NASA’s hunt for alien life has so far focused on detecting exoplanets and basic microbial life in places like Mars and the moons of Saturn.
But the space agency has now chosen to shift some of its focus towards detecting so-called technosignatures – signs of advanced alien activity in space.
These alien technosignatures could be the key to solving the age-old question of “are we alone in the universe?”.
NASA said: “The explosion of knowledge of planets orbiting other stars, called exoplanets, and the results of decades of research on signatures of life – what scientists call biosignatures – have encouraged NASA to address, in a scientifically rigorous way, whether humanity is alone.
“Beyond searching for evidence of just microbial life, NASA now is exploring ways to search for life advanced enough to create technology.
“Technosignatures are signs or signals, which if observed, would allow us to infer the existence of technological life elsewhere in the universe.
“The best known technosignatures are radio signals, but there are many others that have not been explored fully.”
NASA’s definition of technosignatures has now expanded to include a much wider scope of potential alien life markers.
The USA-based space agency will scan distant solar systems and planets for signs of giant structures on their surface or atmospheric pollutants poisoning their skies.
These could all be evidence of intelligent life and activity on alien worlds too far for human probes and spacecraft to reach and study.
And NASA is convinced alien life does exist somewhere in the universe – and it is only a matter of time before it is discovered.
The space agency said: “As NASA’s 2015 astrobiology strategy states: ‘Complex life may evolve into cognitive systems that can employ technology in ways that may be observable.
“Nobody knows the probability, but we know that it is not zero.
“As we consider the environments of other planets, ‘technosignatures’ could be included in the possible interpretations of data we get from other worlds.”
In 1961, astronomer Frank Drake created a formula estimating the number of potentially intelligent alien civilisations spread throughout the galaxy.
The rough estimate, dubbed the Drake equation, suggested 10,000 alien civilisations could be somewhere out there.
But another theory, known as the Fermi Paradox, stipulates if intelligent life does exist in the cosmos, we would have come across it by now.
NASA said: “NASA will continue assessing promising current efforts of research in technosignatures and investigating where investments could be made to advance the science.
“Although we have yet to find signs of extraterrestrial life, NASA is amplifying exploring the solar system and beyond to help humanity answer whether we are alone in the universe.
“From studying water on Mars, probing promising ‘oceans worlds’ such as Europa or Saturn’s moon Enceladus, to looking for biosignatures in the atmospheres of exoplanets, NASA’s science missions are working together with a goal to find unmistakable signs of life beyond Earth.
“And perhaps that life could indeed be more technologically advanced than our own.”