THE DAILY MAIL - Alien life has yet to be found in space, but a new study has uncovered 'telltale' signs of an inhabited planet.
Researchers at the University of California, Riverside (UCR) discovered that greenhouse gases, like those emitted on Earth, would mean a distant world had been terraformed - or artificially altered.
Signatures of methane, ethane, and propane, along with gases made of nitrogen and fluorine or sulfur and fluorine could indicate technology-using life forms due to the gases only forming through manufacturing.
Scientists ran simulations on a hypothetical planet, finding NASA's James Webb Space Telescope (JWST) could spot the gasses as easily as it could ozone on Earth.
UCR astrobiologist and lead study author Edward Schwieterman said: 'For us, these gases are bad because we don't want to increase warming.