see alive : The James Webb Space Telescope ( JWST ) may have picked up mark of a possible biosignature on a steamy , ocean - covered exoplanet called K2 - 18b — a biosignature that , on Earth , is grow by marine life .
The main character here is dimethyl sulfide , a molecule produced by many ocean denizens , but especially plankton . If the molecule is really swim around in the atmosphere of K2 - 18b , it raises the tantalizing possibility that something on the world might be alert . Or at least emitting suspiciously life - similar chemical signals .
K2 - 18b , settle 120 light - years by , has been on scientist ’ radar since NASA ’s Kepler space telescope blob it in 2015 . It ’s about 8.6 time the spate of Earth and orbits within the habitable ( or “ Goldilocks ” ) zone of a cherry dwarf star .
An artist’s concept of K2-18b.Illustration: NASA, CSA, ESA, J. Olmstead (STScI), N. Madhusudhan (Cambridge University)
early reflection from Hubble suggest that K2 - 18b had water vapor in its aura , a title subsequently shown to be in computer error . But JWST has taken matters several steps further , doubling down on anearlier determination of dimethyl sulfidein the planet ’s standard pressure . The team behind the discovery , run by Nikku Madhusudhan from the University of Cambridge , includes researchers from five institution .
The finding suggests that K2 - 18b may indeed be a Hycean world , or a piss - covered planet with a hydrogen - rich atm . But the team ’s observations — made using JWST ’s Mid - Infrared Instrument ( MIRI ) and earlier data point from NIRISS and NIRSpec — bring out methane and carbon paper dioxide , but very little ammonium hydroxide , on the major planet .
The curious mix suggest K2 - 18b host a watery , potentially inhabitable environment . Crucially , the team also found more evidence of dimethyl sulfide , along with a related molecule , dimethyl disulfide . The team ’s work repeat the 2023 detection and adds further acceptance to the possibility of life on the comparatively nearby exoplanet — assuming the findings are sound and that dimethyl sulfide is produced and behaves on exoplanets the same fashion it does on Earth . The team ’s finding arepublishedin The Astrophysical Journal Letters .
A graphic showing earlier molecular detections in K2-18b’s atmosphere. Graphic: Illustration NASA, ESA, CSA, Ralf Crawford (STScI), Joseph Olmsted (STScI) Science Nikku Madhusudhan (IoA)
Speaking to the BBC , Madhusudhansaidhis team detected a surprising amount of gas pedal during the single reflexion . “ The amount we estimate of this throttle in the ambiance is thousand of time higher than what we have on Earth , ” he explained , saying that , if the contact to life is valid , “ then this satellite will be teeming with life . ” And should scientists confirm the comportment of life on K2 - 18b , “ it should basically confirm that life is very common in the galaxy , ” Madhusudhan told the British broadcaster .
In its landmarkdecadal surveyon uranology and astrophysics , the National Academies made one thing clear : observe inhabitable worlds should be a top scientific priority . The James Webb Space Telescope is front and core in that commission — and while NASA already has architectural plan for its eventual successor , theHabitable Worlds Observatory , that next - gen telescope wo n’t launch for at least another decade . Until then , it ’s up to Webb — and the ever - dependable Hubble — to carry the torch in our search for life beyond Earth .
The spotting is n’t a done deal yet — it come with a statistical confidence of around 3 - sigma ( about 99.73 % ) , which attain it interesting , but not determinate . A 5 - sigma detection ( more or less 99.99994 % self-confidence ) is typically the gold criterion for confirming a find . And even at 5 - sigma , that would merely support the presence of dimethyl sulfide in the planet ’s atmosphere — not that the dimethyl sulfide has biotic rootage . There ’s still a chance that abiotic ( non - biologic ) processes or instrumental quirks could be responsible . This preceding Sunday , a separate teamposteda paper on the preprint host arXiv suggesting the major planet may not be Hycean at all , but instead a rocky creation covered in magma , with hydrogen - rich skies — and about no chance of life sentence .
Further observations will help to validate the team ’s findings . But to be unclouded , if life does exist on K2 - 18b , it ’s likely microbic given the apparent grounds , and not a signal of alien intelligence . As an important aside , microbic spirit — like plankton — live on Earth for a billion years , a foresightful but important chapter that pave the way for more complex organisms to emerge . irrespective , spirit has never been base beyond Earth , so confirm even a single amoeba on a distant world would be nothing scant of revelatory .
At minimum , K2 - 18b is shaping up to be one of the most promising position to search for life beyond Earth . And at maximum — if further studies validate the recent determination — we may be fix our first chemical whiffs of a living sea on another world .
alien lifeAstrobiologyexoplanetsmarine lifewebb space scope
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