Florida: In a major leap forward in the search for extraterrestrial life, astronomers have detected chemical signatures in the atmosphere of a distant exoplanet that could point to biological activity.
NASA’s James Webb Space Telescope has focused attention on K2-18 b, a distant planet orbiting a cool red dwarf star approximately 124 light years away in the constellation Leo.
The telescope revealed traces of dimethyl sulfide (DMS) and dimethyl disulfide (DMDS)– complex organic compounds that, on Earth, are exclusively produced by living organisms, primarily marine phytoplankton.
Their presence on K2-18 b suggests that some form of life could potentially exist in its alien oceans or atmosphere. However, scientists stress that this is not definitive proof of life, but rather a tantalizing clue.
“This is the strongest evidence to date for a biological activity beyond the solar system. If this signal is real, it could be a historic turning point in our search for life,” said Prof Nikku Madhusudhan, lead author of the study and astrophysicist at the University of Cambridge.
K2-18 b is classified as a sub-Neptune exoplanet, nearly nine times the mass of Earth and 2.6 times larger, orbiting within the habitable zone- a region where liquid water might exist.
While its exact surface conditions remain unknown, some scientists believe it may host a vast global ocean beneath a hydrogen-rich atmosphere.
The detection was made by observing how the planet’s atmosphere filtered starlight as it passed in front of its host star.
The resulting chemical fingerprints revealed wavelengths that matched DMS and DMDS- compounds never before identified on a habitable-zone exoplanet.
Despite the excitement, researchers urge caution. Some experts believe the molecules could have been formed through unknown geological or chemical processes unrelated to life. Others remain sceptical about whether K2-18 b’s environment is truly suitable for life as we know it.
With current technology unable to explore such distant worlds directly, the discovery marks a significant step toward understanding the potential for life beyond Earth.
