Astronomers detect chemicals on exoplanet that on Earth come from life
The uncertainty of science: Using the Webb Space Telescope, astronomers have detected two different molecules that on Earth are only linked with biology in the atmosphere of an exoplanet orbiting a red dwarf star within its habitable zone.
Earlier observations of K2-18b — which is 8.6 times as massive and 2.6 times as large as Earth, and lies 124 light years away in the constellation of Leo — identified methane and carbon dioxide in its atmosphere. This was the first time that carbon-based molecules were discovered in the atmosphere of an exoplanet in the habitable zone. Those results were consistent with predictions for a ‘Hycean’ planet: a habitable ocean-covered world underneath a hydrogen-rich atmosphere.
However, another, weaker signal hinted at the possibility of something else happening on K2-18b. “We didn’t know for sure whether the signal we saw last time was due to DMS, but just the hint of it was exciting enough for us to have another look with JWST using a different instrument,” said Professor Nikku Madhusudhan from Cambridge’s Institute of Astronomy, who led the research.
…The earlier, tentative, inference of DMS was made using JWST’s NIRISS (Near-Infrared Imager and Slitless Spectrograph) and NIRSpec (Near-Infrared Spectrograph) instruments, which together cover the near-infrared (0.8-5 micron) range of wavelengths. The new, independent observation [of dimethyl sulfide (DMS) and/or dimethyl disulfide (DMDS] used JWST’s MIRI (Mid-Infrared Instrument) in the mid-infrared (6-12 micron) range.
This data is not yet proof of biology. For example, the concentrations of these molecules in K2-18b’s atmosphere is thousands of times greater than on Earth. It is just as likely that numerous as yet unknown non-biological chemical processes in this alien environment have produced these chemicals. The scientists however are encouraged because the theories about ocean life on this kind of habitable ocean-covered superearth had predicted this high concentration of these chemicals.
At the same time, they readily admit there are many uncertainties in their data. They have asked for another 16 to 24 hours of observation time on Webb — a very large chunk rarely given out to one research group — to reduce these uncertainties.
You can read the peer-reviewed paper here [pdf].
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The uncertainty of science: Using the Webb Space Telescope, astronomers have detected two different molecules that on Earth are only linked with biology in the atmosphere of an exoplanet orbiting a red dwarf star within its habitable zone.
Earlier observations of K2-18b — which is 8.6 times as massive and 2.6 times as large as Earth, and lies 124 light years away in the constellation of Leo — identified methane and carbon dioxide in its atmosphere. This was the first time that carbon-based molecules were discovered in the atmosphere of an exoplanet in the habitable zone. Those results were consistent with predictions for a ‘Hycean’ planet: a habitable ocean-covered world underneath a hydrogen-rich atmosphere.
However, another, weaker signal hinted at the possibility of something else happening on K2-18b. “We didn’t know for sure whether the signal we saw last time was due to DMS, but just the hint of it was exciting enough for us to have another look with JWST using a different instrument,” said Professor Nikku Madhusudhan from Cambridge’s Institute of Astronomy, who led the research.
…The earlier, tentative, inference of DMS was made using JWST’s NIRISS (Near-Infrared Imager and Slitless Spectrograph) and NIRSpec (Near-Infrared Spectrograph) instruments, which together cover the near-infrared (0.8-5 micron) range of wavelengths. The new, independent observation [of dimethyl sulfide (DMS) and/or dimethyl disulfide (DMDS] used JWST’s MIRI (Mid-Infrared Instrument) in the mid-infrared (6-12 micron) range.
This data is not yet proof of biology. For example, the concentrations of these molecules in K2-18b’s atmosphere is thousands of times greater than on Earth. It is just as likely that numerous as yet unknown non-biological chemical processes in this alien environment have produced these chemicals. The scientists however are encouraged because the theories about ocean life on this kind of habitable ocean-covered superearth had predicted this high concentration of these chemicals.
At the same time, they readily admit there are many uncertainties in their data. They have asked for another 16 to 24 hours of observation time on Webb — a very large chunk rarely given out to one research group — to reduce these uncertainties.
You can read the peer-reviewed paper here [pdf].
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Robert, your premise is flawed: “astronomers have detected two different molecules that on Earth are *only* linked with biology…”
The Venusian and Martian atmospheres are 95+% CO2, Titan has 5% Methane… last I checked none had any links to biology. And while they may be *linked* to biology here on Earth, they are not *only* linked with biology.
(grok) Volcanoes emit CO₂ during eruptions and through diffuse outgassing from magma, contributing to the atmosphere over geological timescales.
Wikipedia (I know, shoot me): Methane can be generated through geological, biological or industrial routes.
This really proves nothing in terms of a link to biology.
The quoted study only says that, “This was the first time that carbon-based molecules were discovered in the atmosphere of an *exoplanet in the habitable zone*.” Give that such molecules have been widely found on planets and moons in our own solar system, finding an exoplanet with the same is really not very surprising.
John Carter: I think my post is not as clear as it should be. It isn’t the discovery of carbon or methane in this exoplanet’s atmosphere that has gotten these scientists excited. It is the discovery of dimethyl sulfide (DMS) and/or dimethyl disulfide (DMDS]. It is those molecules that on Earth are associated solely with life processes.
However, we are really in agreement. This result is intriguing for sure, but it proves nothing at all at this point.
fairly confident we will never find life on any hycean world… hydrogen atmospheres are just too hot
when we find an oxygen atmosphere around a rocky near-Earth-mass world of a G-class star, then we’ll be on to something
more likely though, Earth is a one-in-a-trillion fluke and all other rocky exoplanets are either like Mars or Venus: too much atmosphere for life or not enough
Nature loves to come up with geological ways to produce compounds exoplanet researchers think only come from life.
It’s cruel that way.