Space.com by Robert Lea
Reports of life signs detected in the atmosphere of the potential ocean world K2-18 b may have been premature. Recent reports of the James Webb Space Telescope (JWST) detecting signs of life of a distant planet outside the solar system are, unfortunately, somewhat premature. That's the conclusion of research conducted by scientists from the University of California Riverside (UCR).
While likely to disappoint all of us eager for the confirmation of extraterrestrial life, however, it doesn't mean the JWST won't find traces of life in the atmosphere of an extrasolar planet, or "exoplanet," in the future.
The recent excitement around the potential detection of life signs on an exoplanet started in 2023 when the JWST detected potential "biosignature" elements in the atmosphere of the exoplanet K2-18 b, a super-Earth located around 120 light-years from Earth.
Though many exoplanets are extreme, violent or at least "alien" in nature — whether they're blasted by intense radiation from their stars, lack a solid surface or are frozen relics at the edge of their systems — K2-18 b was a tantalizing target in the search for life because it is rather similar to our planet.
An Earth-like ocean worldK2-18 b is between two and three times the width of Earth with 8.6 times the mass of our planet. It's also located in the habitable zone of its star, the region neither too hot nor too cold to support liquid water. The exoplanet is thus theorized to be an ocean, or "hycean" world, replete with liquid water — a vital ingredient for life as we know it. Unlike Earth, however, the atmosphere of this exoplanet seems to be mainly hydrogen rather than nitrogen.
More:
https://www.space.com/james-webb-space-telescope-life-earth-exoplanet-study
