you know, it is possible.”