Life is messy. So to find aliens, why not look for their pollution?
As part of its mission, NASA's upcoming James Webb Space Telescope (JWST) will be able to look at starlight filtered through the atmospheres of Earth-sized planets and search for signs of life. Most proposed plans involve hunting for highly reactive gases such as oxygen that usually need a living source to replenish them. But these methods might only hint at relatively simple life such as plants and microbes.
Henry Lin at Harvard University thinks we could find more advanced civilisations if we look instead for industrial pollution. His team calculates that JWST should be able to spot two kinds of chlorofluorocarbons (CFCs), complex carbon-based gases used in solvents and aerosols.To read more, click here.