The quest for alien life has been traditionally relegated to the discovery of electromagnetic radiation from alien civilisations. But a new study suggested that industrial pollution from alien factories may now help search for alien life.
According to a study conducted by a team of astronomers from Harvard, the scientists identified pollutants in the Earth's atmosphere which have significant absorption features. In this case, the study focused on chloroflourocarbons (CFCs) which are almost artificially made gases found in air conditioners and refrigerators.
These chemicals destroy the Earth's ozone layer and could be perceived on planets with atmospheric levels that are 10 times thicker compared with the Earth's atmosphere. To detect the chemicals, the astronomers will be using the powerful James Webb Space Telescope which is scheduled for launch in 2018.
In a press release from Harvard-Smithsonian Center for Astrophysics, the lead author of the study Henry Lin stated that they consider industrial air 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," Lin said.
Harvard co-author Avi Loeb added that the people often referred to ETs as "little green men" but those ETs that can be detected using the powerful telescope are environmentally unfriendly and could not be called as "green."
The study's theory has just one caveat though. It will be feasible as long as the chemicals exist on a planet which is adjacent to the remnants of a star which resembles a sun (white dwarf) because the ability to perceive these industrial pollutants could be interfered with the burning light from the sun. This is particularly applicable if the light distortion is bigger than the planet's atmosphere so the powerful telescope would entirely dodge the planet and losing the CFC signatures in the process.
The astronomers also understand that while the quest for industrial air pollution may help search for alien life, it could also unearth the remains of an alien civilisation that defeated itself. Some CFCs last only as long as 10 years in the Earth's atmosphere but there are some pollutants which could last for as long as 50,000 years.
If this case will hold true, the astronomers speculated that the aliens have become wiser and have learned to clean up their act in the process. The astronomers also stated that the scenario could also serve as a cautionary sign of the perils in not being good stewards of the planet Earth where we live.