New signs of habitable planet found

It is possible that humanity has seen a habitable planet for a long time without knowing it, because it ignored signs of an Earth-like phenomenon.

According to Sci-News, new research led by the University of Birmingham (UK) and the Massachusetts Institute of Technology (MIT-USA) indicates that carbon dioxide levels that are too low compared to neighboring planets could be a sign of a world with liquid water and life.

Is the habitable planet where most of the carbon dioxide in the atmosphere has "disappeared"? - (Graphic image: SCI-NEWS).

Astronomers have discovered more than 5,200 exoplanets to date, as well as measurements to see which ones lie in their parent star's "habitable zone."

However, there is a huge gap between determining a planet is "habitable" and finding life on it.

New research has narrowed that gap significantly.

The authors focus on the discovery of liquid oceans. It is what nurtured Earth's first organisms. It is the most important factor in deciding whether to hunt for life on a planet.

In the Solar System, we can determine the presence of liquid oceans thanks to "mirror reflections" , that is, sunlight shining on the surface of liquid. That is how large lakes were found on the giant planet Saturn's moon Titan.

But with exoplanets, the distance is too great to search for specular reflections .

But when they modeled, the authors discovered something "unique" that only worlds with oceans and life possess: a decline in carbon dioxide in the atmosphere.

Our world has less carbon dioxide in the atmosphere than neighboring planets, because the oceans absorb some of the gas.

Over billions of years, the amount of carbon dioxide swallowed by Earth's oceans is roughly equal to the amount of carbon dioxide that exists in the stifling atmosphere of neighboring planet Venus.

So if in some distant star system there is a planet with much less carbon dioxide than its "neighbors" , that is where we can believe in the existence of liquid oceans and have a great hope for life.

The team believes that the new data, combined with the power of the world's youngest space telescope , the James Webb Space Telescope, will help find a breakthrough in the next few years.

The first potential candidates they thought of were worlds inside TRAPPIST-1, a star system with seven planets, all of which have Earth-like properties.