The search for extraterrestrial technology began in 1959, when astronomers Giuseppe Cocconi and Philip Morrison demonstrated that radio transmissions from Earth could be detected by radio telescopes at interstellar distances.
That same year, Frank Drake launched the first SETI (Search for Extra-Terrestrial Intelligence) quest, Project Ozma, pointing a large radio telescope at two nearby Sun-like stars to see if he could see them. Can detect any incoming radio signal.
However, these early rudimentary attempts at detecting radio or laser signals from other civilizations looked for concentrated and powerful signals that were intentionally sent out into the Solar System and intended to be detected, so they were not very effective.
Although the potential detection of extraterrestrial radio frequencies is a very important part of the search for extraterrestrial intelligence, astronomers are now looking for other types of signals as well.
One of them could be mega-structures created by an extraterrestrial intelligence, such as a Dyson sphere. A hypothetical giant sphere (formulated by astronomer Freeman Dyson) along which a technologically advanced civilization could collect a significant portion of the light from a nearby star as energy.
Another technical issue that astronomers have to think about is pollution. Chemical pollutants, such as nitrogen dioxide and chlorofluorocarbons on Earth, are produced almost exclusively by human industry. So if astronomers find a planet with an atmosphere full of chemicals that can only be produced by technology, it could be a sign of life.
Artificial light or heat from cities and industries can also be detected with large optical and infrared telescopes, just like with a large number of satellites in orbit around a planet.
Scientists at Pennsylvania State University (Penn State) in the United States are working to characterize and detect signs of technology beyond Earth, also known as technosignatures.
To learn more about this method of searching for intelligent life, Metro spoke to astrophysicist Macy Huston.
“Astronomers Have Been Looking for Technosignatures for Decades, But Many Remain to Be Found”
, Macy Huston, doctoral candidate in astronomy and astrophysics at Penn State.
Huston explained to Metro that there are many different ways to find signs of alien technology.
These are some of the most popular:
Search for artificial radio transmissions from space
-Detect artificial laser lights from space
-Look for residual heat or infrared radiation from large scale technology like the Dyson Sphere.
-Discover artificial probes sent to the solar system
Study of the atmospheres of outer planets to search for industrial pollutants
PhD Candidate in Astronomy and Astrophysics at Penn State
Q: Why did you start looking for signs of alien technology?
Man has been wondering for centuries whether there is life outside the earth. The search for signs of extraterrestrial technology, which began around 1960, was partly inspired by the discovery that our human radio transmitters of the time might be detectable at interstellar distances.
Q: What are technical signatures?
Jill Tarter coined the term “technosignature” in 2007, defining it as “evidence of some technology that modifies its environment in detectable ways.”
Q: What are examples of technical signatures?
Some examples of technosignatures are narrowband radio signals, lasers, waste heat, physical probes, and air pollutants. On Earth, some technosignatures produced by humans are intentional METI radio messages, unintentional radio leaks from TV and cell phone towers, lasers from telescopes’ adaptive optics systems, atmospheric pollutants such as nitrogen dioxide and chlorofluorocarbons, and city lights.
Question: Why is it so difficult to find signs of distant and advanced civilizations?
Space is incredibly large. Astronomers have been searching for technosignatures for decades, but there is much more to be discovered. Technosignature detection usually decreases with distance, so, for example, there may be many radio leaking societies like ours that are just too far away for us to detect. Plus, it’s a lot harder to find something when you’re not sure what you’re looking for. It would be unwise to assume that all life in the universe would be like us, but it’s also really hard to know how to find life because we don’t know about it.