Reduced carbon dioxide content: a new indicator of the presence of life on Earth's twin planets
Scientists from the Massachusetts Institute of Technology (MIT), the University of Birmingham and other institutions have proposed a new approach to detect signs of life on planets beyond our solar system. They suggest that low levels of carbon dioxide in the atmosphere of a planet similar in size and temperature to Earth may indicate the presence of liquid water, tectonics and biomass.
This new sign may be discovered thanks to the James Webb» Space Telescope (JWST).
Researchers note that the Earth — the only planet in the solar system on which liquid water exists. They also take into account another difference: Earth has significantly less carbon dioxide in its atmosphere.
Scientists suggest that if a planet has a significant decrease in carbon dioxide levels compared to neighboring planets, this may indicate the presence of liquid oceans and possible life on the surface of the planet.
After careful study of areas ranging from biology to chemistry, and even carbon capture in the context of climate change, researchers have concluded that finding a decrease in the amount of carbon dioxide in the atmosphere is a very likely indicator of the presence of liquid water and life .
In their study, the team defines a strategy for finding habitable planets based on looking for signs of low carbon dioxide in the atmosphere. This approach is most effective in systems like our solar system, where several planets of similar size are located close to each other. The first step is to establish the presence of atmospheres on these planets, primarily by detecting carbon dioxide, which is expected to be present in most planetary atmospheres.
After establishing the presence of atmospheres on planets, the next step is to measure the carbon dioxide content. If one planet shows significantly lower carbon dioxide content compared to others, this may indicate the possibility of liquid oceans and habitability on its surface.
However, the presence of conditions for habitability does not necessarily mean the presence of life. To assess the potential for life, researchers also suggest looking for another atmospheric feature — ozone.
Scientists suggest that if a planet's atmosphere has both ozone and low carbon dioxide, then it has a high probability of being a habitable world with living organisms.
Amauri Trio from the University of Birmingham said: «If we detect ozone, it is highly likely that it is associated with the consumption of carbon dioxide by some living organisms. We are not talking about a few bacteria, but about a biomass on a planetary scale, capable of processing and interacting with huge amounts of carbon».