The Carbon Dioxide Trail Leads MIT Scientists to Potential Alien Life

A low carbon abundance in planetary atmospheres, which the James Webb Space Telescope can detect, could be a signature of habitability.

Scientists at MIT, the University of Birmingham, and elsewhere say that astronomers’ best chance of finding liquid water, and even life on other planets, is to look for the absence, rather than the presence, of a chemical feature in their atmospheres.

The researchers propose that if a terrestrial planet has substantially less carbon dioxide in its atmosphere compared to other planets in the same system, it could be a sign of liquid water — and possibly life — on that planet’s surface.