The search for extraterrestrial or alien life continues stronger than ever and scientists are widening the search to look beyond biosignatures to see if they can find “technological signatures.” We already know the importance of oxygen for life as we know it, but two astronomers propose that it can also be the key to accessing advanced technology at a planetary scale. The research paper published in the journal Nature Astronomy last month looked into what conditions on a planet can send out signals about the existence of intelligent life that can produce technology. They found that “the atmospheric requirements may be quite stringent,” according to co-author Amedeo Balbi, an associate professor of astronomy and astrophysics at the University of Roma Tor Vergata, Italy. Oxygen: For breathing and burning Apart from its importance in respiration and other life processes, oxygen is also a crucial ingredient in developing fire, the researchers propose. And fire is the hallmark of a civilisation that harnesses technology. Technology was developed on Earth thanks to the process of open-air combustion. This elementary process where something burns with fuel and oxygen is crucial for everything from producing tools to building shelter. How much oxygen is too much? Interestingly, the level of oxygen required to sustain complex biological life and even intelligence are not as high as the levels needed to develop technology, according to the researchers. This should mean that even if life were to emerge on a planet with oxygen, it might not be able to become a technological species. “You might be able to get biology—you might even be able to get intelligent creatures—in a world that doesn’t have oxygen but without a ready source of fire, you’re never going to develop higher technology because higher technology requires fuel and melting,” said coauthor Adam Frank, the Helen F. and Fred H. Gowen Professor of Physics and Astronomy at the University of Rochester, in a press statement. The researchers created the term “oxygen bottleneck” to describe the threshold that separates planets capable of fostering technological civilisation from those that cannot. Essentially, oxygen levels act as a bottleneck that can stop an alien lifeform from developing technology. So what? The study looks at a previously unexplored side of the pursuit of extraterrestrial life — there could be a need to prioritise planets that have high oxygen levels when looking for techno-signatures. This could potentially help fine-tune the search for extraterrestrial intelligence.
