{"id":201392,"date":"2025-04-17T14:06:24","date_gmt":"2025-04-17T04:06:24","guid":{"rendered":"https:\/\/www.vibewire.com.au\/?p=201392"},"modified":"2025-04-17T14:08:50","modified_gmt":"2025-04-17T04:08:50","slug":"astronomers-spot-strongest-hints-yet-of-life-on-distant-planet","status":"publish","type":"post","link":"https:\/\/www.vibewire.com.au\/?p=201392","title":{"rendered":"Astronomers spot strongest \u2018hints\u2019 yet of life on distant planet"},"content":{"rendered":"\n

In an astonishing announcement, astronomers claim to have detected the most promising \u201chints\u201d of potential life on a planet beyond our solar system, though other scientists expressed scepticism.<\/p>\n\n\n\n

There has been vigorous debate in scientific circles about whether the planet K2-18b, which is 124 light years away in the Leo constellation, could be an ocean world capable of hosting microbial life.<\/p>\n\n\n\n

Using the James Webb Space Telescope, a British-US team of researchers detected signs of two chemicals in the planet\u2019s atmosphere long considered to be \u201cbiosignatures\u201d indicating extraterrestrial life.<\/p>\n\n\n\n

On Earth, the chemicals dimethyl sulfide (DMS) and dimethyl disulfide are produced only by life, mostly microscopic marine algae called phytoplankton.<\/p>\n\n\n\n

The researchers emphasised caution, saying that more observations were needed to confirm these findings, and that they were not announcing a definitive discovery.<\/p>\n\n\n\n

But the implications could be huge, according to Nikku Madhusudhan, a Cambridge University astrophysicist and lead author of the study, published in The Astrophysical Journal Letters.<\/p>\n\n\n

\n
\"\"<\/figure>\n<\/div>\n\n\n

An 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

\n
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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":[],"_links":{"self":[{"href":"https:\/\/www.vibewire.com.au\/index.php?rest_route=\/wp\/v2\/posts\/201392","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vibewire.com.au\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vibewire.com.au\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vibewire.com.au\/index.php?rest_route=\/wp\/v2\/users\/22"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vibewire.com.au\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=201392"}],"version-history":[{"count":1,"href":"https:\/\/www.vibewire.com.au\/index.php?rest_route=\/wp\/v2\/posts\/201392\/revisions"}],"predecessor-version":[{"id":201398,"href":"https:\/\/www.vibewire.com.au\/index.php?rest_route=\/wp\/v2\/posts\/201392\/revisions\/201398"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vibewire.com.au\/index.php?rest_route=\/wp\/v2\/media\/201397"}],"wp:attachment":[{"href":"https:\/\/www.vibewire.com.au\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=201392"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vibewire.com.au\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=201392"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vibewire.com.au\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=201392"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}