The universe may be sending us revealing clues. In a promising discovery, researchers have announced the potential detection of a life-associated gas in the atmosphere of exoplanet K2-18b, located 124 light-years from Earth. The analysis was performed using data from the James Webb Space Telescope (JWST), the most advanced astronomical instrument ever launched.

The study is led by Professor Nikku Madhusudhan of the University of Cambridge, whose team is behind this potentially historic finding.

Which Gas Was Detected?

The researchers identified signatures of dimethyl sulfide (DMS) or dimethyl disulfide (DMDS)—compounds on Earth produced exclusively by living organisms, especially marine phytoplankton and certain bacteria.

Estimated concentrations on K2-18b would be thousands of times higher than those on our planet, raising the intriguing possibility: could this world harbor life?

Scientific Caution: Not Yet Proof of Life

Despite the excitement, scientists urge caution. The current detection confidence is at three sigma (≈99.7% certainty), which is insufficient for a definitive claim that requires five sigma confidence.

Madhusudhan’s team plans further JWST observations to reduce uncertainty and achieve a more robust confidence level.

Alternative Explanations Under Investigation

It’s paramount to consider nonbiological sources of DMS. Some researchers are testing in laboratories whether geological or chemical processes, yet unknown, could generate this gas.

Another hypothesis suggests that K2-18b might possess a molten-rock ocean rather than liquid water, which precludes Earth-like life. Furthermore, some believe K2-18b is a mini gas giant without a solid surface. On the other hand, the absence of ammonia hints at possible water presence, keeping the debate alive.

Ongoing Scientific Debate

This discovery has sparked intense discussion among experts. Scientists like Catherine Heymans and Oliver Shorttle highlight uncertainties in the planet’s atmospheric composition and the true origin of the detected signal.

Meanwhile, NASA’s Dr. Nicolas Wogan proposes that K2-18b is a gas giant, contrary to earlier JWST–based analyses.

What’s Next?

New JWST observations are already scheduled. If these signals are confirmed, the finding could mark one of the most promising advances in modern science, potentially transforming our understanding of life in the universe.

For Professor Madhusudhan, this may represent a decisive step toward answering humanity’s oldest question: Are we alone in the cosmos?

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Want to follow the latest developments in this discovery? Read the original BBC article here.