Listening In On Aliens
It's time to get far out — NASA has recently approved funding for its new program CATS, or Categorizing Atmospheric Technosignatures, which may aid in identifying technologically advanced civilizations on alien worlds.
The previous ethos in searching for such civilizations had been to look for deliberate messages sent towards Earth, like a universal mathematical constant (Pi, the Fibonacci sequence) broadcast at hydrogen’s electromagnetic frequency. But now the gears have shifted to look for spillover frequencies — just as our presence on Earth produces massive amounts of electromagnetic signs and disruptions to our atmosphere, other advanced civilizations would produce something similar.
The idea of a spillover frequency is not new. In fact, science fiction authors have been aware of the concept for sometime. There's plenty of novels and movies where broadcasts from Earth accidentally make their way to alien worlds without us knowing it. This would be a reverse of that scenario though; instead of aliens stumbling across our radio waves, we're looking for theirs.
This project will make use of the recently launched James Webb Space Telescope, examining distant exoplanets for telltale signs of alien life. Much of the focus will be on industrial byproducts like chlorofluorocarbons and nitrogen dioxide, both of which would indicate intelligent life and could be identified by the JWST’s sensors. There’s also the technological footprint to consider--just as we have left our mark on the solar system with innumerable rovers, satellites, and space junk, a comparably advanced civilization will have also made its mark across its celestial neighborhood.
Of course, the CATS program is no guarantee of finding extraterrestrial life. There is a lot of noise out there to parse through but it’s still providing a better understanding of both the universe out there, and is a reminder of the effect we’re having on our own planet too.