A planet far beyond our solar system might harbor alien life. The exoplanet K2-18b is located about 1,175 trillion kilometers (730 trillion miles) from Earth. Last year, scientists used the powerful James Webb Space Telescope (JWST) to scan the planet’s atmosphere. The cloud of gases surrounding K2-18b appeared to contain high levels of dimethyl sulfide. On Earth, only living things—like plankton in the ocean—produce this chemical. This hints that life might also exist on K2-18b.
Other scientists have since challenged this claim, arguing that when they reexamined the JWST scans, they didn’t find convincing evidence of dimethyl sulfide. “This is an intriguing finding, but we must be cautious,” says Subhajit Sarkar, an astrophysicist from the United Kingdom involved in the original study.