Researchers have often focused on planets similar to Earth in the search for alien life, which are usually full of oxygen and water. However, scientists are open to the possibility that life could exist in conditions very different to ours. This is why, when the James Webb Space Telescope (JWST) launches in 2021, it will look for planets with carbon monoxide in its atmosphere – something which would be extremely poisonous to Earth-based lifeforms.
WST has detectors on it which will be able to spot the make-up of a planet’s atmosphere from thousands of light-years away.
Edward Schwieterman, the study's lead author and a NASA Postdoctoral Program fellow in the University of California - Riverside (UCR) Department of Earth Sciences, said: "With the launch of the James Webb Space Telescope two years from now, astronomers will be able to analyse the atmospheres of some rocky exoplanets,
"It would be a shame to overlook an inhabited world because we did not consider all the possibilities."