Baltimore — An international team of astronomers announced Thursday that new observations from a space-based telescope have confirmed the presence of water vapour in the atmosphere of K2-18b, a temperate exoplanet roughly 120 light-years from Earth long considered a top candidate for habitability studies.
The detection, published in Nature Astronomy, was made possible by analysing how starlight filters through the planet's atmosphere as it passes in front of its host star. Researchers stressed that water vapour alone is not evidence of life, but called the finding "a critical data point" in understanding the planet's broader chemistry.
Follow-up observations are planned to search for additional biosignature gases, including methane and dimethyl sulfide, compounds associated with biological processes on Earth. Lead author Dr. Nikku Madhusudhan cautioned against overinterpreting the result: "This tells us about atmospheric chemistry, not about life. That question needs much more evidence."