James Webb Space Telescope Detects Biosignature Candidate

NASA's James Webb Space Telescope detected tentative spectroscopic evidence of dimethyl sulfide, a molecule exclusively produced by living organisms on Earth, in the atmosphere of exoplanet K2-18b in 2025. This finding is the most significant potential biosignature detection in astronomy history, though scientists caution abiotic production cannot be ruled out. Follow-up observations scheduled for 2026 aim to confirm the signal, which is 30% more promising than the nearest candidate from prior exoplanet studies.