Did scientists find life on the planet K2-18b using the James Webb Space Telescope (JWST)? No, not yet. Here’s what’s been found by Madhusudhan and collaborators: a tentative detection of dimethyl sulphide on K2-18b, a molecule only produced by life here on Earth. Which means it's too early to jump to aliens! It’s only a tentative detection above the noise in the data for now. There’s currently a 99.7% chance their result is not a fluke, but that needs to get up to a 99.99999% chance for us to be confident of the detection. 18 months ago, the same research group claimed the exact same thing with even less evidence and I covered that on my youtube channel if you want more of a deep dive into all of this. As for the planet, K2-18b it is 124 light years away and is 2.5 times bigger than Earth. We think it has a liquid water ocean surrounded by a hydrogen atmosphere (a hycean world), like a cross between Earth and Neptune. It orbits a red dwarf star much smaller than the Sun, and we don’t know yet whether planets around those stars could even host life because of how much dangerous radiation red dwarf stars burp up. And even though dimethyl sulphide is “only produced by life here on Earth” means this result is incredibly intriguing, another option is there some unknown chemistry going on here to produce this on this world very different to Earth. Plus the amount of DMS claimed to have been detected is thousands of times higher than we see on Earth, which sadly makes me more doubtful of this being life... Madhusudhan et al. (2025) - https://arxiv.org/pdf/2504.12267 Madhusudhan et al. (2023) - https://arxiv.org/pdf/2309.05566 Hu et al. (2021) - https://arxiv.org/pdf/2108.04745 👩🏽💻 I'm Dr. Becky Smethurst, an astrophysicist at the University of Oxford (Christ Church). I love making videos about science with an unnatural level of enthusiasm. I like to focus on how we know things, not just what we know. And especially, the things we still don't know. If you've ever wondered about something in space and couldn't find an answer online - you can ask me! My day job is to do research into how supermassive black holes can affect the galaxies that they live in. In particular, I look at whether the energy output from the disk of material orbiting around a growing supermassive black hole can stop a galaxy from forming stars. http://drbecky.uk.com