August 13, 2014

Google Logo Add Us On GoogleAdd SciAm

Air Pollution Could Reveal ET's Home

If intelligent aliens are dumb enough to pollute their atmosphere, NASA’s upcoming James Webb Space Telescope is powerful enough to spot some of the signs on some exoplanets. Clara Moskowitz reports   

 

By Clara Moskowitz

Join Our Community of Science Lovers!

On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.

Searches for extraterrestrial intelligence have focused on various signs of life. And one signature of alien intelligence may be, cough, cough, air pollution.
 
NASA’s James Webb Space Telescope, due to launch in 2018, should be powerful enough to detect chlorofluorocarbons, CFCs. These ozone-destroying chemicals are used in aerosol sprays on Earth. Maybe another planet’s denizens also employ them.  
 
A new analysis of this idea notes that aliens would have to be heavy users. The Webb scope could only detect the chemicals if they were 10 times more prevalent than here on Earth. And even then, the planet would have to orbit a special kind of star, a white dwarf, for the CFCs to show up. White dwarfs—the ultimate destiny of stars like the sun—maximize the pollution signal.
 
The study is in the Astrophysical Journal. [Henry W. Lin, Gonzalo Gonzalez Abad and Abraham Loeb, Detecting industrial pollution in the atmospheres of Earth-like exoplanets]
 
CFCs could hang around in a planet’s atmosphere for a long time. So if an extraterrestrial civilization wised up and stopped polluting, we might still see the effects. Even a society that managed to destroy itself long ago could leave a chemical trace. Let’s hope that’s not how they discover us.
 
—Clara Moskowitz
                                                                                                 
[The above text is a transcript of this podcast.]
 

Rights & Permissions

Clara Moskowitz is chief of reporters at Scientific American, where she covers astronomy, space, physics and mathematics. She has been at Scientific American for more than a decade; previously she worked at Space.com. Moskowitz has reported live from rocket launches, space shuttle liftoffs and landings, suborbital spaceflight training, mountaintop observatories, and more. She has a bachelor’s degree in astronomy and physics from Wesleyan University and a graduate degree in science communication from the University of California, Santa Cruz.

More by Clara Moskowitz

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe
Air Pollution Could Reveal ET's Home