Researchers from the University of Cambridge found dimethyl sulfide levels on K2-18 b exceeding 10 parts per million, thousands of times higher than Earth's atmospheric concentration.
This compound, linked to biological activity on Earth, was detected with a statistical significance up to 3.4 sigma, but confirmation requires five sigma. The findings were published in Astrophysical Journal Letters.
While the result is one of the strongest biosignature indications outside the solar system, independent analyses question the interpretation, and the scientific community urges caution pending further evidence and improved observational methods.
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