April 2025 — In a discovery that could mark a major turning point in the search for extraterrestrial life, scientists using the James Webb Space Telescope (JWST) have detected the strongest signs yet of potential biological activity beyond our solar system.
Researchers observed the presence of dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) gases that, on Earth, are exclusively produced by living organisms, mainly by marine microbes like phytoplankton. These gases were found in the atmosphere of K2-18 b, a distant exoplanet located 124 light-years away in the constellation Leo.
While scientists aren’t declaring the discovery of alien life just yet, the presence of these potential biosignatures has stirred global excitement and cautious optimism.
“This is a transformational moment in the search for life beyond the solar system,” said lead researcher Dr. Nikku Madhusudhan of Cambridge University. “We have demonstrated that it is possible to detect biosignatures on habitable planets with existing technology.”
K2-18 b is classified as a “Hycean” world a theorized type of exoplanet featuring a hydrogen-rich atmosphere and a global ocean potentially teeming with microbial life. The planet is about 8.6 times as massive as Earth and 2.6 times its size, orbiting in the habitable zone of a cool red dwarf star.
Earlier JWST observations of the planet had already revealed methane and carbon dioxide, key carbon-based molecules, but the latest discovery pushes the evidence further. Webb’s instruments detected DMS and/or DMDS at atmospheric levels thousands of times higher than on Earth, which cannot currently be explained by non-biological processes.
Still, Madhusudhan cautioned that more work is needed to confirm the findings. “We must repeat the observations, test them thoroughly, and rule out any non-biological sources for these gases.”
The discovery was made using the transit method, which involves analyzing the starlight filtered through the planet’s atmosphere as it passes in front of its star. This technique lets scientists decode the chemical composition of distant worlds.
The excitement is tempered by scientific skepticism. “These are tantalizing results,” said Dr. Christopher Glein a space scientist not involved in the study. “But we need independent verification and further analysis.”
Madhusudhan acknowledges the limitations: “We’re likely looking at microbial life, if any, not intelligent beings. And while the signals are compelling, it’s still a ‘big if’ and premature to claim we’ve found alien life.”
Still the discovery marks a major milestone. For the first time scientists may be on the verge of answering humanity oldest question: Are we alone in the universe?
