Topline<\/p>\n
A team of astronomers using the James Webb Space Telescope have detected biosignatures in the atmosphere of a possible ocean world 124 light-years from the solar system. The scientists behind the discovery \u2014 confirming a previous detection by Webb \u2014 call it the strongest evidence that life may exist outside our solar system. If confirmed, an ocean \u201cteeming\u201d with marine life is possible.<\/p>\n
Astronomers have detected the most promising signs yet of a possible biosignature outside the solar … More system, although they remain cautious.<\/p>\n
A. Smith, N. Madhusudhan (University of Cambridge) <\/p>\n
Key Facts<\/p>\n
A team of astronomers led by the University of Cambridge in the U.K. found the chemical fingerprints of dimethyl sulfide (DMS) and\/or dimethyl disulfide (DMDS) in the atmosphere of an exoplanet called K2-18b. Its atmosphere appears to contain a high concentration of these molecules that are thousands of times stronger than Earths.<\/p>\n
The source of these molecules in K2-18b\u2019s atmosphere is unknown, but DMS and DMDS are only produced on Earth by microbial life, such as marine phytoplankton. However, DMS is not always a byproduct of biology, having been found on a lifeless comet<\/a>. At worst, the biosignatures are the product of an unknown chemical process. At best, it\u2019s a detection of a potential \u201cplankton planet.\u201d<\/p>\n An exoplanet about 2.6 times the size of Earth, K2-18b, orbits a red dwarf star in the so-called habitable zone \u2014 where liquid water could theoretically exist on its surface \u2014 but it\u2019s no Earth 2.0. The same research team that claims to have confirmed DMS and DMDS on K2-18b is responsible for the concept of \u201cHycean\u201d planets, which do not exist in the solar system. Others think that K2-18b may be a gas planet, or have an ocean of molten rock<\/a>.<\/p>\n Further observations using Webb are planned over the next few years, which could confirm the findings, though there’s no way of visiting a planet 124 light-years distant. If traveling at the speed of NASA\u2019s Parker Solar Probe \u2014 the fastest-moving spacecraft \u2014 it would take approximately 190,000 years to reach.<\/p>\n Why This ‘hycean’ Planet Is Not ‘earth 2.0’<\/p>\n Back in 2021, the same team of scientists identified<\/a> a new class of habitable exoplanets they called Hycean, explaining that they\u2019re not rocky like Earth, instead having oceans and hydrogen-rich atmospheres. Hycean worlds can also have atmospheric temperatures up to 392 degrees Fahrenheit (200 degrees Celsius) and be tidally locked to their star, with a permanent night-side. K2-18b is the ultimate example of such a planet.<\/p>\n \u2018an Ocean Teeming With Life\u2019 Best Fits The Data<\/p>\n K2-18b orbits a very active red dwarf star, so its surface is likely drenched in high-energy radiation, which would be more hostile to life as we know it than Earth, according to NASA<\/a>. However, the concept of Hycean worlds allows scientists to think outside the box and consider if life could exist in completely un-Earth-like environments. \u201cEarlier theoretical work had predicted that high levels of sulfur-based gases like DMS and DMDS are possible on Hycean worlds,\u201d said Professor Nikku Madhusudhan from Cambridge\u2019s Institute of Astronomy, lead author of a paper published<\/a> this week in The Astrophysical Journal Letters. \u201cAnd now we\u2019ve observed it, in line with what was predicted. Given everything we know about this planet, a Hycean world with an ocean that is teeming with life is the scenario that best fits the data we have.\u201d<\/p>\n The Truth About K2-18b<\/p>\n K2-18b has been the subject of many recent claims and counter-claims about biosignatures. Discovered in 2015 by the Kepler Space Telescope, it\u2019s long topped a list of exoplanets that should be investigated using space telescopes. In 2019, the Hubble Space Telescope found evidence of water vapor in its atmosphere<\/a>. In 2023, the same scientists now claiming to have confirmed DMS reported<\/a> a preliminary detection that \u201crequires further validation.\u201d On that occasion, Webb\u2019s NIRISS and NIRSpec instruments were used. This time, Webb\u2019s MIRI instrument was used. \u201cThis is an independent line of evidence, using a different instrument than we did before and a different wavelength range of light, where there is no overlap with the previous observations. The signal came through strong and clear,\u201d said Madhusudhan. \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<\/p>\n A \u2018tipping Point\u2019 In The Search For Life?<\/p>\n The scientists are not yet claiming a definitive discovery, but state that this latest detection has only a 0.3% probability of occurring by chance. They also state that Webb needs 16 and 24 hours of further observations to reach the 0.00006% probability required. \u201cWhile these findings are incredibly exciting, we must be cautious before jumping to the conclusion that K2-18b harbors life,\u201d said Dr. Joe Llama, an astronomer at Lowell Observatory<\/a> in Flagstaff, Arizona, who focuses on exoplanets and stellar astronomy, and who wasn\u2019t connected to the research, in an email. \u201cThese detections will need to be independently confirmed by other instruments and telescopes, and it\u2019s still an open question whether such gases could be produced by non-biological processes that are not yet understood.\u201d He added that the potential detection marks a \u201cthrilling step forward\u201d in the search for life beyond Earth.<\/p>\n Background<\/p>\n Although they\u2019re not Earth-like, there are reasons why some exoplanet-hunters consider Hycean planets like K2-18b to be low-hanging fruit in the search for life. As well as being larger than Earth, they dominate the known exoplanet population and appear to occur relatively close to the sun, making them easier to locate and study than smaller Earth-sized planets. That makes this latest research even more important in the search for life off-Earth \u2014 but it\u2019s not proof of life.<\/p>\n Further ReadingForbesA Major Meteor Shower Begins This Week: When To See It At Its BestBy Jamie Carter<\/a>
\nForbesUpdated: Northern Lights Alert For 17 States After \u2018Double Eruption\u2019 On SunBy Jamie Carter<\/a>ForbesPerseid Meteor Shower 2025: Why You Need To Change Your PlansBy Jamie Carter<\/a> <\/p>\n","protected":false},"excerpt":{"rendered":"Topline A team of astronomers using the James Webb Space Telescope have detected biosignatures in the atmosphere of…\n","protected":false},"author":2,"featured_media":29271,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[17531,17528,17530,17533,17529,17535,17532,7958,17534,70,16,15,17536],"class_list":{"0":"post-29270","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-alien-life-discovery","9":"tag-biosignature","10":"tag-dms-dmds-detection","11":"tag-earth-2-0","12":"tag-exoplanet-k2-18b","13":"tag-how-long-to-get-to-k2-18b","14":"tag-hycean-world","15":"tag-james-webb-space-telescope","16":"tag-k2-18b","17":"tag-science","18":"tag-uk","19":"tag-united-kingdom","20":"tag-where-is-k2-18b"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/114356980582168115","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/29270","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=29270"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/29270\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/29271"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=29270"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=29270"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=29270"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}