![\"\"](\"https:\/\/www.vibewire.com.au\/wp-content\/uploads\/2025\/04\/image-14-1024x576.jpeg\")
<\/figure>\n<\/div>\n\n\nAn artist\u2019s conception of a Hycean exoplanet like K2-18b orbiting a red dwarf star.<\/p>\n\n\n\n
\u201cWhat we are finding at this point are hints of possible biological activity outside the solar system,\u201d he told a press conference.<\/p>\n\n\n\n
\u201cFrankly, I think this is the closest we have come to seeing a feature that we can attribute to life.\u201d<\/p>\n\n\n\n
But outside experts pointed to disputes over previous discoveries about the exoplanet, adding that these chemicals could have been created by unknown means having nothing to do with life.<\/p>\n\n\n\n
Chemical clues<\/strong><\/p>\n\n\n\n More than eight times the mass of Earth and 2.5 times as big, K2-18b is a rare exoplanet that orbits its star in a habitable or \u201cgoldilocks\u201d zone.<\/p>\n\n\n\n This means it is neither too hot nor too cold to have liquid water, considered the most important ingredient for life.<\/p>\n\n\n\n Telescopes observe such far-off exoplanets when they cross in front of their star, allowing astronomers to analyse how molecules block the light streaming through their atmosphere.<\/p>\n\n\n\n In 2023, the Webb telescope detected methane and carbon dioxide in K2-18b\u2019s atmosphere, the first time such carbon-based molecules were detected on an exoplanet in a habitable zone.<\/p>\n\n\n\n It also detected weak signals of the chemical DMS, leading astronomers to turn Webb towards the planet again a year ago, this time using its mid-infrared instrument to detect different wavelengths of light.<\/p>\n\n\n\n They found much stronger signs of the chemicals, though still well below the \u201cfive sigma\u201d threshold of statistical significance scientists seek for such discoveries.<\/p>\n\n\n\n Even if the results are confirmed, it would not necessarily mean that the planet is home to life.<\/p>\n\n\n K2-18b is the only super-Earth exoplanet known to host both water and temperatures that could support life.<\/p>\n\n\n\n Last year, scientists found traces of DMS on a comet, which suggested it can be produced in non-organic ways.<\/p>\n\n\n\n However the concentration of the chemical observed on K2-18b appears to be thousands of times stronger than levels on Earth, strongly suggesting a biological origin, Madhusudhan said.<\/p>\n\n\n\n Are we alone in the universe?<\/strong><\/p>\n\n\n\n K2-18b has long been considered the premier candidate for a \u201chycean planet\u201d \u2014 an ocean world bigger than Earth with a hydrogen-rich atmosphere.<\/p>\n\n\n\n These planets would not be expected to be home to intelligent alien life, but rather tiny microbes similar to those in Earth\u2019s oceans billions of years ago.<\/p>\n\n\n\n Some research has questioned whether the currently proposed hycean planets are too close to their stars to support liquid water, including K2-18b, which orbits its star every 33 days.<\/p>\n\n\n\n Raymond Pierrehumbert, a planetary physics professor at Oxford University, has conducted separate research indicating K2-18b is too hot for life.<\/p>\n\n\n\n If the planet did have water, it would be \u201chellishly hot\u201d and uninhabitable, he told AFP, adding that oceans of lava were more plausible.<\/p>\n\n\n\n Sara Seager, a professor of planetary science at MIT, called for patience, pointing to previous claims of water vapour in K2-18b\u2019s atmosphere that turned out to be a different gas.<\/p>\n\n\n\n And within our solar system, Mars, Venus and moons such as Saturn\u2019s Enceladus all have \u201cmore chance to be realised as life-hosting,\u201d she told AFP.<\/p>\n\n\n\n Madhusudhan estimated that it would take just 16 to 24 more hours of Webb\u2019s time to confirm their findings, which could happen in the next few years.<\/p>\n\n\n\n Even beyond K2-18b, Madhusudhan said Webb and future telescopes could allow humanity to discover life outside our home planet sooner than one might think.<\/p>\n\n\n\n \u201cThis could be the tipping point, where suddenly the fundamental question of whether we\u2019re alone in the universe is one we\u2019re capable of answering,\u201d he said.<\/p>\n","protected":false},"excerpt":{"rendered":" Astronomers claim to have detected the most promising \u201chints\u201d of potential life on a planet beyond our solar system.<\/p>\n","protected":false},"author":22,"featured_media":201397,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":""},"categories":[35,9267],"tags":[16374,16372,16373],"class_list":["post-201392","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-breaking-news","category-space-news","tag-james-webb-space-telescope","tag-k2-18b","tag-leo-constellation"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t![\"\"](\"https:\/\/www.vibewire.com.au\/wp-content\/uploads\/2025\/04\/image-15-1024x576.jpeg\")
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