In 2025, NASA’s James Webb Space Telescope detected a possible whiff of dimethyl sulfide (DMS) in the atmosphere of a planet 120 light-years away. On Earth, this molecule is mostly produced by marine life—like plankton—making it a potential biosignature.

The planet, K2-18b, is a “Hycean” world: larger than Earth, likely covered in oceans, and wrapped in a hydrogen-rich atmosphere. Scientists believe it could be warm enough—and wet enough—to support life.

While the detection isn’t confirmed, DMS is hard to make without biology. If future observations back it up, this sulfur-scented signal might be the first chemical hint of alien life ever recorded.