Title: Absence of Atmospheric Carbon Could Be Key Indicator of Alien Life
A new paper published in Nature Astronomy suggests that the absence, or shortage, of atmospheric carbon on a planet could be a sign that it has good prospects for supporting life beyond Earth.
The paper, authored by an interdisciplinary team, challenges the traditional belief that the presence of carbon in a planet’s atmosphere indicates its potential to support life. Instead, the team argues that low levels of carbon in the atmosphere could be a strong signal of liquid water and potential life.
“All the features that have been talked about so far [as indicators of life] have been beyond the reach of the newest observatories,” Professor Julien de Wit of MIT stated. “Now we have a way to find out if there’s liquid water on another planet. And it’s something we can get to in the next few years.”
The team suggests that the abundance of carbon in a planet’s atmosphere might not be a reliable indicator of its potential to support life. For example, Venus has a thick carbon dioxide atmosphere but is not hospitable to life, while Mars has a thin atmosphere with mostly carbon dioxide. The authors argue that carbon depletion could indicate the presence of liquid water and potential life.
Furthermore, the paper highlights the increasing capabilities of telescopes like the JWST in detecting a planet’s atmospheric carbon levels, particularly for planets that transit their star from our location.
While a shortage of carbon dioxide might indicate potential for life, the paper notes that it would not be proof that life has evolved. The team suggests that other biosignatures, such as ozone, should be the priority in identifying potential alien life.
The research opens up new possibilities for identifying habitable exoplanets and marks a significant advancement in the search for life beyond Earth.