A new investigation with NASA's James Webb Space Telescope into K2-18 b, an exoplanet 8.6 times as massive as Earth, has revealed the presence of carbon-bearing molecules including methane and carbon dioxide.
The astronomers underlined that the star, these planets are orbiting is the second-coolest star found to host planets after TRAPPIST-1. They added that their finding is the second-most favorable habitable-zone terrestrial planet known so far.
It's called TOI-1452b, and measurements of its size and mass suggest a density profile consistent with a global liquid ocean. An exoplanet is just 100 light-years from Earth
As it turns out, organic material, liquid water, sunlight and a large moon might not be enough to ensure an exoplanet’s habitability. It also may depend on whether enough radioactive elements are present in the planet’s core.
An Earth-like world is one that’s rocky and that orbits a Sun-like, or G-Type, star. The Milky Way has 400 billion stars, with 7 % of them being G-type, meaning that less than six billion stars may have Earth-like planets in our Galaxy.
We get excited when we detect water on another world, which so far hasn’t happened often. But this study shows that the presence of water, though tantalizing and worth pursuing scientifically, guarantees nothing.
Accounting for the buildup of toxic gases predicted to occur in the atmospheres of most planets narrows the habitable zone for complex life by half and, in some cases, rules it out altogether, the study concludes.
Hopes for finding life on four rocky exoplanets relatively close to Earth have been boosted by new modelling that shows biological systems could survive the intense and prolonged bursts of X-ray and UV radiation.
A research into how life evolved on Earth has shown that water alone does not guarantee life – nor does the presence of oxygen gas. And that two other major biosignatures, carbon dioxide and carbon monoxide could be needed.
Barnard b or GJ 699 b – might have microbes or other simple life in its environment as long as there is a lot of thermal activity within the planet itself. This would theoretically provide enough energy for life to survive.