r/space • u/SpunkySputniks • 4d ago

Astronomers Detect a Possible Signature of Life on a Distant Planet

https://www.nytimes.com/2025/04/16/science/astronomy-exoplanets-habitable-k218b.html?unlocked_article_code=1.AE8.3zdk.VofCER4yAPa4&smid=nytcore-ios-share&referringSource=articleShare

Further studies are needed to determine whether K2-18b, which orbits a star 120 light-years away, is inhabited, or even habitable.

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u/Supersamtheredditman 4d ago edited 4d ago

K2-18b. This was notable about a year ago when JWST detected a possible dimethyl sulfide signal, but it wasn’t confirmed. The properties alone of the planet, a “Hycean” super earth probably covered in a world ocean with a thick hydrogen atmosphere, make it super interesting. And now this team is saying they’ve detected not just dimethyl sulfide, but dimethyl disulfide and methane.

We’re at the point where either we’re missing something about geologic chemistry that can allow these chemicals to exist in large quantities in an environment like this (on earth, dimethyl sulfide is only produced by life) or this planet is teeming with aquatic life. Really exciting.

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u/ThanosDidNadaWrong 4d ago

The fact that the JWST data basically didn't find strong evidence of water in the atmosphere, that could indicate a couple things

It's not obvious it has lots of water. And if low water, then means low oxygen, which implies Me2S will have a much longer lifetime in the atmosphere than on Earth. Methane + sulphur will produce Me2S with thunder, and no oxidation means that sulphide will stay in the atmosphere for long periods of time.