K2–18b: an inhabited ocean world? Don’t bet on it

<p>This planet, K2&ndash;18b,&nbsp;<a href="https://www.nasa.gov/goddard/2023/webb-discovers-methane-carbon-dioxide-in-atmosphere-of-k2-18b" rel="noopener ugc nofollow" target="_blank">was indeed observed by the JWST</a>, and did have a fantastic spectrum taken of its atmosphere, revealing many fascinating details about it.</p> <p>However, there is no evidence that K2&ndash;18b is a Hycean world at all; no water was detected at all. There&rsquo;s only dubious evidence for dimethyl sulfide, and even if it does exist in the atmosphere, assigning a biological cause to it is an incredibly dubious proposition. Yet if you&rsquo;ve read headlines from around the internet, it isn&rsquo;t just the usual suspects like&nbsp;<a href="https://nypost.com/2023/09/14/nasas-new-telescopes-stunning-discovery-biggest-hint-of-alien-life-so-far/" rel="noopener ugc nofollow" target="_blank">the New York Post</a>&nbsp;or&nbsp;<a href="https://www.dailymail.co.uk/sciencetech/article-12508211/Huge-breakthrough-search-aliens-NASA-discovers-super-Earth-exoplanet-right-conditions-support-life.html" rel="noopener ugc nofollow" target="_blank">the Daily Mail</a>&nbsp;with outrageous, alien life-driven headlines, but normally reliable places like&nbsp;<a href="https://www.nationalgeographic.com/premium/article/hunt-for-alien-life-exoplanet-just-became-top-suspect" rel="noopener ugc nofollow" target="_blank">National Geographic</a>,&nbsp;<a href="https://www.bbc.com/news/science-environment-66786611" rel="noopener ugc nofollow" target="_blank">the BBC</a>, and&nbsp;<a href="https://bigthink.com/13-8/james-webb-space-telescope-life-chemistry-strange-world/" rel="noopener ugc nofollow" target="_blank">right here on Big Think</a>.</p> <p>But I&rsquo;m betting that you don&rsquo;t want hype and exaggeration; you want the scientific truth. Let&rsquo;s take a look at what&rsquo;s really going on with exoplanet K2&ndash;18b.</p> <p><a href="https://medium.com/starts-with-a-bang/k2-18b-an-inhabited-ocean-world-dont-bet-on-it-755b9553817f"><strong>Learn More</strong></a></p>