The Empirical Search for Intelligent Life Outside of Earth ( SETI ) has so far attempted to pick up electromagnetic signals from an extraterrestrial civilization, but now it could open a new front: pollution.
Astronomers at the Harvard-Smithsonian Center for Astrophysics propose that the future James Webb Space Telescope track signs of pollution on other planets.
Experts estimate that the James Webb , scheduled for launch in 2018, will be capable of detecting levels of chlorofluorocarbons (CFCs) gases ten times higher than those that are currently depleting the ozone layer in the Earth’s atmosphere.
There is also another limitation: the telescope will only be able to discover signs of CFCs on planets similar in size to ours orbiting a white dwarf, the rest leaving a star up to ten times the size of the Sun when it runs out of fuel.
It would take much more powerful instruments to capture it on a planet orbiting a star similar to our Sun. However, scientists believe that a white dwarf could also provide a suitable environment for life to proliferate.
In addition, alien contamination could be the posthumous vestige of an extinct civilization (or better to say, self-destructive), since some harmful substances take up to 50,000 years to disappear from the Earth’s atmosphere, while others do so in just ten.
If we only found the first category, that would mean that the resources of its inhabitants would have been exhausted. A sad scenario that would serve us as a lesson.





