The James Webb Space Telescope has detected a potential biosignature in the atmosphere of exoplanet K2-18b, igniting excitement about the possibility of life beyond Earth. K2-18b, located 124 light-years away in the constellation Leo, is under intense scrutiny due to its potential to be an ocean world capable of supporting microbial life.
Scientists have detected traces of dimethyl sulfide (DMS), a chemical compound largely produced by living organisms such as phytoplankton on Earth. Nikku Madhusudhan from the University of Cambridge emphasized that these are the strongest indicators yet of biological activity outside our solar system.
In 2023, the telescope identified methane and carbon dioxide in K2-18b's atmosphere, marking a significant first for an exoplanet within the habitable zone. However, the DMS signals are currently below the statistical threshold required to confirm the discovery definitively. K2-18b is eight times the mass of Earth and completes an orbit around its star in just 33 days.
While the presence of DMS is promising, some scientists remain cautious, suggesting that K2-18b might be too hot to support life. Previous detections of water vapor have also been called into question. Other celestial bodies, including Mars, Venus, and Enceladus, are also considered potential candidates for harboring life.