How to Find Aliens? Look for Pollution on Other Planets

By Brett Israel
Oct 19, 2009 9:25 PMNov 20, 2019 2:57 AM


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Scientists have proposed what seems like an obvious solution to finding life on other planets—look for pollution similar to that found on Earth. Light or air pollution would be a dead giveaway to life on another planet, according to a study to appear in the journal Astrobiology. Of course, this is assuming that extraterrestrial life is even remotely similar to ours, and even if it is, finding the pollution won't be easy, according to

New Scientist


Even if all the electricity we generate was used to produce light, it would still be thousands of times fainter than the glint of sunlight reflected from Earth's surface. To reliably detect even this massive amount of artificial light on a planet orbiting a relatively nearby star—say 15 light years away—would require an array of telescopes with a combined light-collecting area of 1.5 square kilometres....

That's about 370 football fields' worth of telescopes. Chlorofluorocarbons (CFCs) are another source of pollution that would be a tell-tale sign of alien life, according to the study. CFCs do not form naturally and absorb infrared light, so they could be observed from afar. But by looking for CFCs we'd have to assume aliens are dumb enough to spew the pollution into their atmosphere—in other words, that they're as dumb as we are. Related Content: Discoblog: Japan’s First Lady Claims She Went to Venus, Consorted With Aliens Discoblog: A Giant Leap for Cheddarkind: Brits Launch Cheese Into Space Discoblog: Dear Aliens: Would You Like Some Processed Chips?

Image: flickr / LabyrinthX

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