This story is over 5 years old.

To Find Aliens, We Should Look for Industrial, Polluted Wastelands

"We consider industrial pollution as a sign of intelligent life."
July 23, 2014, 5:30pm
Artist's impression of an exoplanet. Image: Luciano Mendez.

The subject of extraterrestrial life tends to bring out both our inner utopianists and dystopianists. In fiction, aliens are usually depicted as either extremely cute and benevolent (E.T.-style) or ruthless planet pillagers (Kaiju-style).

Still, both extremes have one thing in common: The alien characters show basic competence when it comes to ensuring the survival of their race. They may lose their kids on other planets as with E.T., and they may underestimate that priceless Smith/Goldblum chemistry, but they aren't as fundamentally self-destructive as our own species.


But as it turns out, aliens saddled with comparable foibles to humanity might be the easiest for us to find. At least, that's what researchers based out of the Harvard-Smithsonian Center for Astrophysics speculate in a study announced today. The team suggests for signs of specific industrial pollutants in the atmospheres of exoplanets could help streamline the search for alien life.

"We consider industrial pollution as a sign of intelligent life, but perhaps civilizations more advanced than us, with their own SETI programs, will consider pollution as a sign of unintelligent life since it's not smart to contaminate your own air," said lead author Henry Lin in Harvard's statement.

Admittedly, this concept of screening exoplanets for signs of industrial waste is not entirely new. Astronomers have searched for telltale megastructures like Dyson spheres in the spectrums of distant stars, while others have suggested looking for artificial debris used for mining.

What sets the Harvard team's approach apart, however, is its focus on using the James Webb Space Telescope (JWST) to specifically detect chlorofluorocarbons (CFCs) in exoplanet atmospheres.

The JWST is currently scheduled for launch in 2018, and it will have the ability able to root out CFCs—but only in very specific conditions. As in: only on Earth-sized planets with at least 10 times the atmospheric pressure of Earth that also orbit white dwarf stars.

That narrow set of parameters will allow the chemical signal of CFCs to be maximized to levels that the JWST can pick out. Looking for CFCs on exoplanets orbiting Sun-like stars will require a much more advanced telescope, so for now we're stuck with whatever weird civilizations are polluting up a storm on their pressurized exoplanets orbiting white dwarfs.

Of course, it's natural to raise the question of what we would even do if we found such a civilization. Some might be skeptical about reaching out to another unhinged society with self-destructive tendencies. But then again, there's that theory that, to quote Bill Watterson's Calvin, "the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us." It might be nice to have a pal in the same boat.