In the search for extraterrestrial life, we’ve been focusing on basic organisms like microbes—life forms that haven’t even evolved multicellular structures, let alone industrial societies. That means astrobiologists have been focused mostly on identifying biospheres that contain life’s necessities: oxygen, infrared radiation (for photosynthesizing plants), and water.
Buta new study argues that astrobiologists should also be looking for CFCs (chlorofluorocarbons), too, in case intelligent life is actually post-industrial. The authors proved, too, that the James Webb Space Telescope—scheduled to launch in 2018—will be equipped to detect at least two kinds of CFCs, under the right conditions.
Here’s Laura Bliss,writing for CityLab:
The conditions where the new telescope could detect CFCs are specific: It would have to be on an Earthlike planet circling a white dwarf star (which is essentially a dead sun). In that scenario, the starlight would be faint enough to not outshine compounds in the planet’s atmosphere. Finding pollutants on an Earthlike planet orbiting a Sunlike star would call for an even more specialized telescope, possibly one equipped with a gigantic, flower-shaped parasol.
Here’s an image of that (still theoretical) parasol, which puts JPL’s Curiosity parachute to shame. It’s called a “ star shade ,” and it’s designed to block out starlight so that telescopes can image the dim and elusive light coming directly from exoplanets. That way, scientists can discover the atmospheric content of any exoplanet, regardless of whether or not it orbits a white dwarf star.
Discovery of such pollutants on another planet would present a huge turning point in our search for alien life. It might also give an ominous glimpse into our own future, the researchers write: “Detection of high levels of pollutants like CF4 with very long lifetimes without the detection of any shorter-life biosignatures might serve as an additional warning to the ‘intelligent’ life here on Earth about the risks of industrial pollution.”